Embedded GNU/Linux System Architecture

• Intro
  • Linux Intro
    • History of Unix
      • Unix is born
      • Unix spreads
      • hard times
      • Free software
      • more info
        • history of modern computers
        • generations of computers
        • Unix history
    • Origin of Free Software
      • RMS
    • History of Linux
      • Minix was a mess
        • AST vs linus
      • UNIX wars
      • GNU has failed to deliver a kernel (HURD)
      • Internet
      • OpenSource^? (development methodology)
        • Free software (social movement)
    • GNU/Linux
      • more info

YouTube^? - Linus Torvalds on GNU/LinuxYouTube - The Origins of Linux - Linus TorvaldsLinus^? vs. TanenbaumThe^? Tanenbaum-Torvalds DebateLinux^? is obsoleteMore Linux is obsoleteMonolithic vs. MicrokernelLinux^? BlogKernel^? portsLinux KernelLink^? kernel developmentkernel historyfigures of recect Linux Kernels * Background Info

• • • Licensing Models
      • FOSS
      • History of free software
      • Open Letter to hobbyists
      • GPL3
      • GPL3 project watchlist
      • RMS blog
      • RMS vs. Linux
      • Open Soure Activity map
      • Open Source Licenses
      • Example appweb server
    • Standards and Portability in the Unix world
      • GCC
      • The Past and Future of Linux Standards
      • Opengroup base specs
      • Single Unix Specification
      • Filesystem Hierarchy Standard
      • Linux standard base
      • RFCS
        • On Holy Wars and a Plea for Peace
    • Working with Free Software
      • Use the force Luke
      • Spelunking
        • find
        • grep
        • cscope
        • global
        • source navigator (NG)
        • Linux Cross Referencer
        • diff
        • sort
        • wc
        • awk
        • perl
        • python
        • sed
        • patch
        • quilt
        • git
        • doxygen
    • Finding help
      • communities
        • How to ask questions the smart way
      • mailing lists
        • bikeshed
  • Unix Philosophy

artueverything is a filepremature optimizationKISSrule of silencedata dominatessmall is beautifulWhen in doubt, use brute force.

• host playground

architectureshellusers/groupsDetailed look at the Linux filesystem hierarchy devicesuser land-kernel interfacedaemonbootingquick look at /procpermissionshard and soft links three more permission bitsreal/effective uid/gidschedulerprocess/task/threadIPCsimpleshell redirectionshell out (blechen)tempfilesadvancedmessage passingpipesunnamednamedsignalsmessage queuesunnamednamesemaphoresunnamednamedshared memorya two step approachsocketsIPC techniques you should try to avoidHost Linux SetupInstalling^? the ELDKWorking with the ELDKDULGTftp Server ConfigurationDULGSetup^? of the NFS ServerDULGSetup^? of the DHCP ServerDULGTerminal^? Emulation SetupDULGTest^? the host setup

• U-Boot & Linux
  • An Introduction to git
    • Software Configuration Management using git
  • Booting Linux
    • DULG - Booting Embedded Linux

• Designing Unix Applications
  • Unix Design Patterns
  • Simple Unix Interface Design Patterns
  • Advanced Unix Interface Design Patterns
  • Unix Inter Process Communication - Simple Techniques
  • Unix Inter Process Communication - Advanced Techniques
  • IPC techniques to avoid
  • Use case: board test software
  • Domain specific languages (Minilanguages)

• Debugging & Profiling

Debuggingintrowhat is a bug?types of bugs?strategysimple toolslsofstraceproc/proc/pid/proc/topadvanced toolslocal debuggingon hosthello worldcore dumpnull pointeron targettarget gdbtarget gdbtuiremote debuggingtarget gdbserverhostgdbdddJTAG/BDI as gdbserveru-bootbefore relocationafter relocationfind offset addressadd debug info to U-boot to confirm findingsDULG: GDB startup and utility filessimple debugging with bdi u-boot only with JTAG/BDImore infoApplication DebuggingDULG^?: Application debuggingDULG: Linux Kernel debuggingProfilingwhat is profiling?typestime profilingcoverage why?when?how?profiling vs. tracingtoolssystem timerstimegprofgcovoprofilemore infoDULG: Profiling techniquesOptimization Techniques

