BitBake metadata collections
For BitBake, there is no metadata outside a metadata collection. Instead, a metadata collection has a unique name, and the common term the Yocto Project uses for those collections is Layer.
Chapter 1, Meeting the Yocto Project, explains that we have the following layers:
- OpenEmbedded Core: This is inside the
meta
directory - Poky distribution: This is inside the
meta-poky
directory - Yocto Project reference BSP: This is inside the
meta-yocto-bsp
directory
The preceding list describes real examples of layers. Every layer contains a file called conf/layer.conf
. This file defines several layer properties, such as the collection name and priority. The following figure shows the conf/layer.conf
file for the meta-poky
layer:

Figure 4.1 – The conf/layer.conf file for the meta-poky layer
The preceding example is relatively simple but serves as a base for us to illustrate the conf/layer.conf
file principles...