5.2.3. build/conf/bblayers.conf

This file defines layers, which are directory trees, traversed (or walked) by BitBake. If bblayers.conf is not present, it is created from bblayers.conf.sample when you source the environment setup script.

The bblayers.conf file uses the BBLAYERS variable to list the layers BitBake tries to find. The file uses the BBLAYERS_NON_REMOVABLE variable to list layers that must not be removed.