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LSP 1.20 Davinci Linux NOR Flash Device Driver
LSP 1.20 DaVinci Linux NOR Flash Driver User's Guide Literature Number: SPRUF10 April 2008 2 SPRUF10–April 2008 Submit Documentation Feedback Contents 1 Overview............................................................................................................................. 5 1.1 System Requirements .................................................................................................... 5 1.2 Design Overview .......................................................................................................... 6 2 Installation Guide................................................................................................................. 7 2.1 List of Installable Components .......................................................................................... 7 2.2 Component Folder ........................................................................................................ 7 2.3 Development Tools ....................................................................................................... 7 2.4 Build......................................................................................................................... 8 2.5 Steps to Load/Unload the NOR Flash Driver.......................................................................... 8 3 NOR Flash Driver Porting...................................................................................................... 9 3.1 Customizing the NOR-flash partitions ................................................................................. -
Flexible Lustre Management
Flexible Lustre management Making less work for Admins ORNL is managed by UT-Battelle for the US Department of Energy How do we know Lustre condition today • Polling proc / sysfs files – The knocking on the door model – Parse stats, rpc info, etc for performance deviations. • Constant collection of debug logs – Heavy parsing for common problems. • The death of a node – Have to examine kdumps and /or lustre dump Origins of a new approach • Requirements for Linux kernel integration. – No more proc usage – Migration to sysfs and debugfs – Used to configure your file system. – Started in lustre 2.9 and still on going. • Two ways to configure your file system. – On MGS server run lctl conf_param … • Directly accessed proc seq_files. – On MSG server run lctl set_param –P • Originally used an upcall to lctl for configuration • Introduced in Lustre 2.4 but was broken until lustre 2.12 (LU-7004) – Configuring file system works transparently before and after sysfs migration. Changes introduced with sysfs / debugfs migration • sysfs has a one item per file rule. • Complex proc files moved to debugfs • Moving to debugfs introduced permission problems – Only debugging files should be their. – Both debugfs and procfs have scaling issues. • Moving to sysfs introduced the ability to send uevents – Item of most interest from LUG 2018 Linux Lustre client talk. – Both lctl conf_param and lctl set_param –P use this approach • lctl conf_param can set sysfs attributes without uevents. See class_modify_config() – We get life cycle events for free – udev is now involved. What do we get by using udev ? • Under the hood – uevents are collect by systemd and then processed by udev rules – /etc/udev/rules.d/99-lustre.rules – SUBSYSTEM=="lustre", ACTION=="change", ENV{PARAM}=="?*", RUN+="/usr/sbin/lctl set_param '$env{PARAM}=$env{SETTING}’” • You can create your own udev rule – http://reactivated.net/writing_udev_rules.html – /lib/udev/rules.d/* for examples – Add udev_log="debug” to /etc/udev.conf if you have problems • Using systemd for long task. -
Reducing Power Consumption in Mobile Devices by Using a Kernel
IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. Z, NO. B, AUGUST 2017 1 Reducing Event Latency and Power Consumption in Mobile Devices by Using a Kernel-Level Display Server Stephen Marz, Member, IEEE and Brad Vander Zanden and Wei Gao, Member, IEEE E-mail: [email protected], [email protected], [email protected] Abstract—Mobile devices differ from desktop computers in that they have a limited power source, a battery, and they tend to spend more CPU time on the graphical user interface (GUI). These two facts force us to consider different software approaches in the mobile device kernel that can conserve battery life and reduce latency, which is the duration of time between the inception of an event and the reaction to the event. One area to consider is a software package called the display server. The display server is middleware that handles all GUI activities between an application and the operating system, such as event handling and drawing to the screen. In both desktop and mobile devices, the display server is located in the application layer. However, the kernel layer contains most of the information needed for handling events and drawing graphics, which forces the application-level display server to make a series of system calls in order to coordinate events and to draw graphics. These calls interrupt the CPU which can increase both latency and power consumption, and also require the kernel to maintain event queues that duplicate event queues in the display server. A further drawback of placing the display server in the application layer is that the display server contains most of the information required to efficiently schedule the application and this information is not communicated to existing kernels, meaning that GUI-oriented applications are scheduled less efficiently than they might be, which further increases power consumption. -
