Android 9.0.0 Release 2 (PPR1.180610.010)
Snap for 4824048 from f65b344e69ebe936d3148cfb56d446e35e4dce17 to pi-release Change-Id: I8089863ff5918373a83315367a16a0095f49f6f3
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.