You can find these files in the BSP Layer at:
meta-bsp_root_name
/recipes-bsp/*
This optional directory contains miscellaneous recipe
files for the BSP.
Most notably would be the formfactor files.
For example, in the Raspberry Pi BSP there is the
formfactor_0.0.bbappend
file,
which is an append file used to augment the recipe
that starts the build.
Furthermore, there are machine-specific settings used
during the build that are defined by the
machconfig
file further down in
the directory.
Here is the machconfig
file for
the Raspberry Pi BSP:
HAVE_TOUCHSCREEN=0 HAVE_KEYBOARD=1 DISPLAY_CAN_ROTATE=0 DISPLAY_ORIENTATION=0 DISPLAY_DPI=133
If a BSP does not have a formfactor entry, defaults
are established according to the formfactor
configuration file that is installed by the main
formfactor recipe
meta/recipes-bsp/formfactor/formfactor_0.0.bb
,
which is found in the
Source Directory.