User:Arete74/Boot Android from SdCard

Boot Android From SdCard

For extract need file from android image , have need of awutils and android tools.

  $ git clone https://github.com/Ithamar/awutils.git
  $ make

Extract file from Android Image

In this guide the name the Android Image is android.img

  $ awimage -u android.img

this command create an folder android.dump with many files. The three following files are the ones we are interested :

RFSFAT16_BOOT_00000000000 (the boot partition)

RFSFAT16_RECOVERY_0000000 (the recovery partition)

RFSFAT16_SYSTEM_000000000 (the system partition, ext4 sparse).

for simplicity rename:

  $ mv RFSFAT16_BOOT_00000000000 boot.img
  $ mv RFSFAT16_RECOVERY_0000000 recovery.img
  $ mv RFSFAT16_SYSTEM_000000000 system.img

Extract kernel and ramdisk

For extract kernel and boot ramdisk try this command:

  $ ../tools/split_bootimg.pl boot.img
  Page size: 2048 (0x00000800)
  Kernel size: 4215036 (0x004050fc)
  Ramdisk size: 974998 (0x000ee096)
  Second size: 0 (0x00000000)
  Board name:
  Command line: console=ttyS0,115200 rw init=/init loglevel=5
  Writing boot.img-kernel ... complete.
  Writing boot.img-ramdisk.gz ... complete.

decompress the ramdisk data

  $ mkdir boot
  $ cd boot 
  $ gunzip -c ../boot.img-ramdisk.gz | cpio -i
  $ tar -cpvf ../boot.tar *

Convert kernel to uImage

  $ mkimage -A arm -O linux -T kernel  -a 0x40008000 -e 0x40008000 -n "Linux 2.6" -d boot.img-kernel uImage

Extract system image

  $ ../tools/simg2img system.img system1.img
  $ mkdir system
  $ sudo mount -o loop system1.img system
  $ cd system
  $ tar -cpvf ../system.tar *
  $ cd ..
  $ umount system

Extract recovery image

   $ ../tools/split_bootimg.pl recovery.img
  Page size: 2048 (0x00000800)
  Kernel size: 4215036 (0x004050fc)
  Ramdisk size: 974998 (0x000ee096)
  Second size: 0 (0x00000000)
  Board name:
  Command line: console=ttyS0,115200 rw init=/init loglevel=5
  Writing recovery.img-kernel ... complete.
  Writing recovery.img-ramdisk.gz ... complete.

decompress the ramdisk data

  $ mkdir recovery
  $ cd recovery
  $ gunzip -c ../recovery.img-ramdisk.gz | cpio -i
  $ tar -cpvf ../recovery.tar *

SdCard Partition

Partitions description:

partition	Size	Name	Fs	Description
/dev/sdc1	16MiB	bootloader	VFAT	Files to assist the bootloader.
/dev/sdc2	36MiB	boot	EXT4	ramdisk
/dev/sdc3	500 MiB	system	EXT4	Android's /system partition
/dev/sdc4	Fill all space	extend	Extend Partition
/dev/sdc5	300MiB	data	EXT4
/dev/sdc6	16 MiB	misc	EXT4
/dev/sdc7	36 Mib	recovery	EXT4	Android's recovery partition
/dev/sdc8	125 MiB	cache	EXT4
/dev/sdc9	16 MiB	private	EXT4
/dev/sdc10	1-2 GiB	UDISK	VFAT

First identify the device of the card and export it as $card.

  $ card=/dev/sdc

  $ dd if=/dev/zero of=$card bs=1M count=1
  $ sfdisk -R $card
  $ cat <<EOT | sfdisk --in-order -uM $card
  1,16,c
  ,36,83
  ,63,83
  ,,5
  ,300,83
  ,16,83
  ,36,83
  ,125,83
  ,16,83
  ,,83
  EOT

Format

  $ mkfs.vfat -n bootloader /dev/sdc1
  $ mkfs.ext4 -L boot /dev/sdc2
  $ mkfs.ext4 -L system  /dev/sdc3
  $ mkfs.ext4 -L data  /dev/sdc5
  $ mkfs.ext4 -L misc  /dev/sdc6
  $ mkfs.ext4 -L recovery  /dev/sdc7
  $ mkfs.ext4 -L cache  /dev/sdc8
  $ mkfs.ext4 -L private  /dev/sdc9
  $ mkfs.vfat -n UDISK  /dev/sdc10

remove huge_file option from EXT4 fs (android kernel not have this option!!!)

  $ tune2fs -O ^huge_file /dev/sdc2
  $ tune2fs -O ^huge_file /dev/sdc3
  $ tune2fs -O ^huge_file /dev/sdc5
  $ tune2fs -O ^huge_file /dev/sdc6
  $ tune2fs -O ^huge_file /dev/sdc7
  $ tune2fs -O ^huge_file /dev/sdc8
  $ tune2fs -O ^huge_file /dev/sdc9

BootLoader

  $ dd if=spl/sunxi-spl.bin of=$card bs=1024 seek=8
  $ dd if=u-boot.bin of=$card bs=1024 seek=32

Copy File

Copy file to bootloader partition

  $ mount ${card}1 /mnt/
  $ cp uImage  /mnt
  $ cp script.bin /mnt
  $ cat >/mnt/uEnv.txt << EOT
  fexfile=script.bin
  kernel=uImage
  extraargs=root=/dev/mmcblk0p2 loglevel=8 rootwait console=ttyS0,115200 rw init=/init mac_addr=00:AE:99:A3:E4:AF
  boot_mmc=fatload mmc 0 0x43000000 ${fexfile}; fatload mmc 0 0x48000000 ${kernel}; bootm 0x48000000
  EOT
  $ umount /mnt

Copy data to ramdisk partition

  $ mount ${card}2 /mnt
  $ tar -xpvf boot.tar -C /mnt

Modify the name partition in init.sun4i.rc

  $ sed -i "s/nandd/mmcblk0p3/g"  /mnt/init.sun4i.rc
  $ sed -i "s/nande/mmcblk0p5/g"  /mnt/init.sun4i.rc
  $ sed -i "s/nandh/mmcblk0p8/g"  /mnt/init.sun4i.rc
  $ sed -i "s/nandi/mmcblk0p10/g" /mnt/init.sun4i.rc
  $ umount /mnt

Copy data to system partition

  $ mount ${card}3 /mnt
  $ tar -xpvf system.tar -C /mnt
  $ umount /mnt

Now you can boot Android from sd card