Builds as 64bit only so make sure you have propper firmware! # sync omni source Refer to http://source.android.com/source/downloading.html Refer to https://github.com/omnirom/android $ repo init -u git://github.com/omnirom/android.git -b android-11 copy https://github.com/maxwen/android_device_brcm_rpi4/blob/android-11/repo/local_manifest.xml .repo/local_manifests/ If you are not building based on omni to use roomservice check local_manifest_full.xml If you want to use the contents of omni-private.xml please check https://github.com/omnirom/android/README and head over to send us a short email notice. Otherwise you can simple remove the include of that xml file and build without $ repo sync # Build Android source Refer to http://source.android.com/source/building.html # prepare environment $ export ROM_BUILDTYPE=MICROG $ export TEMPORARY_DISABLE_PATH_RESTRICTIONS=true $ export ALLOW_MISSING_DEPENDENCIES=true $ export PRODUCT_EXCLUDE_EXTRA_PACKAGES=true $ source build/envsetup.sh $ lunch omni_rpi4-userdebug # build Use -j[n] option with make, if build host has a good number of CPU cores. # prepare boot device (sdcard or USB device) Devices with GPT partition table cant be used as an USB boot device You must use MBR (msdos) parition table The boot devices MUST contain 4 partitions with the following layout (parition sizes here are the minimum - userdata should be made bigger if you have the space) Device Start End Sectors Size Id Type boot 2 262145 262144 128M c W95 FAT32 (LBA) system 264192 4458495 4194304 2G 83 Linux vendor 4458496 4982783 524288 256M 83 Linux userdata 4982784 16777215 11794432 5.6G 83 Linux THE PARTITION ORDER MUST BE LIKE THIS Starting with android-11 project quotas are mandatory in userdata parition. Prebuilt images have it enabled but if you recreate your userdata you MUST enable project quotas with e.g. tune2fs -O project,quota <userdata partition device> # boot order Switching between booting from sdcard and USB is done in config.txt by enabling the needed overlay ... # booting from sdcard dtoverlay=rpi-android-sdcard # booting from usb dtoverlay=rpi-android-usb .... You can still mess with the fstab if you want and dont use the overlay Note the files in scripts are what I use to create and update feel free to adjust and update to your needs if you want # flash to boot device with e.g. dd