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More content for non-IT readers ED: It’s great to hear from you. We will definitely cover the I have been reading your magazine since the last few years. The topics suggested by you in one of our forthcoming issues. Keep company I work in is in the manufacturing industry. Similarly, reading our magazine. And do feel free to get in touch with us if your subscribers’ database may have more individuals like me you have any such valuable feedback. from companies that are not directly related to the IT industry. Currently, your primary focus is on technical matters, A request for the Backtrack OS to be and the magazine carries articles written by skilled technical bundled on the DVD individuals, so OSFY is really helpful for open source developers. I am a huge fan of Open Source For You. Thank you for However, you also have some non-IT subscribers like us, who bundling the Ubuntu DVD with the May 2014 issue. Some of can understand that something great is available in the open my team members and I require the Backtrack OS. Could you source domain, which they can deploy to reduce their IT costs. provide this in your next edition? I am studying information But, unfortunately, your magazine does not inform us about open sciences for my undergrad degree. Please suggest the important source solutions providers. programming languages that I should become proficient in. I request you to introduce the companies that provide end-to- —aravind naik; end IT solutions on open source platforms including thin clients, aravindnaik23@gmail.com desktops, servers, virtualisation, embedded customised OSs, ERP, CRM, MRP, emails and file servers, etc. Kindly publish relevant ED: Thanks for writing in to us. We’re pleased to know that you case studies, with the overall cost savings and benefits. Just as you liked the DVD. Backtrack is no longer being maintained. The feature job vacancies, do give us information about the solutions updated version for penetration testing is now known as ‘Kali providers I mentioned above. Linux’ and we bundled it with the April 2014 issue of OSFY. For —Shekhar Ranjankar; career related queries, you can refer to older OSFY issues or you [email protected] can find related articles on www.opensourceforu.com

ED: Thank you for your valuable feedback. We do carry case studies Overseas subscriptions of companies deploying open source, from time to time. We also Previously, I used to get the copies of LINUX For You/ Open regularly carry a list of different solutions providers from different Source For You and Electronics For You from local book stores open source sectors. We will surely take note of your suggestion and but, lately, none of them carry these magazines any more. So try to continue carrying content that interests non-IT readers too. how can I get the copies of all these magazines in Malaysia, and where can I get previous issues too? Requesting an article on Linux server migration —Abdullah Abd. Hamid; I am glad to receive my first copy of OSFY. I have a [email protected] suggestion to make: if possible, please include an article on migrating to VMware (from a Linux physical server to ED: Thank you for reaching out to us. Currently, we do not have VMware ESX). Also, do provide an overview of some open any reseller or distributor in Malaysia for news stand sales, but you source tools (like Ghost for Linux) to take an image of a can always subscribe to the print edition or the e-zine version of the physical Linux server. magazines. You can find the details of how to subscribe to the print —Rohit Rajput; editions on www.pay.efyindia.com and for the e-zine version, please [email protected] go to www.ezines.efyindia.com

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CentOS 7 now available A rare SMS worm is attacking The CentOS Project has announced the general availability of CentOS 7, the first your Android device! release of the free Linux distro based on the source code for RedHat Enterprise Android does get attacked with Linux (RHEL) 7. It is the first major release after the collaboration between the Trojan apps that have no self- CentOS Project and Red Hat. CentOS 7 is built from the freely available RHEL 7 propagation mechanism, so users source code tree. The features closely resemble that of Red Hat’s latest operating don’t notice the malfunction. But system. Just like RHEL 7, it here’s a different, rather rare, mode is now powered by version of attack that Android devices are 3.10.0 of the Linux kernel, with now facing. Selfmite is a SMS a default file system. It is also worm attack. It is the second of such the first version to include a deadly viruses found in the past two management engine, systemd, months. Selfmite automatically sends dynamic firewall system called the firewalld, and the boot loader, GRUB2. SMSs to the users with their name The default Java Development Kit has also been upgraded to OpenJDK 7, and in the message. The SMS contains a the system now ships with open VMware tools and 3D graphics drivers, out-of- shortened URL which triggers users the-box. Also, like RHEL 7, this is the version of CentOS that claims to offer an in- to install a third part APK file called place upgrade path. Soon, users will be able to upgrade from CentOS 6.5 to CentOS TheSelfTimerV1.apk. The SMS 7 without reformatting their systems. says, “Dear [name], Look the Self- The CentOS team has launched a new build process, in which the entire time..” Some remote server hosts this distro is built from code hosted at the CentOS Project’s own Git repository. malware application. Users can find Source code packages (SRPMs) are created as a side effect of the build cycle, SelfTimer installed in the app drawer and will be hosted on the main CentOS download servers. of their Android devices. Disc images of CentOS 7, which include separate builds for the Gnome and KDE The Selfmite worm desktops, a live CD image and a network-installable version, are also now available. shows a pop-up to download mobogenie_122141003.apk, which Google to launch Android One smartphones with MediaTek chipset offers synchronisation between Google made an announcement Android devices and PCs. The app about its Android One program has over 50 million downloads on at the recent Google I/O 2014, Play Store, but all are through various San Francisco, California. The paid referral schemes and promotion company plans to launch devices programmes. Researchers at Adaptive powered by Android One in Mobile believe that a number of India first, with companies like Mobogenie downloads are promoted Micromax, Spice and Karbonn. through some malicious software Android One has been launched used by an unknown advertising to reduce the production costs of phones. The manufacturers mentioned earlier platform. A popular vendor of security will be able to launch US$ 100 phones based on this platform. Google will solutions in North America detected handle the software part, using Android One. So phones will get firmware dozens of devices that were infected updates directly from Google. This is surprising because low budget phones with Selfmite. The attack campaign usually don’t receive any software updates. Sundar Pichai, Android head at was launched using Google. The short Google, showcased a Micromax device at the show. The Micromax Android linked URL of this malicious app was One phone has an 11.43 cm (4.5 inch) display, FM radio, SD card slot and dual distributed in the Google shortlink SIM slot. Google has reportedly partnered with MediaTek for chipsets to power format. The APK link was visited the Android One devices. We speculate that it is MediTek’s MT6575 dual core 2,140 times. Later, Google disabled it. processor that has been packed into Micromax’s Android One phone. Android devices detect apps from It is worth mentioning here that 78 per cent of the smartphones launched unknown and unauthorised developers. in Q1 of 2014 were priced around US$ 200 in India. So Google’s Android One But some users enable installation will definitely herald major changes in this market. Google will also provide authentication even for apps from manufacturers with guidelines on hardware designs. And it has tied up with ‘unknown sources’. Their devices hardware component companies to provide high volume parts to manufacturers at a become the targets for worms like this. lower cost in order to bring out budget Android smartphones.

14 | aUGUST 2014 | OPEN SOURCE For You | www.OpenSourceForU.com OSFYClassifieds Classifieds for Linux &Open SourceITTraining Institutes

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Expect Android Wear app section along with Google Play Calendar of forthcoming events Service update Google recently started rolling out its Google Name, Date and Venue Description Contact Details and Website

Play Service update 5.0 to all the devices. 4th Annual Datacenter The event aims to assist the community in Praveen Nair; Email: Praveen.nair@ This version is an advance from the existing Dynamics Converged. the data centre domain by exchanging ideas, datacenterdynamics.com; Ph: +91 September 18, 2014; accessing market knowledge and launching 9820003158; Website: 4.4, bringing the Android wearable services Bengaluru new initiatives. http://www.datacenterdynamics.com/ API and much more. Mainly focused on CIOs and senior IT executives from across the Gartner Symposium IT Xpo, developers, this version was announced in world will gather at this event, which offers Website: October 14-17, 2014; Grand talks and workshops on new ideas and strate- http://www.gartner.com 2014. According to the search giant’s blog, Hyatt, Goa the newest version of the Google Play store gies in the IT industry. includes many updates that can increase app Open Source India, Asia’s premier open source conference that Omar Farooq; Email: omar.farooq@ performance. These include wearable APIs, November 7-8, 2014; aims to nurture and promote the open source efy.in; Ph: 09958881862 dynamic security provider, improvements NIMHANS Center, Bengaluru ecosystem across the sub-continent. http://www.osidays.com in Drive, Wallet and Google Analytics, etc. CeBit This is one of the world’s leading business IT Website: The main focus is on the Android Wearable November 12-14, 2014; events, and offers a combination of services http://www.cebit-india.com/ BIEC, Bengaluru and benefits that will strengthen the Indian IT platform and APIs, which will enable more and ITES markets. applications on these devices. In addition to this, Google has announced a separate section 5th Annual Datacenter The event aims to assist the community in Praveen Nair; Email: Praveen.nair@ Dynamics Converged; the datacentre domain by exchanging ideas, datacenterdynamics.com; Ph: +91 for Android Wear apps in the Play store. December 9, 2014; Riyadh accessing market knowledge and launching 9820003158; Website: These apps for the Android Wear section new initiatives. http://www.datacenterdynamics.com/ in the Google Play store come from Google Hostingconindia This event will be attended by Web hosting Website: December 12-13, 2014; companies, Web design companies, domain http://www.hostingcon.com/ itself. The collection includes official NCPA, Jamshedji Bhabha and hosting resellers, ISPs and SMBs from contact-us/ companion apps for Android devices, Theatre, Mumbai across the world. Hangouts and Google Maps. The main purpose of the Android Wear Companion New podcast app for Linux is now ready for testing app is to let users manage their devices from An all-new podcast app for Ubuntu was launched recently. This app, called Android smartphones. It provides voice ‘Vocal’, has a great UI and design. Nathan Dyer, who is the developer of this support, notifications and more. There are project, has released unstable beta builds of the app for Ubuntu 14.04 and 14.10, third party apps as well from Pinterest, for testing purposes. Banjo and Duolingo. Only next-gen easy-to-use desktops are capable of running the beta version of Vocal. Installing beta versions of the app on Ubuntu is not as difficult as Google plans to remove installing them on KDE, GNOME or Unity, but users can’t try the beta version of QuickOffice from app stores Vocal without installing the unstable elementary desktop PPA. Vocal is an open Google has announced the company’s source app, and one can easily port it to mainstream Linux versions from Ubuntu. future plans about Google Docs, However, Dyer suggests users wait until the first official beta version of the app for Slides and Sheets. It has integrated the easy-to-use desktops is available. QuickOffice service in Google Docs The official developer’s blog has a detailed report on the project. now. So, there is no longer a need for the separate Google QuickOffice app. CoreOS Linux comes out with Linux containers as a service! QuickOffice was acquired by Google in CoreOS has launched a commercial service to ease the workload of systems 2012. It served free document viewing administrators. The new commercial Linux distribution service can update and editing on Android and iOS for two automatically. Systems administrators do not have to perform any major update years. Google has decided to discontinue manually. Linux-based companies like RedHat and SUSE use open source this free service. and free applications and libraries for their operations, yet offer commercial The firm has integrated QuickOffice subscription services for enterprise editions of Linux. These services cover into the Google Docs, Sheets and Slides software, updates, integration and technical support, bug fixes, etc. app. The QuickOffice app will be removed CoreOS has a different strategy compared to competitive services offered by from the Play Store and Apple’s App Store other players in the service, support and distribution industries. Users will not soon and users will not be able to see or receive any major updates, since CoreOS wants to save you the hassle of manually install it. Existing users will be able to updating all packages. The company plans to stream copies of updates directly to continue to use the old version of the app. the OS. CoreOS has named the software ‘CoreUpdate’. It controls and monitors

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software packages, their updates and also provides the controls to administrators to manually update a few packages if they want to. It has a roll-back feature in case Linux Foundation releases an update causes any malfunction in a machine. CoreUpdate can manage multiple Automotive Grade Linux to systems at a time. power cars CoreOS was designed to promote the use of open source OS kernel, which The Linux Foundation recently is used in a lot of cloud based virtual released Automotive Grade Linux servers. The CoreOS consumes less (AGL) to power automobiles, a than half of instance as compared move that marks its first steps into to other Linux distribution services. the automotive industry. The Linux Applications of distributions run in Foundation is sponsoring the AGL a virtualised container called Docker. They can start instantly. CoreOS was project to collaborate with the launched in December last year. It uses two partitions, which help in easily automotive, computing hardware updating distributions. One partition contains the current OS, while the other and communications industries, is used to store the updated OS. This smoothens out the entire process of apart from academia and other upgrading a package or an entire distribution. The service can be directly sectors. The first release of this installed and run in the system or via cloud services like Amazon, Google or system is available for free on the Rackspace. The venture capital firm, Kleiner Perkins Caulfield and Byers, Internet. A Linux-based platform has invested over US$ 8 million in CoreOS. The company was also backed by called Tizen IVI is used to power Sequoia Capital and Fuel Capital in the past. AGL. Tizen IVI was primarily designed for a broad range of Mozilla to launch Firefox-based streaming Dongle, Netcast devices—from smartphones and After the successful launch of TVs to cars and laptops. Google’s Chromecast, which Here is the list of features sold in millions, everyone else that you can experience in the has discovered the potential of first release of AGL: a dashboard, streaming devices. Recently, Bluetooth calling, Google Maps, Amazon and Roku launched HVAC, audio controls, Smartphone their devices. According to Link Integration, media playback, GigaOM, Mozilla will soon home screen and news reader. The enter the market with its Linux Foundation and its partners Firefox-powered streaming are expecting this project to change device. A Mozilla enthusiast, the future of open source software. Christian Heilmann, recently They hope to see next-generation uploaded a photo of Mozilla’s prototype streaming device on Twitter. car entertainment, navigation People at GigaOM managed to dig out more on it and even got their hands on and other tools to be powered by the prototype as soon as that leaked photo went viral on Twitter. The device provides open source software. The Linux better functionality and options than Chromecast. Mozilla has partnered with some Foundation expects collaborators to as yet unknown manufacturer to build this device. The prototype has been sent to add new features and capabilities some developers for testing and reviews. This device, which is called Netcast, has a in future releases. Development hackable open bootloader, which makes it run some Chromecast apps. of AGL is expected to continue Mozilla has always looked for an open environment for its products. It is expected steadily.

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that the company’s streaming stick will come with open source technology, which will Microsoft to abandon help developers to develop HDTV streaming apps for smartphones. X-Series Android smartphones too Opera is once again available on Linux It hasn’t been long since Microsoft Australian Web browser company, Opera, has ventured into the Android market with finally released a beta version for its Linux OS. its X series devices and the company This Opera 24 version for Linux has the same has already revealed plans to abandon features as Opera 24 on the Windows and Mac the series. With the announcement of platforms. Chrome and Firefox are currently the up to 18,000 job cuts, the company is two most used browsers on the Linux platform. also phasing out its feature phones and Opera 24 will be a good alternative to them. recently launched Nokia X Android As of now, only the developer or beta version of Opera for Linux is smartphones. available. We are hoping to see a stable version in the near future. In this beta Here are excerpts of an internal version, Linux users will get to experience popular Opera features like Speed email sent by Jo Harlow, who heads Dial, Discover, Stash, etc. Speed Dial is a home page that gives users an the phone business under Microsoft overview of their history, folders and bookmarks. Discover is an RSS reader, devices, to Microsoft employees: embedded within the browser. Gathering and reading articles of interest would “Placing Mobile Phone services in be more authentic with the Discover feature. Stash is like Pinterest, within a maintenance mode: With the clear browser. Its UI is inspired from Pinterest. It allows users to collect websites and focus on Windows Phones, all Mobile categorise them. Stash is designed to enable users to plan their travel, work and Phones-related services and enablers personal lives with a collection of links. are planned to move into maintenance mode; effective: immediately. This Unlock your Moto X with your tattoo means there will be no new features Motorola is implementing an or updates to services on any Mobile alternative security system Phones platform as a result of these for Moto X. It is frustrating to plans. We plan to consider strategic remember difficult passwords options for Xpress Browser to enable while simpler passwords are easy continuation of the service outside to crack. To counter this, VivaLnk of Microsoft. We are committed to has launched digital tattoos. This supporting our existing customers, tattoo will automatically unlock and will ensure proper operation the Moto X when applied to the during the controlled shutdown of skin. services over the next 18 months. A This technology is based detailed plan and timeline for each on Near Field Communication to connect with smartphones and authenticate service will be communicated over the access. Motorola is working on optimising digital tattoos with Google’s Advance coming weeks. Technology and Projects. “Transitioning developer The pricing is on the higher side but this is a great initiative in wearable efforts and investments: We technology. Developing user friendly alternatives to the password and PIN number plan to transition developer has been a major focus of tech companies. Motorola had talked about this in the efforts and investments to focus introductory session of the D11 conference at California this May, when it discussed on the Windows ecosystem the idea of passwords in pills or tattoos. The idea may seem like a gimmick, but you while improving the company’s never know when it will become commonly used. VivaLnk is working on making financial performance. To focus this technology compatible with other smartphones too. It is considering entering on the growing momentum behind the domain of creating tattoos of different types and designs. Windows Phone, we plan to immediately begin ramping down OpenSSL flaws fixed by PHP developer engagement activities PHP recently pushed out new versions for its popular scripting language, which fix related to Nokia X, Asha and many crucial bugs and, out of those, two are of OpenSSL. The flaws are not serious Series 40 apps, and shift support to like Heartbleed, which popped up a couple of months back. One flaw is directly maintenance mode.” related to OpenSSL handling time stamps and the other is related to the same thing in a different way. PHP 5.5.14 and 5.4.30 have fixed both flaws.

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Other bugs which were fixed were not security related but of a more general type. iberry introduces the Auxus Linea L1 smartphone and Auxus AX04 tablet in India In a bid to expand its portfolio in the Indian market, iberry has introduced two new Android KitKat-powered devices in the country—a smartphone and a tablet. The Auxus Linea L1 smartphone is priced at Rs 6,990 and the Auxus AX04 tablet is priced at Rs 5,990. Both have been available from the online megastore eBay India, since June 25, this year. The iberry Auxus Linea L1 smartphone features a 11.43 cm (4.5 inch) display with OGS technology and Gorilla Glass protection. It is powered by a 1.3GHz quad-core MediaTek (MT6582) processor coupled with 1 GB of DDR3 RAM. It sports a 5 MP rear camera with an LED flash and a 2 MP front- facing camera. It comes with 4 GB of inbuilt storage expandable up to 64 GB via microSD card. The dual-SIM device runs Android 4.4 KitKat, out-of-the-box. The 3G-supporting smartphone has a 2000mAh battery. Meanwhile, the iberry Auxus AX04 tablet features a 17.78 cm (7 inch) IPS display. It is powered by a 1.5 GHz dual-core processor (unspecified chipset) coupled with 512 MB of RAM. The voice-supporting tablet sports a 2 MP rear camera and a 0.3 MP front-facing camera. It comes with 4 GB of built-in storage expandable up to 64 GB via micro-SD card slot. The dual-SIM device runs Android 4.4 KitKat out-of-the-box. It has a 3000mAh battery. Google to splurge a whopping Rs 1,000 million on marketing Android One Looks like global search engine giant Google wants to leave no stone unturned in its quest to make its ambitious Android One smartphone-for- the-masses project reach its vastly dispersed target audience in emerging economies (including India). The buzz is that Google is planning to splurge over a whopping Rs 1,000 milllion with its official partners on advertising and marketing for the platform. Even as Sundar Pichai, senior VP at Google who is in charge of Android, Chrome and Apps, is all set to launch the first batch of low budget Android smartphones in India sometime in October this year, the latest development shows how serious Google is about the project. It was observed that Google’s OEM partners were forced into launching a new smartphone every nine months to stay ahead in the cut-throat competition. However, thanks to Google’s new Android hardware and software reference platform, its partners will now be able to save money and get enough time to choose the right components, before pushing their smartphones into the market. Android One will also allow them to push updates to their Android devices, offering an optimised stock Android experience. With the Android One platform falling into place, Google will be able to ensure a minimum set of standards for Android-based smartphones.

www.OpenSourceForU.com | OPEN SOURCE For You | aUGUST 2014 | 19 FOSSBYTES

Linux kernel 3.2.61 LTS With the Android One platform, Google aims to reach the 5 billion officially released people across the world who still do not own a smartphone. According to The launch of the Linux kernel 3.2.61 Pichai, less than 10 per cent of the world’s population owns smartphones LTS, the brand-new maintenance in emerging countries. The promise of a stock Android experience at release of the 3.2 kernel series, has a low price point is what Android One aims to provide. Home-grown been officially announced by Ben manufacturers such as Micromax, Karbonn and Spice will create and sell Hutchings, the maintainer of the these Android One phones for which hardware reference points, software Linux 2.6 kernel branch. While and subsequent updates will be provided by Google. Even though the spec highlighting the slew of changes that sheet of Android One phones hasn’t been officially released, Micromax is come bundled along with the latest already working on its next low budget phone, which many believe will release, Hutchings advised users to be an Android One device. upgrade to it as early as possible. The Linux kernel 3.2.61 is an SQL injection vulnerability patched in Ruby on Rails important release in the cycle, according to Two SQL injection vulnerabilities were patched in Ruby on Rails, which is Hutchings. It introduces better support for an open source Web development framework now used by many developers. the x86, ARM, PowerPC, s390 and MIPS Some high profile websites also use this framework. The Ruby on Rails architectures. At the same time, it also developers recently launched versions 3.2.19, 4.0.7 and 4.1.3, and advised improves support for the EXT4, ReiserFS, users to upgrade to these versions as soon as possible. And a few hours later, Btrfs, NFS and UBIFS file systems. It also they again released versions 4.0.8 and 4.1.4 to fix problems caused by the comes with updated drivers for wireless 4.0.7 and 4.1.3 updates. connectivity, InfiniBand, USB, ACPI, One of the two SQL injection vulnerabilities affects applications running Bluetooth, SCSI, Radeon and Intel i915, on Ruby versions 2.0.0 through to 3.2.18, which also use the PostgreSQL among others. database system and query bit string data types. Another vulnerability affects Meanwhile, Linux founder Linus applications running on Ruby on Rails versions 4.0.0 to 4.1.2, which use Torvalds has officially announced the PostgreSQL and querying range data types. fifth Release Candidate (RC) version Despite affecting different versions, these two flaws are related and allow of the upcoming Linux kernel 3.16. attackers to inject arbitrary SQL code using crafted values. The RC5 is a successor to Linux 3.16- rc4. It is now available for download The city of Munich adopts Linux in a big way! and testing. However, since it is a It’s certainly not a case of an overnight conversion. The city of Munich began development version, it should not be to seek open source alternatives way installed on production machines. back in 2003. With a population of about 1.5 Motorola brings out Android million citizens and thousands of 4.4.4 KitKat upgrade for employees, this German city took its Moto E, Moto G and Moto X time to adopt open source. Tens of Motorola has unveiled the Android thousands of government workstations 4.4.4 KitKat update for its devices in were to be considered for the change. Its India, for Moto E, Moto G and Moto initial shopping list had suitably rigid X. This latest version of Android has specifications, spanning everything from an extra layer of security for browsing avoiding vendor lock-in and receiving Web content on the phone. regular hardware support updates, to With this phased rollout, users having access to an expansive range of will receive notifications that will free applications. enable them to update their OS but, In its first stage of migration, in 2006, alternatively, the update can also be Debian was introduced across a small percentage of government workstations, accessed by way of the settings menu. with the remaining Windows computers switching to OpenOffice.org, followed This release goes on to shore up by Firefox and Thunderbird. Motorola’s commitment to offering its Debian was substituted for a custom Ubuntu-based distribution named customers a pure, bloatware-free and ‘LiMux‘ in 2008, after the team handling the project ‘realised Ubuntu was the seamless Android experience. platform that could satisfy our requirements best.’

20 | aUGUST 2014 | OPEN SOURCE For You | www.OpenSourceForU.com In The News SUSE Partners with Karunya University to Make Engineers Employable In one of the very first initiatives of its kind, SUSE and Novell have partnered with Karunya University, Coimbatore, to ensure its students are industry-ready.

ut of the many interviews that we have conducted standards than they did with proprietary technologies. This with recruiters asking them about what they look for trend makes it even more critical to incorporate open source Oin a candidate, one common requirement seems to technologies in the college curriculum. be knowledge of open source technology. As per NASSCOM Speaking about the initiative, Venkatesh Swaminathan, reports, between 20 to 33 per cent of the million students that country head, The Attachmate Group (Novell, NetIQ, graduate out of India’s engineering colleges every year, run the SUSE and Attachmate), said, “This is one of the first risk of being unemployed. implementations of its kind but we do have The Attachmate Group, along with engagements with universities on various Karunya University, has taken a step other formats. Regarding this partnership with forward to address this issue. Novell India, Karunya, we came out with a kind of a joint in association with Karunya University, has strategy to make engineering graduates ready introduced Novell’s professional courses for the jobs enterprises offer today. We thought as part of the university’s curriculum. about the current curriculum and how we Students enrolled in the university’s M. could modify it to make it more effective. Our Tech course for Information Technology current education system places more emphasis will be offered industry-accepted courses. on theory rather than the practical aspects of Apart from this, another company of the engineering. With our initiative, we aim to bring Attachmate Group, SUSE, has also pitched in more practical aspects into the curriculum. So in to make the students familiar with the we have looked at what enterprises want from world of open source technology. engineers when they deploy some solutions. Speaking about the initiatives, Dr Venkatesh Swaminathan, Today, though many enterprises want to use J Dinesh Peter, associate professor and country head, The Attachmate Group open source technologies effectively, the (Novell, NetIQ, SUSE and Attachmate) HoD I/C, Department Of Information unavailability of adequate talent to handle those Technology, said, “We have already started with our first batch technologies is a major issue. So, the idea was to bridge the of students, who are learning SUSE. I think adding open source gap between what enterprises want and what they are getting, technology in the curriculum is a great idea because nowadays, with respect to the talent they require to implement and most of the tech companies expect knowledge on open manage new technologies.” source technology for the jobs that they offer. Open source Going forward, the company aims to partner with at least technology is the future, and I think all universities must have it another 15 – 20 universities this year to integrate its courseware incorporated in their curriculum in some form or the other.” into the curriculum to benefit the maximum number of students The university has also gone ahead to provide professional in India. “The onus of ensuring that the technical and engineering courses from Novell to the students. Dr Peter said, “In India, students who graduate every year in our country are world-class where the problem of employability of technical graduates is and employable lies on both the academia as well as the industry. acute, this initiative could provide the much needed shot in With this collaboration, we hope to take a small but important the arm. We are pleased to be associated with Novell, which step towards achieving this objective,” Swaminathan added. has offered its industry-relevant courses to our students. With growing competition and demand for skilled employees in About The Attachmate Group the technology industry, it is imperative that the industry and Headquartered in Houston, Texas, The Attachmate Group academia work in sync to address the lacuna that currently is a privately-held software holding company, comprising exists in our system.” distinct IT brands. Principal holdings include Attachmate, Growth in the amount of open source software that NetIQ, Novell and SUSE. enterprises use has been much faster than growth in proprietary software usage, over the past 2-3 years. One major reason By: Diksha P Gupta for this is that open source technology helped companies slash huge IT budgets, while maintaining higher performance The author is senior assistant editor at EFY.

