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Shorten Device Boot Time for Automotive IVI and Navigation Systems
Shorten Device Boot Time for Automotive IVI and Navigation Systems Jim Huang ( 黃敬群 ) <[email protected]> Dr. Shi-wu Lo <[email protected]> May 28, 2013 / Automotive Linux Summit (Spring) Rights to copy © Copyright 2013 0xlab http://0xlab.org/ [email protected] Attribution – ShareAlike 3.0 Corrections, suggestions, contributions and translations You are free are welcome! to copy, distribute, display, and perform the work to make derivative works Latest update: May 28, 2013 to make commercial use of the work Under the following conditions Attribution. You must give the original author credit. Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. For any reuse or distribution, you must make clear to others the license terms of this work. Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. License text: http://creativecommons.org/licenses/by-sa/3.0/legalcode Goal of This Presentation • Propose a practical approach of the mixture of ARM hibernation (suspend to disk) and Linux user-space checkpointing – to shorten device boot time • An intrusive technique for Android/Linux – minimal init script and root file system changes are required • Boot time is one of the key factors for Automotive IVI – mentioned by “Linux Powered Clusters” and “Silver Bullet of Virtualization (Pitfalls, Challenges and Concerns) Continued” at ALS 2013 – highlighted by “Boot Time Optimizations” at ALS 2012 About this presentation • joint development efforts of the following entities – 0xlab team - http://0xlab.org/ – OSLab, National Chung Cheng University of Taiwan, led by Dr. -
MLNX OFED Documentation Rev 5.0-2.1.8.0
MLNX_OFED Documentation Rev 5.0-2.1.8.0 Exported on May/21/2020 06:13 AM https://docs.mellanox.com/x/JLV-AQ Notice This document is provided for information purposes only and shall not be regarded as a warranty of a certain functionality, condition, or quality of a product. NVIDIA Corporation (“NVIDIA”) makes no representations or warranties, expressed or implied, as to the accuracy or completeness of the information contained in this document and assumes no responsibility for any errors contained herein. NVIDIA shall have no liability for the consequences or use of such information or for any infringement of patents or other rights of third parties that may result from its use. This document is not a commitment to develop, release, or deliver any Material (defined below), code, or functionality. NVIDIA reserves the right to make corrections, modifications, enhancements, improvements, and any other changes to this document, at any time without notice. Customer should obtain the latest relevant information before placing orders and should verify that such information is current and complete. NVIDIA products are sold subject to the NVIDIA standard terms and conditions of sale supplied at the time of order acknowledgement, unless otherwise agreed in an individual sales agreement signed by authorized representatives of NVIDIA and customer (“Terms of Sale”). NVIDIA hereby expressly objects to applying any customer general terms and conditions with regards to the purchase of the NVIDIA product referenced in this document. No contractual obligations are formed either directly or indirectly by this document. NVIDIA products are not designed, authorized, or warranted to be suitable for use in medical, military, aircraft, space, or life support equipment, nor in applications where failure or malfunction of the NVIDIA product can reasonably be expected to result in personal injury, death, or property or environmental damage. -
Interrupt Handling in Linux
Department Informatik Technical Reports / ISSN 2191-5008 Valentin Rothberg Interrupt Handling in Linux Technical Report CS-2015-07 November 2015 Please cite as: Valentin Rothberg, “Interrupt Handling in Linux,” Friedrich-Alexander-Universitat¨ Erlangen-Nurnberg,¨ Dept. of Computer Science, Technical Reports, CS-2015-07, November 2015. Friedrich-Alexander-Universitat¨ Erlangen-Nurnberg¨ Department Informatik Martensstr. 3 · 91058 Erlangen · Germany www.cs.fau.de Interrupt Handling in Linux Valentin Rothberg Distributed Systems and Operating Systems Dept. of Computer Science, University of Erlangen, Germany [email protected] November 8, 2015 An interrupt is an event that alters the sequence of instructions executed by a processor and requires immediate attention. When the processor receives an interrupt signal, it may temporarily switch control to an inter- rupt service routine (ISR) and the suspended process (i.e., the previously running program) will be resumed as soon as the interrupt is being served. The generic term interrupt is oftentimes used synonymously for two terms, interrupts and exceptions [2]. An exception is a synchronous event that occurs when the processor detects an error condition while executing an instruction. Such an error condition may be a devision by zero, a page fault, a protection violation, etc. An interrupt, on the other hand, is an asynchronous event that occurs at random times during execution of a pro- gram in response to a signal from hardware. A proper and timely handling of interrupts is critical to the performance, but also to the security of a computer system. In general, interrupts can be emitted by hardware as well as by software. Software interrupts (e.g., via the INT n instruction of the x86 instruction set architecture (ISA) [5]) are means to change the execution context of a program to a more privileged interrupt context in order to enter the kernel and, in contrast to hardware interrupts, occur synchronously to the currently running program. -
