Book Image

Embedded Linux Development Using Yocto Project Cookbook - Second Edition

By : Alex Gonzalez
Book Image

Embedded Linux Development Using Yocto Project Cookbook - Second Edition

By: Alex Gonzalez

Overview of this book

The Yocto Project has become the de facto distribution build framework for reliable and robust embedded systems with a reduced time to market.You'll get started by working on a build system where you set up Yocto, create a build directory, and learn how to debug it. Then, you'll explore everything about the BSP layer, from creating a custom layer to debugging device tree issues. In addition to this, you’ll learn how to add a new software layer, packages, data, scripts, and configuration files to your system. You will then cover topics based on application development, such as using the Software Development Kit and how to use the Yocto project in various development environments. Toward the end, you will learn how to debug, trace, and profile a running system. This second edition has been updated to include new content based on the latest Yocto release.
Table of Contents (13 chapters)
Title Page
Packt Upsell

Adding a custom kernel and bootloader

The BSP that encapsulates the hardware modifications for a given platform is mostly located in the bootloader, usually U-Boot (Das U-Boot) for ARM devices, and the Linux kernel. Both U-Boot and the Linux kernel have upstream development trees, at and respectively, but it is very common for manufacturers of embedded hardware to provide their own trees for both bootloader and kernel.

Development in U-Boot and the Linux kernel is usually done externally to Yocto, as they are easy and quicker to build using a cross-compilation toolchain, like the one provided by Yocto's SDK.

The development work is then integrated into Yocto in one of two ways:

  • With patches added to the kernel and U-Boot bbappend files. This method will build the same source as the reference design board we are using as a base, and apply our changes over it. This is what we have seen in the previous recipe.
  • Using a different Git repository, forked from the Linux...