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 21 Buyers’ Guide SSDs Move Ahead to Overtake Hard Disk Drives High speed, durable and sleek SSDs are moving in to replace ‘traditional’ HDDs.

solid state drive (SSD) is a data storage device medium. Kingston offers an entire range of SSDs, including that uses integrated circuit assemblies as its entry levels variants as well as options for general use. A memory to store data. Now that everyone is There are a lot of factors to keep in mind when you switching over to thin tablets and high performance are planning to buy an SSD—durability, portability, notebooks, carrying heavy, bulky hard disks may be power consumption and speed. Gupta adds that, “The difficult. SSDs, therefore, play a vital role in today’s performance of SSDs is typically indicated by their IOPS world as they combine high speed, durability and smaller (Input output operation per second), so one should look at sizes, with vast storage and power efficiency. the specifications of the product. Also, check the storage SSDs consume minimal power because they do not have capacity. If you’re looking for an SSD when you already any movable parts inside, which leads to less consumption of have a PC or laptop, then double check the compatibility internal power. between your system and the SSD you’ve shortlisted. If you’re buying a new system, then you can always check HDDs vs SSDs with the vendors as to what SSD options are available. The new technologies embedded in SSDs make them costlier Research the I/O speeds and get updates about how reliable than HDDs. “SSDs, with their new technology, will gradually the product is.” overtake hard disk drives (HDDs), which have been around “For PC users, some of the important performance ever since PCs came into prominence. It takes time for a new parameters of SSDs are related to battery life, heating of the technology to completely take over the traditional one. Also, device and portability. An SSD is 100 per cent solid state new technologies are usually expensive. However, users are technology and has no motor inside, so the advantage is that it ready to pay a little more for a new technology because it consumes less energy; hence, it extends the battery life of the offers better performance,” explains Rajesh Gupta, country device and is quite portable,” explains Gupta. head and director, Sandisk Corporation India. Listed below are a few broad specifications of SSDs, SSDs use integrated circuit assemblies as memory for which can help buyers decide which variant to go in for. storing data. The technology uses an electronic interface which is compatible with traditional block input/output Portability HDDs. So SSDs can easily replace HDDs in commonly Portability is one of the major concerns when buying an used applications. external hard drive because, as discussed earlier, everyone An SSD uses a flash-based medium for storage. It is is gradually shifting to tablets, iPads and notebooks and believed to have a longer life than an HDD and also consumes so would not want to carry around an external hard disk less power. “SSDs are the next stage in the evolution of PC that is heavier than the computing device. The overall storage. They run faster, and are quieter and cooler than the portability of an SSD is evaluated on the basis of its size, aging technology inside hard drives. With no moving parts, shape, how much it weighs and its ruggedness. SSDs are also more durable and reliable than hard drives. They not only boost the performance but can also be used High speed to breathe new life into older systems,” says Vishal Parekh, Speed is another factor people look for, while buying an marketing director, Kingston Technology India. SSD. If it is not fast, it is not worth the buy. SSDs offer data transfer read speeds that range from approximately 530 How to select the right SSD MBps to 550 MBps, whereas a HDD offers only around If you’re a videographer, or have a studio dedicated to audio/ 30 to 50 MBps. SSDs can also boot any operating system video post-production work, or are in the banking sector, you almost four times faster than a traditional 7200 RPM 500 can look at ADATA’s latest launch, which has been featured GB hard drive disk. With SSDs, the applications provide a later in the article. Kingston, too, has introduced SSDs for all 12 times faster response compared to the HDD. A system possible purposes. SSDs are great options even for gamers, or equipped with an SSD also launches applications faster and those who want to ensure their data has been saved in a secure offers a high performance overall.

22 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com

Buyers’ Guide

Durability new PC by reviving the system you already own,” As an SSD does not have any moving parts like a motor adds Parekh. and uses a flash-based medium for storing data, it is more likely to keep the data secure and safe. Some of the SSDs A few options to choose from are coated with metal, which extends their life. There are Many companies, including Kingston, ADATA and almost no chances of their getting damaged. Even if you Sandisk, have launched their SSDs and it is quite a task drop your laptop or PC, the data stays safe and does not trying to choose the best among them. Kingston has get affected. always stood out in terms of delivering good products to not just the Indian market but worldwide. Ashu Mehrotra, Power consumption marketing manager, ADATA, speaks about his firm’s In comparison to a HDD, a solid state drive consumes SSDs: “ADATA has been putting a lot of resources into minimal power. “Usually, a PC user faces the challenge of a R&D for SSDs, because of which its products provide limited battery life. But since an SSD is 100 per cent solid unique advantages to customers.” Gupta says, “Sandisk state technology and has no motor inside, it consumes less is a completely vertically integrated solutions provider energy; hence, it extends the life of the battery and the PC,” and is also a key manufacturer of flash-based storage adds Rajesh Gupta. systems, which are required for SSDs. Because of this, There are plenty of other reasons for choosing a SSD we are very conscious about the categories to be used in over a HDD. These include the warranty, cost, efficiency, the SSD. We also make our own controllers and do our etc. “Choosing a SSD can save you the cost of buying a own integration.”

HyperX Fury from Kingston Technology • It is a 6.35 cm and 7 mm solid state drive (SSD) • Delivers impressive performance at an affordable price • It speeds up system boot up, application loading time and file execution • Controller: SandForce SF-2281 • Performance: SATA Rev 3.0 (6 GBps) • Read/write speed: 500 MBps to boost overall system responsiveness and performance • Reliability: Cool, rugged and durable drive to push your system to the limits • Warranty: Three years

Extreme PRO SSD from Sandisk Consistently fast data transfer speeds Lower latency times Reduces power consumption Comes in the following capacities: 64 GB, 128 GB and 256 GB Speed: 520 MBps Compatibility: SATA Revision 3.0 (6 GBps) Warranty: Three years

24 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Buyers’ Guide Premier Pro SP920 from ADATA It is designed to meet the high-performance requirements of multimedia file transfers It provides up to 7 per cent more space on its SSD due to the right combination of controller and high quality flash It weighs 70 grams and its dimensions are 100×69.85×7 mm Controller: Marvell It comes in the following capacities: 128 GB, 256 GB, 512 GB and 1 TB NAND flash synchronous MLC Interface: SATA 6 GBps Read/write speed: From 560 to 180 MBps Power consumption: 0.067 W idle/0.15 W active

SSD 840 EVO from Samsung

Capacity: 500 GB (1 GB =1 billion bytes) Dimensions: 100 x 69.85 x 6.80 mm Weight: Max 5.3 kg Interface: SATA 6 GBps (compatible with SATA 3 GBps and SATA 1.5 GBps) Controller: Samsung 3-core MEX controller Warranty: Three years

1200 SSD from Seagate

It is designed for applications demanding the fast, consistent performance and has dual port 12 GBps SAS It comes with 800 GB capacity Random read/write performance of up to 110K /40K IOPS Sequential read/write performance from 500 MBps to 750 MBps

By: Manvi Saxena With inputs from ADATA, Kingston and Sandisk. The author is a part of the editorial team at EFY.

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 25 Developers How To An Introduction to the Linux Kernel

This article provides an introduction to the Linux kernel, and demonstrates how to write and compile a module.

ave you ever wondered how a computer manages the allowing communication and data sharing between processes most complex tasks with such efficiency and accuracy? through inter-process communication (IPC). Additionally, HThe answer is, with the help of the operating system. It with the help of the process scheduler, it schedules processes is the operating system that uses hardware resources efficiently and enables resource sharing. to perform various tasks and ultimately makes life easier. At a Memory management: This subsystem handles all high level, the OS can be divided into two parts—the first being memory related requests. Available memory is divided into the kernel and other is the utility programs. Various user space chunks of a fixed size called ‘pages’, which are allocated or processes ask for system resources such as the CPU, storage, de-allocated to/from the process, on demand. With the help of memory, network connectivity, etc, and the kernel services the memory management unit (MMU), it maps the process’ these requests. This column will explore loadable kernel virtual address space to a physical address space and creates modules in GNU/Linux. the illusion of a contiguous large address space. The Linux kernel is monolithic, which means that the File system: The GNU/Linux system is heavily dependent entire OS runs solely in supervisor mode. Though the kernel on the file system. In GNU/Linux, almost everything is a file. is a single process, it consists of various subsystems and This subsystem handles all storage related requirements like each subsystem is responsible for performing certain tasks. the creation and deletion of files, compression and journaling Broadly, any kernel performs the following main tasks. of data, the organisation of data in a hierarchical manner, Process management: This subsystem handles the and so on. The Linux kernel supports all major file systems process’ ‘life-cycle’. It creates and destroys processes, including MS Windows’ NTFS.

Developers How To

Device control: Any computer system requires various manage the contents of the ring buffer. devices. But to make the devices usable, there should be a device driver and this layer provides that functionality. There Preparing the system are various types of drivers present, like graphics drivers, a Now it’s time for action. Let’s create a development Bluetooth driver, audio/video drivers and so on. environment. In this section, let’s install all the required Networking: Networking is one of the important aspects packages on an RPM-based GNU/Linux distro like CentOS of any OS. It allows communication and data transfer between and a Debian-based GNU/Linux distro like Ubuntu. hosts. It collects, identifies and transmits network packets. Additionally, it also enables routing functionality. Installing CentOS First install the gcc compiler by executing the following Dynamically loadable kernel modules command as a root user: We often install kernel updates and security patches to make sure our system is up-to-date. In case of MS Windows, a reboot [root]# yum -y install gcc is often required, but this is not always acceptable; for instance, the machine cannot be rebooted if is a production server. Then install the kernel development packages: Wouldn’t it be great if we could add or remove functionality to/from the kernel on-the-fly without a system reboot? The [root]# yum -y install kernel-devel Linux kernel allows dynamic loading and unloading of kernel modules. Any piece of code that can be added to the kernel at Finally, install the ‘make’ utility: runtime is called a ‘kernel module’. Modules can be loaded or unloaded while the system is up and running without any [root]# yum -y install make interruption. A kernel module is an object code that can be dynamically linked to the running kernel using the ‘insmod’ Installing Ubuntu command and can be unlinked using the ‘rmmod’ command. First install the gcc compiler:

A few useful utilities [mickey] sudo apt-get install gcc GNU/Linux provides various user-space utilities that provide useful information about the kernel modules. Let us explore them. After that, install kernel development packages: lsmod: This command lists the currently loaded kernel modules. This is a very simple program which reads the /proc/ [mickey] sudo apt-get install kernel-package modules file and displays its contents in a formatted manner. insmod: This is also a trivial program which inserts a And, finally, install the ‘make’ utility: module in the kernel. This command doesn’t handle module dependencies. [mickey] sudo apt-get install make rmmod: As the name suggests, this command is used to unload modules from the kernel. Unloading is done only if Our first kernel module the current module is not in use. rmmod also supports the -f Our system is ready now. Let us write the first kernel module. or --force option, which can unload modules forcibly. But this Open your favourite text editor and save the file as hello.c option is extremely dangerous. There is a safer way to remove with the following contents: modules. With the -w or --wait option, rmmod will isolate the module and wait until the module is no longer used. #include modinfo: This command displays information about #include the module that was passed as a command-line argument. If the argument is not a filename, then it searches the /lib/ int init_module(void) modules/ directory for modules. modinfo shows { each attribute of the module in the field:value format. printk(KERN_INFO “Hello, World !!!\n”);

Note: is the kernel version. We can obtain it return 0; by executing the uname -r command. }

dmesg: Any user-space program displays its output on the void cleanup_module(void) standard output stream, i.e., /dev/stdout but the kernel uses { a different methodology. The kernel appends its output to printk(KERN_INFO “Exiting ...\n”); the ring buffer, and by using the ‘dmesg’ command, we can }

MODULE_LICENSE(“GPL”); MODULE_VERSION(“1.0”); MODULE_AUTHOR(“Narendra Kangralkar.”); MODULE_DESCRIPTION(“Hello world module.”); Here, the __init and __exit keywords imply initialisation MODULE_VERSION(“1.0”); and clean-up functions, respectively.

Any module must have at least two functions. The first Compiling and loading the module is initialisation and the second is the clean-up function. Now, let us understand the module compilation In our case, init_module() is the initialisation function procedure. To compile a kernel module, we are going to and cleanup_module() is the clean-up function. The use the kernel’s build system. Open your favourite text initialisation function is called as soon as the module editor and write down the following compilation steps is loaded and the clean-up function is called just before in it, before saving it as Makefile. Please note that the unloading the module. MODULE_LICENSE and other kernel modules hello.c and Makefile must exist in the macros are self-explanatory. same directory. There is a printk() function, the syntax of which is similar to the user-space printf() function. But unlike obj-m += hello.o printf() , it doesn’t print messages on a standard output stream; instead, it appends messages into the kernel’s all: ring buffer. Each printk() statement comes with a make -C /lib/modules/$(shell uname -r)/build M=$(PWD) priority. In our example, we used the KERN_INFO modules priority. Please note that there is no comma (,) between ‘KERN_INFO’ and the format string. In the absence of clean: explicit priority, DEFAULT_MESSAGE_LOGLEVEL make -C /lib/modules/$(shell uname -r)/build M=$(PWD) priority will be used. The last statement in init_module() clean is return 0 which indicates success. The names of the initialisation and clean-up To build modules, kernel headers are required. The functions are init_module() and cleanup_module() above makefile invokes the kernel’s build system from the respectively. But with the new kernel (>= 2.3.13) kernel’s source and finally the kernel’s makefile invokes we can use any name for the initialisation and clean- our Makefile to compile the module. Now that we have up functions. These old names are still supported everything to build our module, just execute the make for backward compatibility. The kernel provides command, and this will compile and create the kernel module_init and module_exit macros, which register module named hello.ko: initialisation and clean-up functions. Let us rewrite the same module with names of our own choice for [mickey] $ ls initialisation and cleanup functions: hello.c Makefile

#include [mickey]$ make #include make -C /lib/modules/2.6.32-358.el6.x86_64/build M=/home/ static int __init hello_init(void) mickey modules { make[1]: Entering directory `/usr/src/kernels/2.6.32-358. printk(KERN_INFO “Hello, World !!!\n”); el6.x86_64’ CC [M] /home/mickey/hello.o return 0; Building modules, stage 2. } MODPOST 1 modules CC /home/mickey/hello.mod.o static void __exit hello_exit(void) LD [M] /home/mickey/hello.ko.unsigned { NO SIGN [M] /home/mickey/hello.ko printk(KERN_INFO “Exiting ...\n”); make[1]: Leaving directory `/usr/src/kernels/2.6.32-358.el6. } x86_64’

module_init(hello_init); [mickey]$ ls module_exit(hello_exit); hello.c hello.ko hello.ko.unsigned hello.mod.c hello. MODULE_LICENSE(“GPL”); mod.o hello.o Makefile modules.order Module.symvers MODULE_AUTHOR(“Narendra Kangralkar.”); MODULE_DESCRIPTION(“Hello world module.”); We have now successfully compiled our first kernel

28 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 29 Developers How To module. Now, let us look at how to load and unload this of the current->pid variable. Given below is the complete module in the kernel. Please note that you must have super- working code (pid.c): user privileges to load/unload kernel modules. To load a module, switch to the super-user mode and execute the #include insmod command, as shown below: #include #include [root]# insmod hello.ko static int __init pid_init(void) insmod has done its job successfully. But where is the { output? It is appended to the kernel’s ring buffer. So let’s printk(KERN_INFO “pid = %d\n”, current->pid); verify it by executing the dmesg command: return 0; [root]# dmesg } Hello, World !!! static void __exit pid_exit(void) We can also check whether our module is loaded or not. { For this purpose, let’s use the lsmod command: /* Don’t do anything */ } [root]# lsmod | grep hello hello 859 0 module_init(pid_init); module_exit(pid_exit); To unload the module from the kernel, just execute the rmmod command as shown below and check the output of the MODULE_LICENSE(“GPL”); dmesg command. Now, dmesg shows the message from the MODULE_AUTHOR(“Narendra Kangralkar.”); clean-up function: MODULE_DESCRIPTION(“Kernel module to find PID.”); MODULE_VERSION(“1.0”); [root]# rmmod hello The Makefile is almost the same as the first makefile, with [root]# dmesg a minor change in the object file’s name: Hello, World !!! Exiting ... obj-m += pid.o

In this module, we have used a couple of macros, which all: provide information about the module. The modinfo command make -C /lib/modules/$(shell uname -r)/build M=$(PWD) displays this information in a nicely formatted fashion: modules

[mickey]$ modinfo hello.ko clean: filename: hello.ko make -C /lib/modules/$(shell uname -r)/build M=$(PWD) version: 1.0 clean description: Hello world module. author: Narendra Kangralkar. Now compile and insert the module and check the output license: GPL using the dmesg command: srcversion: 144DCA60AA8E0CFCC9899E3 depends: [mickey]$ make vermagic: 2.6.32-358.el6.x86_64 SMP mod_unload modversions [root]# insmod pid.ko

Finding the PID of a process [root]# dmesg Let us write one more kernel module to find out the Process pid = 6730 ID (PID) of the current process. The kernel stores all process related information in the task_struct structure, which is A module that spans multiple files defined in the header file. It provides a So far we have explored how to compile a module from a current variable, which is a pointer to the current process. single file. But in a large project, there are several source To find out the PID of a current process, just print the value files for a single module and, sometimes, it is convenient to

divide the module into multiple files. Let us understand the clean procedure of building a module that spans two files. Let’s divide the initialization and cleanup functions from the hello.c The Makefile is self-explanatory. Here, we are saying: file into two separate files, namely startup.c and cleanup.c. “Build the final kernel object by using startup.o and Given below is the source code for startup.c: cleanup.o.” Let us compile and test the module:

#include [mickey]$ ls #include cleanup.c Makefile startup.c

static int __init hello_init(void) [mickey]$ make { printk(KERN_INFO “Function: %s from %s file\n”, __func__, Then, let’s display module information using the modinfo __FILE__); command:

return 0; [mickey]$ modinfo final.ko } filename: final.ko version: 1.0 module_init(hello_init); description: Startup module. author: Narendra Kangralkar. MODULE_LICENSE(“GPL”); license: GPL MODULE_AUTHOR(“Narendra Kangralkar.”); version: 1.1 MODULE_DESCRIPTION(“Startup module.”); description: Cleanup module. MODULE_VERSION(“1.0”); author: Narendra Kangralkar. license: BSD And “cleanup.c” will look like this. srcversion: D808DB9E16AC40D04780E2F depends: #include vermagic: 2.6.32-358.el6.x86_64 SMP mod_unload #include modversions

static void __exit hello_exit(void) Here, the modinfo command shows the version, { description, licence and author-related information from each printk(KERN_INFO “Function %s from %s file\n”, __func__, module. __FILE__); Let us load and unload the final.ko module and verify the } output:

module_exit(hello_exit); [mickey]$ su - Password: MODULE_LICENSE(“BSD”); MODULE_AUTHOR(“Narendra Kangralkar.”); [root]# insmod final.ko MODULE_DESCRIPTION(“Cleanup module.”); MODULE_VERSION(“1.1”); [root]# dmesg Function: hello_init from /home/mickey/startup.c file Now, here is the interesting part -- Makefile for these modules: [root]# rmmod final

obj-m += final.o [root]# dmesg final-objs := startup.o cleanup.o Function: hello_init from /home/mickey/startup.c file Function hello_exit from /home/mickey/cleanup.c file all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) Passing command-line arguments to the module modules In user-space programs, we can easily manage command line arguments with argc/ argv. But to achieve the same clean: functionality through modules, we have to put in more of make -C /lib/modules/$(shell uname -r)/build M=$(PWD) an effort.

To achieve command-line handling in modules, MODULE_AUTHOR(“Narendra Kangralkar.”); we first need to declare global variables and use the MODULE_DESCRIPTION(“Module with command line arguments.”); module_param() macro, which is defined in the header file. There is also the MODULE_ PARM_DESC() macro which provides descriptions After compilation, first insert the module without about arguments. Without going into lengthy theoretical any arguments, which display the default values of the discussions, let us write the code: variable. But after providing command-line arguments, default values will be overridden. The output below #include illustrates this: #include #include [root]# insmod parameters.ko static char *name = “Narendra Kangralkar”; [root]# dmesg static long roll_no = 1234; Name : Narendra Kangralkar static int total_subjects = 5; Roll no : 1234 static int marks[5] = {80, 75, 83, 95, 87}; Subjectwise marks Subject-1 = 80 module_param(name, charp, 0); Subject-2 = 75 MODULE_PARM_DESC(name, “Name of the a student”); Subject-3 = 83 Subject-4 = 95 module_param(roll_no, long, 0); Subject-5 = 87 MODULE_PARM_DESC(rool_no, “Roll number of a student”); [root]# rmmod parameters module_param(total_subjects, int, 0); MODULE_PARM_DESC(total_subjects, “Total number of subjects”); Now, let us reload module with command-line arguments and verify the output. module_param_array(marks, int, &total_subjects, 0); MODULE_PARM_DESC(marks, “Subjectwise marks of a student”); [root]# insmod ./parameters.ko name=”Mickey” roll_no=1001 marks=10,20,30,40,50 static int __init param_init(void) { [root]# dmesg static int i; Name : Mickey Roll no : 1001 printk(KERN_INFO “Name : %s\n”, name); Subjectwise marks printk(KERN_INFO “Roll no : %ld\n”, roll_no); Subject-1 = 10 printk(KERN_INFO “Subjectwise marks “); Subject-2 = 20 Subject-3 = 30 for (i = 0; i < total_subjects; ++i) { Subject-4 = 40 printk(KERN_INFO “Subject-%d = %d\n”, i + 1, Subject-5 = 50 marks[i]); } If you want to learn more about modules, the Linux kernel’s source code is the best place to do so. You can return 0; download the latest source code from https://www.kernel. } org/. Additionally, there are a few good books available in the market like ‘Linux Kernel Development’ (3rd Edition) static void __exit param_exit(void) by Robert Love and ‘Linux Device Drivers’ (3rd Edition). { You can also download the free book from http://lwn.net/ /* Don’t do anything */ Kernel/LDD3/. } By: Narendra Kangralkar module_init(param_init); module_exit(param_exit); The author is a FOSS enthusiast and loves exploring anything related to open source. He can be reached at [email protected] MODULE_LICENSE(“GPL”);

jQuery, the cross-platform JavaScript library designed to simplify the client-side scripting of HTML, is used by over 80 per cent of the 10,000 most popularly visited websites. jQuery is free open source software which has a wide range of uses. In this article, the author suggests some best practices for writing jQuery code.

his article aims to explain how to use jQuery in frameworks like jQuery and writing numerous lines of a rapid and more sophisticated manner. Websites code to do some fairly minor task. Tfocus not only on backend functions like user For example, if one wants to write code to show the registration, adding new friends or validation, but also on datepicker selection, on onclick event in plain Javascript, how their Web pages will get displayed to the user, how the flow is: their pages will behave in different situations, etc. For 1. For onclick event create one div element. example, doing a mouse-over on the front page of a site 2. Inside that div, add content for dates, month and year. will either show beautiful animations, properly formatted 3. Add navigation for changing the months and year. error messages or interactive hints to the user on what can 4. Make sure that, on first client, div can be seen, and on be done on the site. second client, div is hidden; and this should not affect jQuery is a very handy, interactive, powerful and rich any other HTML elements. Just creating a datepicker client-side framework built on JavaScript. It is able to is a slightly more difficult task and if this needs to be handle powerful operations like HTML manipulation, implemented many times in the same page, it becomes events handling and beautiful animations. Its most more complex. If the code is not properly implemented, attractive feature is that it works across browsers. When then making modifications can be a nightmare. using plain JavaScript, one of the things we need to ensure This is where jQuery comes to our rescue. By using it, we is whether the code we write tends towards perfection. It can show the datepicker as follows: should handle any exception. If the user enters an invalid type of value, the script should not just hang or behave $(“#id”).datepicker(); badly. However, in my career, I have seen many junior developers using plain JavaScript solutions instead of rich That’s it! We can reuse the same code multiple times by

PB | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 33 Developers Insight just changing the id(s); and without any kind of collision, 4. Use proper selectors and try to use more ‘find()’, because we can show multiple datepickers in the same page. That find can traverse DOM faster. For example, if we want to is the beauty of jQuery. In short, by using it, we can focus find content of #id3… more on the functionality of the system and not just on small parts of the system. And we can write more complex code //demo code snippet like a rich text editor and lots of other operations. But if

we write jQuery code without proper guidance and proper methodology, we end up writing bad code; and sometimes

Here is the content.

that can become a nightmare for other team members to

understand and modify for minor changes. Developers often make silly mistakes during jQuery code //developer generally uses implementation. So, based on some silly mistakes that I have var content = $(‘#id1 .divClass’).html(); encountered, here are some general guidelines that every developer should keep in mind while implementing jQuery code. //the better way is [This is faster in execution] var content = $(‘#id1’).find(‘div.divClass’).html(); General guidelines for jQuery 1. Try to use ‘this’ instead of just using the id and class of 5. Write functions wherever required: Generally, the DOM elements. I have seen that most developers are developers write the same code multiple times. To happy with just using $(‘#id’) or $(‘.class’) everywhere: avoid this, we can write functions. To write functions, let’s find the block that will repeat. For example, if //What developers are doing: there is a validation of an entry for a text box and the $(‘#id’).click(function(){ same gets repeated for many similar text boxes, then var oldValue = $(‘#id’).val(); we can write a function for the same. Given below is a var newValue = (oldValue * 10) / 2; simple example of a text box entry. If the value is left $(‘#id’).val(newValue); empty in the entry, then function returns 0; else, if the }); user has entered some value, then it should return the same value. //What should be done: Try to use more $(this) in your code. $(‘#id’).click(function(){ //Javascript $(this).val(($(this).val() * 10) / 2); function doValidation(elementId){ }); //get value using elementId //check and return value 2. Avoid conflicts: When working with a CMS like } WordPress or Magento, which might be using other JavaScript frameworks instead of jQuery, you need to //simple jQuery work with jQuery inside that CMS or project. Then use $(“input[type=’text’]”).blur(function(){ the noConflicts of jQuery. //get value using $(this) //check and return value var $abc = jQuery.noConflict(); }); $abc(‘#id’).click(function(){ //do something //best way to implement }); //now you can use this function easily with click event also $.doValidation = function(){ 3. Take care of absent elements: Make sure that the element //get value on which your jQuery code is working/manipulating is //check and return value not absent. If the element on which your code manipulates }; is dynamically added, then first find it, if that element is added on DOM. $(“input[type=’text’]”).blur($.doValidation);

$(‘#divId’).find(‘#someId’).length 6. Object organisation: This is another thing that each developer needs to keep in mind. If one bunch of This code returns 0 if there isn’t an element with ‘someId’ variables is related to one task and another bunch of found; else it will return the total number of elements that are variables is related to another task, then get them better inside ‘divId’. organised, as shown below:

//bad way if (callback && typeof (callback) === “function”) { var disableTask1 = false; callback(); var defaultTask1 = 5; } var pointerTask1 = 2; } var disableTask2 = true; var defaultTask2 = 10; function task2(callback){ var currentValueTask2 = 10; //do something //like that many other variables if (callback && typeof (callback) === “function”) { callback(); } //better way } var task1 = { disable: false, //Better jQuery way default: 5, $.task1 = function(){ pointer: 2, //do something getNewValue: function(){ }; //do some thing return task1.default + 5; $.task2 = function(){ } //do something }; };

var task2 = { var callbacks = $.Callbacks(); disable: true, callbacks.add($.task1); default: 10, callbacks.add($.task2); currentValue: 10 callbacks.fire(); }; 8. Use of ‘each’ for iteration: The snippet below shows how //how to use them each can be used for iteration. if(task1.disable){ //do some thing… var array; return task1.default; //javascript way } var length = array.length; for(var i =0; i

task1(function(){ task1(); By: Savan Koradia }); The author works as a senior PHP Web developer at Multidots Solutions Pvt Ltd. He writes tutorials to help other developers function task1(callback){ to write better code. You can contact him at: savan.koradia@ multidots.in; Skype: savan.koradia.multidots //do something

34 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 35 Developers Let’s Try Back Up a Shared Server in MongoDB Continuing the series on MongoDB, in this article, readers learn how to set up a backup for the sharded environment that was set up over the previous two articles.

n the previous article in this series, we set up a sharded config servers store the same metadata and since we environment in MongoDB. This article deals with one have three of them just to ensure availability, we’ll Iof the most intriguing and crucial topics in database be backing just one config server for demonstration administration—backups. The article will demonstrate the purposes. So open a command prompt and type the MongoDB backup process and will make a backup of the following command to back up the config database of sharded server that was configured earlier. So, to proceed, you our config server: must set up your sharded environment as per our previous article as we’ll be using the same configuration. C:\Users\viny\Desktop\mongodb-win32-i386-2.6.0\ Before we move on with the backup, make sure that bin>mongodump --host localhost:59020 --db config the balancer is not running. The balancer is the process that This command will dump ensures that data is distributed your config database under evenly in a sharded cluster. the dump directory of your This is an automated process MongoDB root directory. in MongoDB and at most Now let’s back up our times, you won’t be bothered actual data by taking backups with it. In this case, though, it of all of our shards. Issue the needs to be stopped so that no following commands, one by chunk migration takes place one, and take a backup of all while we back up the server. the three replica sets of both If you’re wondering what the the shards that we configured term ‘chunk migration’ means, earlier: let me tell you that if one shard in a sharded MongoDB environment has more data mongodump --host localhost:38020 --out .\shard1\replica1 stored than its peers, then the balancer process migrates mongodump --host localhost:38021 --out .\shard1\replica2 some data to other shards. Evenly distributed data ensures mongodump --host localhost:38022 --out .\shard1\replica3 optimal performance in a sharded environment. mongodump --host localhost:48020 --out .\shard2\replica1 So now connect to a Mongo process by opening a mongodump --host localhost:48021 --out .\shard2\replica2 command prompt, going to the MongoDB root directory and mongodump --host localhost:48022 --out .\shard2\replica3 typing ‘Mongo’. Type sh.getBalancerState() to find out the balancer’s status. If you get true as the output, your balancer The --out parameter defines the directory where is running. Type sh.stopBalancer() to stop the balancer. MongoDB will place the dumps. Now you can start the The next step is to back up the config server, which balancer by issuing the sh.startBalancer() command stores metadata about shards. In the previous article, we and resume normal operations. So we’re done with our set up three config servers for our shard. Since all the backup operation. If you want to explore a bit more about backups and restores in MongoDB, you can check MongoDB documentation and the article in http://www.thegeekstuff. com/2013/09/mongodump-mongorestore/ which will give you some good insights into Mongodump and Mongorestore commands.

