Stefano Cordibella - An introduction to Yocto Project
- 1. Software Embedded Applicazioni e Strumenti Software Soluzioni integrate Introduction to Yocto Project Stefano Cordibella 1
- 2. About Me âą EDALab s.r.l. â 15+ collaborators â active from 2007 in Verona â main areas: âą embedded solutions âą wireless sensor network âą HMI on touchscreen Stefano Cordibella 2
- 3. Agenda âą Introduction: â Embedded Linux â Yocto Project âą Openembedded Core: â directory structure â layer structure âą Bitbake âą Qt5 in Yocto Project Stefano Cordibella 3
- 4. Embedded Linux Operating systems based on Linux Kernel used in embedded systems. Pros: âą complete system âą high customization Cons: âą need to manage heterogeneous software âą many different tools to automate processes âą update and maintain the whole system Stefano Cordibella 4
- 5. Yocto Project Suite of tools and metadata to build and manage your own linux distribution. âą it is NOT a linux distro âą it is a set of open source tools Advantages: âą high level software management âą hardware producer involved into the project âą you can spend more time on your product Stefano Cordibella 5
- 6. Yocto Project Main components: âą Yocto Project: umbrella project that maintains tools for embedded linux âą Poky: Yocto Projects reference distro âą Bitbake: build engine, metadata interpreter âą Openembedded Core: metadata collection âą 3rd parties metadata: for specific machine or software libraries Stefano Cordibella 6
- 8. Openembedded Core âą Organize the metadata in files called recipes. âą Recipes are grouped in a modular structure called layers. âą Contains about 1000 recipes for applications and libraries. Quick start: 1. download the Yocto Project code 2. run the setup script 3. select a target machine 4. run bitbake on the selected image. Stefano Cordibella 8
- 9. Openembedded Core Poky directory structure: âą bitbake: build engine code and binary, âą meta-* : layer directory A layer could be: âą part of the oe core â meta-yocto-bsp âą provided by a 3rd parties â meta-freescale, meta-qt5 âą created by the user â meta-edalab Stefano Cordibella 9
- 10. Openembedded Core Layer entities: âą Recipe: rules to create a software package âą Package Group: set of packages âą Image: data to create a root filesystem âą Machine: definitions about the target platform âą Distro: package version and feature definitions Stefano Cordibella 10
- 11. Recipes âą Rules to create a binary or a software library. âą Grouped in functional group named recipes-*. Stefano Cordibella 11
- 12. Recipes âą Recipes are divided in logical block called tasks: â do_fecth: to download source code â do_patch, do_configure, do_compile: to build software â do_install, do_package: create package and deploy âą Tasks can be extended or overwritten âą Recipes can inherit from predefined build system: â autotools, cmake, qmake Stefano Cordibella 12
- 15. Package Groups âą Set of recipes that can be managed like one entity. Stefano Cordibella 15
- 16. Images âą List of software to install. âą Features: â splash, â readonly rootfs, â debug tools, â ⊠⹠File system type: â ext3, â jffs2, â ⊠⹠Post process actions. Stefano Cordibella 16
- 18. Distro âą Feature enable for the distro. âą Specify package version number. âą Disambiguate packages. Stefano Cordibella 18
- 19. Machine âą Specify target architecture. âą Feature supported by the hardware. âą Memory region for bootloader, kernel. Stefano Cordibella 19
- 21. Bitbake âą Execute the tasks on a recipe or an image. âą If a recipe has dependency it execute the dependency first creating the dependency graph. âą Execute tasks in parallel. Examples: Execute all the tasks for the specified <recipe>, that could be an image. Stefano Cordibella 21
- 22. Bitbake Execute the single task <nometask> for the recipe <recipe> and terminate. Perform the clean task on the recipe. Show all the tasks for the recipe. Stefano Cordibella 22
- 23. Bitbake Open the development shell on the source code for the recipe after the do_patch task. The developer can make local changes on the sources and create patches for oe. Stefano Cordibella 23
- 24. Qt5 in Yocto Project 24Stefano Cordibella
- 25. Qt5 in Yocto Project Layer created to integrate qt5 framework in YP. Stefano Cordibella 25 âą classes: definitions for qmake5 and cmake_qmake âą recipes-qt: â how to compile the qt5 framework â recipes for the meta toolchain â application examples
- 27. Thank you for your attention Any question? Stefano Cordibella 27