Understanding BitBake’s metadata
The amount of metadata used by BitBake is enormous. Therefore, to get the maximum benefit from Poky, we must master it. As we learned in Chapter 4, Meeting the BitBake Tool, metadata covers three major areas:
- Configuration (the
.conf
files): The configuration files define the global content that configures how the classes and recipes will work. - Classes (the
.bbclass
files): Classes can be inherited for easier maintenance and to promote code reuse and avoid code duplication. - Recipes (the
.bb
or.bbappend
files): The recipes describe the tasks to be run and provide the required information to allow BitBake to generate the required task chain. They are the most commonly used metadata, as they define the variables and tasks for the recipes. The most common types of recipes generate packages and images.
The classes and recipes use a mix of Python and Shell Script code, which is parsed by BitBake, generating a massive number...