By: Vinayak Pandey The author is an experienced database developer, with exposure to various database and data warehousing tools and techniques, including Oracle, Teradata, Informatica PowerCenter and MongoDB. Figure 1: Balancer status

or the past few months, we have been to convert what constitutes our intuitive knowledge discussing information retrieval and natural about how to look for a company’s name in a text Flanguage processing (NLP), as well as the document into rules that can be automatically algorithms associated with them. In this month’s checked by a program. This is the task that is faced column, let’s continue our discussion on NLP while by NLP applications which try to do Named Entity also covering an important NLP application called Recognition (NER). The point to note is that while ‘Named Entity Recognition’ (NER). As mentioned the simple heuristics we use to identify names of earlier, given a large number of text documents, NLP companies does work well in many cases, it is also techniques are employed to extract information from quite possible that it misses out extracting names the documents. One of the most common sources of companies in certain other cases. For instance, of textual information is newspaper articles. Let us consider the possibility of the company’s name consider a simple example wherein we are given all being represented as IBM instead of I.B.M, or as the newspaper articles that appeared in the last one International Business Machines. The rule-based year. The task that is assigned to us is related to the system could potentially miss out recognising it. world of business. We are asked to find out all the Similarly, consider a sentence like, “Indian Oil mergers and acquisitions of businesses. We need to and Natural Gas Company decided that…” In this extract information on which companies bought over case, it is difficult to figure out whether there are other firms as well as the companies that merged two independent entities, namely, ‘Indian Oil’ and with each other. Our first rudimentary steps towards ‘Natural Gas Company’ being referred to in the getting this information will perhaps be to look sentence or if it is a single entity whose name is for keyword-based searches that used terms such ‘Indian Oil and Natural Gas Company’. It requires as ‘merger’ or ‘buys’. Once we find the sentences considerable knowledge about the business world containing those keywords, we could then perhaps to resolve the ambiguity. We could perhaps consult look for the names of the companies, if any occur in the ‘World Wide Web’ or Wikipedia to clear our those sentences. Such a task requires us to identify doubts. The use of such sources of knowledge is all company names present in the document. quite common in Named Entity Recognition (NER) For a person reading the newspaper article, systems. Now let us look a bit deeper into NER such a task seems simple and straightforward. Let systems and their uses. us first try to list down the ways in which a human being would try to identify the company names that Types of entities could be present in a text document. We need to use What are the types of entities that are of interest to heuristics such as: (a) Company names typically a NER system? Named entities are by definition, would begin with capital letters; (b) They can contain proper nouns, i.e., nouns that refer to a particular words such as ‘Corporation’ or ‘Ltd’; (c) They can person, place, organisation, thing, date or time, such be represented by letters of the alphabet separated as Sandya, Star Wars, Pride and Prejudice, Cubbon by full stops, such as I.B.M. We could also use Park, March, Friday, Wipro Ltd, Boy Scouts, and the contextual clues such as ‘X’s stock price went up’ Statue of Liberty. Note that a named entity can span to infer that X is a business or company. Now, the more than one word, as in the case of ‘Cubbon Park’. question we are left with is whether it is possible Each of these entities are assigned different tags such

as Person, Company, Location, Month, Day, Book, etc. If While rule-based NER systems and gazetteer the above example is tagged with entities, it will be tagged as approaches work well for a domain-specific NER, machine Sandya , Star Wars, learning approaches generally perform well when applied Pride and Prejudice , Cubbon across multiple domains. Many of the machine learning Park , etc. based approaches use supervised learning techniques, by It is not only important that the NER system recognises a which a large corpus of text is annotated manually with phrase correctly as an entity but also that it labels it with the named entities and the goal is to use the annotated data to right entity type. Consider the sentence, “Washington Jr went train the learner. These systems use statistical models and to school in England, but for graduate studies, he moved to some form of feature identification to make predictions the United States and studied at Washington.” This sentence about named entities in unlabelled text, based on what contains two references to the noun ‘Washington’, one as a they have learnt from the annotated text. Typically, person: ‘Washington Jr’ and another as a location: ‘Washington, supervised learning systems study the features of positive United States’. While it may appear that if an NER system has a and negative examples, which have been tagged as named list of all pronouns, it can correctly extract all entities, in reality, entities in the hand-annotated training set. They use that this is not true. Consider the two sentences, “Jobs are hard to information to either come up with statistical models, find…” and “Jobs said that the employment rate is picking up..” which can predict whether a newly encountered phrase is Even if the NER system has an exhaustive list of pronouns, it a named entity or not. If it is a named entity, supervised needs to figure out that the word ‘Jobs’ appearing in the first learning systems predict its type as well. In the next sentence does not refer to an entity, whereas the reference ‘Jobs’ column, we will continue our discussion on how hidden in the second sentence is an entity. Markov models and maximum entropy models can be used Given our discussion so far, it is clear to us that NER to construct learner systems. systems can be built in a number of ways, though no single method can be considered to be superior to others and a My ‘must-read book’ for this month combination of techniques is needed. We saw that rule- This month’s book suggestion comes from one of our readers, based NER systems tend to be incomplete and have the Jayshankar, and his recommendation is very appropriate for disadvantage of requiring manual extension quite frequently. this month’s column. He recommends an excellent resource Rule-based systems use typical pattern matching techniques for text mining—a book called ‘Taming Text’ by Ingersol, to identify the entities. On the other hand, it is possible Morton and Farris. The book describes different algorithms to extract features associated with named entities and use for text search, text clustering and classification. There is also them to train classifiers that can tag entities, using machine a detailed chapter on Named Entity Recognition, which will learning techniques. Machine learning approaches for be useful supplementary reading for this month’s column. identifying entities can be based on: (a) supervised learning Thank you, Jay, for sharing this book link. techniques; (b) semi-supervised learning techniques; and (c) If you have a favourite programming book or article that unsupervised learning techniques. you think is a must-read for every programmer, please do The third kind of NER systems can be based on gazetteers, send me a note with the book’s name, and a short write-up on wherein a lexicon or gazette for names is constructed and why you think it is useful, so I can mention it in the column. made available to the NER system which then tags the text, This would help many readers who want to improve their identifying entities in the text based on the lexicon entries. software skills. Once a gazetteer is available, all that the NER needs to do is If you have any favourite programming questions or to have an efficient lookup in the gazetteer for each phrase software topics that you would like to discuss on this forum, it identifies in the text, and tag it based on the information please send them to me, along with your solutions and it finds in the gazette. A gazette can also help to embed feedback, at sandyasm_AT_yahoo_DOT_com. Till we meet external world information, which can help in name entity again next month, happy programming! resolution. But first, the gazette needs to be built for it to be available to the NER system. Building a gazette can consume considerable manual effort. One of the alternatives is to build By: Sandya Mannarswamy the lexicon or gazetteer itself through automatic means, which The author is an expert in systems software and is currently working brings us back to the problem of recognising named entities with Hewlett Packard India Ltd. Her interests include compilers, automatically from various document sources. Typically, multi-core and storage systems. If you are preparing for systems external world sources such as Wikipedia or Twitter can be software interviews, you may find it useful to visit Sandya's LinkedIn used as the information sources from which the gazette can group ‘Computer Science Interview Training India’ at http://www.linkedin.com/groups?home=HYPERLINK "http://www. be built. Sometimes a combination of approaches can be used linkedin.com/groups?home=&gid=2339182"&HYPERLINK "http:// with a lexicon, in conjunction with a rules-based or machine www.linkedin.com/groups?home=&gid=2339182"gid=2339182 learning approach.

Exploring Software Guest Column

Anil Seth Big Data on a Desktop: A Virtual Machine in an OpenStack Cloud OpenStack is a worldwide collaboration between developers and cloud computing technologists aimed at developing the cloud computing platform for public and private clouds. Let’s install it on our desktop.

nstalling OpenStack using Packstack is very simple. # route add -net 172.24.4.224 netmask 255.255.255.240 gw After a test installation in a virtual machine, you will find 192.168.122.54 Ithat the basic operations for creating and using virtual machines are now quite simple when using a Web interface. Now, browse http://192.168.122.54/dashboard and create a new project and a user associated with the project. The environment 1. Sign in as the admin. It is important to understand the virtual environment. While 2. Under the Identity panel, create a user (youser) and everything is running on a desktop, the setup consists of a project (Bigdata). Sign out and sign in as youser to multiple logical networks interconnected via virtual routers create and test a cloud VM. and switches. You need to make sure that the routes are 3. Create a private network for the project under defined properly because otherwise, you will not be able to Project/Network/Networks: access the virtual machines you create. • Create the private network 192.168.10.0/24 with On the desktop, the virt-manager creates a NAT-based the gateway 192.168.10.254 network by default. NAT assures that if your desktop can • Create a router and set a gateway to the public access the Internet, so can the virtual machine. The Internet network. Add an interface to the private network access had been used when the OpenStack distribution was and ip address 192.168.10.254. installed in the virtual machine. 4. To be able to sign in using ssh, under the Project/ The Packstack installation process creates a virtual Compute/Access & Security, in the Security public network for use by the various networks created Groups tab, add the following rules to the default within the cloud environment. The virtual machine security group: on which OpenStack is installed is the gateway to the • Allow ssh access: Custom TCP Rule for allowing physical network. traffic on Port 22. • Allow icmp access: Custom ICMP Rule with Virtual Network on the Desktop (virbr0 interface): Type and Code value -1. 192.168.122.0/32 5. For password-less signing into the VM, under the IP address of eth0 interface on OpenStack VM: 192.168.122.54 Project/Compute/Access & Security, in the Key Pairs Public Virtual Network created by packstack on OpenStack VM: tab the following: 172.24.4.224/28 • Select the Import Key Pair option and give it a IP address of the br-ex interface OpenStack VM: 172.24.4.225 name, e.g., ‘desktop user login’. • In your desktop terminal window, use ssh-keygen Testing the environment to create a public/private key pair in case you In the OpenStack VM console, verify the network addresses. don't already have one. In my case, I had to explicitly give an ip to the br-ex • Copy the contents of ~/.ssh/id_rsa.pub from your interface, as follows: desktop account and paste them in the public key. 6. Allocate a public IP for accessing the VM under # ifconfig Project/Compute/Access & Security in the Floating # ip addr add 172.24.4.225/28 dev br-ex Ips tab, and allocate IP to the project. You may get a value like 172.24.4.229 On the desktop, add a route to the public virtual network 7. Now launch the instance under Project/Compute/ on OpenStack VM: Instance:

• Give it a name - test and choose the m1- tiny flavour. virbr0 eth0 br-ext • Select the boot source as ‘Boot from image' em1 with the image name ‘cirros', a very small image included in the installation. Desktop OpenStack VM • Once it is launched, associate the floating Internet ip obtained above with this instance. Now, you are ready to log in to the VM created in your local cloud. In a terminal eth0 window, type: Router ssh [email protected] VM

You should be signed into the virtual machine Figure 1: Simplified network diagram without needing a password. You can experiment with importing the Fedora VM Should Packstack install OpenStack client tools [y|n] [y] image you used for the OpenStack VM and launching it : y in the cloud. Whether you succeed or not will depend on the resources available in the OpenStack VM. The answers to the other questions will depend on the network interface and the IP address of your desktop, but Installing only the needed OpenStack services there is no ambiguity here. You should answer with the You will have observed that OpenStack comes with a interface ‘lo' for CONFIG_NOVA_COMPUTE_PRIVIF and very wide range of services, some of which are not likely CONFIG_NOVA_NETWORK_PRIVIF. You don't need an to be very useful for your experiments on the desktop, extra physical interface as the compute services are running e.g., the additional networks and router created in the on the same server. tests above. Here is a part of the dialogue for installing Now, you are ready to test your OpenStack the required services on the desktop: installation on the desktop. You may want to create a project and add a user to the project. Under Project/ [root@amd ~]# packstack Compute/Access & Security, you will need to add Welcome to Installer setup utility firewall rules and key pairs, as above. Enter the path to your ssh Public key to install on However, you will not need to create any additional servers: private network or a router. Packstack changed given value to required value /root/. Import a basic cloud image, e.g., from http://fedoraproject. ssh/id_rsa.pub org/get-fedora#clouds under Project/Compute/Images. Should Packstack install MySQL DB [y|n] [y] : y You may want to create an additional flavour for a Should Packstack install OpenStack Image Service (Glance) virtual machine. The m1.tiny flavour has 512MB of RAM [y|n] [y] : y and 4GB of disk and is too small for running Hadoop. The Should Packstack install OpenStack Block Storage (Cinder) m1.small flavour has 2GB of RAM and 20GB of disk, service [y|n] [y] : n which will restrict the number of virtual machines you Should Packstack install OpenStack Compute (Nova) service can run for testing Hadoop. Hence, you may create a mini [y|n] [y] : y flavour with 1GB of RAM and 10GB of disk. This will Should Packstack install OpenStack Networking (Neutron) need to be done as the admin user. service [y|n] [y] : n Now, you can create an instance of the basic cloud Should Packstack install OpenStack Dashboard (Horizon) image. The default user is fedora and your setup is ready [y|n] [y] : y for exploration of Hadoop data. Should Packstack install OpenStack Object Storage (Swift) [y|n] [y] : n Should Packstack install OpenStack Metering (Ceilometer) By: Dr Anil Seth [y|n] [y] : n The author has earned the right to do what interests him. Should Packstack install OpenStack Orchestration (Heat) You can find him online at http://sethanil.com, http://sethanil. blogspot.com, and reach him via email at [email protected] [y|n] [n] : n

42 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 43 Developers Let's Try MariaDB The MySQL Fork that Google has Adopted MariaDB is a community developed fork of MySQL, which has overtaken MySQL. That many leading corporations in the cyber environment, including Google, have migrated to MariaDB speaks for its importance as a player in the database firmament.

ariaDB is a high performance, open source History database that helps the world's busiest websites In 2008, Sun Microsystems bought MySQL for US$ 1 Mdeliver more content, faster. It has been created billion. But the original developer, Monty Widenius, was by the developers of MySQL with the help of the FOSS quite disappointed with the way things were run at Sun and community and is a fork of MySQL. It offers various features founded his own new company and his own fork of MySQL and enhancements like alternate storage engines, server - MariaDB. It is named after Monty's younger daughter, optimisations and patches. Maria. Later, when Oracle announced the acquisition of The lead developer of MariaDB is Michael ‘Monty’ Sun, most of the MySQL developers jumped to its forks: Widenius, who is also the founder of MySQL and Monty MariaDB and Drizzle. Program AB. MariaDB version numbers follow MySQL numbers No single person or company nurtures MariaDB/MySQL till 5.5. Thus, all the features in MySQL are available in development. The guardian of the MariaDB community, MariaDB. After MariaDB 5.5, its developers started a new the MariaDB Foundation, drives it. It states that it has the branch numbered MariaDB 10.0, which is the development trademark of the MariaDB server and owns mariadb.org, which version of MariaDB. This was done to make it clear that ensures that the official MariaDB development tree is always MariaDB 10.0 will not import all the features from MySQL open to the developer community. The MariaDB Foundation 5.6. Also, at times, some of these features do not seem to be assures the community that all the patches, as well as MySQL solid enough for MariaDB’s standards. Since new specific source code, are merged into MariaDB. The Foundation also features have been developed in MariaDB, the team decided provides a lot of documentation. MariaDB is a registered to go for a major version number. The currently used trademark of SkySQL Corporation and is used by the MariaDB version, MariaDB 10.0, is built on the MariaDB 5.5 series Foundation with permission. It is a good choice for database and has back ported features from MySQL 5.6 along with professionals looking for the best and most robust SQL server. entirely new developments.

Why MariaDB is better than MySQL Now, add the apt-get repository as per your Ubuntu When comparing MariaDB and MySQL, we are comparing version. different development cultures, features and performance. For Ubuntu 13.10 The patches developed by MariaDB focus on bug fixing and performance. By supporting the features of MySQL, $ sudo add-apt-repository 'deb http://ftp.kaist.ac.kr/ MariaDB implements more improvements and delivers mariadb/repo/5.5/ubuntu saucy main' better performance without restrictions on compatibility with MySQL. It also provides more storage engines than MySQL. For Ubuntu 13.04 What makes MariaDB different from MySQL is better testing, fewer bugs and fewer warnings. The goal of MariaDB is to be $ sudo add-apt-repository 'deb http://ftp.kaist.ac.kr/ a drop-in replacement for MySQL, with better developments. mariadb/repo/5.5/ubuntu raring main' Navicat is a strong and powerful MariaDB administration and development tool. It is graphic database management and For Ubuntu 12.10 development software produced by PremiumSoft CyberTech Ltd. It provides a native environment for MariaDB database $ sudo add-apt-repository 'deb http://ftp.kaist.ac.kr/ management and supports the extra features like new storage mariadb/repo/5.5/ubuntu quantal main' engines, microsecond and virtual columns. It is easy to convert from MySQL to MariaDB, as we For Ubuntu 12.04 LTS need not convert any data and all our old connectors to other languages work unchanged. As of now MariaDB is capable of $ sudo add-apt-repository 'deb http://ftp.kaist.ac.kr/ handling data in terabytes, but more needs to be done for it to mariadb/repo/5.5/ubuntu precise main' handle data in petabytes. Step 2: Install MariaDB using the following commands: Features Here is a list of features that MariaDB provides: $ sudo apt-get update Since it has been released under the GPL version 2, it is free. $ sudo apt-get install mariadb-server It is completely open source. Open contributions and suggestions are encouraged. Provide the root account password as shown in Figure 1. MariaDB is one of the fastest databases available. Step 3: Log in to MariaDB using the following Its syntax is pretty simple, flexible and easy to manage. command, after installation: It can be easily imported or exported from CSV and XML. It is useful for both small as well as large databases, mysql -u root -p containing billions of records and terabytes of data in hundreds of thousands of tables. MariaDB includes pre-installed storage engines like Aria, XtraDB, PBXT, FederatedX and SphinxSE. The use of the Aria storage engine makes complex queries faster. Aria is usually faster since it caches row data in memory and normally doesn't have to write the temporary rows to disk. Some storage engines and plugins are pre-installed in MariaDB. It has a very strong community. Figure 1: Configuring MariaDB Installing MariaDB Now let’s look at how MariaDB is installed. Step 1: First, make sure that the required packages are installed along with the apt-get key for the MariaDB repository, by using the following commands:

$ sudo apt-get install software-properties-common $ sudo apt-key –recv-keys –keyserver hkp://keyserver.ubuntu. com:80 0xcbcb082a1bb943db Figure 2: Logging into MariaDB

Figure 3: A sample table created

Creating a database in MariaDB When entering the account administrator password set up Figure 4: Inserting data into a table during installation, you will be given a MariaDB prompt. Create a database on students by using the following Inserting data into a MariaDB table command: To insert data into a MariaDB table, use the following commands:

CREATE DATABASE students; INSERT INTO details(name,age,marks) values ("anu",15,450);

Switch to the new database using the following command (this INSERT INTO details(name,age,marks) VALUES("Bob",15,400); is to make sure that you are currently working on this database): The output will be as shown in Figure 4. USE students;

Now that the database has been created, create a table: We need not add values in student_id. It is automatically incremented. All other values are given in quotes. CREATE TABLE details(student_id int(5) NOT NULL AUTO_ INCREMENT, Deleting a table name varchar(20) DEFAULT NULL, To delete a table, type the following command: age int(3) DEFAULT NULL, marks int(5) DEFAULT NULL, DROP TABLE table_name; PRIMARY KEY(student_i)d ); Once the table is deleted, the data inside it cannot be To see what we have done, use the following command: recovered. We can view the current table using the show tables show columns in details; command, which gives all the tables inside the database:

Each column in the table creation command is separated SHOW tables; by a comma and is in the following format: After deleting the table, use the following commands: Column_Name Data_Type[(size_of_data)] [NULL or NOT NULL] [DEFAULT default_value] DROP TABLE details; [AUTO_INCREMENT] Query OK, 0 rows affected (0.02 sec)

These columns can be defined as: SHOW tables; Column Name: Describes the attribute being assigned. Data Type: Specifies the type of data in the column. The output will be: Null: Defines whether null is a valid value for that field –- it can be ‘null’or ‘not null’. Empty set (0.00 sec) Default Value: Sets the initial value of all newly created records that do not specify a value. Google waves goodbye to MySQL auto_increment: MySQL will handle the sequential Google has now switched to MariaDB and dumped MySQL. numbering of any column marked with this option, internally, “For the Web community, Google’s big move might be a in order to provide a unique value for each record. paradigm shift in the DBMS ecosystem,” said a Google engineer. Ultimately, before closing the table definition, Major Linux distributions, like Red Hat and SUSE, and well- we need to use the primary key by typing PRIMARY known websites such as Wikipedia, have also switched from KEY(column name). It guarantees that this column will MySQL to MariaDB. This is a great blow to MySQL. serve as a unique field. Google has migrated applications that were previously

present in MariaDB, yet. And then it will be difficult to switch back to the previous database. MariaDB has the advantage of being bigger in terms of the number of users, than its forks and clones. MySQL took a lot of time and effort before emerging as the choice of many companies. So, it is a little hard to introduce MariaDB in the commercial field. Being a new open source standard, we can only hope that MariaDB will overtake other databases in a short span of time. Figure 5: Tables in the database

running on MySQL on to MariaDB without changing the References application code. There are five Google technicians working part- [1] http://en.wikipedia.org/wiki/MariaDB time on MariaDB patches and bug fixes, and Google continues [2] https://mariadb.org/ to maintain its internal branch of MySQL to have complete [3] http://tecadmin.net/install-mariadb-5-5-in-ubuntu/# control over the improvement. Google running thousands of [4] https://www.digitalocean.com/community/tutorials/how- to-create-a-table-in-mysql-and-mariadb-onan-ubuntu- MariaDB servers can only be good news for those who feel more cloud-server comfortable with a non-Oracle future for MySQL. [5] http://en.wikibooks.org/wiki/MariaDB/Introduction Though multinational corporations like Google have switched to MariaDB, it does have a few shortcomings. By: Amrutha S. MariaDB’s performance is slightly better in multi-core The author is currently studying for a bachelor’s degree in Computer machines, but one suspects that MySQL could be tweaked Science and Engineering at Amrita University in Kerala, India. She is to match the performance. All it requires is for Oracle to an open source enthusiast and also an active member of the Amrita improve MySQL by adding some new features that are not FOSS club. She can be contacted at [email protected].

Please share your feedback/ thoughts/ views via email at [email protected]

46 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 47 Developers Let's Try Haskell: The Purely Functional Programming Language Haskell, an open source programming language, is the outcome of 20 years of research. Named after the logician, Haskell Curry, it has all the advantages of functional programming and an intuitive syntax based on mathematical notation. This second article in the series on Haskell explores a few functions.

onsider the function sumInt to compute the sum of two Loading package ghc-prim ... linking ... done. Cintegers. It is defined as: Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. sumInt :: Int -> Int -> Int sumInt x y = x + y Prelude> :l Sum.hs [1 of 1] Compiling Main ( Sum.hs, interpreted ) The first line is the type signature in which the function name, Ok, modules loaded: Main. arguments and return types are separated using a double colon (::). The arguments and the return types are separated by the symbol *Main> :t sumInt (->). Thus, the above type signature tells us that the sum function sumInt :: Int -> Int -> Int takes two arguments of type Int and returns an Int. Note that the function names must always begin with the letters of the alphabet *Main> sumInt 2 3 in lower case. The names are usually written in CamelCase style. 5 You can create a Sum.hs Haskell source file using your favourite text editor, and load the file on to the Glasgow If we check the type of sumInt with arguments, we get the Haskell Compiler interpreter (GHCi) using the following code: following output:

$ ghci *Main> :t sumInt 2 3 GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help sumInt 2 3 :: Int

*Main> :t sumInt 2 from a list: sumInt 2 :: Int -> Int *Main> tail a The value of sumInt 2 3 is an Int as defined in the type signature. [2,3,4,5] We can also partially apply the function sumInt with one argument and its return type will be Int -> Int. In other words, sumInt 2 takes *Main> :t tail an integer and will return an integer with 2 added to it. tail :: [a] -> [a] Every function in Haskell takes only one argument. So, we can think of the sumInt function as one that takes an argument and The last function returns the last element of a list: returns a function that takes another argument and computes their sum. This return function can be defined as a sumTwoInt function *Main> last a that adds a 2 to an Int using the sumInt function, as shown below: 5

sumTwoInt :: Int -> Int *Main> :t last sumTwoInt x = sumInt 2 x last :: [a] -> a

The ‘=’ sign in Haskell signifies a definition and not The init function returns everything except the last a variable assignment as seen in imperative programming element of a list: languages. We can thus omit the ‘x' on either side and the code becomes even more concise: *Main> init a [1,2,3,4] sumTwoInt :: Int -> Int sumTwoInt = sumInt 2 *Main> :t init init :: [a] -> [a] By loading Sum.hs again in the GHCi prompt, we get the following: The length function returns the length of a list:

*Main> :l Sum.hs *Main> length a [1 of 1] Compiling Main ( Sum.hs, interpreted ) 5 Ok, modules loaded: Main. *Main> :t length *Main> :t sumTwoInt length :: [a] -> Int sumTwoInt :: Int -> Int The take function picks the first ‘n' elements from a list: *Main> sumTwoInt 3 5 *Main> take 3 a [1,2,3] Let us look at some examples of functions that operate on lists. Consider list ‘a', which is defined as [1, 2, 3, 4, 5] (a list *Main> :t take of integers) in the Sum.hs file (re-load the file in GHCi before take :: Int -> [a] -> [a] trying the list functions). The drop function drops ‘n' elements from the beginning a :: [Int] of a list, and returns the rest: a = [1, 2, 3, 4, 5] *Main> drop 3 a The head function returns the first element of a list: [4,5]

*Main> head a *Main> :t drop 1 drop :: Int -> [a] -> [a]

*Main> :t head The zip function takes two lists and creates a new list of head :: [a] -> a tuples with the respective pairs from each list. For example:

The tail function returns everything except the first element *Main> let b = ["one", "two", "three", "four", "five"]

*Main> zip a b 1 [(1,"one"),(2,"two"),(3,"three"),(4,"four"),(5,"five")] *Main> factorial 1 1 *Main> :t zip *Main> factorial 2 zip :: [a] -> [b] -> [(a, b)] 2 *Main> factorial 3 The let expression defines the value of ‘b' in the GHCi 6 prompt. You can also define it in a way that’s similar to the *Main> factorial 4 definition of the list ‘a' in the source file. 24 The lines function takes input text and splits it at new lines: *Main> factorial 5 120 *Main> let sentence = "First\nSecond\nThird\nFourth\nFifth" Functions operating on lists can also be called recursively. *Main> lines sentence To compute the sum of a list of integers, you can write the ["First","Second","Third","Fourth","Fifth"] sumList function as:

