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)

Preferring and providing recipes

Dependency is a relation between two things; one side can only be fulfilled if the other side exists. However, a dependency only specifies that some functionality or characteristic is needed to be fulfilled, not precisely how it must be fulfilled.

For example, when a recipe depends on A, the first thought is that it depends on a recipe called A. However, there are two possible ways to satisfy the dependency requirement of A:

  • A recipe called A
  • A recipe that provides a functionality or characteristic called A

For a recipe to communicate to BitBake that it can fulfill a functionality or characteristic requirement, it must use the PROVIDES keyword. A subtle consequence is that two or more recipes can deliver the same functionality or characteristic. We must inform BitBake which recipe should fulfill that requirement using the PREFERRED_PROVIDER keyword.

So, if a recipe called depends on bar, BitBake lists all recipes...