# Setup build envoronment https://source.android.com/setup/build/initializing $ sudo apt install libssl-dev python3-setuptools # Download Android source https://github.com/android-rpi/local_manifests # Build Android Refer to http://source.android.com/source/building.html $ source build/envsetup.sh $ lunch rpi4-eng $ make ramdisk systemimage vendorimage Use -j[n] option with make, if build host has a good number of CPU cores. # Prepare sd card Partitions of the card should be set-up like followings. p1 128MB for boot : Do fdisk, set W95 FAT32(LBA) & Bootable type, mkfs.vfat p2 1024MB for /system : Do fdisk, new primary partition p3 128MB for /vendor : Do fdisk, new primary partition p4 remainings for /data : Do fdisk, mkfs.ext4 Set volume label of /data partition as userdata : use -L option for mkfs.ext4 # Write system & vendor partition $ cd out/target/product/rpi4 $ sudo dd if=system.img of=/dev/<p2> bs=1M $ sudo dd if=vendor.img of=/dev/<p3> bs=1M # Copy firmware & ramdisk to boot partition device/arpi/rpi4/boot/* to p1:/ out/target/product/rpi4/ramdisk.img to p1:/ # Download & Build kernel source https://github.com/android-rpi/kernel_manifest # Copy kernel binaries to boot partition <kernel directory>/out/arpi-5.15/dist/Image.gz to p1:/ <kernel directory>/out/arpi-5.15/dist/bcm2711-rpi-*.dtb to p1:/ <kernel directory>/out/arpi-5.15/dist/vc4-kms-v3d-pi4.dtbo to p1:/overlays/