*Main> :t lines sumList :: [Int] -> Int lines :: String -> [String] sumList [] = 0 sumList (x:xs) = x + sumList xs The words function takes input text and splits it on white space: The notation (x:xs) represents a list, where ‘x' is the first element in the list and ‘xs' is the rest of the list. On running *Main> words "hello world" sumList with GHCi, you get the following: ["hello","world"] *Main> sumList [] *Main> :t words 0 words :: String -> [String] *Main> sumList [1,2,3] 6 The map function takes a function and a list, and applies the function to every element in the list: Sometimes, you will need a temporary function for a computation, which you will not need to use elsewhere. *Main> map sumTwoInt a You can then write an anonymous function. A function to [3,4,5,6,7] increment an input value can be defined as:

*Main> :t map *Main> (\x -> x + 1) 3 map :: (a -> b) -> [a] -> [b] 4

The first argument to map is a function that is enclosed These are called Lambda functions, and the '\' represents within parenthesis in the type signature (a -> b). This function the notation for the symbol Lambda. Another example is takes an input of type ‘a' and returns an element of type ‘b'. given below: Thus, when operating over a list [a], it returns a list of type [b]. Recursion provides a means of looping in functional *Main> map (\x -> x * x) [1, 2, 3, 4, 5] programming languages. The factorial of a number, for example, [1,4,9,16,25] can be computed in Haskell, using the following code: It is a good practice to write the type signature of factorial :: Int -> Int the function first when composing programs, and then factorial 0 = 1 write the body of the function. Haskell is a functional factorial n = n * factorial (n-1) programming language and understanding the use of functions is very important. The definition of factorial with different input use cases is called pattern matching on the function. On running the above By: Shakthi Kannan example with GHCi, you get the following output: The author is a free software enthusiast and blogs at shakthimaan.com *Main> factorial 0

Qt-WebKit, a major engine that can render Web pages and execute JavaScript code, is the answer to the developer’s prayer. Let’s take a look at a few examples that will aid developers in making better use of this engine.

his article is for Qt developers. It is assumed that the Q_INVOKABLE intended audience is aware of the famous Signals and This is a macro that is similar to Slot, except that it has a TSlots mechanisms of Qt. Creating an HTML page is return type. Thus, we will prefix Q_INVOKABLE to the very quick compared to any other way of designing a GUI. methods that can be called by the JavaScript. The advantage An HTML page is nothing but a fancy page that doesn’t have here is that we can have a return type with Q_INVOKABLE, any logic in its build. With the amalgamation of JavaScript, as compared to Slot. however, the HTML page builds in some intelligence. As everything cannot be collated in JavaScript, we need a back-end Developing a sample HTML page with JavaScript for it. Qt provides a way to mingle (HTML+Java) with C++. intelligence Thus, you can call the C++ methods through JavaScripts and Here is a sample form in HTML-JavaScript that will allow vice-versa. This is possible by using the Qt-WebKit framework. us to multiply any two given numbers. However, the logic of The applications developed in Qt are not just limited to various multiplication should reside in the C++ method only. desktop platforms. They are even ported over several mobile platforms. Thus, you can design your apps that can just fit into the Windows, iOS and Android worlds, seamlessly. class object to the JavaScript window object. In short, this class object will be visible to JavaScript once it is added to the JavaScript window object. However, JavaScript can invoke

view->show(); return a.exec(); } #include "main.moc" Please note that in the above HTML code, myoperations is a class object. And MultOfNumbers is its public Q_ The output is given in Figure 1. Invokable class method. How to install a callback from C++ code to the How to call the C++ methods from the Web Web page using the Qt-WebKit framework page using the Qt-WebKit framework We have already seen the call to C++ methods by Let's say, I have the following class that has the JavaScript. Now, how about a callback from C++ to Q_Invokable method, MultOfNumbers. JavaScript? Yes, it is possible with the Qt-WebKit. There are two ways to do so. However, for the sake of neatness in class MyJavaScriptOperations : public QObject { design, let’s discuss only the Signals and Slots mechanisms Q_OBJECT for the JavaScript callback. public: Q_INVOKABLE qint32 MultOfNumbers(int a, int b) { Installing Signals and Slots for the JavaScript qDebug() << a * b; function return (a*b); Here are the steps that need to be taken for the callback to be } installed: }; a) Add a JavaScript window object to the javaScriptWindowObjectCleared slot. This class object should be added to the JavaScript b) Declare a signal in the class. window object by the following API: c) Emit the signal. d) In JavaScript, connect the signal to the JavaScript addToJavaScriptWindowObject("name of the object", new (class function slot. that can be accessed)) Here is the syntax to help you connect:

Here is the entire program: ..connect(); #include #include Note, you can make a callback to JavaScript only after #include the Web page is loaded. This can be ensured by connecting #include to the Slot emitted by the Signal loadFinished() in the C++ #include application. #include Let’s look at a real example now. This will fire a callback once the Web page is loaded. class MyJavaScriptOperations : public QObject { The callback should be addressed by the JavaScript Q_OBJECT function, which will show up an alert window. public: Q_INVOKABLE qint32 MultOfNumbers(int a, int b) { qDebug() << a * b; return (a*b); } }; int main(int argc, char *argv[]) { QApplication a(argc, argv); Figure 1: QT DEMO output

QT_DEMO

} MyJavaScriptOperations::MyJavaScriptOperations() { Here is the main file: qDebug()<<__PRETTY_FUNCTION__; view = new QWebView(); #include view->resize(400, 500); #include connect(view->page()->mainFrame(), SIGNAL(javaScriptWindowObj #include ectCleared()), this, SLOT(JS_ADDED())); #include connect(view, SIGNAL(loadFinished(bool)), this, #include SLOT(loadFinished(bool))); #include view->load(QUrl("./index.html")); class MyJavaScriptOperations : public QObject { view->show(); Q_OBJECT } public: int main(int argc, char *argv[]) QWebView *view; { MyJavaScriptOperations(); QApplication a(argc, argv); signals: MyJavaScriptOperations *jvs = new MyJavaScriptOperations; void alert_script_signal(); return a.exec(); public slots: } void JS_ADDED(); #include "main.moc" void loadFinished(bool); }; The output is shown in Figure 2. Qt is a rich framework for C++ developers. It not only void MyJavaScriptOperations::JS_ADDED() provides these amazing features, but also has some interesting { attributes like in-built SQlite, D-Bus and various containers. It's qDebug()<<__PRETTY_FUNCTION__; easy to develop an entire GUI application with it. You can even view->page()->mainFrame()->addToJavaScriptWindowObject("myope port an existing HTML page to Qt. This makes Qt a wonderful rations", this); choice to develop a cross-platform application quickly. It is } now getting popular in the mobile world too.

void MyJavaScriptOperations::loadFinished(bool oper) By: Shreyas Joshi { The author is a technology enthusiast and software developer qDebug()<<__PRETTY_FUNCTION__<< oper; at Pace Micro Technology. You can connect with him at [email protected]. emit alert_script_signal();

This article focuses on Yocto – a complete embedded Linux development environment that offers tools, metadata and documentation.

he Yocto Project helps developers and companies encourages the Linux community. Its goals are: get their project off the ground. It is an open source To develop custom Linux-based embedded systems Tcollaboration project that provides templates, tools and regardless of the architecture. methods to create custom Linux-based systems for embedded To provide interoperability between tools and working code, products, regardless of the hardware architecture. which will reduce the money and time spent on the project. While building Linux-based embedded products, it is To develop licence-aware build systems that make it important to have full control over the software running on the possible to include or remove software components embedded device. This doesn’t happen when you are using a based on specific licence groups and the corresponding normal Linux OS for your device. The software should have restriction levels. full access as per the hardware requirements. That’s where To provide a place for open source projects that help in the Yocto Project comes in handy. It helps you create custom the development of Linux-based embedded systems and Linux-based systems for any hardware architecture and makes customisable Linux platforms. the device easier to use and faster than expected. To focus on creating single build systems that address the The Yocto Project was founded in 2010 as a solution needs of all users that other software components can later for embedded Linux development by many open source be tethered to. vendors, hardware manufacturers and electronic companies. To ensure that the tools developed are architecturally The project aims at helping developers build their own independent. Linux distributions, specific to their own environments. The To provide a better graphical user interface to the build project provides developers with interoperable tools, methods system, which eases access. and processes that help in the development of Linux-based To provide resources and information, catering to both embedded systems. The central goal of the project is to enable new and experienced users. the user to reuse and customise tools and working code. It To provide core system component recipes provided by encourages interaction with embedded projects and has been the OpenEmbedded project. a steady contributor to the OpenEmbedded core, BitBake, the To further educate the community about the benefits Linux kernel development process and several other projects. of this standardisation and collaboration in the Linux It not only deals with building Linux-based embedded community and in the industry. systems, but also the tool chain for cross compilation and software development kits (SDK) so that users can choose the The Yocto Project community package manager format they intend to use. The community shares many common traits with a typical open source organisation. Anyone who is interested can contribute to The goals of the Yocto Project the development of the project. The Yocto Project is developed Although the main aim is to help developers of customised and governed as a collaborative effort by an open community Linux systems supporting various hardware architectures, it of professionals, volunteers and contributors. has also a key role in several other fields where it supports and The project’s governance is mainly divided into two wings

Latest updates Yocto Project 1.6 The latest release of Yocto Project (YP) 1.6 ‘Daisy’ has a great set of features to help developers build with a very good user interface. The Toaster, a new UI to the YP build system, enables detailed examination of the build output, with great control over the view of the data. The Linux kernel update and the GCC update to 4.8.2 adds further functionality to the latest release. It also supports building Python 3. The new client for reporting errors to a central Web interface helps developers to focus on problem management. AMD and LG Electronics partner with Yocto The introduction of new standardised features to ensure quick access to the latest Board Support Packages (BSP) Figure1: YP community for AMD 64-bit x86 architecture has made AMD a new gold member in the YP community. LG Electronics, joining as a new member organisation to help support and guide the project, is of great importance. Developer- Commercial Specific Layer Layer Embedded Linux Conference 2014 The Yocto Project is one of the silver sponsors of this premier vendor-neutral technical conference for companies and developers that use Linux in embedded products. Sponsored by the Linux Foundation, it has a key role in Hardware- encouraging newcomers to the world of open source and UI-Specific Layer Specific BSP embedded products. Toaster prototype Toaster, a part of the latest YP 1.6 release, is a Web interface for BitBake, build system. Toaster collects all kinds of data about the building process, so that it is easy to Yocto-Specific OpenEmbedded search and query through this data in a specific way. Layer Metadata Core Metadata Technical leaders: Those who work within the sub- projects, doing the same thing as the layer maintainers. Figure 2: YP layers Upstream projects: Many Yocto Project components such as the Linux kernel are dependent on the upstream projects. —administrative and technical. The administrative board Advisory board: The advisory board gives direction to the includes executive leaders from organisations that participate project and helps in setting the requirements for the project. on the advisory board and also in several sub-groups that perform several non-technical services including community Layers management, financial management, infrastructure The build system is composed of different layers, which are management, advocacy and outreach. The technical board the containers for the building blocks used to construct the includes several sub-groups, which oversee tasks that range system. The layers are grouped according to functionality, from submitting patches to the project architect to deciding on which makes the management of extensions and who is the final authority on the project. customisations easier. The building of the project requires the coordinated efforts of many people, who work in several roles. These roles References are listed below. Architect: One who holds the final authority and provides [1] https://www.yoctoproject.org/ [2] https://wiki.yoctoproject.org/wiki/Main_Page overall leadership to the project’s development. Sub-system maintainers: The project is further divided By: Vishnu N K into several sub-projects and the maintainers are assigned to these sub-projects. The author, an open source enthusiast, is in the midst of his B. Tech Layer maintainers: Those who ensure the components’ degree in Computer Science at Amrita Vishwa Vidyapeetham and contributes to Mediawiki. Contact him at [email protected] excellence and functionality.

One of the aspects of hacking a Linux kernel is to port it. While this might sound difficult, it won’t be once you read this article. The author explains porting techniques in a simplified manner.

ith the evolution of embedded systems, porting target. There may be a need to change a few lines here and has become extremely important. Whenever there, before it is up and running. But, the key thing to Wyou have new hardware at hand, the first and know is, what needs to be changed and where. the most critical thing to be done is porting. For hobbyists, what has made this even more interesting is the open source What Linux kernel porting involves nature of the Linux kernel. So, let’s dive into porting and Linux kernel porting involves two things at a higher level: understand the nitty-gritty of it. architecture porting and board porting. Architecture, in Porting means making something work on an Linux terminology, refers to CPU. So, architecture porting environment it is not designed for. Embedded Linux porting means adapting the Linux kernel to the target CPU, which means making Linux work on an embedded platform, may be ARM, Power PC, MIPS, and so on. In addition for which it was not designed. Porting is a broader term to this, SOC porting can also be considered as part of and when I say ‘embedded Linux porting’, it not only architecture porting. As far as the Linux kernel is concerned, involves Linux kernel porting, but also porting a first stage most of the times, you don't need to port it for architecture bootloader, a second stage bootloader and, last but not the as this would already be supported in Linux. However, you least, the applications. Porting differs from development. still need to port Linux for the board and this is where the Usually, porting doesn't involve as much of coding as in major focus lies. Architecture porting entails porting of development. This means that there is already some code initial start-up code, interrupt service routines, dispatcher available and it only needs to be fine-tuned to the desired routine, timer routine, memory management, and so on.

Whereas board porting involves writing custom drivers and initialisation code for devices specific to the board. Building a Linux kernel for the target platform Kernel building is a two-step process: first, the kernel needs to be configured for the target platform. There are many ways to configure the kernel, based on the preferred configuration interface. Given below are some of the common methods. To run the text-based configuration, execute the following Figure 1: Plain text-based kernel configuration command:

$ make config

This will show the configuration options on the console as seen in Figure 1. It is a little cumbersome to configure the kernel with this, as it prompts every configuration option, in order, and doesn't allow the reversion of changes. To run the menu-driven configuration, execute the following command:

$ make menuconfig

This will show the menu options for configuring the Figure 2: Menu-driven kernel configuration kernel, as seen in Figure 2. This requires the ncurses library to be installed on the system. This is the most popular interface ARCH= used to configure the kernel. CROSS-COMPILE = To run the window-based configuration, execute the following command: The first line defines the architecture the kernel needs to be built for, and the second line defines the cross compilation $ make xconfig toolchain prefix. So, if the architecture is ARM and the toolchain is say, from CodeSourcery, then it would be: This allows configuration using the mouse. It requires QT to be installed on the system. ARCH=arm For details on other options, execute the following CROSS_COMPILE=arm-none-linux-gnueabi- command in the kernel top directory: Optionally, make can be invoked as shown below: $ make help $ make ARCH=arm menuconfig - For configuring the kernel Once the kernel is configured, the next step is to build $ make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- - For the kernel with the make command. A few commonly used compiling the kernel commands are given below: The kernel image generated after the compilation is $ make vmlinux - Builds the bare kernel usually vmlinux, which is in ELF format. This image can't $ make modules - Builds the modules be used directly with embedded system bootloaders such as $ make modules_prepare – Sets up the kernel for building the u-boot. So convert it into the format suitable for a second modules external to kernel. stage bootloader. Conversion is a two-step process and is done with the following commands: If the above commands are executed as stated, the kernel will be configured and compiled for the host system, which arm-none-linux-gnueabi-objcopy -O binary vmlinux vmlinux.bin is generally the x86 platform. But, for porting, the intention mkimage -A arm -O linux -T kernel -C none -a 0x80008000 -e is to configure and build the kernel for the target platform, 0x80008000 -n linux-3.2.8 -d vmlinux.bin uImage which in turn, requires configuration of makefile. Two things -A ==> set architecture that need to be changed in the makefile are given below: -O ==> set operating system

-T ==> set image type means it won't be built at all. Where are these values stored? -C ==> set compression type There is a file called .config in the top level directory, which -a ==> set load address (hex) holds these values. So, the .config file is the output of the -e ==> set entry point (hex) configuration target such as menuconfig. -n ==> set image name Where are these symbols used? In makefile, as shown below: -d ==> use image data from file obj-$(CONFIG_MYDRIVER) += my_driver.o The first command converts the ELF into a raw binary. This binary is then passed to mkimage, which is a utility to So, if CONFIG_MYDRIVER is set to value ‘y', the driver generate the u-boot specific kernel image. mkimage is the my_driver.c will be built as part of the kernel image and if set utility provided by u-boot. The generated kernel image is to value ‘m', it will be built as a module with the extension named uImage. .ko. And, for value ‘n', it won't be compiled at all. As you now know a little more about kbuild, let’s The Linux kernel build system consider adding a simple character driver to the kernel tree. One of the beautiful things about the Linux kernel is that it The first step is to write a driver and place it at the correct is highly configurable and the same code base can be used location. I have a file named my_driver.c. Since it’s a character for a variety of applications, ranging from high end servers driver, I will prefer adding it at the drivers/char/ sub-directory. to tiny embedded devices. And the infrastructure, which So copy this at the location drivers/char in the kernel. plays an important role in achieving this in an efficient The next step is to add a configuration entry in the drivers/ manner, is the kernel build system, also known as kbuild. char/Kconfig file. Each entry can be of type bool, tristate, int, The kernel build system has two main components – string or hex. bool means that the configuration symbol can have makefile and Kconfig. the values ‘y' or ‘n', while tristate means it can have values ‘y', Makefile: Every sub-directory has its own makefile, which is ‘m' or ‘n'. And ‘int', ‘string' and ‘hex' mean that the value can be used to compile the files in that directory and generate the object an integer, string or hexadecimal, respectively. Given below is code out of that. The top level makefile percolates recursively the segment of code added in drivers/char/Kconfig: into its sub-directories and invokes the corresponding makefile to build the modules and finally, the Linux kernel image. The config MY_DRIVER makefile builds only the files for which the configuration option tristate "Demo for My Driver" is enabled through the configuration tool. default m Kconfig: As with the makefile, every sub-directory has a help Kconfig file. Kconfig is in configuration language and Kconfig Adding this small driver to kernel for files located inside each sub-directory are the programs. demonstrating the kbuild Kconfig contains the entries, which are read by configuration targets such as make menuconfig to show a menu-like structure. The first line defines the configuration symbol. The So we have covered makefile and Kconfig and at present second specifies the type for the symbol and the text which they seem to be pretty much disconnected. For kbuild to will be shown as the menu. The third specifies the default work properly, there has to be some link between the Kconfig value for this symbol and the last two lines are for the help and makefile. And that link is nothing but the configuration message. Another thing that you will generally find in a symbols, which generally have a prefix CONFIG_. These Kconfig file is ‘depends on'. This is very useful when you symbols are generated by a configuration target such as want to select the particular feature, only if its dependency menuconfig, based on entries defined in the Kconfig file. is selected. For example, if we are writing a driver for And based on what the user has selected in the menu, these i2c EEPROM, then the menu option for the driver should symbols can have the values ‘y', ‘n', or ‘m'. appear only if the 2c driver is selected. This can be achieved Now, as most of us are aware, Linux supports hot with the ‘depends on' entry. plugging of the drivers, which means, we can dynamically After saving the above changes in Kconfig, execute the add and remove the drivers from the running kernel. The following command: drivers which can be added/removed dynamically are known as modules. However, drivers that are part of the kernel $ make menuconfig image can't be removed dynamically. So, there are two ways to have a driver in the kernel. One is to build it as a part of Now, navigate to Device Drivers->Character devices and the kernel, and the other is to build it separately as a module you will see an entry for My Driver. for hot-plugging. The value ‘y' for CONFIG_, means the By default, it is supposed to be built as a module. Once corresponding driver will be part of the kernel image; the you are done with configuration, exit the menu and save the value ‘m' means it will be built as a module and value ‘n' configuration. This saves the configuration in .config file. Now,

open the .config file, and there will be an entry as shown below:

CONFIG_MY_DRIVER=m

Here, the driver is configured to be built as a module. Also, one thing worth noting is that the symbol ‘MY_ DRIVER' in Kconfig is prefixed with CONFIG_. Now, just adding an entry in the Kconfig file and configuration alone won't compile the driver. There has to be the corresponding change in makefile as well. So, add the following line to makefile:

obj-$(CONFIG_MYDRIVER) += my_driver.o Figure 3: Menu option for My Driver

After the kernel is compiled, the module my_driver.ko will board-specific custom code and needs to be specifically be placed at drivers/char/. This module can be inserted in the brought in with the kernel. And this collection of board- kernel with the following command: specific initialisation and custom code is referred to as a Board Support Package or, in Linux terminology, a LSP. In $ insmod my_driver.ko simple words, whatever software code you require (which is specific to the target platform) to boot up the target with Aren't these configuration symbols needed in the C code? the operating system can be called LSP. Yes, or else how will the conditional compilation be taken care of? How are these symbols included in C code? During Components of LSP the kernel compilation, the Kconfig and .config files are read, As the name itself suggests, BSP is dependent on the things that and are used to generate the C header file named autoconf.h. are specific to the target board. So, it consists of the code which This is placed at include/generated and contains the #defines is specific to that particular board, and it applies only to that for the configuration symbols. These symbols are used by the board. The usual list includes Interrupt Request Numbers (IRQ), C code to conditionally compile the required code. which are dependent on how the various devices are connected Now, let’s suppose I have configured the kernel and that it on the board. Also, some boards have an audio codec and you works fine with this configuration. And, if I make some new need to have a driver for that codec. Likewise, there would be changes in the kernel configuration, the earlier ones will be switch interfaces, a matrix keypad, external eeprom, and so on. overwritten. In order to avoid this from happening, we can save .config file in the arch/arm/configs directory with a name like LSP placement my_config, for instance. And next time, we can execute the LSP is placed under a specific folder of the kernel's following command to configure the kernel with older options: arch folder. For example, architecture-specific code for ARM resides in the arch/arm directory. This is about the code, but $ make my_config_defconfig you also need the headers which are placed under arch/arm/ include/asm. However, board-specific code is placed at arch/ Linux Support Packages (LSP)/Board Support arm/mach- and corresponding headers are Packages (BSP) placed at arch/arm/mach-/include. For One of the most important and probably the most example, LSP for Beagle Board is placed at arch/arm/mach- challenging thing in porting is the development of Board omap2/board-omap3beagle.c and corresponding headers Support Packages (BSP). BSP development is a one- are placed at arch/arm/mach-omap2/include/mach/. This is time effort during the product development lifecycle and, shown in figure 4. obviously, the most critical. As we have discussed, porting involves architecture porting and board porting. Board Machine ID porting involves board-specific initialisation code that Every board in the kernel is identified by a machine ID. includes initialisation of the various interfaces such as This helps the kernel maintainers to manage the boards memory, peripherals such as serial, and i2c, which in turn, based on ARM architecture in the source tree. This ID is involves the driver porting. passed to the kernel from the second stage bootloader such There are two categories of drivers. One is the standard as u-boot. For the kernel to boot properly, there has to be a device driver such as the i2c driver and block driver match between the kernel and the second stage boot loader. located at the standard directory location. Another is the This information is available in arch/arm/tools/mach-types custom interface or device driver, which includes the and is used to generate the file linux/include/generated/

done here. This function should be defined during the board porting. This includes things such as setting up the pin multiplexing, initialisation of the serial console, initialisation of RAM, initialisation of Ethernet, USB and so on. MACHINE_END ends the macro. This macro is defined in arch/arm/include/asm/mach/arch.h. How to begin with porting The most common and recommended way to begin with Figure 4: LSP placement in kernel source porting is to start with some reference board, which closely resembles yours. So, if you are porting for a board based on mach-types.h. The macros defined by mach-types.h are OMAP3 architecture, take Beagle Board as a reference. Also, used by the rest of the kernel code. For example, the for porting, you should understand the system very well. machine ID for Beagle Board is 1546, and this is the Depending on the features available on your board, configure number which the second stage bootloader passes to the the kernel accordingly. To start with, just enable the minimal kernel. For registering the new board for ARM, provide set of features required to boot the kernel. This may include the board details at http://www.arm.linux.org.uk/developer/ but not be limited to initialisation of RAM, Gpio subsystems, machines/?action=new. serial interfaces, and filesystems drivers for mounting the root filesystem. Once the kernel boots up with the minimal Note: The porting concepts described over here are configuration, start adding the new features, as required. specific to boards based on the ARM platform and may So, let’s summarise the steps involved in porting: differ for other architectures. 1. The first step is to register the machine with the kernel maintainer and get the unique ID for your board. While this MACHINE_START macro is not necessary to begin with porting, it needs to be done One of the steps involved in kernel porting is to define the eventually, if patches are to be submitted to the mainline. initialisation functions for the various interfaces on the board, Place the machine ID in arch/arm/tools/mach-types. such as serial, Ethernet, Gpio, etc. Once these functions are 2. Create the board-specific file ‘board-' defined, they need to be linked with the kernel so that it can at arch/arm/mach- and define the MACHINE_ invoke them during boot-up. For this, the kernel provides the START for the new board. For example, the board- macro MACHINE_START. Typically, a MACHINE_START specific file for the Panda Board resides at arch/arm/ macro looks like what’s shown below: mach-omap2/board-omap4panda.c. 3. Update the Kconfig file at arch/arm/mach_ to add MACHINE_START(MY_BOARD, "My Board for Demo") an entry for the new board as shown below: .atag_offset = 0x100, .init_early = my_board_early, config MACH_MY_BOARD .init_irq = my_board_irq, bool “My Board for Demo” .init_machine = my_board_init, depends on ARCH_OMAP3 MACHINE_END default y

Let's understand this macro. MY_BOARD is machine 4. Update the corresponding makefile, so that the board- ID defined in arch/arm/tools/mach-types. The second specific file gets compiled.This is shown below: parameter to the macro is a string describing the board. The next few lines specify the various initialisation functions, obj-$(CONFIG_MACH_MY_BOARD) += board-my_board.o which the kernel has to invoke during boot-up. These include the following: 5. Create a default configuration file for the new board.To .atag_offset: Defines the offset in RAM, where the boot begin with, take any .config file as a starting point and parameters will be placed. These parameters are passed from customise it for the new board. Place the working .config the second stage bootloader, such as u-boot. file at arch/arm/configs/my_board_defconfig. my_board_early: Calls the SOC initialisation functions. This function will be defined by the SOC vendor, if the kernel By: Pradeep Tewani is ported for it. The author works at Intel, Bangalore. He shares his learnings on my_board_irq: Intialisation related to interrupts is done Linux & embedded systems through his weekend workshops. over here. Learn more about his experiments at http://sysplay.in. He can be reached at [email protected]. my_board_init: All the board-specific initialisation is

60 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | PB How To Developers Writing an RTC Driver Based on the SPI Bus Most computers have one or more hardware clocks that display the current time. These are ‘Real Time Clocks’ or RTCs. Battery backup is provided for one of these clocks so that time is tracked even when the computer is switched off. RTCs can be used for alarms and other functions like switching computers on or off. This article explains how to write Linux device drivers for SPI-based RTC chips.

e will focus on the RTC DS1347 to explain how this case, the slave device is RTC DS1347. Describing the device drivers are written for RTC chips. You can SPI slave device is an independent task that can be done as Wrefer to the RTC DS1347 datasheet for a complete discussed in the section on ‘Registering RTC DS1347 as an understanding of this driver. SPI slave device’. The SPI protocol driver: This interface provides methods Linux SPI subsystem to read and write the SPI slave device (RTC DS1347). In Linux, the SPI subsystem is designed in such a way that Writing an SPI protocol driver is described in the section on the system running Linux is always an SPI master. The SPI ‘Registering the DS1347 SPI protocol driver’. subsystem has three parts, which are listed below. The steps for writing an RTC DS1347 driver based on the The SPI master driver: For each SPI bus in the system, SPI bus are as follows: there will be an SPI master driver in the kernel, which has 1. Register RTC DS1347 as an SPI slave device with the SPI routines to read and write on that SPI bus. Each SPI master master driver, based on the SPI bus number to which the driver in the kernel is identified by an SPI bus number. For the SPI slave device is connected. purposes of this article, let’s assume that the SPI master driver 2. Register the RTC DS1347 SPI protocol driver. is already present in the system. 3. Once the probe routine of the protocol driver is called, The SPI slave device: This interface provides a way of register the RTC DS1347 protocol driver to read and write describing the SPI slave device connected to the system. In routines to the Linux RTC subsystem.

