The files in these directories are meant to be used as a base for an Android kernel config. All devices must have the options in
android-base.cfg configured as specified. If an
android-base-ARCH.cfg file exists for the architecture of your device, the options in that file must be configured as specified also.
While not mandatory, the options in
android-recommended.cfg enable advanced Android features.
Assuming you already have a minimalist defconfig for your device, a possible way to enable these options would be to use the
merge_config.sh script in the kernel tree. From the root of the kernel tree:
ARCH=<arch> scripts/kconfig/merge_config.sh <...>/<device>_defconfig <...>/android-base.cfg <...>/android-base-<arch>.cfg <...>/android-recommended.cfg
This will generate a
.config that can then be used to save a new defconfig or compile a new kernel with Android features enabled.
Because there is no tool to consistently generate these config fragments, lets keep them alphabetically sorted instead of random.