This configuration file defines
layers,
which are directory trees, traversed (or walked) by BitBake.
The bblayers.conf
file uses the
BBLAYERS
variable to list the layers BitBake tries to find.
If bblayers.conf
is not present when you
start the build, the OpenEmbedded build system creates it from
bblayers.conf.sample
when
you source
the top-level build environment
setup script (i.e.
oe-init-build-env
).
The source bblayers.conf.sample
file used
depends on the $TEMPLATECONF
script variable,
which defaults to meta-poky/conf
when you are building from the Yocto Project development
environment and defaults to meta/conf
when
you are building from the OpenEmbedded Core environment.
Because the script variable points to the source of the
bblayers.conf.sample
file, this implies that
you can base your build from any layer by setting the variable in
the top-level build environment setup script as follows:
TEMPLATECONF=your_layer
/conf
Once the build process gets the sample file, it uses
sed
to substitute final
${
OEROOT
}
values for all ##OEROOT##
values.
TEMPLATECONF
variable
scripts/oe-setup-builddir
script in the
Source Directory.
You can find the Yocto Project version of the
bblayers.conf.sample
file in the
meta-poky/conf
directory.