I.MX Linux® Reference Manual
i.MX Linux® Reference Manual Document Number: IMXLXRM Rev. 1, 01/2017 i.MX Linux® Reference Manual, Rev. 1, 01/2017 2 NXP Semiconductors Contents Section number Title Page Chapter 1 About this Book 1.1 Audience....................................................................................................................................................................... 27 1.1.1 Conventions................................................................................................................................................... 27 1.1.2 Definitions, Acronyms, and Abbreviations....................................................................................................27 Chapter 2 Introduction 2.1 Overview.......................................................................................................................................................................31 2.1.1 Software Base................................................................................................................................................ 31 2.1.2 Features.......................................................................................................................................................... 31 Chapter 3 Machine-Specific Layer (MSL) 3.1 Introduction...................................................................................................................................................................37 3.2 Interrupts (Operation).................................................................................................................................................. -
Networking with Wicked in SUSE® Linux Enterprise 12
Networking with Wicked in SUSE® Linux Enterprise 12 Something Wicked This Way Comes Guide www.suse.com Solution Guide Server Server Solution Guide Networking with Wicked in SUSE Linux Enterprise 12 Wicked QuickStart Guide Abstract: Introduced with SUSE® Linux Enterprise 12, Wicked is the new network management tool for Linux, largely replacing the sysconfig package to manage the ever-more-complicated network configurations. Wicked provides network configuration as a service, enabling you to change your configuration dynamically. This paper covers the basics of Wicked with an emphasis on Recently, new technologies have accelerated the trend toward providing correlations between how things were done previ- complexity. Virtualization requires on-demand provisioning of ously and how they need to be done now. resources, including networks. Converged networks that mix data and storage traffic on a shared link require a tighter integra- Introduction tion between stacks that were previously mostly independent. When S.u.S.E.1 first introduced its Linux distribution, network- ing requirements were relatively simple and static. Over time Today, more than 20 years after the first SUSE distribution, net- networking evolved to become far more complex and dynamic. work configurations are very difficult to manage properly, let For example, automatic address configuration protocols such as alone easily (see Figure 1). DHCP or IPv6 auto-configuration entered the picture along with a plethora of new classes of network devices. Modern Network Landscape While this evolution was happening, the concepts behind man- aging a Linux system’s network configuration didn’t change much. The basic idea of storing a configuration in some files and applying it at system boot up using a collection of scripts and system programs was pretty much the same. -
Communicating Between the Kernel and User-Space in Linux Using Netlink Sockets
SOFTWARE—PRACTICE AND EXPERIENCE Softw. Pract. Exper. 2010; 00:1–7 Prepared using speauth.cls [Version: 2002/09/23 v2.2] Communicating between the kernel and user-space in Linux using Netlink sockets Pablo Neira Ayuso∗,∗1, Rafael M. Gasca1 and Laurent Lefevre2 1 QUIVIR Research Group, Departament of Computer Languages and Systems, University of Seville, Spain. 2 RESO/LIP team, INRIA, University of Lyon, France. SUMMARY When developing Linux kernel features, it is a good practise to expose the necessary details to user-space to enable extensibility. This allows the development of new features and sophisticated configurations from user-space. Commonly, software developers have to face the task of looking for a good way to communicate between kernel and user-space in Linux. This tutorial introduces you to Netlink sockets, a flexible and extensible messaging system that provides communication between kernel and user-space. In this tutorial, we provide fundamental guidelines for practitioners who wish to develop Netlink-based interfaces. key words: kernel interfaces, netlink, linux 1. INTRODUCTION Portable open-source operating systems like Linux [1] provide a good environment to develop applications for the real-world since they can be used in very different platforms: from very small embedded devices, like smartphones and PDAs, to standalone computers and large scale clusters. Moreover, the availability of the source code also allows its study and modification, this renders Linux useful for both the industry and the academia. The core of Linux, like many modern operating systems, follows a monolithic † design for performance reasons. The main bricks that compose the operating system are implemented ∗Correspondence to: Pablo Neira Ayuso, ETS Ingenieria Informatica, Department of Computer Languages and Systems. -
