+ +
- -
Systèmes d'Exploitation
Calendrier  Détails
Programmation
 
Calendrier  Détails
Processeurs ARM
 
Calendrier  Détails
Processeurs PowerPC
 
 
 
 
Calendrier  Détails
Communications
 
 
Calendrier  Détails
+ +
> >
- -

Dernières Nouvelles

Workshop gratuit Linux Embarqué avec System Workbench for Linux le 24 Septembre 2019 à Lyon Saint-Priest, avec ARROW

 
ac6 >> ac6-training >> Systèmes d'Exploitation >> Linux >> Embedded Linux with Yocto Télécharger le catalogue Télécharger la page Ecrivez nous Version imprimable

D1Y Embedded Linux with Yocto

Building embedded Linux platforms using Yocto

Building embedded Linux platforms using Yocto
formateur
Objectives
  • Understanding the architecture of the Linux system
  • Learn how to install Linux on your hardware and create a BSP
  • Explore the Linux system architecture
  • Booting Linux
  • Initializing the system
  • Install existing packages on the target
  • Learn how to install Linux on flash chips
  • Using and customizing Yocto
  • Creating Yocto-based Embedded Linux platforms
  • Using Yocto to develop components
Labs can be conducted either on qemu or on target boards, that can be:
    Dual Cortex/A7-based "STM32MP15-DISCO" boards from STMicroelectronics.
    Quad Cortex/A9-based "SabreLite" boards from NXP.
    Quad Cortex/A53-based "imx8q-evk" boards from NXP.
We use the latest Yocto version supported by the chip provider
We use a recent (4.x) linux kernel, as supported by the chip supplier
Course environment
  • Printed course material (in English)
  • One Linux PC for two trainees.
  • One target platform for two trainees (if not using qemu)
Prerequisite

