Parsing metadata
As previously said, there are three metadata groups—configuration, class, and recipe.
The first parsed metadata in BitBake is configuration metadata, identified by the .conf
file extension. This metadata is global, and therefore, affects all recipes and tasks which are executed.
BitBake first searches the current working directory for an optional build/conf/bblayers.conf
configuration file, and it is expected to contain a BBLAYERS
variable that is a space-delimited list of layer directories. For each directory in this list, a build
/conf/layer.conf
file is searched for and parsed with the LAYERDIR
variable being set to the directory where the layer was found. This process automatically sets up BBPATH
and other variables for a given build directory for the user.
Tip
The order of the listed layers in the BBLAYERS
variable is followed by BitBake when parsing the metadata. In case your layer needs to be parsed first, be sure to have it listed in the right order in BBLAYERS...