Book Image

Embedded Linux Development using Yocto Projects - Second Edition

By : Otavio Salvador, Daiane Angolini
Book Image

Embedded Linux Development using Yocto Projects - Second Edition

By: Otavio Salvador, Daiane Angolini

Overview of this book

Yocto Project is turning out to be the best integration framework for creating reliable embedded Linux projects. It has the edge over other frameworks because of its features such as less development time and improved reliability and robustness. Embedded Linux Development using Yocto Project starts with an in-depth explanation of all Yocto Project tools, to help you perform different Linux-based tasks. The book then moves on to in-depth explanations of Poky and BitBake. It also includes some practical use cases for building a Linux subsystem project using Yocto Project tools available for embedded Linux. The book also covers topics such as SDK, recipetool, and others. By the end of the book, you will have learned how to generate and run an image for real hardware boards and will have gained hands-on experience at building efficient Linux systems using Yocto Project.
Table of Contents (22 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
7
Diving into BitBake Metadata
Index

Understanding BitBake's tasks


BitBake uses execution units, which are in essence a set of clustered instructions that run in sequence. These units are known as tasks. There are many tasks being scheduled, executed, and checked by BitBake during every recipe's build, provided by classes to form the framework that we use to build a recipe. It is important to understand some of these as we often use, extend, implement, or replace them ourselves when writing a recipe.

Run the following command:

 $ bitbake <recipe>

BitBake runs a set of scheduled tasks. When we wish to run a specific task, we can use the following command:

$ bitbake <recipe> -c <task>

To list the tasks defined for a recipe, we can use the following command:

 $ bitbake <recipe> -c listtasks

We will briefly describe each of these here:

  • do_fetch: The first step when building a recipe is fetching the required source. This is done using the fetching backends feature we discussed previously in this chapter. It is important...