Book Image

Embedded Linux Development Using Yocto Project - Third Edition

By : Otavio Salvador, Daiane Angolini
Book Image

Embedded Linux Development Using Yocto Project - Third Edition

By: Otavio Salvador, Daiane Angolini

Overview of this book

The Yocto Project is the industry standard for developing dependable embedded Linux projects. It stands out from other frameworks by offering time-efficient development with enhanced reliability and robustness. With Embedded Linux Development Using Yocto Project, you’ll acquire an understanding of Yocto Project tools, helping you perform different Linux-based tasks. You’ll gain a deep understanding of Poky and BitBake, explore practical use cases for building a Linux subsystem project, employ Yocto Project tools available for embedded Linux, and uncover the secrets of SDK, recipe tool, and others. This new edition is aligned with the latest long-term support release of the aforementioned technologies and introduces two new chapters, covering optimal emulation in QEMU for faster product development and best practices. By the end of this book, you’ll be well-equipped to generate and run an image for real hardware boards. You’ll gain hands-on experience in building efficient Linux systems using the Yocto Project.
Table of Contents (20 chapters)

Applying a patch

For cases where we need to apply a patch to an existing package, we should use FILESEXTRAPATHS, which includes new directories in the searching algorithm, making the additional file visible to BitBake, as shown here:

Figure 13.4 – The content of .bbappend is used only to apply mypatch.patch

Figure 13.4 – The content of .bbappend is used only to apply mypatch.patch

In the preceding example, THISDIR expands to the current directory, and PN and PV expand to the package name and version, respectively. This new path is then included in the directories list used for file searching. The prepend operator is crucial as it guarantees that the file is picked from this directory, even if a file with the same name is added in the lower priority layers in the future.

BitBake assumes that every file with a .patch or .diff extension is a patch and applies them accordingly.