After all this, the Linux RTC subsystem can use the registered protocol driver’s read and write routines to read and SPI Master Linux Kernel SPI RCT driver write the RTC. BUS DS1347 spi master spi master read write

RTC DS1347 hardware overview SPI Subsystem RTC DS1347 is a low current SPI compatible real time clock. C Slave device spi write operation spi read The information it provides includes the seconds, minutes and registration operation P struct spi_device hours of the day, as well as what day, date, month and year U SPI Slave device SPI Protocol Driver it is. This information can either be read from or be written struct spi_board_info struct spi_driver

RTC RTC to the RTC DS1347 using the SPI interface. RTC DS1347 read write acts as a slave SPI device and the microcontroller connected to it acts as the SPI master device. The CS pin of the RTC is RTC Subsystem asserted ‘low’ by the microcontroller to initiate the transfer, and de-asserted ‘high’ to terminate the transfer. The DIN pin of the RTC transfers data from the microcontroller to the Figure 1: RTC DS1347 driver block diagram RTC and the DOUT pin transfers data from the RTC to the microcontroller. The SCLK pin is used to provide a clock by 1. Specify the driver’s RTC read and write routines through the microcontroller to synchronise the transfer between the the function pointer interface provided by the RTC microcontroller and the RTC. subsystem. The RTC DS1347 works in the SPI Mode 3. Any transfer 2. Register with the RTC subsystem using devm_rtc_device_ between the microcontroller and the RTC requires the register API. microcontroller to first send the command/address byte to the The RTC subsystem requires that the driver fill the struct RTC. Data is then transferred out of the DOUT pin if it is a rtc_class_ops routine, which has the following function read operation; else, data is sent by the microcontroller to the pointers. DIN pin of the RTC if it is a write operation. If the MSB bit read_time: This routine is called by the kernel when the of the address is one, then it is a read operation; and if it is user application executes a system call to read the RTC time. zero, then it is a write operation. All the clock information is set_time: This routine is called by the kernel when the mapped to SPI addresses as shown in Table 1. user application executes a system call to set the RTC time. There are other function pointers in the structure, but the above Read Write RTC Range address address register two are the minimum an interface requires for an RTC driver. Whenever the kernel wants to perform any operation on 0x81 0x01 Seconds 0 - 59 the RTC, it calls the above function pointer, which will call 0x83 0x03 Minutes 0 - 59 the driver’s RTC routines. 0x85 0x05 Hours 0 - 23 After the above RTC operations structure has been filled, 0x87 0x07 Date 1 - 31 it has to be registered with the Linux RTC subsystem. This is 0x89 0x09 Month 1 - 12 done through the kernel API: 0x8B 0x0B Day 1 - 7 devm_rtc_device_register(struct device *dev, const char 0x8D 0x0D Year 0 - 99 *name, const struct rtc_class_ops *ops, struct module 0x8F 0x0F Control 00H - 81H *owner); 0x97 0x17 Status 03H - E7H 0xBF 0x3F Clock burst - The first parameter is the device object, the second is the name of the RTC driver, the third is the driver RTC operations Table 1: RTC DS1347 SPI register map structure that has been discussed above, and the last is the When the clock burst command is given to the RTC, the owner, which is THIS_MODULE macro. latter will give out the values of seconds, minutes, hours, the date, month, day and year, one by one, and continuously. The Registering the RTC DS1347 as an SPI slave device clock burst command is used in the driver to read the RTC. The Linux kernel requires a description of all devices connected to it. Each subsystem in the Linux driver model The Linux RTC subsystem has a way of describing the devices related to that subsystem. The Linux RTC subsystem is the interface through which Similarly, the SPI subsystem represents devices based on the Linux manages the time of the system. The following SPI bus as a struct spi_device. This structure defines the SPI procedure is what the driver goes through to register the RTC slave device connected to the processor running the Linux with the Linux RTC subsystem. kernel. The device structure is written in the board file in the

Linux kernel, which is a part of the board support package. In the above specified manner, any SPI slave device is The board file resides in arch/ directory in Linux (for registered with the Linux kernel and the struct spi_device is example, the board file for the Beagle board is in arch/arm/ created and linked to the Linux SPI subsystem to describe mach-omap2/board-omap3beagle.c). The struct spi_device the device. This spi_device struct will be passed as a is not directly written but a different structure called struct parameter to the SPI protocol driver probe routine when the spi_board_info is filled and registered, which creates the SPI protocol driver is loaded. struct spi_device in the kernel automatically and links it to the SPI master driver that contains the routines to read and write Registering the RTC DS1347 SPI protocol driver on the SPI bus. The struct spi_board_info for RTC DS1347 The driver is the medium through which the kernel interacts can be written in the board file as follows: with the device connected to the system. In case of the SPI device, it is called the SPI protocol driver. The first step in struct spi_board_info spi_board_info[] __initdata = { writing an SPI protocol driver is to fill the struct spi_driver .modalias = “ds1347”, structure. For RTC DS1347, the structure is filled as follows: .bus_num = 1, .chip_select = 1, static struct spi_driver ds1347_driver = { }; .driver = { .name = "ds1347", Modalias is the name of the driver used to identify the .owner = THIS_MODULE, driver that is related to this SPI slave device—in which case }, the driver will have the same name. Bus_num is the number .probe = ds1347_probe, of the SPI bus. It is used to identify the SPI master driver that }; controls the bus to which this SPI slave device is connected. Chip_select is used in case the SPI bus has multiple chip The name field has the name of the driver (this should be select pins; then this number is used to identify the chip select the same as in the modalias field of the structspi_board_info ). pin to which this SPI slave device is connected. ‘Owner’ is the module that owns the driver, THIS_MODULE The next step is to register the struct spi_board_info is the macro that refers to the current module in which the with the Linux kernel. In the board file initialisation code, the driver is written (the ‘owner’ field is used for reference structure is registered as follows: counting of the module owning the driver). The probe is the most important routine that is called when the device and the spi_register_board_info(spi_board_info, 1); driver are both registered with the kernel. The next step is to register the driver with the kernel. The first parameter is the array of the struct spi_board_ This is done by a macro module_spi_driver (struct spi_ info and the second parameter is the number of elements in driver *). In the case of RTC DS1347, the registration is the array. In the case of RTC DS1347, it is one. This API done as follows: will check if the bus number specified in the spi_board_info structure matches with any of the master driver bus numbers module_spi_driver(ds1347_driver); that are registered with the Linux kernel. If any of them do match, it will create the struct spi_device and initialise the The probe routine of the driver is called if any of the fields of the spi_device structure as follows: following cases are satisfied: 1. If the device is already registered with the kernel and then master = spi_master driver which has the same bus number as the driver is registered with the kernel. bus_num in the spi_board_info structure. 2. If the driver is registered first, then when the device is chip_select = chip_select of spi_board_info registered with the kernel, the probe routine is called. modalias = modalias of spi_board_info In the probe routine, we need to read and write on the SPI bus, for which certain common steps need to be followed. After initialising the above fields, the structure is These steps are written in a generic routine, which is called registered with the Linux SPI subsystem. The following are throughout to avoid duplicating steps. The generic routines the fields of the struct spi_device, which will be initialised are written as follows: by the SPI protocol driver as needed by the driver, and if not 1. First, the address of the SPI slave device is written on needed, will be left empty. the SPI bus. In the case of the RTC DS1347, the address should contain its most significant bit, reset for the write max_speed_hz = the maximum rate of transfer to the bus. operation (as per the DS1347 datasheet). bits_per_word = the number of bits per transfer. 2. Then the data is written to the SPI bus. mode = the mode in which the SPI device works. Since this is a common operation, a separate routine ds1347_

write_reg is written as follows: registered. The first thing the probe routine does is to set the SPI parameters to be used to write on the bus. The parameters static int ds1347_write_reg(struct device *dev, unsigned char are the mode in which the SPI device works. In the case of address, unsigned char data) RTC DS1347, it works on Mode 3 of the SPI: { struct spi_device *spi = to_spi_device(dev); spi->mode = SPI_MODE_3; unsigned char buf[2]; bits_per_word is the number of bits transferred. In the buf[0] = address & 0x7F; case of RTC DS1347, it is 8 bits. buf[1] = data; spi->bits_per_word = 8; return spi_write_then_read(spi, buf, 2, NULL, 0); } After changing the parameters, the kernel has to be informed of the changes, which is done by calling the spi_ The parameters to the routine are the address to which the setup routine as follows: data has to be written and the data which has to be written to the device. spi_write_then_read is the routine that has the spi_setup(spi); following parameters: struct spi_device: The slave device to be written. The following steps are carried out to check and configure tx_buf: Transmission buffer. This can be NULL if the RTC DS1347. reception only. 1. First, the RTC control register is read to see if the RTC is tx_no_bytes: The number of bytes in the tx buffer. present and if it responds to the read command. rx_buf: Receive buffer. This can be NULL if 2. Then the write protection of the RTC is disabled so that transmission only. the code is able to write on the RTC registers. rx_no_bytes: The number of bytes in the receive buffer. 3. Then the oscillator of the RTC DS1347 is started so that In the case of the RTC DS1347 write routine, only two the RTC starts working. bytes are to be written: one is the address and the other is the Till this point the kernel is informed that the RTC is on an SPI data on that address. bus and it is configured. After the RTC is ready to be read and The reading of the SPI bus is done as follows: written by the user, the read and write routines of the RTC are to be 1. First, the address of the SPI slave device is written on registered with the Linux kernel RTC subsystem as follows: the SPI bus. In the case of RTC DS1347, the address should contain its most significant bit set for the read operation (as rtc = devm_rtc_device_register(&spi->dev, "ds1347", &ds1347_ per the DS1347 datasheet). rtc_ops, THIS_MODULE); 2. Then the data is read from the SPI bus. Since this is a common operation, a separate routine, The parameters are the name of the RTC driver, the ds1347_read_reg, is written as follows: RTC operation structure that contains the read and write operations of the RTC, and the owner of the module. After static int ds1347_read_reg(struct device *dev, unsigned char this registration, the Linux kernel will be able to read address, unsigned char *data) and write on the RTC of the system. The RTC operation { structure is filled as follows: struct spi_device *spi = to_spi_device(dev); static const struct rtc_class_ops ds1347_rtc_ops = { *data = address | 0x80; .read_time = ds1347_read_time, .set_time = ds1347_set_time, return spi_write_then_read(spi, data, 1, data, 1); }; } The RTC read routine is implemented as follows. In the case of RTC DS1347, only one byte, which is the The RTC read routine has two parameters, one is the address, is written on the SPI bus and one byte is to be read device object and the other is the pointer to the Linux RTC from the SPI device. time structure struct, rtc_time. The rtc_time structure has the following fields, which RTC DS1347 driver probe routine have to be filled by the driver: When the probe routine is called, it passes an spi_device tm_sec: seconds (0 to 59, same as RTC DS1347) struct, which was created when spi_board_info was tm_min: minutes (0 to 59, same as RTC DS1347)

tm_hour: hour (0 to 23, same as RTC DS1347) /* year in linux is from 1900 i.e in range of 100 tm_mday: day of month (1 to 31, same as RTC DS1347) in rtc it is from 00 to 99 */ tm_mon: month (0 to 11 but RTC DS1347 provides dt->tm_year = dt->tm_year % 100; months from 1 to 12, so the value returned by RTC needs to have 1 subtracted from it) buf[7] = bin2bcd(dt->tm_year); tm_year: year (year since 1900; RTC DS1347 stores years buf[8] = bin2bcd(0x00); from 0 to 99, and the driver considers the RTC valid from 2000 to 2099, so the value returned from RTC is added to 100 After this, the data is sent to the RTC device, and the and as a result the offset is the year from 1900) status of the write is sent to the kernel as follows: First the clock burst command is executed on the RTC, which gives out all the date and time registers through the SPI return spi_write_then_read(spi, buf, 9, NULL, 0); interface, i.e., a total of 8 bytes: Contributing to the RTC subsystem buf[0] = DS1347_CLOCK_BURST | 0x80; The RTC DS1347 is a Maxim Dallas RTC. There are err = spi_write_then_read(spi, buf, 1, buf, 8); various other RTCs in the Maxim database and they are if (err) not supported by the Linux kernel, just like it is with return err; various other manufacturers of RTCs. All the RTCs that are supported by the Linux kernel are present in the drivers/rtc Then the read date and time is stored in the Linux date directory of the kernel. The following steps can be taken to and time structure of the RTC. The time in Linux is in binary write support for the RTC in the Linux kernel. format so the conversion is also done: 1. Pick any RTC from the ‘Manufacturer’ (e.g., Maxim) database which does not have support in the Linux kernel dt->tm_sec = bcd2bin(buf[0]); (see the drivers/rtc directory for supported RTCs). dt->tm_min = bcd2bin(buf[1]); 2. Download the datasheet of the RTC and study its features. dt->tm_hour = bcd2bin(buf[2] & 0x3F); 3. Refer to rtc-ds1347.c and other RTC files in the drivers/ dt->tm_mday = bcd2bin(buf[3]); rtc directory in the Linux kernel and go over even this dt->tm_mon = bcd2bin(buf[4]) - 1; article for how to implement RTC drivers. dt->tm_wday = bcd2bin(buf[5]) - 1; 4. Write the support for the RTC. dt->tm_year = bcd2bin(buf[6]) + 100; 5. Use git (see ‘References’ below) to create a patch for the RTC driver written. After storing the date and time of the RTC in the Linux 6. Submit the patch by mailing it to the Linux RTC mailing list: RTC date and time structure, the date and time is validated • [email protected] through rtc_valid_tm API. After validation, the validation • [email protected] status from the API is returned—if the date and time is valid, • [email protected] then the kernel will return the date and time in the structure 7. The patch will be reviewed and any changes required will to the user application; else it will return an error: be suggested, and if everything is fine, the driver will be acknowledged and be added to the Linux tree. return rtc_valid_tm(dt);

The RTC write routine is implemented as follows. References First, the local buffer is filled with the clock burst write command, and the date and time passed to the driver write [1] DS1347 datasheet, datasheets.maximintegrated.com/en/ds/ DS1347.pdf routine. The clock burst command informs the RTC that [2] DS1347 driver file https://git.kernel.org/cgit/linux/kernel/git/ the date and time will follow this command, which is to torvalds/linux.git/tree/drivers/rtc/rtc-ds1347.c be written to the RTC. Also, the time in RTC is in the bcd [3] Writing and submitting your first Linux kernel patch video, format; so the conversion is also done: https://www.youtube.com/watch?v=LLBrBBImJt4 [4] Writing and submitting your first Linux kernel patch text file and presentation, https://github.com/gregkh/kernel-tutorial buf[0] = DS1347_CLOCK_BURST & 0x7F; buf[1] = bin2bcd(dt->tm_sec); By: Raghavendra Chandra Ganiga buf[2] = bin2bcd(dt->tm_min); buf[3] = (bin2bcd(dt->tm_hour) & 0x3F); The author is an embedded firmware development engineer at General Industrial Controls Pvt Ltd, Pune. His interests lie in buf[4] = bin2bcd(dt->tm_mday); microcontrollers, networking firmware, RTOS development and buf[5] = bin2bcd(dt->tm_mon + 1); Linux device drivers. buf[6] = bin2bcd(dt->tm_wday + 1);

Use GIT for Linux Kernel Development

This article is aimed at newbie developers who are planning to set up a development environment or move their Linux kernel development environment to GIT.

IT is a free, open source distributed version control communications between the software and hardware using tool. It is easy to learn and is also fast, as most of IPC and system calls. It resides in the main memory (RAM), Gthe operations are performed locally. It has a very when any operating system is loaded in memory. small footprint. Just to compare GIT with another SVN The kernel is mainly of two types - the micro kernel and (Source Version Control) tool, refer to http://git-scm.com/ the monolithic kernel. The Linux kernel is monolithic, as is about/small-and-fast. depicted clearly in Figure 2. GIT allows multiple local copies (branches), each Based on the above diagram, the kernel can be viewed totally different from the other—it allows the making of as a resource manager; the managed resource could be a clones of the entire repository so each user will have a full process, hardware, memory or storage devices. More details backup of the main repository. Figure 1 gives one among about the internals of the Linux kernel can be found at http:// the many pictorial representations of GIT. Developers can kernelnewbies.org/LinuxVersions and https://www.kernel.org/ clone the main repository, maintain their own local copy doc/Documentation/. (branch and branch1) and push the code changes (branch1) to the main repository. For more information on GIT, refer Linux kernel files and modules to http://git-scm.com/book. In Ubuntu, kernel files are stored under the /boot/ directory (run ls /boot/ from the command prompt). Inside this Note: GIT is under development and hence changes are directory, the kernel file will look something like this: often pushed into GIT repositories. To get the latest GIT code, use the following command: ‘vmlinuz-A.B.C-D’ $git clone git://git.kernel.org/pub/scm/git/git.git … where A.B is 3.2, C is your version and D is a patch or fix. The kernel Let’s delve deeper into certain aspects depicted in Figure 3: The kernel is the lowest level program that manages Vmlinuz-3.2.0-29-generic: In vmlinuz, ‘z’ indicates the

‘compressed’ Linux kernel. With the development of Public1 virtual memory, the prefix vm was used to indicate that the Public2 Main repository kernel supports virtual memory. Initrd.img-3.2.0-29-generic: An initial ‘ramdisk’ for your kernel. Config-3.2.0-29-generic: The ‘config’ file is used to configure the kernel. We can configure, define options and determine which modules to load into the kernel image Developer Developer Integration while compiling. System.map-3.2.0-29-generic: This is used for memory management before the kernel loads. Figure 1: GIT

Kernel modules User Applications The interesting thing about kernel modules is that they can be Kernel loaded or unloaded at runtime. These modules typically add System Call functionality to the kernel—file systems, devices and system Virtual File System calls. They are located under /lib/modules with the extension .ko. Process Physical/ virtual Management & Memory & Device Driver architecture Management Setting up a development environment Let’s set up the host machine with Ubuntu 14.04. Building the Linux kernel requires a few tools like GIT, make, gcc and Hardware Storage & other ctag/ncurser-dev. Run the following command: Memory CPU devices

Sudo apt-get install git-core gcc make libncurses5-dev exuberant-ctags Figure 2: Linux kernel architecture

Once GIT is installed on the local machine (I am using Ubuntu), open a command prompt and issue the following commands to create an account: Figure 3: Locating Ubuntu Linux kernel files git config --global user.name “Vinay Patkar” git config –global user. Email [email protected]

Let’s set up our own local repository for the Linux kernel.

Note: 1. Multiple Linux kernel repositories exist online. Here, we pull Linus Torvald’s Linux-2.6 GIT code -- Git clone http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git 2. In case you are behind a proxy-server, set the proxy by running git config –global https.proxy https://domain\ usernmae:password@proxy:port. Figure 4: GIT pull

Now you can see a directory named linux-2.6 in the Next, find the latest stable kernel tag by running the current directory. Do a GIT pull to update your repository: following code:

Cd linux-2.6 git tag -l | less Git pull git checkout -b stable v3.9

Note: Alternatively, you can clone the latest stable build as shown below: Note: RC is the release candidate, and it is a functional but not stable build. git clone git://git.kernel.org/pub/scm/linux/kernel/git/ stable/linux-stable.git Once you have the latest kernel code pulled, create your cd linux-2.6 own local branch using GIT. Make some changes to the code and to commit changes to the code, run git commit –a.

your current config. There are multiple files that start with config; find the file that is associated with your kernel by running uname –a. Then run:

cp /boot/config-`uname -r`* .config or cp /boot/config-3.13.0-24-generic .config Make defconfig <---- for default configuration Or Make nconfig <---- for minimal configuration, here we can enable or disable features

Figure 5: GIT checkout At this point edit MakeFile as shown below VERSION = 3 PATCHLEVEL = 9 SUBLEVEL = 0 EXTRAVERSION = -rc9 <-- there [edit this part] NAME = Saber-toothed Squirrel

Now run:

Make

This will take some time and if everything goes well, Figure 6: Make install the newly built kernel by running the following command:

Sudo make modules_install Sudo make install

At this point, you should have your own version of the kernel, so reboot the machine and log in as the super user (root) and check uname –a. It should list your own version of the Linux kernel (something like ‘Linux Kernel 3.9.0rc9’).

References [1] http://linux.yyz.us/git-howto.html [2] http://kernelnewbies.org/KernelBuild Figure 7: Modules_install and Install [3] https://www.kernel.org/doc/Documentation/ [4] http://kernelnewbies.org/LinuxVersions Setting up the kernel configuration Many kernel drivers can be turned on or off, or be built By: Vinay Patkar on modules. The .config file in the kernel source directory The author works as a software development engineer at Dell determines which drivers are built. When you download the India R&D Centre, Bengaluru, and has close to two years’ source tree, it doesn’t come with a .config file. You have several experience in automation and Windows Server OS. He is interested in virtualisation and cloud computing technologies. options for generating a .config file. The easiest is to duplicate

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68 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | PB How To Admin Managing Your IT Infrastructure Effectively with Zentyal Zentyal (formerly eBox Platform) is a program for servers used by small and medium businesses (SMBs). It plays multiple roles—as a gateway, network infrastructure manager, unified threat manager, office server, unified communications server or a combination of all of the above. This is the third and last article in our series on Zentyal.

n previous articles in this series, we discussed various 4. From the dashboard, select HTTP Proxy under the scenarios that included DHCP, DNS and setting Gateway section. This will show different options Iup a captive portal. In this article, let’s discuss the like General settings, Access rules, Filter profiles, HTTP proxy, traffic shaping and setting up of ‘Users and Categorized Lists and Bandwidth throttling. Computers’ modules. 5. Select General settings to configure some basic parameters. The HTTP proxy set-up 6. Under General settings, select Transparent Proxy. This We will start with the set-up of the HTTP proxy module of option is used to manage proxy settings without making Zentyal. This module will be used to filter out unwanted clients aware about the proxy server. traffic from our network. The steps for the configuration are 7. Check Ad Blocking, which will block all the as follows: advertisements from the HTTP traffic. 1. Open the Zentyal dashboard by using the domain name 8. Cache size defines the stored HTTP traffic storage area. set up in the previous article or use the IP address. Mention the size in MBs. 2. The URL will be https://domain-name. 9. Click Change and then click Save changes. 3. Enter the user ID and password. 10. To filter the unwanted sites from the network, block

them using Filter profiles. Click Filter profiles under 2. Click Add new to add the network object. HTTP proxy. 3. Enter the name of the object, like LAN. Click Add, and 11. Click Add new. then Save changes. 12. Enter the name of the profile. In our case, we used 4. After you have added the network object, you have to Spam. Click Add and save changes. configure members under that object. Click the icon 13. Click the button under Configuration. under Members. 14. To block all spam sites, let’s use the Threshold option. 5. Click Add new to add members. The various options of Threshold will decide how to 6. Enter the names of the members. We will use LAN users. block the enlisted sites. Let’s select Very strict under 7. Under IP address, select the IP address range. Threshold and click Change. Then click Save changes 8. Enter the range of your DHCP address range, since we to save the changes permanently. would like to apply it to all the users in the network. 15. Select Use antivirus to block all incoming files, 9. Click Add and then Save changes. which may be viruses. Click the Change and the Save 10. Till now, we have added all the users of the network, on changes buttons. which we wish to apply the bandwidth throttling rule. 16. To add a site to be blocked by proxy, click Domain and Now we will apply the rule. To do this, click HTTP URLs and under Domain and URL rules, click the Add Proxy and select Bandwidth throttling. new button. 11. This setting will be used to set the total amount of 17. You will then be asked for the domain name. Enter bandwidth that a single client can use. Click Enable per the domain name of the site which is to be blocked. client limit. Decision option will instruct the proxy to allow or deny 12. Enter the Maximum unlimited size per client, to be the specified site. Then click Add and Save changes. set as a limit for a user under the network object. Enter 18. To activate the Spam profile, click Access rules under ‘50 MB’. A client can now download a 50 MB file with HTTP proxy. maximum speed, but if the client tries to download a file 19. Click Add new. Define the time period and the days of a greater size than the specified limit, the throttling when the profile is to be applied. rule will limit the speed to the maximum download rate 20. Select Any from Source dropdown menu and then per client. This speed option is set in the next step. select Apply filter profile from Decision dropdown 13. Enter the maximum download rate per client (for our menu. You will see a Spam profile. example, enter 20). This means that if the download 21. Click Add and Save changes. reaches the threshold, the speed will be decreased to With all the above steps, you will be able to either block 20 KBps. or allow sites, depending on what you want your clients to 14. Click Add and Save changes. have access to. All the other settings can be experimented with, as per your requirements. Traffic shaping set-up With bandwidth throttling, we have set the upper limit for Bandwidth throttling downloads, but to effectively manage our bandwidth we The setting under HTTP proxy is used to add delay pools, have to use the Traffic shaping module. Follow the steps so that a big file that users wish to download does not shown below: hamper the download speed of the other users. 1. Click on Traffic shaping under the Gateway section. To do this, follow the steps mentioned below: 2. Click on Rules. This will display two sections: rules for 1. First create the network object on which you wish to internal interfaces and rules for external interfaces. apply the rule. Click Network and select Objects under 3. Follow the example rules given in Table 1-- these can be Network options. used to shape the bandwidth on eth1.

Table 1 Based on Service Source Destination Priority Guaranteed Limited rate the firewall rate (KBps) (KBps) Yes Any Any 2 512 0

Yes Any Any 1 512 0

Yes Any Any 3 1024 2048 Yes Any Any 3 1024 2048 Yes Any Any 7 0 10

Table 2 Based on the Service Source Destination Priority Guaranteed Limited firewall rate (KBps) rate (KBps) Yes Any Any 7 0 10

No (Prioritise small - -- 0 60 200 packets)

The rules mentioned in Table 1 will set protocols with Users’ set-up: To set up users for the domain system and their priority over other protocols, for guaranteed speed. captive portal, follow the steps shown below. 4. The rules given in Table 2 will manage the upload speed 1. Click Users and Computers under the Office section. for the protocols on eth0. 2. Click Manage. Here you will see the LDAP tree. Select 5. After adding all the rules, click on Save changes. Users and click on the plus sign. 6. With these steps, you have set the priorities of the With all the information entered and passed, users can protocols and applications. One last thing to be done here log in to the system through the captive portal. is to set the upload and download rates of the server. To do this, click Interface rates under Traffic Shaping. 7. Click Action. Change the upload and download speed References of the server, supplied by your service provider. Click [1] http://en.wikipedia.org/wiki/Proxy_server#Transparent_proxy Change and then Save changes. [2] http://en.wikipedia.org/wiki/Bandwidth_throttling [3] http://doc.zentyal.org/en/qos.html Setting up Users and Computers Setting up of groups and users can be done as follows. By: Gaurav Parashar Group set-up: For this, follow the steps shown below. The author is a FOSS enthusiast, and loves to work with open 1. Click Users and Computers under the Office section. source technologies like Moodle and Ubuntu. He works as an 2. Click Manage. Select groups from the LDAP tree. Click assistant dean (for IT students) at Inmantec Institutions, Ghaziabad, on the plus sign to add groups. UP. He can be reached at [email protected]

Customer Feedback Form Open Source For You

None

Table 1 Based on Service Source Destination Priority Guaranteed Limited rate the firewall rate (KBps) (KBps) Yes Any Any 2 512 0 OSFY?

