Conditional selection based on layers

We can use BBFILE_COLLECTIONS to conditionally decide which recipes to include in our BBFILES. To do this, we need to use logic that is similar to the following in our layer.conf:

1. Firstly, add the following two lines to our layer.conf file:

   BBFILES += "${@' '.join('${LAYERDIR}/%s/recipes-*/*/*.bbappend' % layer \
                  for layer in BBFILE_COLLECTIONS.split())}"
   BBFILES += "${@' '.join('${LAYERDIR}/%s/recipes-*/*/*.bb' % layer \
                  for layer in BBFILE_COLLECTIONS.split())}"

2. Secondly, arrange your recipes-* directories under directories named according to other layers found in BBFILE_COLLECTION. For example, we might need to add some metadata that is specific only to it, and we want it applied only when we have meta-ti included in our bblayers.conf file. What we will do in this case is create a directory under our layer—say, test/meta-t/—and move all of the recipe...