First Day
Introduction to Linux
  • Linux history and Version management
  • Linux system architecture
    • Processes and MMU
    • System calls
    • Shared libraries
  • Linux system components
    • Toolchain
    • Bootloader
    • Kernel
    • Root file system
  • Linux packages
  • The various licenses used by Linux (GPL, LGPL, etc)
Cross compiling toolchains
  • Pre-compiled toolchains
  • Toolchain generation tools
    • Crosstool-ng
    • Buildroot
  • Manual toolchain compilation
Linux tools for embedded systems
  • Boot loaders (UBoot, Redboot, barebox)
  • Optimized libraries (glibc, uClibc-ng, musl)
  • Embedded GUIs
  • Busybox
  • Embedded distributions
    • Commercial
    • Standard
    • Tools for building custom distributions
The U-Boot bootloader
  • Introduction to U-Boot
  • Booting the board through U-Boot
    • Booting from NOR
    • Booting from NAND
    • Booting from eMMC
  • U-Boot environment variables
    • User-defined variables
    • Predefined variables
    • Variables substitution
  • The U-Boot minimal shell
    • Writing scripts in variables
    • Executing scripts
    • Using variables in scripts: the set-script pattern
  • U-Boot main commands
    • Booting an OS
    • Accessing flash chips
    • Accessing file systems (NFS, FAT, EXTx, JFFS2…)
  • The full U-Boot shell
    • Script structure
    • Control flow instructions (if, for…)
  • Booting Linux
    • Linux kernel parameters
    • The Linux startup sequence
  • Building and installing U-Boot with its native build system
Exercise :  Booting the board on NFS, using pre-existing images
Exercise :  Configuring and building u-boot with its native build system
Building the kernel
  • The Linux build system
  • Downloading stable source code
    • Getting a tarball
    • Using GIT
  • Configuring the kernel
  • Compiling the kernel and its modules
    • Modules delivered in-tree
    • Out-of-tree modules
  • Installing the kernel and the modules
Exercise :  Configuring and compiling a target kernel for the target board with the kernel build system
Second Day
The Linux BSP
  • Linux BSP architecture
    • Overall structure
    • The ARM BSP
    • The Linux build system
  • Defining and initializing the board
  • Linux device drivers overview
    • Using the Flattened Device Tree
Exercise :  Create a minimal BSP for the target board
Creating a root file system
  • Packages
    • Tools to build packages (gcc, Makefile, pkg-config)
    • Autotools
    • Cross-compiling a package with autotools
  • The all-in-one applications
    • Busybox, the basic utilities
    • Dropbear: encrypted communications (ssh)
  • Manually building your root file system
    • Device nodes, programs and libraries
    • Configuration files (network, udev, …)
    • Installing modules
    • Looking for and installing the needed libraries
    • Testing file system consistency and completeness
Exercise :  Cross-compiling an autotools-based package
Exercise :  Configuring and compiling Busybox and Dropbear
Exercise :  Creating a minimal root file system using busybox and dropbear
The Linux Boot
  • Linux kernel parameters
  • The Linux startup sequence
  • Various initialization systems
    • busybox init
    • system V init
    • systemd
  • Automatically starting an embedded system
Exercise :  Boot Linux automatically starts a user application
Embedded file systems
  • Storage interfaces
    • Block devices
    • MTD
  • Flash memories and Linux MTDs
    • NOR flashes
    • NAND flashes
    • ONENAND flashes
  • The various flash file system formats
    • JFFS2, YAFFS2, UBIFS
  • Read-only file system
    • CRAMFS, SQUASHFS
  • Standard Linux file systems
    • Ext2/3/4, FAT, NFS
  • Ramdisks and initrd
    • Creating an initramfs
    • Booting through an initramfs
  • Choosing the right file system formats
  • Flashing the file system
Exercise :  Building an initrd root file system
Third Day
Introduction to Yocto
  • Overview of Yocto
    • History
    • Yocto, Open Embedded and Poky
    • Purpose of the Yocto project
    • The main projects
  • Yocto architecture
    • Overview
    • Recipes and classes
    • Tasks
The Yocto build system
  • Build system objectives
    • Building deployable images
  • Layers and layer priorities
  • Directory layout
  • Configuration files (local, machine and distribution)
  • The bitbake tool
    • Common options
  • Using Yocto
    • Building a package
    • Building an image (root file system + u-boot + kernel)
  • Miscellaneous tools around Yocto
    • Yocto SDK
    • Extensible SDK
Exercise :  Building a root file system using Yocto
Exercise :  Use bitbake commands to build package & images
Exercise :  Build an extensible SDK for the generated image
Exercise :  Deploy the generated image using NFS
Yocto package recipes structure
  • Recipe architecture
    • Tasks
    • Task dependencies
    • Recipe dependencies
  • The bitbake language
    • Standard variables and functions
    • Classes and recipes
    • The base Yocto classes
    • Main bitbake commands
  • Adding a new layer
    • Layer structure
    • Various kinds of layers
Exercise :  Adding a new layer
Fourth Day
Writing package recipes for Yocto
  • Various kind of recipes and classes
    • Bare program
    • Makefile-based package
    • autotools-based package
    • u-boot
    • kernel
    • Out-of-tree module
  • Recipe creation strategies
    • From scratch
    • Using devtool
    • Using recipetool
    • From an existing, similar, recipe
  • Debugging recipes
    • Debugging recipe selection
    • Debugging dependencies
    • Debugging tasks
  • Defining packaging
    • Package splitting
  • Automatically starting a program
Exercise :  Writing a recipe for a local user-maintained package
Exercise :  Writing and debugging a package recipe for an autotools-based package
Exercise :  Starting a program at boot (systemd)
Modifying recipes
  • Customizing an existing package recipe (.bbappend)
  • Recipe dependencies
  • Creating and adding patches
    • Creating a patch for a community-provided component
    • Creating a patch for an user-maintained component
  • Defining new tasks
    • Task declaration
    • Coding tasks
Exercise :  Adding patches and dependencies to a community package
Exercise :  Adding a rootfsinstall task to directly copy the output of a user package in the rootfs image
Fifth Day
Development process using the extensible SDK and devtool
  • Using devtool to create a package and its recipe
  • Using devtool to modify an existing package and recipe
  • Using devtool to update a recipe to build a new version of a package
Exercise :  Create, test and modify a recipe for an existing package using devtool
Creating new kinds of recipes
  • Creating classes
    • Creating new independent classes
    • Inheriting from an existing class
Exercise :  Create a class to generalize the “rootfsinstall” task
Creating a root file system
  • Building a root file system with Yocto
    • Creating a custom root file system
  • Writing an image recipe
    • Selecting the packages to build
    • Selecting the file system types
    • The various kinds of images
  • Inheriting and customizing images
    • Customizing system configuration files (network, mount points, …)
  • Package management
    • rpm
    • opkg
Exercise :  Writing and building an image recipe
Exercise :  Create an image with package support for OTA deployment
Exercise :  Test OTA update on the generated image