[Raspberry] 如何製作Raspberry Pi 4的Android Image

1. Android電腦架設

OS需安裝Ubuntu,CPU能力將決定build image的時間

https://source.android.com/setup/build/initializing

2. 下載Android source code

# repo init -u https://android.googlesource.com/platform/manifest -b android-12.1.0_r5

# git clone https://github.com/android-rpi/local_manifests .repo/local_manifests -b arpi-12

# repo sync

3. 上patch

https://github.com/android-rpi/device_arpi_rpi4/wiki/arpi-12-:-framework-patch

4.製作Android Image

# source build/envsetup.sh

# lunch rpi4-eng

# make -j 16 ramdisk systemimage vendorimage

(須等一段時間)

5. 編譯Android Kernel

# mkdir arpi-5.10

# cd arpi-5.10

# repo init -u https://github.com/android-rpi/kernel_manifest -b arpi-5.10

# repo sync

# build/build.sh

檔案會產生在out/arpi-5.10/dist/

需要的檔案為Image.gz, bcm2711-rpi-*.dtb 和 vc4-kms-v3d-pi4.dtbo

6. 插入記憶卡到電腦,用fdisk產生下列partition 

(假如記憶卡device node為sda)

# fdisk /dev/sda

  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, use -L option for mkfs.ext4

7. 處理記憶卡開機用partition

1) 格式化FAT32 partition

# mkfs.fat /dev/sda1

# mount /dev/sda1 /mnt

8. 拷貝需要的開機檔案

# cp device/arpi/rpi4/boot/* /mnt

# cp out/target/product/rpi4/ramdisk.img /mnt

# cp arpi-5.10/out/arpi-5.10/dist/Image.gz to /mnt

# cp arpi-5.10/out/arpi-5.10/dist/bcm2711-rpi-*.dtb /mnt

# cp arpi-5.10/out/arpi-5.10/dist/vc4-kms-v3d-pi4.dtbo /mnt/overlays/

9.更新system.img和vendor.img至記憶卡

# cd out/target/product/rpi4

# sudo dd if=system.img of=/dev/sda2 bs=1M

# sudo dd if=vendor.img of=/dev/sda3 bs=1M

10. 完成.  將記憶卡插入記憶卡開機