ECE 598 – Advanced Operating Systems Lecture 19
ECE 598 { Advanced Operating Systems Lecture 19 Vince Weaver http://web.eece.maine.edu/~vweaver [email protected] 7 April 2016 Announcements • Homework #7 was due • Homework #8 will be posted 1 Why use FAT over ext2? • FAT simpler, easy to code • FAT supported on all major OSes • ext2 faster, more robust filename and permissions 2 btrfs • B-tree fs (similar to a binary tree, but with pages full of leaves) • overwrite filesystem (overwite on modify) vs CoW • Copy on write. When write to a file, old data not overwritten. Since old data not over-written, crash recovery better Eventually old data garbage collected • Data in extents 3 • Copy-on-write • Forest of trees: { sub-volumes { extent-allocation { checksum tree { chunk device { reloc • On-line defragmentation • On-line volume growth 4 • Built-in RAID • Transparent compression • Snapshots • Checksums on data and meta-data • De-duplication • Cloning { can make an exact snapshot of file, copy-on- write different than link, different inodles but same blocks 5 Embedded • Designed to be small, simple, read-only? • romfs { 32 byte header (magic, size, checksum,name) { Repeating files (pointer to next [0 if none]), info, size, checksum, file name, file data • cramfs 6 ZFS Advanced OS from Sun/Oracle. Similar in idea to btrfs indirect still, not extent based? 7 ReFS Resilient FS, Microsoft's answer to brtfs and zfs 8 Networked File Systems • Allow a centralized file server to export a filesystem to multiple clients. • Provide file level access, not just raw blocks (NBD) • Clustered filesystems also exist, where multiple servers work in conjunction. -
User Manual Issue 2.0.2 September 2017
The Embedded I/O Company TDRV015-SW-82 Linux Device Driver Reconfigurable FPGA Version 2.0.x User Manual Issue 2.0.2 September 2017 TEWS TECHNOLOGIES GmbH Am Bahnhof 7 25469 Halstenbek, Germany Phone: +49 (0) 4101 4058 0 Fax: +49 (0) 4101 4058 19 e-mail: [email protected] www.tews.com TDRV015-SW-82 This document contains information, which is Linux Device Driver proprietary to TEWS TECHNOLOGIES GmbH. Any Reconfigurable FPGA reproduction without written permission is forbidden. Supported Modules: TEWS TECHNOLOGIES GmbH has made any TAMC631 (TPLD001) effort to ensure that this manual is accurate and TAMC640 (TPLD002) complete. However TEWS TECHNOLOGIES GmbH TAMC641 (TPLD003) reserves the right to change the product described TAMC651 (TPLD004) in this document at any time without notice. TPMC632 (TPLD005) TEWS TECHNOLOGIES GmbH is not liable for any damage arising out of the application or use of the device described herein. 2011-2017 by TEWS TECHNOLOGIES GmbH Issue Description Date 1.0.0 First Issue March 14, 2011 1.0.1 SupportedModulesadded September30,2011 2.0.0 New API implemented March 7, 2012 2.0.1 IncludestatementinExampleCodescorrected August 18, 2015 Reference to Engineering Documentation removed 2.0.2 Filelistmodified(licenseadded) September28,2017 TDRV015-SW-82 - Linux Device Driver Page 2 of 75 Table of Contents 1 INTRODUCTION......................................................................................................... 4 2 INSTALLATION......................................................................................................... -
Chapter 19 RECOVERING DIGITAL EVIDENCE from LINUX SYSTEMS
Chapter 19 RECOVERING DIGITAL EVIDENCE FROM LINUX SYSTEMS Philip Craiger Abstract As Linux-kernel-based operating systems proliferate there will be an in evitable increase in Linux systems that law enforcement agents must process in criminal investigations. The skills and expertise required to recover evidence from Microsoft-Windows-based systems do not neces sarily translate to Linux systems. This paper discusses digital forensic procedures for recovering evidence from Linux systems. In particular, it presents methods for identifying and recovering deleted files from disk and volatile memory, identifying notable and Trojan files, finding hidden files, and finding files with renamed extensions. All the procedures are accomplished using Linux command line utilities and require no special or commercial tools. Keywords: Digital evidence, Linux system forensics !