Yes Any Any 1 512 0

Yes Any Any 3 1024 2048 Yes Any Any 3 1024 2048

Yes Any Any 7 0 10 You can mail us at [email protected] You can send this form to ‘The Editor’, OSFY, D-87/1, Okhla Industrial Area, Phase-1, New Delhi-20. Phone No. 011-26810601/02/03, Fax: 011-26817563

Insight Admin

Windows as the host OS since Type 2 hypervisors depend on an OS, they are not in full • VMware workstation (Any guest OS) control of the end user’s machine. • VirtualBox (Any guest OS) Hypervisor Type 1 products • Hyper-V (Any guest OS) • VMware ESXi Linux as the host OS • Citrix Xen • VMware workstation • KVM (Kernel Virtual Machine) • Microsoft virtual PC • Hyper-V • VMLite workstation Hypervisor Type 2 products • VMware Workstation • VirtualBox • VirtualBox • Xen A hypervisor or virtual machine monitor (VMM) is a piece Table 1 of computer software, firmware or hardware that creates and Hypervisors and their cloud service providers runs virtual machines. A computer on which a hypervisor is Hypervisor Cloud service provider running one or more VMs is defined as a host machine. Each Xen Amazon EC2 VM is called a guest machine. The hypervisor presents the IBM SoftLayer guest OSs with a virtual operating platform, and manages the Fujitsu Global Cloud Platform execution of the guest operating systems. Multiple instances Linode OrionVM of a variety of operating systems may share the virtualised ESXi VMware Cloud hardware resources. KVM Red Hat HP Hypervisors of Type 1 (bare metal installation) Dell and Type 2 (hosted installation) Rackspace When implementing and deploying a cloud service, Type 1 Hyper-V Microsoft Azure hypervisors are used. These are associated with the concept of bare metal installation. It means there is no need of any host Data centres and uptime tier levels operating system to install the hypervisor. When using this Just as a virtual machine is mandatory for cloud computing, technology, there is no risk of corrupting the host OS. These the data centre is also an essential part of the technology. All hypervisors are directly installed on the hardware without the cloud computing infrastructure is located in remote data the need for any other OS. Multiple VMs are created on this centres where resources like computer systems and associated hypervisor. components, such as telecommunications and storage A Type 1 hypervisor is a type of client hypervisor that systems, reside. Data centres typically include redundant interacts directly with hardware that is being virtualised. It or backup power supplies, redundant data communications is completely independent of the operating system, unlike a connections, environmental controls, air conditioning, fire Type 2 hypervisor, and boots before the OS. Currently, Type suppression systems as well as security devices. 1 hypervisors are being used by all the major players in the The tier level is the rating or evaluation aspect of the desktop virtualisation space, including but not limited to data centres. Large data centres are used for industrial scale VMware, Microsoft and Citrix. operations that can use as much electricity as a small town. The classical virtualisation software or Type 2 hypervisor The standards comprise a four-tiered scale, with Tier 4 being is always installed on any host OS. If the host OS gets corrupt the most robust and full-featured (Table 2). or crashes for any reason, the virtualisation software or Type 2 hypervisor will also crash and, obviously, all VMs and other Cloud simulations resources will be lost. That’s why the hypervisor technology Cloud service providers charge users depending upon the or bare metal installation is very popular in the cloud space or service provided. computing world. In R&D, it is not always possible to have the actual cloud Type 2 (hosted) hypervisors execute within a conventional infrastructure for performing experiments. For any research OS environment. With the hypervisor layer as a distinct scholar, academician or scientist, it is not feasible to hire second software level, guest OSs run at the third level cloud services every time and then execute their algorithms or above the hardware. A Type 2 hypervisor is a type of implementations. client hypervisor that sits on top of an OS. Unlike a Type For the purpose of research, development and testing, 1 hypervisor, a Type 2 hypervisor relies heavily on the open source libraries are available, which give the feel operating system. It cannot boot until the OS is already up and of cloud services. Nowadays, in the research market, running, and if for any reason the OS crashes, all end users cloud simulators are widely used by research scholars and are affected. This is a big drawback of Type 2 hypervisors, as practitioners, without the need to pay any amount to a cloud they are only as secure as the OS on which they rely. Also, service provider.

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 73 Admin Insight

Table 2 Tier Possible unavailability Requirements Level in a given year 1 • Single non-redundant distribution path serving the IT equipment 1729.224 minutes • Non-redundant capacity components (28.8 hours) • Basic site infrastructure with expected availability of 99.671 per cent 2 • Meets or exceeds all Tier 1 requirements 1361.304 minutes • Redundant site infrastructure capacity components with expected availability of 99.741 per (22.6 hours) cent 3 • Meets or exceeds all Tier 1 and Tier 2 requirements 94.608 minutes • Multiple independent distribution paths serving the IT equipment (1.5 hours) • All IT equipment must be dual-powered and fully compatible with the topology of a site’s architecture • Concurrently maintainable site infrastructure with expected availability of 99.982 per cent 4 • Meets or exceeds all Tier 1, Tier 2 and Tier 3 requirements 26.28 minutes • All cooling equipment is independently dual-powered, including chillers, heaters, ventilation (0.4 hours) and air-conditioning (HVAC) systems • Fault-tolerant site infrastructure with electrical power storage and distribution facilities with expected availability of 99.995 per cent

Using cloud simulators, researchers can execute their • CloudAnalyst algorithmic approaches on a software-based library and • GreenCloud can get the results in different parameters including energy • iCanCloud optimisation, security, integrity, confidentiality, bandwidth, • MDCSim power and many others. • NetworkCloudSim • VirtualCloud Tasks performed by cloud simulators • CloudMIG Xpress The following tasks can be performed with the help of • CloudAuction cloud simulators: • CloudReports • Modelling and simulation of large scale cloud • RealCloudSim computing data centres • DynamicCloudSim • Modelling and simulation of virtualised server hosts, • WorkFlowSim with customisable policies for provisioning host resources to VMs CloudSim • Modelling and simulation of energy-aware CloudSim is a famous simulator for cloud parameters developed in computational resources the CLOUDS Laboratory, at the Computer Science and Software • Modelling and simulation of data centre network Engineering Department of the University of Melbourne. topologies and message-passing applications The CloudSim library is used for the following • Modelling and simulation of federated clouds operations: • Dynamic insertion of simulation elements, stopping Large scale cloud computing at data centres and resuming simulation Virtualised server hosts with customisable policies • User-defined policies for allocation of hosts to VMs, Support for modelling and simulation of large scale cloud and policies for allotting host resources to VMs computing data centres Support for modelling and simulation of virtualised server Scope and features of cloud simulations hosts, with customisable policies for provisioning host The scope and features of cloud simulations include: resources to VMs • Data centres Support for modelling and simulation of energy-aware • Load balancing computational resources • Creation and execution of cloudlets Support for modelling and simulation of data centre • Resource provisioning network topologies and message-passing applications • Scheduling of tasks Support for modelling and simulation of federated clouds • Storage and cost factors Support for dynamic insertion of simulation elements, as • Energy optimisation, and many others well as stopping and resuming simulation Support for user-defined policies to allot hosts to VMs, Cloud simulation tools and plugins and policies for allotting host resources to VMs Cloud simulation tools and plugins include: User-defined policies for allocation of hosts to virtual • CloudSim machines

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The major limitation of CloudSim is the lack of a contains the CloudSim examples class files graphical user interface (GUI). But despite this, CloudSim is jars/CloudSim-examples-< CloudSimVersion >-sources. still used in universities and the industry for the simulation of jar-- contains the CloudSim examples source code files cloud-based algorithms. Steps to integrate CloudSim with Eclipse Downloading, installing and integrating CloudSim After installing Eclipse IDE, let’s create a new project and CloudSim is free and open source software available at http:// integrate CloudSim into it. www.cloudbus.org/CloudSim/. It is a code library based on 1. Create a new project in Eclipse. Java. This library can be directly used by integrating with the 2. This can be done by File->New->Project->Java JDK to compile and execute the code. Project For rapid applications development and testing, CloudSim is integrated with Java-based IDEs (Integrated Development Environment) including Eclipse or NetBeans. Using Eclipse or NetBeans IDE, the CloudSim library can be accessed and the cloud algorithm implemented. The directory structure of the CloudSim toolkit is given below: CloudSim/ -- CloudSim root directory docs/ -- API documentation examples/ -- Examples jars/ -- JAR archives sources/ -- Source code tests/ -- Unit tests CloudSim needs to be unpacked for installation. To uninstall CloudSim, the whole CloudSim directory needs to be removed. There is no need to compile CloudSim source code. The JAR files with the CloudSim package have been provided to compile and run CloudSim applications: jars/CloudSim-.jar-- contains the CloudSim class files Figure 2: Assigning a name to the Java Project jars/CloudSim-< CloudSimVersion >-sources.jar-- contains the CloudSim source code files jars/CloudSim-examples-< CloudSimVersion >.jar--

Figure 1: Creating a new Java Project in Eclipse Figure 3: Build path for CloudSim library

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Starting Cloud Simulation with Dynamic and Hybrid Secured Key Initialising... MD5 Hash Digest(in Hex. format):: 6e47ed33cde35ef1cc100a78d3da9c9f Hybrid Approach (SHA+MD5) Hash Hex format: b0a309c58489d6788262859da2e7da45b6ac20a052b6e606ed1759648e43e40b Hybrid Approach Based (SHA+MD5) Security Key Transmitted => ygcxsbyybpr4¢ ª¢£?¡®£ Starting CloudSim version 3.0 CloudDatacentre-1 is starting... CloudDatacentre-2 is starting... Broker is starting... Entities started. Figure 4: Go to the path of CloudSim library 0.0: Broker: Cloud Resource List received with 2 resource(s) 0.0: Broker: Trying to Create VM #0 in CloudDatacentre-1 0.0: Broker: Trying to Create VM #1 in CloudDatacentre-1 [VmScheduler.vmCreate] Allocation of VM #1 to Host #0 failed by MIPS 0.1: Broker: VM #0 has been created in Datacentre #2, Host #0 0.1: Broker: Creation of VM #1 failed in Datacentre #2 0.1: Broker: Trying to Create VM #1 in CloudDatacentre-2 0.2: Broker: VM #1 has been created in Datacentre #3, Host #0 0.2: Broker: Sending cloudlet 0 to VM #0 0.2: Broker: Sending cloudlet 1 to VM #1 0.2: Broker: Sending cloudlet 2 to VM #0 160.2: Broker: Cloudlet 1 received 320.2: Broker: Cloudlet 0 received 320.2: Broker: Cloudlet 2 received Figure 5: Select all JAR files of CloudSim for integration 320.2: Broker: All Cloudlets executed. Finishing... 320.2: Broker: Destroying VM #0 3. Give a name to 320.2: Broker: Destroying VM #1 your project. Broker is shutting down... 4. Configure the Simulation: No more future events build path for adding CloudInformationService: Notify all CloudSim entities for the CloudSim library. shutting down. 5. Search and select CloudDatacentre-1 is shutting down... the CloudSim JAR files. CloudDatacentre-2 is shutting down... In the integration Broker is shutting down... and implementation Simulation completed. of Java code and Simulation completed. CloudSim, the Java- based methods and ======OUTPUT ======packages can be used. Cloudlet ID STATUS Data centre ID VM ID Time Start Time In this approach, the Finish Time Java library is directly ======associated with 1 SUCCESS 3 1 160 0.2 160.2 CloudSim code. 0 SUCCESS 2 0 320 0.2 320.2 After executing 2 SUCCESS 2 0 320 0.2 320.2 the code in Eclipse, the following output Cloud Simulation Finish Figure 6: JAR files of CloudSim visible in the referenced libraries of Eclipse with Java Project will be generated, which Simulation Scenario Finish with Successful Matching of the Keys makes it evident that the Simulation Scenario Execution Time in MillSeconds => 5767 integration of the dynamic key exchange is implemented with Security Parameter => 30.959372773933122 the CloudSim code: 2014-07-09 16:15:21.19

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Communities of users and data centres supporting the social networks are characterised and based on their location. Parameters such as user experience while using the social network application and the load on the data centre are obtained/logged. CloudAnalyst is used to model and analyse real world problems through case studies of social networking applications deployed on the cloud. The main features of CloudAnalyst are: User friendly graphical user interface (GUI) Simulation with a high degree of configurability and Figure 7: Create a new Java program for integration with CloudSim flexibility Performs different types of experiments with repetitions Connectivity with Java for extensions The GreenCloud cloud simulator GreenCloud is also getting famous in the international market as the cloud simulator that can be used for energy- aware cloud computing data centres with the main focus on cloud communications. It provides the features for detailed fine-grained modelling of the energy consumed by the data centre IT equipment like the servers, communication switches and communication links. GreenCloud simulator allows Figure 8: Writing the Java code with the import of CloudSim packages researchers to investigate, observe, interact and measure the cloud’s performance based on multiple parameters. Most of the code of GreenCloud is written in C++. TCL is also included in the library of GreenCloud. GreenCloud is an extension of the network simulator ns-2 that is widely used for creating and executing network scenarios. It provides the simulation environment that enables energy-aware cloud computing data centres. GreenCloud mainly focuses on the communications within a cloud. Here, all of the processes related to communication are simulated at the packet level.

Figure 9: Execution of the Java code integrated with CloudSim By: Dr Gaurav Kumar By: Anil Kumar Pugalia The CloudAnalyst cloud simulator The author is associated with various academic and research CloudAnalyst is another cloud simulator that is completely institutes, delivering lectures and conducting technical workshops on the latest technologies and tools. Contact him at GUI-based and supports the evaluation of social network tools [email protected] according to the geographic distribution of users and data centres. EB Times • Electronics • Trade Channel • Updates is Becoming Regional Get North, East, West & South Edition at you doorstep. Write to us at [email protected] and get EB Times regularly This monthly B2B Newspaper is a resource for traders, distributors, dealers, and those who head channel business, as it aims to give an impetus to channel sales

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Docker is an open source project, which packages applications and their dependencies in a virtual container that can run on any Linux server. Docker has immense possibilities as it facilitates the running of several OSs on the same server.

echnology is changing faster than styles in the fashion a single host. LXC does this by using kernel level name world, and there are many new entrants specific to space, which helps to isolate containers from the host. Tthe open source, cloud, virtualisation and DevOps Now questions might arise about security. If I am logged technologies. Docker is one of them. The aim of this article in to my container as the root user, I can hack my base OS; is to give you a clear idea of Docker, its architecture and its so is it not secured? This is not the case because the user functions, before getting started with it. name space separates the users of the containers and the Docker is a new open source tool based on Linux host, ensuring that the container root user does not have container technology (LXC), designed to change how you the root privilege to log in to the host OS. Likewise, there think about workload/application deployments. It helps are the process name space and the network name space, you to easily create light-weight, self-sufficient, portable which ensure that the display and management of the application containers that can be shared, modified and processes run in the container but not on the host and the easily deployed to different infrastructures such as cloud/ network container, which has its own network device and compute servers or bare metal servers. The idea is to IP addresses. provide a comprehensive abstraction layer that allows developers to ‘containerise’ or ‘package’any application and Cgroups have it run on any infrastructure. Cgroups, also known as control groups, help to implement Docker is based on container virtualisation and it is not resource accounting and limiting. They help to limit resource new. There is no better tool than Docker to help manage kernel utilisation or consumption by a container such as memory, the level technologies such as LXC, cgroups and a copy-on-write CPU and disk I/O, and also provide metrics around resource filesystem. It helps us manage the complicated kernel layer consumption on various processes within the container. technologies through tools and APIs. Copy-on-write filesystem What is LXC (Linux Container)? Docker leverages a copy-on-write filesystem (currently I will not delve too deeply into what LXC is and how it works, AUFS, but other filesystems are being investigated). This but will just describe some major components. allows Docker to spawn containers (to put it simply—instead LXC is an OS level virtualisation method for running of having to make full copies, it basically uses ‘pointers’ back multiple isolated Linux operating systems or containers on to existing files).

Image: An image is a read-only layer used to build a container. Container: This is a self-contained runtime environment libcontainer that is built using one or more images. It also allows us to commit changes to a container and create an image. Docker registry: These are the public or private servers, where anyone can upload their repositories so that they can Systemd- LXC libvirt nspawn be easily shared. The detailed architecture is outside the scope of this article. Have a look at http://docker.io for detailed information.

Linux Kernel Note: I am using CentOS, so the following netlink netfilter SELinux instructions are applicable for CentOS 6.5. cgroups apparmor namespace Docker is part of Extra Packages for Enterprise Linux (EPEL), which is a community repository of non-standard packages for the RHEL distribution. First, we need to install the EPEL repository using the command shown below: Hardware (Intel, AMD) [root@localhost ~] # rpm -ivh http://dl.fedoraproject.org/ pub/epel/6/x86_64/epel-release-6-8.noarch.rpm Figure 1: Linux Container As per the best practice update, Containerisation vs virtualisation What is the rationale behind the container-based [root@localhost ~] # yum update -y approach or how is it different from virtualisation? Figure 2 speaks for itself. docker-io is the package that we need to install. As Containers virtualise at the OS level, whereas I am using CentOS, Yum is my package manager; so both Type-I and Type-2 hypervisor-based solutions depending on your distribution ensure that the correct virtualise at the hardware level. Both virtualisation and command is used, as shown below: containerisation are a kind of virtualisation; in the case of VMs, a hypervisor (both for Type-I and Type-II) slices [root@localhost ~] # yum -y install docker-io the hardware, but containers make available protected portions of the OS. They effectively virtualise the OS. If Once the above installation is done, start the Docker you run multiple containers on the same host, no container service with the help of the command below: will come to know that it is sharing the same resources because each container has its own abstraction.LXC takes [root@localhost ~] # service docker start the help of name spaces to provide the isolated regions known as containers. Each container runs in its own To ensure that the Docker service starts at each reboot, use allocated name space and does not have access outside of the following command: it. Technologies such as cgroups, union filesystems and container formats are also used for different purposes [root@localhost ~] # chkconfig docker on throughout the containerisation. Linux containers Unlike virtual machines, with the help of LXC you can share multiple containers from a single source disk OS image. LXC is very lightweight, has a faster start-up and needs less resources. Installation of Docker Before we jump into the installation process, we should be aware of certain terms commonly used in Docker documentation. Figure 2: Virtualisation

To check the Docker version, use the following Run the following command to see your new image in command: the list. You will find the newly created image ‘lamp-image’ is shown in the output: [root@localhost ~] # docker version [root@localhost ~] # docker images How to create a LAMP stack with Docker REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE We are going to create a LAMP stack on a CentOS VM. lamp-image latest b71507766b2d 2 minutes ago However, you can work on different variants as well. First, 339.7 MB let’s get the latest CentOS image. The command below will centos latest 0c752394b855 13 days ago help us to do so: 124.1 MB

[root@localhost ~] # docker pull centos:latest Let’s log in to this image/container to check the PHP version: Next, let’s make sure that we can see the image by running the following code: [root@localhost ~] # docker run -i -t lamp-image /bin/bash bash-4.1# php -v [root@localhost ~] # docker image centos PHP 5.3.3 (cli) (built: Dec 11 2013 03:29:57) REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE Zend Engine v2.3.0 Copyright (c) 1998-2010 Zend Technologies centos latest 0c752394b855 13 days ago 124.1 MB Now, let us configure Apache. Log in to the container and create a file called index.html. Running a simple bash shell to test the image also helps If you don’t want to install VI or VIM, use the Echo you to start a new container: command to redirect the following content to the index.html file:

[root@localhost ~] # docker run -i -t centos /bin/bash

If everything is working properly, you'll get a simple Start the Apache process with the following command: bash prompt. Now, as this is just a base image, we need to install the PHP, MySQL and the LAMP stack: [root@localhost ~] # /etc/init.d/httpd start

[root@localhost ~] # yum install php php-mySQL mySQL-server And then test it with the help of browser/curl/links utilities. httpd If you’re running Docker inside a VM, you’ll need to forward port 80 on the VM to another port on the VM’s The container now has the LAMP stack. Type ‘exit’ to host machine. The following command might help you quit from the bash shell. to configure port forwarding. Docker has the feature to We are going to create this as a golden image, so that forward ports from containers to the host. the next time we need another LAMP container, we don’t need to install it again. [root@localhost ~] # docker run -i -t -p :80 lamp-image / Run the following command and please note the bin/bash ‘CONTAINER ID’ of the image. In my case, the ID was ‘4de5614dd69c’: For detailed information on Docker and other technologies related to container virtualisation, check out the [root@localhost ~] # docker ps -a links given under ‘References’.

The ID shown in the listing is used to identify the References container you are using, and you can use this ID to tell [1] Docker: https://docs.docker.com/ Docker to create an image. [2] LXC: https://linuxcontainers.org/ Run the command below to make an image of the previously created LAMP container. The syntax is docker By: Pradyumna Dash commit . I have used the The author is an independent consultant, and works as a cloud/ previous container ID, which we got in the earlier step: DevOps architect. An open source enthusiast, he loves to cook good food and brew ideas. He is also the co-founder of the site http:/www.sillycon.org/ [root@localhost ~] # docker commit 4de5614dd69c lamp-image

80 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | PB How To Admin Wireshark: Essential for a Network Professional’s Toolbox This article, the second in the series, presents further experiments with Wireshark, the open source packet analyser. In this part, Wireshark will be used to analyse packets captured from an Ethernet hub.

he first article in the Wireshark series, published in the Wireshark. So start the capture and once you have sufficient July 2014 issue of OSFY, covered Wireshark architecture, packets, stop and view the packets before you continue reading. Tits installation on Windows and Ubuntu, as well as various An interesting observation about this capture is ways to capture traffic in a switched environment. Interpretation that, unlike only broadcast and host traffic in a switched of DNS and ICMP Ping protocol captures was also covered. environment, it contains packets from all source IP addresses Let us now carry the baton forward and understand additional connected in the network. Did you notice this? Wireshark features and protocol interpretation. The traffic thus contains: To start with, capture some traffic from a network Broadcast packets connected to an Ethernet hub—which is the simplest way to Packets from all systems towards the Internet capture complete network traffic. PC-to-PC communication packets Interested readers may purchase an Ethernet hub from a Multicast packets second hand computer dealer at a throwaway price and go Now, at this point, imagine analysing traffic captured from ahead to capture a few packets in their test environment. The hundreds of computers in a busy network—the sheer volume of aim of this is to acquire better hands-on practice of using captured packets will be baffling. Here, an important Wireshark

Figure 1: Traffic captured using HUB

Figure 3: ARP protocol

source or the destination IP address is 192.168.51.1 Click on ‘Save’ to store the required filter for future use. By default, the top 10 custom filters created are available for ready use under the dropdown menu of the ‘Filter’ dialogue box. With this background, let us look at two simple protocols —ARP and DHCP. Figure 2: Default Wireshark display filters Address Resolution Protocol (ARP) feature called ‘Display Filter' can be used very effectively. This is used to find the MAC address from the IP address. It works in two steps—the ARP request and ARP reply. Here Wireshark’s Display Filter are the details. This helps to sort/view the network traffic using various Apply the appropriate display filter (ARP) and view only parameters such as the traffic originating from a particular IP ARP traffic from the complete capture. Also, refer to Figure or MAC address, traffic with a particular source or destination 3 - the ARP protocol. port, ARP traffic and so on. It is impossible to imagine The protocol consists of the ARP request and ARP reply. Wireshark without display filters! ARP request: This is used to find the MAC address of a Click on ‘Expressions’ or go to ‘Analyse – Display filters’ system with a known IP address. For this, an ARP request is to find a list of pre-defined filters available with Wireshark. sent as a broadcast towards the MAC broadcast address: You can create custom filters depending upon the analysis requirements—the syntax is really simple. Sender MAC address – 7c:05:07:ad:42:53 As seen in Figure 2, the background colours of the display Sender IP address – 192.168.51.208 filter box offer ready help while creating proper filters. A green Target MAC address – 00:00:00:00:00:00 background indicates the correct command or syntax, while a Target IP address – 192.168.51.1 red background indicates an incorrect or incomplete command. Use these background colours to quickly identify syntax and Note: Target IP address indicates the IP address for gain confidence in creating the desired display filters. which the MAC address is requested. A few simple filters are listed below: tcp: Displays TCP traffic only Wireshark displays the ARP request under the‘Info’ box arp: Displays ARP traffic as: Who has 192.168.51.1? tell 192.168.51.208 eth.addr == aa:bb:cc:dd:ee:ff: Displays traffic where the ARP reply: This ARP request broadcast is received by Ethernet MAC address is aa:bb:cc:dd:ee:ff all systems connected to the network segment of the sender ip.src == 192.168.51.203: Displays traffic where the (below the router), mind well, this broadcast also reach router source IP address is 192.168.51.203 port connected to this segment. ip.dst == 4.2.2.1: Displays traffic where the destination IP The system with the destination IP address mentioned in address is 4.2.2.1 the ARP request packet replies with its MAC address via an ip.addr == 192.168.51.1: Displays traffic where the ARP reply. The important contents of the ARP reply are:

Sender MAC Address – Belonging to system which replies to the ARP request Updated by the system – 00:21:97:88:28:21 Sender IP Address – Belonging to system which replies to the ARP request – 192.168.51.1 Target MAC Address – Source MAC of ARP request packet – 7c:05:07:ad:42:53 Target IP Address – Source IP address of the ARP request packet – 192.168.51.208

Wireshark displays the ARP reply under the ‘Info’ box as: 192.168.51.1 is at 00:21:97:88:28:21. Thus, with the help of an ARP request and reply, system 192.168.51.208 has detected the MAC address belonging to 192.168.51.1. Dynamic Host Configuration Protocol (DHCP) This protocol saves a lot of time for network engineers by offering a unique dynamic IP address to a system without an IP address, which is connected in a network. This also helps to avoid IP conflicts (the use of one IP address by multiple systems) to a certain extent. The computer users also benefit by the ability to connect to various networks without knowing the corresponding IP address range and the unused IP address. This DHCP protocol consists of four phases—DHCP discover, DHCP offer, DHCP request and DHCP ACK. Let us understand the protocol and interpret how these packets are seen in Wireshark.

Figure 4: DHCP protocol

1. The DHCP Server Identifier field, which specifies the IP address of the accepted server. 2. The host name of the client computer. Use Pane 2 of Wireshark to view these parameters under ‘Bootstrap Protocol’ – Options 54 and 12. The DHCP request packet also contains additional client requests for the server to provide more configuration parameters such as the default gateway, DNS (Domain Name Server), address, etc. DHCP acknowledgement: The server acknowledges a DHCP request by sending information on the lease duration and other configurations, as requested by the client during the DHCP request phase, thus completing the DHCP cycle. For better understanding, capture a few packets, use Wireshark ‘Display Filters’ to filter and view ARP and DHCP, and read them using Wireshark panes. Saving packets Packets captured using Wireshark can be saved from the menu ‘File – Save as’ in different formats such as Wireshark, Novell LANalyzer and Sun Snoop, to name a few. In addition to saving all captured packets in various file formats, the ‘File – Export Specified Packets’ option offers users the choice of saving ‘Display Filtered’ packets or a range of packets. Figure 5: Screenshot of DHCP protocol Please feel free to download the pcap files used for preparing this article from opensourceforu.com. I believe all When a system configured with the ‘Obtain an IP address OSFY readers will enjoy this interesting world of Wireshark, automatically’ setting is connected to a network, it uses DHCP packet capturing and various protocols! to get an IP address from the DHCP server. Thus, this is a client–server protocol. To capture DHCP packets, users may Troubleshooting tips start Wireshark on such a system, then start packet capture Capturing ARP traffic could reveal ARP poisoning (or ARP and, finally, connect the network cable. spoofing) in the network. This will be discussed in more Please refer to Figures 4 and 5, which give a diagram and detail at a later stage. Similarly, studying the capture of DHCP a screenshot of the DHCP protocol, respectively. protocol may lead to the discovery of an unintentional or a Discovering DHCP servers: To discover DHCP server(s) rogue DHCP server within the network. in the network, the client sends a broadcast on 255.255.255.255 with the source IP as 0.0.0.0, using UDP port 68 (bootpc) as A word of caution the source port and UDP 67 (bootps) as the destination. This Packets captured using the test scenarios described in message also contains the source MAC address as that of the this series of articles are capable of revealing sensitive client and ff:ff:ff:ff:ff:ff as the destination MAC. information such as login names and passwords. Some A DHCP offer: The nearest DHCP server receives this scenarios, such as using ARP spoofing may disrupt the ‘discover’ broadcast and replies with an offer containing network temporarily. Make sure to use these techniques the offered IP address, the subnet mask, the duration of the only in a test environment. If at all you wish to use them in default gateway lease and the IP address of the DHCP server. a live environment, do not forget to get the explicit written The source MAC address is that of the DHCP server and the permission before doing so. destination MAC address is that of the requesting client. Here, the UDP source and destination ports are reversed. DHCP requests: Remember that there can be more than By: Rajesh Deodhar one DHCP server in a network. Thus, a client can receive The author has been an IS auditor and network security consultant- multiple DHCP offers. The DHCP request packet is broadcast trainer for the last two decades. He is a BE in Industrial Electronics, by the client with parameters similar to discovering a DHCP and holds CISA, CISSP, CCNA and DCL certifications. He can be contacted at [email protected] server, with two major differences:

84 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | PB Let's Try Open Gurus Building the Android Platform: Compile the Kernel Tired of stock ROMs? Build and flash your own version of Android on your smartphone. This new series of articles will see you through from compiling your kernel to flashing it on your phone.

any of us are curious and eager to learn how to port or flash a new version of Android to our Mphones and tablets. This article is the first step towards creating your own custom Android system. Here, you will learn to set up the build environment for the Android kernel and build it on Linux. Let us start by understanding what Android is. Is it an application framework or is it an operating system? It can be called a mobile operating system based on the Linux kernel, for the sake of simplicity, but it is much more than that. It consists of the operating system, middleware, and application software that originated from a group of companies led by Google, known as the Open Handset Alliance.

