The basic concepts of layers

Let's dive into the basic concepts of layers:

Theory

A layer, in the technical sense of the term, has some properties. They are as follows:

• Name: This usually starts with the string meta- (mandatory for better comprehension).

• Priority: This is the value used by BitBake to decide which recipe to use and the order in which the .bbappend files should be joined. It means that if two layers include the same recipe (.bb) file, the one with the higher priority is used.

Note

For example, a layer with a priority value set to 6 has a higher chance of its recipe being used than one with a priority value set to 5.

Furthermore, each layer is listed according to its functionality on this page:

http://layers.openembedded.org/layerindex/branch/master/layers/

• The software layer:  This layer provides software families that can be used on any architecture (x86_64, ARM, PPC, MIPS, and so on). For example, we have meta-java (for Java support), meta-efl (for the Enlightenment environment...