• Introduction Linux systems will be increasingly encountered at crime scenes as Linux increases in popularity, particularly as the OS of choice for servers. The skills and expertise required to recover evidence from a Microsoft- Windows-based system, however, do not necessarily translate to the same tasks on a Linux system. For instance, the Microsoft NTFS, FAT, and Linux EXT2/3 file systems work differently enough that under standing one tells httle about how the other functions. In this paper we demonstrate digital forensics procedures for Linux systems using Linux command line utilities. The ability to gather evidence from a running system is particularly important as evidence in RAM may be lost if a forensics first responder does not prioritize the collection of live evidence. The forensic procedures discussed include methods for identifying and recovering deleted files from RAM and magnetic media, identifying no- 234 ADVANCES IN DIGITAL FORENSICS tables files and Trojans, and finding hidden files and renamed files (files with renamed extensions. -
Seminar HPC Trends Winter Term 2017/2018 New Operating System Concepts for High Performance Computing
Seminar HPC Trends Winter Term 2017/2018 New Operating System Concepts for High Performance Computing Fabian Dreer Ludwig-Maximilians Universit¨atM¨unchen [email protected] January 2018 Abstract 1 The Impact of System Noise When using a traditional operating system kernel When running large-scale applications on clusters, in high performance computing applications, the the noise generated by the operating system can cache and interrupt system are under heavy load by greatly impact the overall performance. In order to e.g. system services for housekeeping tasks which is minimize overhead, new concepts for HPC OSs are also referred to as noise. The performance of the needed as a response to increasing complexity while application is notably reduced by this noise. still considering existing API compatibility. Even small delays from cache misses or interrupts can affect the overall performance of a large scale In this paper we study the design concepts of het- application. So called jitter even influences collec- erogeneous kernels using the example of mOS and tive communication regarding the synchronization, the approach of library operating systems by ex- which can either absorb or propagate the noise. ploring the architecture of Exokernel. We sum- Even though asynchronous communication has a marize architectural decisions, present a similar much higher probability to absorb the noise, it is project in each case, Interface for Heterogeneous not completely unaffected. Collective operations Kernels and Unikernels respectively, and show suffer the most from propagation of jitter especially benchmark results where possible. when implemented linearly. But it is hard to anal- yse noise and its propagation for collective oper- ations even for simple algorithms. -
Faux Disk Encryption: Realities of Secure Storage on Mobile Devices August 4, 2015 – Version 1.0
NCC Group Whitepaper Faux Disk Encryption: Realities of Secure Storage On Mobile Devices August 4, 2015 – Version 1.0 Prepared by Daniel A. Mayer — Principal Security Consultant Drew Suarez — Senior Security Consultant Abstract In this paper, we discuss the challenges mobile app developers face in securing data stored on devices including mobility, accessibility, and usability requirements. Given these challenges, we first debunk common misconceptions about full-disk encryption and show why it is not sufficient for many attack scenarios. We then systematically introduce the more sophisticated secure storage techniques that are available for iOS and Android respectively. For each platform, we discuss in-depth which mechanisms are available, how they technically operate, and whether they fulfill the practical security and usability requirements. We conclude the paper with an analysis of what still can go wrong even when current best-practices are followed and what the security and mobile device community can do to address these shortcomings. Table of Contents 1 Introduction ......................................................................... 3 2 Challenges in Secure Mobile Storage .................................................. 4 3 Threat Model Considerations ......................................................... 5 4 Secure Data Storage on iOS .......................................................... 6 4.1 Fundamentals of iOS Data Protection .................................................. 7 4.2 Filesystem Encryption .............................................................. -
MC-1200 Series Linux Software User's Manual