Android system architecture Application framework: Applications written in Java Before we begin building an Android platform, let’s directly interact with this layer. understand how it works at a higher level. Figure 1 illustrates Binder IPC: It is an Android-specific IPC mechanism. how Android works at the system level. Android system services: To access the underlying We will not get into the finer details of the architecture in hardware application framework, APIs often communicate this article since the primary goal is to build the kernel. Here via system services. is a quick summary of what the architecture comprises. HAL: This acts as a glue between the Android system and the underlying device drivers. Applications and Framework Linux kernel: At the bottom of the stack is a Linux kernel, with some architectural changes/additions including binder, ashmem, pmem, logger, wavelocks, different out- Binder IPC of-memory (OOM) handling, etc.

Android System Services In this article, I describe how to compile the kernel for the Samsung Galaxy Star Duos Media Services System Services (GT-S5282) with Android MediaPlayer Window AudioFlinger Service Search Service Manager version 4.1.2. The build

Camera process was performed on Service Activity Other Media Manager Other System Services Services and Managers an Intel i5 core processor running 64-bit Ubuntu Linux

HAL 14.04 LTS (Trusty Tahr). However, the process should Camera HAL Audio HAL Graphics HAL Other HALs work with any Android kernel and device, with minor

Linux Kernel modifications. The handset

Audio Driver Camera Driver (ALSA, OSS, Display Drivers details are shown in the etc) Other Drivers screenshot (Figure 2) taken from the Setting ->About Figure 1: Android system architecture Figure 2: Handset details for GT-S5282 device menu of the phone.

System and software requirements respectively. Before you download and build the Android kernel, ensure that your system meets the following requirements: $ mkdir ~/android Linux system (Linux running on a virtual machine will $ mkdir ~/android/kernel also work but is not recommended). Steps explained $ mkdir ~/android/ndk in this article are for Ubuntu 14.04 LTS to be specific. Other distributions should also work. Now extract the archive: Around 5 GB of free space to install the dependent software and build the kernel. $ cd ~/Downloads/kernel Pre-built tool-chain. Dependent software should include GNU Make, $ unzip GT-S5282_SEA_JB_Opensource.zip libncurses5-dev, etc. Android kernel source (as mentioned earlier, this $ tar -C ~/android/kernel -zxf Kernel.tar.gz article describes the steps for the Samsung Galaxy Star kernel). The unzip command will extract the zip archive, Optionally, if you are planning to compile the whole which contains the following files: Android platform (not just the kernel), a 64-bit Kernel.tar.gz: The kernel to be compiled. system is required for Gingerbread (2.3.x) and newer Platform.tar.gz: Android platform files. versions. README_Kernel.txt: Readme for kernel compilation. It is assumed that the reader is familiar with Linux README_Platform.txt: Readme for Android platform commands and the shell. Commands and file names are compilation. case sensitive. Bash shell is used to execute the commands If the unzip command is not installed, you can extract in this article. the files using any other file extraction tool. By running the tar command, we are extracting the Step 1: Getting the source code kernel source to ~/android/kernel. While creating a sub- The Android Open Source Project (AOSP) maintains directory for extracting is recommended, let’s avoid it the complete Android software stack, which includes here for the sake of simplicity. everything except for the Linux kernel. The Android Linux kernel is developed upstream and also by various Step 3: Install and set up the toolchain handset manufacturers. There are several ways to install the toolchain. We will The kernel source can be obtained from: use the Android NDK to compile the kernel. 1. Google Android kernel sources: Visit https://source. Please visit https://developer.android.com/tools/sdk/ android.com/source/building-kernels.html for details. ndk/index.html to get details about NDK. The kernel for a select set of devices is available here. For 64-bit Linux, download Android NDK android- 2. From the handset manufacturers or OEM website: I ndk-r9-linux-x86_64-legacy-toolchains.tar.bz2 from am listing a few links to the developer sites where you http://dl.google.com/android/ndk/android-ndk-r9-linux- can find the kernel sources. Please understand that the x86_64-legacy-toolchains.tar.bz2 links may change in the future. Ensure that the file is saved in the ~/android/ndk Samsung: http://opensource.samsung.com/ directory. HTC: https://www.htcdev.com/ Sony: Most of the kernel is available on github. Note: To be specific, we need the GCC 4.4.3 3. Developers: They provide a non-official kernel. version to compile the downloaded kernel. Using This article will use the second method—we will get the latest version of Android NDK will yield to the official Android kernel for Samsung Galaxy Star (GT- compilation errors. S5282). Go to the URL http://opensource.samsung.com/ and search for GT-S5282. Download the file GT-S5282_ Extract the NDK to ~/android/ndk: SEA_JB_Opensource.zip (184 MB). Let’s assume that the file is downloaded in the ~/ $ cd ~/android/ndk Downloads/kernel directory. # For 64 bit version $ tar -jxf android-ndk-r9-linux-x86_64-legacy- Step 2: Extract the kernel source code toolchains.tar.bz2 Let us create a directory ‘android’ to store all relevant files in the user's home directory. The kernel and Android Add the toolchain path to the PATH environment NDK will be stored in the kernel and ndk directories, variable in .bashrc or the equivalent:

you are unsure. Step 5: Build the kernel Finally, we are ready to fire the build. Run the make command, as follows:

$ make zImage

If you want to speed up the build, specify the -j option to the make command. For example, if you have four processor Figure 3: Kernel configuration – making changes cores, you can specify the -j4 option to make:

#Set the path for Android build env (64 bit) $ make -j4 zImage export PATH=${HOME}/android/ndk/android-ndk-r9/toolchains/ arm-linux-androideabi-4.4.3/prebuilt/linux-x86_64/ The compilation process will take time to complete, based bin:$PATH on the options available in the kernel configuration (.config) and the performance of the build system. On completion, the Step 4: Configure the Android kernel kernel image (zImage) will be generated in the arch/arm/boot/ Install the necessary dependencies, as follows: directory of the kernel source. Compile the modules: $ sudo apt-get install libncurses5-dev build-essential $ make modules Set up the architecture and cross compiler, as follows: This will trigger the build for kernel modules, and .ko files $ export ARCH=arm should be generated in the corresponding module directories. $ export CROSS_COMPILE=arm-linux-androideabi- Run the find command to get a list of .ko files in the kernel directory: The kernel Makefile refers to the above variables to select the architecture and cross compile. The cross $ find . -name “*.ko” compiler command will be ${CROSS_COMPILE}gcc which is expanded to arm-linux-androideabi-gcc. The same What next? applies for other tools like g++, as, objdump, gdb, etc. Now that you have set up the Android build environment, Configure the kernel for the device: and compiled an Android kernel and necessary modules, how do you flash it to the handset so that you can see the $ cd ~/android/kernel kernel working? This requires the handset to be rooted first, $ make mint-vlx-rev03_defconfig followed by flashing the kernel and related software. It turns out that there are many new concepts to understand before The device-specific configuration files for ARM we get into this. So be sure to follow the next article on architecture are available in the arch/arm/configs directory. rooting and flashing your custom Android kernel. Executing the configuration command may throw a few warnings. You can ignore these warnings now. The command will create a .config file, which contains the References kernel configuration for the device. https://source.android.com/ To view and edit the kernel configuration, run the https://developer.android.com/ following command: http://xda-university.com

$ make menuconfig By: Mubeen Jukaku Mubeen is technology head at Emertxe Information Technologies Next, let’s assume you want to change lcd overlay (http://www.emertxe.com). His area of expertise is the architecture support. and design of Linux-based embedded systems. He has vast Navigate to Drivers → Graphics → Support for experience in kernel internals, device drivers and application porting, framebuffer devices. The option to support lcd overlay and is passionate about leveraging the power of open source for building innovative products and solutions. He can be reached at should be displayed as shown in Figure 3. [email protected] Skip the menuconfig step or do not make any changes if

86 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 87 For U & Me Let’s Try Lists: The Building Blocks of Maxima This 20th article in our series on Mathematics in Open Source showcases the list manipulations in Maxima, the programming language with an ALGOL-like syntax but Lisp-like semantics.

ists are the basic building blocks of Maxima. The its arguments. Note that makelist() is limited by the variation fundamental reason is that Maxima is implemented in it can have, which to be specific, is just one – ‘i’ in the first LLisp, the building blocks of which are also lists. two examples and ‘x’ in the last one. If we want more, the To begin with, let us walk through the ways of creating create_list() function comes into play. a list. The simplest method to get a list in Maxima is to just create_list(f, x1, L1, ..., xn, Ln) creates and returns a list define it, using []. So, [x, 5, 3, 2*y] is a list consisting of four with members of the form ‘f’, evaluated for the variables x1, members. However, Maxima provides two powerful functions ..., xn using the values from the corresponding lists L1, ..., Ln. for automatically generating lists: makelist() and create_list(). Here is just a glimpse of its power: makelist() can take two forms. makelist (e, x, x0, xn) creates and returns a list using the expression ‘e’, evaluated $ maxima -q for ‘x’ using the values ranging from ‘x0’ to ‘xn’. makelist(e, (%i1) create_list(concat(x, y), x, [p, q], y, [1, 2]); x, L) creates and returns a list using the expression ‘e’, (%o1) [p1, p2, q1, q2] evaluated for ‘x’ using the members of the list L. Check out (%i2) create_list(concat(x, y, z), x, [p, q], y, [1, 2], z, [a, the example below for better clarity: b]); (%o2) [p1a, p1b, p2a, p2b, q1a, q1b, q2a, q2b] $ maxima -q (%i3) create_list(concat(x, y, z), x, [p, q], y, [1, 2, 3], z, (%i1) makelist(2 * i, i, 1, 5); [a, b]); (%o1) [2, 4, 6, 8, 10] (%o3) [p1a, p1b, p2a, p2b, p3a, p3b, q1a, q1b, q2a, q2b, q3a, (%i2) makelist(concat(x, 2 * i - 1), i, 1, 5); q3b] (%o2) [x1, x3, x5, x7, x9] (%i4) quit(); (%i3) makelist(concat(x, 2), x, [a, b, c, d]); (%o3) [a2, b2, c2, d2] Note that ‘all possible combinations’ are created using the (%i4) quit(); values for the variables ‘x’, ‘y’ and ‘z’. Once we have created the lists, Maxima provides a host of Note the interesting usage of concat() to just concatenate functions to play around with them. Let’s take a look at these.

88 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Let’s Try For U & Me

Testing the lists members in the list L The following set of functions demonstrates the various checks reverse(L) - returns a list with members of the list L in on lists: reverse order atom(v) - returns ‘true’ if ‘v’ is an atomic element; ‘false’ otherwise $ maxima -q listp(L) - returns ‘true’ if ‘L’ is a list; ‘false’ otherwise (%i1) L: makelist(i, i, 1, 10); member(v, L) - returns ‘true’ if ‘v’ is a member of list L; (%o1) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] ‘false’ otherwise (%i2) cons(0, L); some(p, L) - returns ‘true’ if predicate ‘p’ is true for at least (%o2) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] one member of list L; ‘false’ otherwise (%i3) endcons(11, L); every(p, L) - returns ‘true’ if predicate ‘p’ is true for all (%o3) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] members of list L; ‘false’ otherwise (%i4) rest(L); (%o4) [2, 3, 4, 5, 6, 7, 8, 9, 10] $ maxima -q (%i5) rest(L, 3); (%i1) atom(5); (%o5) [4, 5, 6, 7, 8, 9, 10] (%o1) true (%i6) rest(L, -3); (%i2) atom([5]); (%o6) [1, 2, 3, 4, 5, 6, 7] (%o2) false (%i7) join(L, [a, b, c, d]); (%i3) listp(x); (%o7) [1, a, 2, b, 3, c, 4, d] (%o3) false (%i8) delete(6, L); (%i4) listp([x]); (%o8) [1, 2, 3, 4, 5, 7, 8, 9, 10] (%o4) true (%i9) delete(4, delete(6, L)); (%i5) listp([x, 5]); (%o9) [1, 2, 3, 5, 7, 8, 9, 10] (%o5) true (%i10) delete(4, delete(6, join(L, L))); (%i6) member(x, [a, b, c]); (%o10) [1, 1, 2, 2, 3, 3, 5, 5, 7, 7, 8, 8, 9, 9, 10, 10] (%o6) false (%i11) L1: rest(L, 7); (%i7) member(x, [a, x, c]); (%o11) [8, 9, 10] (%o7) true (%i12) L2: rest(rest(L, -3), 3); (%i8) some(primep, [1, 4, 9]); (%o12) [4, 5, 6, 7] (%o8) false (%i13) L3: rest(L, -7); (%i9) some(primep, [1, 2, 4, 9]); (%o13) [1, 2, 3] (%o9) true (%i14) append(L1, L2, L3); (%i10) every(integerp, [1, 2, 4, 9]); (%o14) [8, 9, 10, 4, 5, 6, 7, 1, 2, 3] (%o10) true (%i15) reverse(L); (%i11) every(integerp, [1, 2, 4, x]); (%o15) [10, 9, 8, 7, 6, 5, 4, 3, 2, 1] (%o11) false (%i16) join(reverse(L), L); (%i12) quit(); (%o16) [10, 1, 9, 2, 8, 3, 7, 4, 6, 5, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10] List recreations (%i17) unique(join(reverse(L), L)); Next is a set of functions operating on list(s) to create and return (%o17) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] new lists: (%i18) L; cons(v, L) - returns a list with ‘v’, followed by members of L (%o18) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] endcons(v, L) - returns a list with members of L followed by ‘v’ (%i19) quit(); rest(L, n) - returns a list with members of L, except the first ‘n’ members (if ‘n’ is non-negative), otherwise except the last ‘-n’ Note that the list L is still not modified. For that matter, , members. ‘n’ is optional, in which case, it is taken as 1 even L1, L2, L3 are not modified. In fact, that is what is meant join(L1, L2) - returns a list with members of L1 and L2 when we state that all these functions recreate new modified interspersed lists, rather than modify the existing ones. delete(v, L, n) - returns a list like L but with the first ‘n’ occurrences of ‘v’ deleted from it. ‘n’ is optional, in which List extractions case all occurrences of ‘v’ are deleted Here is a set of functions extracting the various members of a append(L1, ..., Ln) - returns a list with members of L1, ..., list. first(L), second(L), third(L), fourth(L), fifth(L), sixth(L), Ln, one after the other seventh(L), eight(L), ninth(L), and tenth(L), respectively return unique(L) - returns a list obtained by removing the duplicate the first, second, ... member of the list L. last(L) returns the last

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 89 For U & Me Let’s Try member of the list L. (%o8) [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] (%i9) K: copylist(L); $ maxima -q (%o9) [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] (%i1) L: create_list(i * x, x, [a, b, c], i, [1, 2, 3, 4]); (%i10) length(L); (%o1) [a, 2 a, 3 a, 4 a, b, 2 b, 3 b, 4 b, c, 2 c, 3 c, 4 c] (%o10) 10 (%i2) first(L); (%i11) pop(L); (%o2) a (%o11) 2 (%i3) seventh(L); (%i12) length(L); (%o3) 3 b (%o12) 9 (%i4) last(L); (%i13) K; (%o4) 4 c (%o13) [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] (%i5) third(L); last(L); (%i14) L; (%o5) 3 a (%o14) [4, 6, 8, 10, 12, 14, 16, 18, 20] (%o6) 4 c (%i15) pop([1, 2, 3]); /* Actual list is not allowed */ (%i7) L; arg must be a symbol [1, 2, 3] (%o7) [a, 2 a, 3 a, 4 a, b, 2 b, 3 b, 4 b, c, 2 c, 3 c, 4 c] #0: symbolcheck(x=[1,2,3])(basic.mac line 22) (%i8) quit(); #1: pop(l=[1,2,3])(basic.mac line 26) -- an error. To debug this try: debugmode(true); Again, note that the list L is still not modified. However, we (%i16) quit(); may need to modify the existing lists, and none of the above functions will do that. It could be achieved by assigning the Advanced list operations return values of the various list recreation functions back to And finally, here is a bonus of two sophisticated list operations: the original list. However, there are a few functions, which do sublist_indices(L, p) - returns the list indices for the modify the list right away. members of the list L, for which predicate ‘p’ is ‘true’. assoc(k, L, d) - L must have all its members in the form List manipulations of x op y, where op is some binary operator. Then, assoc() The following are the two list manipulating functions provided searches for ‘k’ in the left operand of the members of by Maxima: L. If found, it returns the corresponding right operand, push(v, L) - inserts ‘v’ at the beginning of the list L otherwise it returns‘d’; or it returns false, if ‘d’ is missing. pop(L) - removes and returns the first element from list L Check out the demonstration below for both the above L must be a symbol bound to a list, not the list itself, in operations both the above functions, for them to modify it. Also, these functionalities are not available by default, so we need to load $ maxima -q the basic Maxima file. Check out the demonstration below. (%i1) sublist_indices([12, 23, 57, 37, 64, 67], primep); We may display L after doing these operations, or even check the (%o1) [2, 4, 6] length of L to verify the actual modification of L. In case we need to (%i2) sublist_indices([12, 23, 57, 37, 64, 67], evenp); preserve a copy of the list, the function copylist() can be used. (%o2) [1, 5] (%i3) sublist_indices([12, 23, 57, 37, 64, 67], oddp); $ maxima -q (%o3) [2, 3, 4, 6] (%i1) L: makelist(2 * x, x, 1, 10); (%i4) sublist_indices([2 > 0, -2 > 0, 1 = 1, x = y], identity); (%o1) [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] (%o4) [1, 3] (%i2) push(0, L); /* This doesn’t work */ (%i5) assoc(2, [2^r, x+y, 2=4, 5/6]); (%o2) push(0, [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]) (%o5) r (%i3) pop(L); /* Nor does this work */ (%i6) assoc(6, [2^r, x+y, 2=4, 5/6]); (%o3) pop([2, 4, 6, 8, 10, 12, 14, 16, 18, 20]) (%o6) false (%i4) load(basic); /* Loading the basic Maxima file */ (%i7) assoc(6, [2^r, x+y, 2=4, 5/6], na); (%o4) /usr/share/maxima/5.24.0/share/macro/basic.mac (%o7) na (%i5) push(0, L); /* Now, this works */ (%i8) quit(); (%o5) [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20] (%i6) L; By: Anil Kumar Pugalia (%o6) [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20] TheBy: author Anil is aKumar gold medallist Pugalia from NIT, Warangal and IISc, (%i7) pop(L); /* Even this works */ Bengaluru. Mathematics and knowledge-sharing are two of (%o7) 0 his many passions. Learn more about him at http://sysplay.in. He can be reached at [email protected]. (%i8) L;

90 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Overview For U & Me Replicant: A Truly Free Version of Android Replicant is a free and open source mobile operating system based on the Android platform. It aims at replacing proprietary Android apps and components with open source alternatives. It is security focused, as it blocks all known Android backdoors.

martphones have evolved from being used just for will help you if you are stuck with a problem. communicating with others to offering a wide range When Android was first launched in 2007, Google also Sof functions. The fusion between the Internet and announced the ‘Open Handset Alliance (OHA)’ to work with smartphones has made these devices very powerful and useful other mobile vendors to create an open source mobile operating to us. Android had been a grand success in the smartphone system, which would allow anyone to work on it. This seemed business. It’s no exaggeration to say that more than 80 per cent of to be a good deal for the mobile vendors, because Apple’s the smartphone market is now occupied by Android, which has iPhone practically owned the smartphone market at that time. become the preference of most mobile vendors today. The mobile vendors needed another player, or ‘game changer’, The reason is simple, Android is free and available to public. in the smartphone market and they got Android. But there’s a catch. Have you ever wondered how well When Google releases the Android source code to the public Android respects ‘openness’ ? And how much Android for free, it is called ‘stock Android’. This comprises only the respects your freedom? If you haven’t thought about it, please very basic system. The mobile vendors take this stock Android take a moment to do so. When you’re done, you will realise and tailor it according to their device’s specifications—featuring that Android is not completely open to everyone. unique visual aspects such as themes, graphics and so on. That’s why we’re going to explore Replicant –- a truly OHA has many terms and conditions, so if you want to use free version of Android. Android in your devices, you have to play by Google’s rules. The following aspects are mandatory for each Android phone: Android and openness Google setup-wizard Let’s talk about openness first. The problem with a closed Google phone-top search source program is that you cannot feel safe with it. There have Gmail apps been many incidents, which suggest that people can easily be Google calendar spied upon through closed source programs. Google Talk On the other hand, since open source code is open and Google Hangouts available to everyone, one cannot plant a bug in an open source YouTube program because the bug can easily be found. Apart from that Google maps for mobiles aspect, open source programs can be continually improved by Google StreetView people contributing to them—enhancing a feature and writing Google Play store software patches, also there are many user communities that Google voice search

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 91 For U & Me Overview

These specifications are in Google’s ‘Mobile Application The following list features devices supported by Replicant and Distribution Agreement- (MADA)’ which was leaked in their corresponding Replicant versions. • HTC Dream/HTC Magic: Replicant 2.2 February 2014. • Nexus One: Replicant 2.3 There are some exceptions in the market such as • Nexus S: Replicant 4.2 Amazon’s Kindle Fire, which is based on the Android OS but • Galaxy S: Replicant 4.2 doesn’t feature the usual Google stuff and has Amazon’s App • Galaxy S2: Replicant 4.2 • Galaxy Note: Replicant 4.2 Store instead of Google Play. • Galaxy Nexus: Replicant 4.2 For a while, we were all convinced that Android was • Galaxy Tab 2 7.0: Replicant 4.2 free and open to everyone. It may seem so on the surface but • Galaxy Tab 2 10.1: Replicant 4.2 under the hood, Android is not so open. We all know that, • Galaxy S3: Replicant 4.2 • Galaxy Note 2: Replicant4.2 at its core, Android has a Linux kernel, which is released • GTA04: Replicant 2.3 under the GNU Public License, but that’s only a part of Separate installation instructions for these devices can be found Android. Many other components are licensed under the on the Replicant website. Apache licence, which allows the source code of Android to be distributed freely and not necessarily to be released to the confidential data such as bank account numbers, passwords, public. Some mobile vendors make sure that their devices etc, on it. It’s not an exaggeration to state that our smartphones run their very own tailored Android version by preventing contain more confidential data than any other secure vault in users from installing any other custom ROMs. A forcibly this world. In today’s world, the easiest way to track people’s installed custom ROM in your Android will nullify the whereabouts is via their phones. So you should realise that warranty of the device. So, most users are forced to keep the you are holding a powerful device in your hands, and you are Android version shipped with the device. responsible for keeping your data safe. Another frustrating aspect for Android users is with respect People use smartphones to stay organised, set reminders to the updates. In Android, updates are very complex, because or keep notes about ideas. Some of the apps use centralised there is no uniformity among the various devices running the servers to store the data. What users do not realise is that you Android OS. Even closed OSs support their updates—for lose control of your data when you trust a centralised server example, Apple’s iOS 5 supports iPhone 4, 4s, iPad and iPad 2; that is owned by a corporation you don’t know. You are kept and Microsoft allows its users to upgrade to Windows 7 from ignorant about how your data is being used and protected. If Windows XP without hassles. As you have probably noticed, an attacker can compromise that centralised server, then your only a handful of devices receive the new Android version. data could be at risk. To make things even more complicated, The rest of the users are forced to change their phones. Most an attacker could erase all that precious data and you wouldn’t users are alright with that, because today, the life expectancy of even know about it. mobiles is a maximum of about two years. People who want to Most of the apps in the Google Play store are closed source. stay updated as much as possible, change their phones within a Some apps are malicious in nature, working against the interests year. The reason behind this mess is that updates depend mostly of the user. Some apps keep tabs on you, or worse, they can on the hardware, the specs of which differ from vendor to steal the most confidential data from your device without your vendor. Most vendors upgrade their hardware specs as soon as knowledge. Some apps act as tools for promoting non-free a new Android version hits the market. So the next time you try services or software by carrying ads. Several studies reveal to install an app which doesn’t work well on your device, just that these apps track their users’ locations and store other remember, “It’s time to change your phone!” background information about them. You may think of this as paranoia, but the thing is that cyber Android and freedom criminals thrive on the ignorance of the public. It may be argued Online privacy is becoming a myth, since security threats pose that most users do not have any illegal secrets in the phone, a constant challenge. No matter how hard we work to make nor are they important people, so why should they worry about our systems secure, there’s always some kind of threat arising being monitored? Thinking along those lines resembles the man daily. That’s why systems administrators continually evaluate who ignores an empty gun at his door step. He may not use that security and take the necessary steps to mitigate threats. gun, but is completely ignorant of the fact that someone else Not long ago, we came to know about PRISM –- an NSA might use that gun and frame him for murder. (USA) spy program that can monitor anyone, anywhere in the world, at any time. Thanks to Edward Snowden, who leaked Replicant this news, we now realise how vulnerable we are online. Despite the facts that stack up against Android, it is almost Although some may think that worrying about this borders on impossible to underestimate its benefits. For a while, Linux was being paranoid, there’s sufficient proof that all this is happening considered a ‘nerdy’ thing, used only by developers, hackers as you read this article. Many of us use smartphones for almost and others in research. Typically, those in the ‘normal’ user everything. We keep business contacts, personal details, and community did not know much about Linux. After the arrival of