AMD Alchemy™ Processors Building a Root File System for Linux® Incorporating Memory Technology Devices
AMD Alchemy™ Processors Building a Root File System for Linux® Incorporating Memory Technology Devices 1.0 Scope This document outlines a step-by-step process for building and deploying a Flash-based root file system for Linux® on an AMD Alchemy™ processor-based development board, using an approach that incorporates Memory Technology Devices (MTDs) with the JFFS2 file system. Note: This document describes creating a root file system on NOR Flash memory devices, and does not apply to NAND Flash devices. 1.1 Journaling Flash File System JFFS2 is the second generation of the Journaling Flash File System (JFFS). This file system provides a crash-safe and powerdown-safe Linux file system for use with Flash memory devices. The home page for the JFFS project is located at http://developer.axis.com/software/jffs. 1.2 Memory Technology Device The MTD subsystem provides a generic Linux driver for a wide range of memory devices, including Flash memory devices. This driver creates an abstracted device used by JFFS2 to interface to the actual Flash memory hardware. The home page for the MTD project is located at http://www.linux-mtd.infradead.org. 2.0 Building the Root File System Before being deployed to an AMD Alchemy platform, the file system must first be built on an x86 Linux host PC. The pri- mary concern when building a Flash-based root file system is often the size of the image. The file system must be designed so that it fits within the available space of the Flash memory, with enough extra space to accommodate any runtime-created files, such as temporary or log files. -
Ensuring Data Confidentiality Via Plausibly Deniable Encryption and Secure Deletion – a Survey Qionglu Zhang1,2,3, Shijie Jia1,2*, Bing Chang4 and Bo Chen5*
Zhang et al. Cybersecurity (2018) 1:1 Cybersecurity https://doi.org/10.1186/s42400-018-0005-8 SURVEY Open Access Ensuring data confidentiality via plausibly deniable encryption and secure deletion – a survey Qionglu Zhang1,2,3, Shijie Jia1,2*, Bing Chang4 and Bo Chen5* Abstract Ensuring confidentiality of sensitive data is of paramount importance, since data leakage may not only endanger data owners’ privacy, but also ruin reputation of businesses as well as violate various regulations like HIPPA and Sarbanes-Oxley Act. To provide confidentiality guarantee, the data should be protected when they are preserved in the personal computing devices (i.e., confidentiality during their lifetime); and also, they should be rendered irrecoverable after they are removed from the devices (i.e., confidentiality after their lifetime). Encryption and secure deletion are used to ensure data confidentiality during and after their lifetime, respectively. This work aims to perform a thorough literature review on the techniques being used to protect confidentiality of the data in personal computing devices, including both encryption and secure deletion. Especially for encryption, we mainly focus on the novel plausibly deniable encryption (PDE), which can ensure data confidentiality against both a coercive (i.e., the attacker can coerce the data owner for the decryption key) and a non-coercive attacker. Keywords: Data confidentiality, Plausibly deniable encryption, Secure deletion Introduction Spahr LLP: State and local governments move swiftly to Modern computing devices (e.g., desktops, laptops, smart sue equifax 2017); Third, it will directly violate regulations phones, tablets, wearable devices) are increasingly used like HIPAA (Congress 1996), Gramm-Leach-Bliley Act to process sensitive or even mission critical data. -
ANDROID PRIVACY THROUGH ENCRYPTION by DANIEL
ANDROID PRIVACY THROUGH ENCRYPTION by DANIEL DEFREEZ A THESIS Presented to the Department of Computer Science in partial fullfillment of the requirements for the degree of Master of Science in Mathematics and Computer Science Ashland, Oregon May 2012 ii APPROVAL PAGE “Android Privacy Through Encryption,” a thesis prepared by Daniel DeFreez in partial fulfillment of the requirements for the Master of Science in Mathematics and Computer Science. This project has been approved and accepted by: Dr. Lynn Ackler, Chair of the Examining Committee Date Pete Nordquist, Committee Member Date Hart Wilson, Committee Member Date Daniel DeFreez c 2012 iii ABSTRACT OF THESIS ANDROID PRIVACY THROUGH ENCRYPTION By Daniel DeFreez This thesis explores the field of Android forensics in relation to a person’s right to privacy. As the field of mobile forensics becomes increasingly sophisticated, it is clear that bypassing common privacy measures, such as disk encryption, will become routine. A new keying method for eCryptfs is proposed that could significantly mitigate memory attacks against encrypted file systems. It is shown how eCryptfs could be modified to implement this keying method on an Android device. iv ACKNOWLEDGMENTS I would like to thank Dr. Lynn Ackler for introducing me to the vast world of computer security and forensics, cultivating a healthy paranoia, and for being a truly excellent teacher. Dr. Dan Harvey, Pete Nordquist, and Hart Wilson provided helpful feedback during the preparation of this thesis, for which I thank them. I am deeply indebted to my friends and colleagues Brandon Kester, Andrew Krug, Adam Mashinchi, Jeff McJunkin, and Stephen Perkins, for their enthusiastic interest in the forensics and security fields, insightful comments, love of free software, and encouraging words. -