MC-1200 Series Linux Software User’s Manual Version 1.0, November 2020 www.moxa.com/product © 2020 Moxa Inc. All rights reserved. MC-1200 Series Linux Software User’s Manual The software described in this manual is furnished under a license agreement and may be used only in accordance with the terms of that agreement. Copyright Notice © 2020 Moxa Inc. All rights reserved. Trademarks The MOXA logo is a registered trademark of Moxa Inc. All other trademarks or registered marks in this manual belong to their respective manufacturers. Disclaimer Information in this document is subject to change without notice and does not represent a commitment on the part of Moxa. Moxa provides this document as is, without warranty of any kind, either expressed or implied, including, but not limited to, its particular purpose. Moxa reserves the right to make improvements and/or changes to this manual, or to the products and/or the programs described in this manual, at any time. Information provided in this manual is intended to be accurate and reliable. However, Moxa assumes no responsibility for its use, or for any infringements on the rights of third parties that may result from its use. This product might include unintentional technical or typographical errors. Changes are periodically made to the information herein to correct such errors, and these changes are incorporated into new editions of the publication. Technical Support Contact Information www.moxa.com/support Moxa Americas Moxa China (Shanghai office) Toll-free: 1-888-669-2872 Toll-free: 800-820-5036 Tel: +1-714-528-6777 Tel: +86-21-5258-9955 Fax: +1-714-528-6778 Fax: +86-21-5258-5505 Moxa Europe Moxa Asia-Pacific Tel: +49-89-3 70 03 99-0 Tel: +886-2-8919-1230 Fax: +49-89-3 70 03 99-99 Fax: +886-2-8919-1231 Moxa India Tel: +91-80-4172-9088 Fax: +91-80-4132-1045 Table of Contents 1. -
The Linux Device File-System
The Linux Device File-System Richard Gooch EMC Corporation [email protected] Abstract 1 Introduction All Unix systems provide access to hardware via de- vice drivers. These drivers need to provide entry points for user-space applications and system tools to access the hardware. Following the \everything is a file” philosophy of Unix, these entry points are ex- posed in the file name-space, and are called \device The Device File-System (devfs) provides a power- special files” or \device nodes". ful new device management mechanism for Linux. Unlike other existing and proposed device manage- This paper discusses how these device nodes are cre- ment schemes, it is powerful, flexible, scalable and ated and managed in conventional Unix systems and efficient. the limitations this scheme imposes. An alternative mechanism is then presented. It is an alternative to conventional disc-based char- acter and block special devices. Kernel device drivers can register devices by name rather than de- vice numbers, and these device entries will appear in the file-system automatically. 1.1 Device numbers Devfs provides an immediate benefit to system ad- ministrators, as it implements a device naming scheme which is more convenient for large systems Conventional Unix systems have the concept of a (providing a topology-based name-space) and small \device number". Each instance of a driver and systems (via a device-class based name-space) alike. hardware component is assigned a unique device number. Within the kernel, this device number is Device driver authors can benefit from devfs by used to refer to the hardware and driver instance. -
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. -
Mellanox Linux Switch †
SOFTWARE PRODUCT BRIEF Mellanox Linux Switch † – Taking Open Ethernet to the next level, Mellanox Linux Switch provides users with the ability to deploy any standard Linux operating HIGHLIGHTS system on their switch devices – Mellanox Linux Switch enables users to natively install and use any standard Linux distribution as • 100% free open source software the switch operating system on the Open Ethernet Mellanox Spectrum® switch platforms. Mellanox Linux Switch is based on Switchdev, a Linux kernel driver model for Ethernet switches. Mellanox is • L2/L3 switch system as standard Linux the first switch vendor to embrace this model by implementing the switchdev driver for its Mellanox server Spectrum switches. This revolutionary concept breaks the dependency of using vendor-specific • Uniform Linux interfaces software development kits (SDK). Instead of proprietary APIs, fully standard Linux kernel interfaces are used to control the switch chip. This allows users to natively install and use any standard Linux • Fully supported by the Linux distribution as the switch operating system, while the switchdev driver ensures all network traffic is community seamlessly offloaded to the switch hardware. • Hardware independent abstraction layer Openness and Freedom • User choice of Linux operating The 100% free open-source Mellanox switchdev driver is developed and maintained as part of the systems and network applications Linux kernel and is promoted by the Linux community. There is no longer a need for closed code from switch vendors, no more binary blobs, and no need to sign a service level agreement (SLA). • Industry’s highest performance switch systems portfolio, including the high- Linux Switch provides users the flexibility to customize and optimize the switch to their exact needs density half-width Mellanox SN2100 without paying for expensive proprietary software that includes features they neither need nor will never use.