Parsing

Configuration Files

The first of the classifications of metadata in BitBake is configuration metadata. This metadata is global, and therefore affects all packages and tasks which are executed. Currently, BitBake has hardcoded knowledge of a single configuration file. It expects to find 'conf/bitbake.conf' somewhere in the user specified BBPATH. That configuration file generally has include directives to pull in any other metadata (generally files specific to architecture, machine, local and so on.

Only variable definitions and include directives are allowed in .conf files.

Classes

BitBake classes are our rudamentary inheritence mechanism. As briefly mentioned in the metadata introduction, they're parsed when an inherit directive is encountered, and they are located in classes/ relative to the dirs in BBPATH.

.bb Files

A BitBake (.bb) file is a logical unit of tasks to be executed. Normally this is a package to be built. Inter-.bb dependencies are obeyed. The files themselves are located via the BBFILES variable, which is set to a space seperated list of .bb files, and does handle wildcards.