• Using the BDM/JTAG Debugger, BDI2000, Part 1
  • BDI2000 Installation and Configuration
  • DULG Installation using a BDB/JTAG debugger
  • Downloading U-Boot to flash

• Real-time

prerequisiteskernel-user spaceinterruptsreentrant codewhat is real-time?Real-time Linuxvanilla Linux vs. real-time Linuxreal-time performace/effort staircaseexplicit preemption pointsimplicit preemption pointreal-time preemption patchCan Linux handle real-time requirements?fully preemptive kernelhard real-time extensionsRTLinuxRTAIXenomaiXenomai vs. RTAIReal time with Adeos/Xenomai (Introduction)AdeosThe Xenomai real time frameworkXenomai ArchitectureInterrupt^? shield (better RTDM)SW stackskinsroadmap - future outlookXenomai 3transition to itRTDMXenomai/SoloCase study: Migrating from RTOS (VRTXsa) to Xenomai-LinuxTry it outwhich kernel/adeos patch?get adeos patchget kernelget xenomaipatch kernelbuild kernel + fdtcopy over to tftpadjust symbolic linksbuild xenomai user space supportinstall xenomai user space supportcyclictestload the cputelnetdmore info:Appnote

• EliMiscellanious
  • Installing and using Embedded WEB Servers
    • rebuilding ELDK packages
  • Tools, Scripts, Tipps and Tricks
  • More information

• unsorted
  • a.out! The early PDP-11 did not contain memory protection. One was expected to jell ‘A.OUT’ before trying new software...
  • SW release

Administrationversion controlbug trackingwikicentral build environment per platformhost Linux distrotarget Linux distrotoolchainlibrariesheaderspackages rootfskernelbootloadertransition from windozeDevelopmentbuild scripts/makefilescodinguser spacekernel spacedebugginguser spacekernel spacecode reviewscoding standardhow to reproduce a release?build environmenthost Linux distro snapshottarget Linux distro snapshotcodeversion control * errno

• target playground
  • How to run Linux on the target (kilauea)?
  • files needed
    • kilauea.cfg [JTAG/BDI config file (tftp)]
    • u-boot.bin [bootloader (JTAG/tftp)]
      • what is u-boot?
      • scripting
      • get it
        • git intro
      • build it
      • flash it (JTAG/BDI)
      • check it
      • commands
      • restore factory settings
      • downloadable environment
        • create
        • download
        • execute
      • more info

U-Boot and LinuxDULG^? - U-Boot and LinuxThe^? powerful U-Boot command line interfaceDULG - U-Boot Command Line InterfaceDULG^? - Information CommandsDULG^? - Memory CommandsDULG^? - Flash Memory CommandsDULG^? - Execution Control CommandsDULG^? - Download CommandsDULG^? - Environment Variables CommandsDULG^? - Flattened Device Tree supportDULG - Special CommandsDULG^? - Storage devicesDULG - Miscellaneous CommandsDULG^? - U-Boot Environment VariablesDULG^? - U-Boot Scripting CapabilitiesDULG^? - U-Boot Standalone ApplicationsDULG^? - U-Boot Image FormatsDULG^? - U-Boot Advanced FeaturesBuilding^? U-BootDULG U-BootU-Boot Tips and Tricks: preboot, update, etc.U-Boot Design Principles * uImage [kernel (tftp)]

• • • • what is uImage?
      • which kernel to use?
        • the one with ELDK
        • latest DENX tested on kilauea
        • latest stable mainline
        • latest and greatest DENX
        • something in between
      • get kernel
        • show how for each
      • build the kernel
      • more info
        • Configuring and building the Linux kernel
          • DULG Embedded Linux Configuration
    • rootfs [root file system (NFS here)]
      • at the moment given by ELDK
    • kilauea.dtb [flat device tee blob (tftp)]
      • what is flat device tree?
      • build it
  • make kernel, device tree,... available
    • copy them over to tftp
    • adjust symbolic links
  • run it on board
    • serial
    • telnet to JTAG/BDI
  • DULG: Designing and buildling root file systems

compressed ramdisk imagerootfs on a ramdiskcreaterunMTDrootfs on JFFS2createcaveat: does it fit?increase partitionmtd memory mapmtdpartsflat device treerunrootfs on cramfscreatecaveat: mkcramfsrunrootfs on read only ext2comparison flash file systemsfurther infoDULG: Flash file systems Using Flash filesystems