92 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Overview For U & Me

Android, everyone has the Linux kernel in their hands. Android mentioned earlier, people who value their freedom above all acts as a gateway for Linux to reach all kinds of people. The else, find Replicant very appealing. FOSS community believes in Android, but since Android poses The Replicant team is gradually making progress in adding a lot of problems due to the closed nature of its source code, support for more devices. For some devices, the conversion some people thought of creating a mobile operating system from closed source to open source becomes cumbersome, without relying on any closed or proprietary code or services. which is why these devices are rejected by the Replicant team. That’s how Replicant was born. Most of Android’s non-free code deals with hardware F-Droid such as the camera, GPS, RIL (Radio interface layer), etc. So, One of the reasons for the grand success of Android is the Replicant attempts to build a fully functional Android operating wide range of apps that is readily available on the Google system that relies completely on free and open source code. Play store for anyone to download. The project began in 2010—named after the fictional For Replicant, you cannot use Google Play but you can Replicant androids in the movie ‘Blade Runner’. Denis use an alternative—F-Droid, which has only free and open ‘GNUtoo’ Carikli and Paul Kocialkowski are the current lead source software. developers for the Replicant. The problem with Google Play is that many apps on it are In the beginning, they began by writing code for the closed source. So since we may not be able to look at their source HTC ‘Dream’ in order to make it a fully functional phone code, there’s a great possibility of an app that could spy on you that did not rely on any non-free code. They made a little or worse, steal your data being installed on it. By installing progress such as getting the audio to work with fully apps from Google Play, users inadvertently promote non-free free and open source code, and after that they succeeded software. Some apps also track their users’ whereabouts. in making and receiving calls. You can find a video of F-Droid, on the other hand, makes sure all apps are built Replicant working on the HTC Dream on YouTube. from their source code. When an application is submitted to The earlier versions of Replicant were based on AOSP F-Droid, it is in the form of source code. The F-Droid team (Android Open Source Project) but in order to support more builds it into a nice APK package from the source, so the user devices, the base was changed to Cynogenmod—another is assured that no other malicious code is added to that app custom ROM which is free but still has some proprietary since you can view the source code. drivers. The Replicant version 4.2 was released on January The F-Droid client app can be downloaded from 22, 2014, which is based on Cynogenmod 10.1. the F-Droid website. This app is extremely handy for On January 3, 2014, the Replicant team released its downloading and installing apps without hassle. You don’t full-libre Replicant SDK. You’ve probably noticed that the need an account but can install various versions of apps Android SDK is no longer open source software. When you provided there. You can choose the one that works best for try to download it, you will be presented with lengthy ‘terms you and also easily get automatic updates. and conditions’, clearly stating that you must agree to that If you’re an Android user but want FOSS on your device, license’s terms or you are not allowed to use that SDK. F-Droid is available to you. You have to allow your device Replicant is all about freedom. As you can see, the to install apps from sources other than Google Play (which Replicant team is labelling it the truly free version of Android. would be F-Droid). Using the single F-Droid client, you can The team didn’t focus much on open source, although the easily browse through various sections of apps and easily source code for Replicant is open to everyone. When it comes remove the installed apps in your device or update your apps. to freedom, from the users’ perspective, the word simply Using Replicant doesn’t grant your device complete means that they are given complete control over their device, protection, but it can make your device less vulnerable to even though they might not know what to do with that control. threats. It can offer you real control over your device and The Replicant team isn’t making any compromises when it you can enjoy true freedom. If your device doesn’t support comes to the user’s freedom. Although there may be some Replicant, you can use Cynogenmod instead, which is trade-offs concerning freedom, the biggest challenge for the officially prescribed as an alternative to Replicant. Replicant team is to write hardware drivers and firmware that As Benjamin Franklin put it, “Those who give up can support various devices. This is a difficult task since one essential liberty to purchase a little temporary safety, deserve Android device may differ from another. It’s not surprising that neither liberty nor safety.” It’s up to you to choose between they mainly differ in their hardware capabilities. That is why liberty and temporary safety. some apps that work well on one device may not necessarily work well on another. This problem could be solved if device manufacturers decide that the drivers and firmware should be By: Magimai Prakash given to the public, but we all know that’s not going to happen. TheBy: author Anil has Kumar completed aPugalia B.E. in computer science. As he That’s why there are some devices running on Replicant that is deeply interested in Linux, he spends most of his leisure time exploring open source. still don’t have 3D graphics, GPS, camera access, etc, but as

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 93 For U & Me Open Strategy Firefox May Change the Mobile Market! TCL Communication’s smartphone brand, Alcatel One Touch, launched the Alcatel One Touch Fire smartphone ‘globally’ last year. Fire was the first ever phone to run the Firefox OS, an open source operating system created by Mozilla. According to many, this OS is in some ways on par with Android, if not better. Sadly, Fire has failed to see the light of day in India, because our smartphone market has embraced Android on such a large scale that other OSs find it hard to make an impact. In a candid chat, Piyush A Garg, project manager, APAC BU India, spoke to Saurabh Singh from Open Source For You about how the Firefox OS could be the next big thing and why Alcatel One Touch has not yet given up on it.

t was not very long ago (July 25, 2011, to be precise) that but there’s such a big hoo-ha about Android. Last year, it Andreas Gal, director of research at Mozilla Corporation, was a big thing. First, you have to create some space for the Iannounced the ‘Boot to Gecko’ project (B2G) to build a OS itself, and then create a buzz,” revealed Piyush A Garg, complete, standalone operating system for the open Web, which project manager, APAC BU India. could provide a community-based alternative to commercially According to Garg, there’s still a basic lack of awareness developed operating systems such as Apple’s iOS and regarding the Firefox OS in India. “Techies might be aware of Microsoft’s Windows Phone. Besides, the Linux-based operating what the Firefox OS is but the average end user may not. And system for smartphones and tablets (among others) also aimed ultimately, it is the end user who has to purchase the phone. to give Google’s Android, Jolla’s Sailfish OS as well as other We have to communicate the advantages of Mozilla Firefox community-based open source systems such to the end user, create awareness and only then launch a as Ubuntu Touch, a run for their money product based on it,” he said. (pun intended!). Although, on paper, the project boasts of Alcatel’s plans for Firefox-based tremendous potential, it has smartphones failed to garner the kind of So the bottom line is, India will not response its developers had see the Alcatel One Touch Fire any initially hoped for. The time soon; or maybe not see it at relatively few devices in a all. “Sadly, yes. Fire is not coming market that is flooded with to India at all. It’s not going to the much-loved Android come to India because Fire was OS could be one possible an 8.89 cm (3.5 inch) product. reason. Companies like Instead, we might be coming up ZTE, Telefónica and with an 8.89-10.16 cm (3.5-4 inch) GeeksPhone have taken the product. Initially, we were considering onus of launching Firefox OS- a 12.7-13.97 cm (5-5.5 inch) device. based devices; however, giants However, we are looking to come in the field have shied away from up with a low-end phone and such adopting it, until now. a device cannot come in the 12.7 cm Hong Kong’s Alcatel One (5 inch) segment. So, once the product is Touch is one of the few companies launched with an 8.89—10.16 cm (3.5-4 inch) that has bet on Firefox by launching the screen with the Firefox OS, we may launch a whole series of Alcatel One Touch Fire smartphone globally, last year. Firefox OS-based devices,” said Garg. The Firefox OS 1.0-based Fire was primarily intended for emerging markets with the aim of ridding the world of The Firefox OS ecosystem needs a push in India feature phones. Sadly, the Indian market was left out when With that said, it has taken a fairly long time for the company to the first Firefox OS-based smartphone was tested—could realise that the Firefox OS could be a deal-breaker in an extensive Android dominance be the reason? “Alcatel Fire (Alcatel market such as India. “Firefox OS may change the mobile game. 4012) was launched globally last year. We tried everything, However, it still needs to grow in India. Considering the fact

94 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Open Strategy For U & Me that Android has such a huge base in India, we are waiting ideas. Then either we accept them, which means we buy the idea, for the right time to launch the Firefox-based smartphones or we work out some kind of association with which developers here,” he said. But is the Firefox OS really a ‘deal-breaker’ get revenue out of the collaboration. In China, more than 100,000 for customers? “The Firefox OS can be at par with Android. developers are engaged in building apps for Alcatel. India is on The major advantages of Mozilla Firefox are primarily the our to-do list for building a community of app dvelopers. It’s memory factor and the space that it takes—the entire OS as currently at an ‘amateur stage’; however, we expect things to well as the applications. It’s not basically an API kind of OS; happen eventually,” he said. it’s an installation directly coming from HTML. That’s a major Although there’s no definite time period for the launch advantage. Also, apps for the OS are of Alcatel’s One Touch Firefox built using HTML5, which means OS-based smartphone in India that, in theory, they run on the Web (Garg is confident it will be here and on your phone or tablet. What by the end of 2014, followed by made Android jump from Jelly a whole series, depending upon Bean to KitKat (which requires low how it’s received), one thing that memory) is the fact that the end user is is certain is that the device will looking at a low memory OS. Mozilla be very affordable. Cutting costs Firefox is also easy to use. I won’t while developing such low-end say ‘better’ or ‘any less’, but at par devices is certainly a challenge with Android,” said Garg, evidently for companies, since customers do confident of the platform. tend to choose ‘value for money’ To take things forward, vis-à-vis when making their purchases. the platform, Alcatel One Touch is “We are not allowed to do any also planning to come up with an ‘trimming’ with respect to the exclusive App Store, with its own set hardware quality—since we of apps. “We have already planned our are FCC-compliant, we cannot ‘play store’, and tied up with a number compromise on that,” said Garg. of developers to build our own apps. I cannot comment on the So what do companies like Alcatel One Touch actually timeline of the app store but it’s in the pipeline. We currently do to cut manufacturing costs? “We look at larger quantities have as many as five R&D centres in China. We are not yet in that we can sell at a low cost, using competitive chipsets India, although we are looking to engage developers here as that are offered at a low price. On the hardware side, we well. We’re already in the discussion phase on that front,” said may not give lamination in a low-cost phone, or we may not Garg. So, what’s the company’s strategy to engage developers in offer Corning glass or an IPS, and instead give a TFT, for particular? “We invite developers to come up and give in their instance,” Garg added.

OSFY Magazine Attractions During 2014-15

Month Theme Featured List buyers’ guide

March 2014 Network monitoring Security ------April 2014 Android Special Anti Virus Wifi Hotspot Devices May 2014 Backup and Data Storage Certification External Storage June 2014 Open Source on Windows Mobile Apps UTMs fo SMEs July 2014 Firewall and Network security Web Hosting Solutions Providers MFD Printers for SMEs August 2014 Kernel Development Big Data solution Providers SSDs for Servers September 2014 Open Source for Start-ups Cloud Android Devices October 2014 Mobile App Development Training on Programming Languages Projectors November 2014 Cloud Special Virtualisation Solutions Providers Network Switches and Routers December 2014 Web Development Leading Ecommerce Sites AV Conferencing January 2015 Programming Languages IT Consultancy Service Providers Laser Printers for SMEs February 2015 Top 10 of Everything on Open Source Storage Solutions Providers Wireless Routers

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 95

Interview For U & Me

HP’s latest mantra is the ‘new style of IT’. Conventional It is the time for converged systems, servers and data storage systems do not work for the company which are opening up an altogether and its style of IT any longer. This is about the evolution of new dimension of IT. With converged converged systems that have taken over the traditional forms of IT. The company is taking its mantra forward in every systems, you get three different possible way. systems comprising the compute part, HP has recently launched the HP Apollo family of and the storage and the networking high-performance computing (HPC) systems. The company claims that HP Apollo is capable of delivering up to four parts, to work together. times the performance of standard rack servers while using less space and energy. The new offerings reset data centre oriented database like Vertica, we have a converged system expectations by combining a modular design with improvised for virtualisation. Some time back, servers were a sprawl, but power distribution and cooling techniques. Apart from this, these days, virtual machines are a big sprawl. the company claims that HP Apollo has a higher density at a lower total cost of ownership. The air-cooled HP Apollo Converged systems have been around for about 18 6000 System maximises performance efficiency and makes Qmonths now. Can you throw some light on customers’ HPC capabilities accessible to a wide range of enterprise experiences with these systems? customers. It is a supercomputer that combines high levels of Yes, converged systems have been around for a while now processing power with a water-cooling design for ultra-low and we have incrementally improved on their management. energy usage. What we have today as a CSM for virtualisation or CSM for These servers add to the fast pace of changes going on in Hanna, wasn’t there a year back. The journey has been good the IT space today. Vikram K from HP shares his deep insight and plenty of enterprises have expressed interest in such into how IT is changing. Read on... evolved IT. With respect to the adoption rate, the IT/ITES segment has been the first large adopter of converged systems, Since you have just launched your latest servers here, what primarily because it has a huge issue about just doing the Qis your take on the Indian server market? systems integration of ‘X’ computers that compute ‘Y’ storage From a server standpoint, we are very excited, because virtually while somebody else takes care of the networks . Now, it every month and a half, we’ve been offering a new enhancement is the time for systems that come integrated with all three or releasing a new product, which is different from the previous elements, and the best part is that it is very workload specific. one. So the question is - how are these different? Well, we have We see a lot of converged systems being adopted in the basically gone back and looked at things through the eyes of the area of manufacturing also. People who had deployed SAP customer to understand what they expect from IT. They want earlier have some issues. One of them is that it is multi-tier, to get away from conventional IT and move to an improvised i.e., it has multiple application servers and multiple instances level of IT. So we see three broad areas: admin controlled IT; in the database. So when they want to run analytics, it gets user controlled IT, which is more like the cloud and is workload extremely slow because a lot of tools are used to extract specific; and then there is application-specific ‘compute and information. We came up with a solution, which customers serve’ IT. These are the three distinct combinations. Within across the manufacturing and IT/ITES segments are now these three areas, we have had product launches, one after the discovering. That is why we see a very good adoption of other. The first one, of course, is an area where we dominate. So, converged systems across segments. we decided to extend the lead and that is how the innovations continue to happen. We hear a lot about software defined data centres Q(SDCs). Many players like VMware are investing a lot in What do you mean by ‘new style of IT’? this domain. How do you think SDCs are evolving in India? QIt is the time for converged systems, which are opening up The software-defined data centre really does have the potential an altogether new dimension of IT. With converged systems, to transform the entire IT paradigm and the infrastructure and you get three different systems comprising the compute part, application landscape. We have recently launched new products and the storage and the networking parts, to work together. and services in the networking, high-performance computing, A variety of IT heads are opting for this primarily because storage and converged infrastructure areas. They will allow they want to either centralise IT, consolidate or improve enterprises to build software-defined data centres and hybrid the overall efficiency and performance. When they do that, cloud infrastructures. Big data, mobility, security and cloud they need to have better converged systems management. computing are forcing organisations to rethink their approach to So we have combined our view of converged systems and technology, causing them to invest heavily in IT infrastructure. made them workload specific. These days we have workload So, when we are talking about software defined data centres, we specific systems. For example, with something like a column- are talking about a scenario in which it can be a heterogeneous

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 97 For U & Me Interview setup of hypervisors, infrastructure, et al, which will help you So, are SMBs ready to jump onto the integrated systems’ migrate from one to another, seamlessly. Qbandwagon? Yes, there are quite a few SMBs in India that are very So, software defined data centres could replace positive about integrated systems. Customers, irrespective Qtraditional data centres in the future? Therefore, can we of the segment that they belong to, look at it from the angle consider them a part of new-age IT? of how the business functions, and what kind of specificity Well, I don’t believe that is so. We have been living with old TP they want to get to. I wouldn’t be particularly concerned for about 30-35 years. As the cloud, big data and mobility pick about the segment, but I would look at it from the context of up even more, and are used in the context of analytics, you will what workload specificity a customer wants. still have two contexts residing together, which is old TP and old AP. Then you would have more converged systems and will What are the issues that you have seen IT heads face talk about converged system management. That is exactly our Qwhile adopting converged IT systems? version of how we want to define software defined data centres. Fortunately, we have not heard of many challenges that the IT heads have faced while adopting converged IT We talk a lot about integrated and converged systems. It solutions. In fact, it has eased things for them, primarily Qsounds like a great idea as it would involve all the solutions because they have been told in advance about what they coming in from one vendor. But does that not lead to some kind are getting into. They are no more dealing with three of vendor lock-in? separate items. They are getting into one whole thing, No it doesn’t, primarily because these are workload specific. which is getting deployed and what they used to take So, one would not implement a converged system just for months to achieve, is done in two or three days. This the sake of it. As I mentioned, it has to be workload specific. is because we run the app maps prior to the actual sale So, if you want to virtualise, then you would do one type and tell them what exactly will reach them, how it will of converged system or integrated system. If you want to run and what kind of performance it will deliver. The do Hanna, that is an entirely different converged system. major challenges are related to the fact that they are on What helps the customers is that it breaks down the cycle of the verge of a transition (from the business perspective), project deployment and hence, frees up a lot of resources that and they see any transition as being slightly risky. would otherwise be consumed for mere active deployment or Hence, they thoroughly check on the ROI and are transitioning from one context to another. generally very cautious.

Swap Space for Linux: How Much is Really Needed? Linux divides its physical memory (RAM) into chunks called pages. Swapping is the process whereby pages get transferred to a preconfigured hard disk area. The quantum of swap space is determined during the Linux installation process. This article is all about swap space, and explains the term in detail so that newbies don’t find it a problem choosing the right amount of it when installing Linux.

he virtual memory of any system is a combination swap space should be double the amount of physical memory of two things - physical memory, which can be (RAM) available, i.e., if we have 16 GB of RAM, then we T accessed, i.e., RAM, and swap space. The latter ought to allot 32 GB to the swap space. But this is not very holds the inactive pages that are not accessed by any effective these days. running application. Swap space is used when the RAM Actually, the amount of swap space depends on the kind has insufficient space for active processes, but it has of application you run and the kind of user you are. If you are certain spaces which are inactive at that point in time. a hacker, you need to follow the old rule. If you frequently These inactive pages are temporarily transferred to the use hibernation, then you would need more swap space swap space, which frees up space in the RAM for active because during hibernation, the kernel transfers all the files processes. Hence, the swap space acts as temporary from the memory to the swap area. storage that is required if there is insufficient space So how can the swap space improve the performance of in your RAM for active processes. But as soon as the Linux? Sometimes, RAM is used as a disk cache rather than application is closed, the files that were temporarily to store program memory. It is, therefore, better to swap out stored in the swap space are transferred back to the RAM. a program that is inactive at that moment and, instead, keep The access time for swap space is less. In short, swapping the often-used files in cache. Responsiveness is improved by is required for two reasons: swapping pages out when the system is idle, rather than when When more memory than is available in physical memory the memory is full. (RAM) is required by the system, the kernel swaps less- Even though we know that swapping has many used pages and gives the system enough memory to run advantages, it does not necessarily improve the performance the application smoothly. of Linux on your system, always. Swapping can even make Certain pages are required by the application only at your system slow if the right quantity of it is not allotted. the time of initialisation and never again. Such files are There are certain basic concepts behind this also. Compared transferred to the swap space as soon as the application to memory, disks are very slow. Memory can be accessed in accesses these pages. nanoseconds, while disks are accessed by the processor in After understanding the basic concept of swap space, milliseconds. Accessing the disk can be many times slower one should know what amount of space needs to be actually than accessing the physical memory. Hence, the more the allotted to the swap space so that the performance of Linux swapping, the slower the system. We should know the actually improves. An earlier rule stated that the amount of amount of space that we need to allot for swapping. The

PB | july 2014 | OPEN SOURCE For You | www.OpenSourceForU.com www.OpenSourceForU.com | OPEN SOURCE For You | july 2014 | 99 For U & Me Overview following rules can effectively help to improve Linux’s cat /proc/sys/vm/swappiness performance on your system. For normal servers: A temporary change (lost at reboot) in a swappiness value Swap space should be equal to RAM size if RAM size is of 10, for example, can be done with the following command: less than 2 GB. Swap space should be equal to 2 GB if RAM size is sudosysctlvm.swappiness=10 greater than 2 GB. For heavy duty servers with fast storage requirements: For a permanent change, edit the configuration file as follows: Swap space should be equal to RAM size if RAM size is less than 8 GB. gksudogedit /etc/sysctl.conf Swap space should be equal to 0.5 times the size of the RAM if the RAM size is greater than 8 GB. If the swappiness value is 0, then the kernel restricts the If you have already installed Linux, you can check swapping process; and if the value is 100, the kernel swaps your swap space by using the following command in the very aggressively. Linux terminal: So, while Linux as an operating system has great powers, you should know how to use those powers effectively so that cat /proc/swaps you can improve the performance of your system.

Swappiness and how to change it By: Roopak T J Swappiness is a parameter that controls the tendency of the The author is an open source contributor and enthusiast. He kernel to transfer the processes from physical memory to has contributed to a couple of open source organisations ‘swap space’. It has a value between 0 to 100 and in Ubuntu, including Mediawiki and LibreOffice. He is currently in his it has a default value of 60. To check the swappiness value, second year at Amrita University (B. Tech). You can contact him at [email protected] use the following command:

THE COMPLETE MAGAZINE ON OPEN SOURCE www.electronicsforu.com www.eb.efyindia.com www.OpenSourceForu.com www.ffymag.com www.efyindia.com

TIPS &TRICKS

Booting an ISO directly from the hard Now reboot the system. The new menu entry will be drive using GRUB 2 added in the Grub boot option. We often find ourselves in a situation in which we have —Kiran P S, an ISO image of Ubuntu on our hard disk and we need [email protected] to test it by first running it. Try out this method for using the ISO image. Playing around with arguments Create a GRUB menu entry by editing the /etc/ While writing shell scripts, we often need to use grub.d/40_custom file. Add the text given below just after different arguments passed along with the command. Here is the existing text in the file: a simple tip to display the argument of the last command. Use ‘!!:n’ to select the nth argument of the last command, #gksu gedit /etc/grub.d/40_custom and ‘!$’ for the last argument.

Add the menu entry: dev@home$ echo a b c d

menuentry “Ubuntu 12.04.2 ISO” a b c d

{ dev@home$ echo !$

set isofile=”/home//Downloads/ubuntu-12.04.2- echo d desktop-amd64.iso” #path of isofile d loopback loop (X,Y)$isofile dev@home$ echo a b c d linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/ filename=$isofile noprompt noeject a b c d

initrd (loop)/casper/initrd.lz dev@home$ echo !!:3

} echo c c isofile variable is not required but simplifies the —Shivam Kotwalia, creation of multiple Ubuntu ISO menu entries. [email protected] The loopback line must reflect the actual location of the ISO file. In the example, the ISO file is stored in the user’s Retrieving disk information from Downloads folder. X is the drive number, starting with 0; the command line Y is the partition number, starting with 1. sda5 would be Want to know details of your hard disk even without physically designated as (hd0,5) and sdb1 would be (hd1,1). Do not touching it? Here are a few commands that will do the trick. I use (X,Y) in the menu entry but use something like (hd0,5). will use /dev/sda as my disk device, for which I want the details. Thus, it all depends on your system’s configuration. Save the file and update the GRUB 2 menu: smartctl -i /dev/sda

#sudo update-grub smartctl is a command line utility designed to perform

102 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com SMART (Self-Monitoring, Analysis and Reporting is that a single command does a single operation and does it well. Technology) tasks such as printing the SMART self-test and error logs, enabling and disabling SMART automatic testing, —Pankaj Rane, and initiating device self-tests. When the command is used [email protected] with the ‘ –i ’ switch, it gives information about the disk. The output of the above command will show the model Downloading/converting HTML pages to PDF family, device model, serial number, firmware version, user wkhtmltopdf is a software package that converts capacity, etc, of the hard disk (sda). HTML pages to PDF. If this is not installed on your system, You can also use the hdparm command: use the following command to do so: hdparm -I /dev/sda $sudo apt-get install wkhtmltopdf

hdparm can give much more information than smartctl. After installing, you can run the command using the following syntax: —Munish Kumar, [email protected] $wkhtmltopdf URL[oftheHTMLfile] NAME[of the PDF file].pdf

Writing an ISO image file to a CD-ROM For example, by using: from the command line We usually download ISO images of popular Linux distros for $wkhtmltopdf opensourceforu.com OSFY.pdf installation or as live media, but end up using a GUI CD burning tool to create a bootable CD or DVD ROM. But, if you’re feeling …the OSFY.PDF will be downloaded to the current a bit geeky, you could try doing so from the command line too: working directory. You can read the documentation to know more about this. # cdrecord -v speed=0 driveopts=burnfree -eject dev=1,0,0 —Manu Prasad, [email protected] speed=0 instructs the program to write the disk at the lowest possible drive speed. But, if you are in a hurry, you can try Going invisible on the terminal speed=1 or speed=2. Keep in mind that these are relative speeds. Did you ever think that you could type commands that The -eject switch instructs the program to eject the disk would be invisible on your system but still would execute, after the operation is complete. provided you typed them correctly? This can easily be done by Now, the most important part to specify is the device’s ID. It changing the terminal settings using the following command: is absolutely important that you specify the device ID of your CD ROM drive correctly or you may end up writing the ISO to some stty -echo other place on the disk and corrupting your entire hard disk. To find out the device ID of your CD ROM drive, just run the To restore the visibility of your commands, just type the following command prior to running the first command: following command:

#cdrecord -scanbus stty echo

Your CD ROM’s device ID should look something like what’s shown below: Note: Only the ‘minus’ sign has been removed.

1,0,0 —Sumit Agarwal, [email protected] Also, note that you cannot create a bootable DVD disk using this command. But, do not be disheartened—there is another simpler command to burn a bootable DVD, which is: Share Your Linux Recipes! The joy of using Linux is in finding ways to get around # growisofs -dvd-compat -speed=0 -Z /dev/dvd=myfile.iso problems—take them head on, defeat them! We invite you to share your tips and tricks with us for publication in OSFY so that they can reach a wider audience. Your tips could be related Here, /dev/dvd is the device file that represents your DVD to administration, programming, troubleshooting or general ROM. It is quite likely to be the same on your system as well. tweaking. Submit them at www.linuxforu.com. The sender of each published tip will get a T-shirt. Do not use growisofs to burn a CD ROM. The beauty of Linux

www.OpenSourceForU.com | OPEN SOURCE For You | August 2014 | 103 For U & Me Overview The Mozilla Location Service: Addressing Privacy Concerns Dubbed a research project, Mozilla Location Service is the crowd-sourced mapping of wireless networks (Wi-Fi access points, cell phone towers, etc) around the world. This information is commonly used by mobile devices and computers to ascertain their location when GPS services are not available. The entry of Mozilla into this field is expected to be a game changer. So get to know more about Mozilla’s MozStumbler mobile app as well as Ichnaea.

he Mozilla mission statement expresses a desire to There are several services that a user might not even promote openness, innovation and opportunity on be aware of while using a cell phone. The network-based Tthe Web. And Mozilla is trying to comply with this location service is one of the most used services by cell pretty seriously. phone owners to determine their location if the GPS Firefox, Thunderbird, Firefox OS… the list of service is not available. Several companies currently offer Mozilla’s open source products is growing. Yet there are this service but there are major privacy concerns associated several areas in which tech giants like Google, Nokia with it. It is no secret that advertising companies track a and Apple are dominant and the mobile ecosystem is one user’s location history and offer ads or services based on it. of them. Mozilla is now trying to break into this space. Till now, there was no transparent option among After Firefox OS, the foundation now offers a new these services but Mozilla has come to our rescue, to service for mobile users. prevent tech giants sniffing out our locations. As stated on

104 | August 2014 | OPEN SOURCE For You | www.OpenSourceForU.com Overview For U & Me

Figure 1: The MozStumbler app Figure 2: MozStumbler options Figure 3: MozStumbler settings

Mozilla’s location service website, “The Mozilla Location You can optionally give your username in this app to track Service is a research project to investigate crowd-sourced your contributions. Mozilla has also created a leader board to mapping of wireless networks (Wi-Fi access points, cell let users track and rank their contributions, apart from more towers, etc) around the world. Mobile devices and desktop detailed statistics that are available on this website. No user computers commonly use this information to figure out their identifiable information is collected through this app. location when GPS satellites are not accessible.” Mozilla is not only collecting the data but also providing In the same statement, Mozilla acknowledges the presence users with a publicly accessible API. It has code named the API of and the challenges presented by the other services, ‘Ichnaea’, which means ‘the tracker’. This API can be accessed saying, “There are few high-quality sources for this kind of to submit data, search data or search your location. As the data geolocation data currently open to the public. The Mozilla collection is still in progress, it is not recommended to use this Location Service aims to address this issue by providing an service for commercial applications, but you can try it out on open service to provide location data.” your own just for fun. This service provides geolocation lookups based on publicly observable cell tower and Wi-Fi access point Note: Mozilla Ichnaea can be accessed at information. Mozilla has come out with an Android app to https://mozilla-ichnaea.readthedocs.org collect publicly observable cell towers and Wi-Fi data; it’s called MozStumbler. The MozStumbler app provides an option for geofencing, This app scans and uploads information of cell towers which means you can pause the scanning within a one km radius of and Wi-Fi access points to Mozilla servers. The latest the desired location. This deals with user concerns over collecting stable version of this app is ver 0.20.5 which is ready for behavioural commute data such as Home, Work and travelling habits. download. MozStumbler provides the option to upload this In short, Mozilla is trying to provide a high quality location scanned data over a Wi-Fi or cellular network. But you service to the general public at no cost! Recently, Mozilla India don’t need to be online while scanning; you can upload this held a competition ‘Mozilla Geolocation Pilot Project India’, data afterwards. which encouraged more and more users to scan their area. To contribute to this project, you can fork the repository on github or Note: 1. This app is not available on Google Play just install the app; you will be welcomed aboard. store but you can download it from https://github.com/ MozStumbler/releases/ By: Vinit Wankhede 2. The Firefox OS version of this app is on its way too. You The author is a fan of free and open source software. He is can stay abreast of what’s happening with the Firefox OS currently contributing to the translation of the MozStumbler app app at http://github.com/FxStumbler/ for Mozilla location services.

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