Beancounters
Resource Management: Beancounters Pavel Emelianov Denis Lunev Kirill Korotaev [email protected] [email protected] [email protected] July 31, 2007 Abstract The paper outlines various means of resource management available in the Linux kernel, such as per-process limits (the setrlimit(2) interface), shows their shortcomings, and illustrares the need for another resource control mechanism: beancounters. Beancounters are a set of per-process group parameters (proposed and implemented by Alan Cox and Andrey Savochkin and further developed for OpenVZ) which can be used with or without containers. Beancounters history, architecture, goals, efficiency, and some in-depth implementation details are given. 1 Current state of resource Again, most of these resource limits apply to a management in the Linux single process, which means, for example, that all the memory may be consumed by a single user run- kernel ning the appropriate number of processes. Setting the limits in such a way as to have the value of Currently the Linux kernel has only one way to multiplying the per-process limit by the number of control resource consumption of running processes processes staying below the available values is im- – it is UNIX-like resource limits (rlimits). practical. Rlimits set upper bounds for some resource us- age parameters. Most of these limits apply to a single process, except for the limit for the number 2 Beancounters of processes, which applies to a user. For some time now Linus has been accepting The main goal of these limits is to protect pro- patches adding the so-called namespaces into the cesses from an accidental misbehavior (like infi- kernel. -
Postmodern Strace Dmitry Levin
Postmodern strace Dmitry Levin Brussels, 2020 Traditional strace [1/30] Printing instruction pointer and timestamps print instruction pointer: -i option print timestamps: -r, -t, -tt, -ttt, and -T options Size and format of strings string size: -s option string format: -x and -xx options Verbosity of syscall decoding abbreviate output: -e abbrev=set, -v option dereference structures: -e verbose=set print raw undecoded syscalls: -e raw=set Traditional strace [2/30] Printing signals print signals: -e signal=set Dumping dump the data read from the specified descriptors: -e read=set dump the data written to the specified descriptors: -e write=set Redirecting output to files or pipelines write the trace to a file or pipeline: -o filename option write traces of processes to separate files: -ff -o filename Traditional strace [3/30] System call filtering trace only the specified set of system calls: -e trace=set System call statistics count time, calls, and errors for each system call: -c option sort the histogram printed by the -c option: -S sortby option Tracing control attach to existing processes: -p pid option trace child processes: -f option Modern strace [4/30] Tracing output format pathnames accessed by name or descriptor: -y option network protocol associated with descriptors: -yy option stack of function calls: -k option System call filtering pathnames accessed by name or descriptor: -P option regular expressions: -e trace=/regexp optional specifications: -e trace=?spec new syscall classes: %stat, %lstat, %fstat, %statfs, %fstatfs, %%stat, %%statfs -
Compression and Replication of Device Files Using Deduplication Technique
Compression and Replication of Device Files using Deduplication Technique {tag} {/tag} International Journal of Computer Applications © 2012 by IJCA Journal Volume 45 - Number 1 Year of Publication: 2012 Authors: Bharati Siddhant Agarwal Abhishek Somani Rukmi Patel Ankita Shingvi 10.5120/6744-8847 {bibtex}pxc3878847.bib{/bibtex} Abstract One of the biggest challenges to the data storage community is how to effectively store data without taking the exact same data and storing again and again in different locations on the back end servers. In this paper, we outline the performance achievements that can be achieved by exploiting block level data deduplication in File Systems. We have achieved replication of data by storing a deduplicated copy of the original data on the backup partition, which can enable us to access or restore data in case of a system crash. References - Request-based Device-mapper multipath and Dynamic load balancing by kiyoshi Ueda, Jun'ichi Nomura and Mike Christie. 1 / 2 Compression and Replication of Device Files using Deduplication Technique - A Device Mapper based Encryption Layer for TransCrypt by Sainath Vella. - Edward Goggin, Linux Multipathing Proceedings of the Linux Symposium, 2005. - Jens Axboe, Notes on the Generic Block Layer Rewrite in Linux 2. 5, Documentation/block/ biodoc. txt, 2007. - Netlink - Communication between kernel and userspace (PF NETLINK). Manual Page Netlink. - Satyam Sharma, Rajat Moona, and Dheeraj Sanghi. TransCrypt: A Secure and Transparent Encrypting File System for Enterprises. - Mike Anderson, SCSI Mid-Level Multipath, Proceedings of the Linux Symposium, 2003. - Daniel Pierre Bovet and Marco Cesati. Understanding the Linux Kernel. O'Reilly& Associates, Inc.