eMMC binaries
This is the efi partition table as exists on the emmc
Sector# Size Name
256 128K xloader
512 256K bootloader
2048 8M recovery
18432 8M boot
34816 512M system
1083392 256M cache
1607680 512M userdata
2656256 2183M media
[edit] Creating the GPT table
On Target
- Connect a USB cable to the OTG port on your platform
- Boot your platform up with a stock u-boot and MLO
- Once you platform is booted you will see the following:
Fastboot entered...
On Host Machine
locate fastboot in you android filesystem
cd $mydroid/out/host/linux-x86/bin/fastboot
Search for fastboot devices
fastboot devices
Create GPT table on eMMC/SD card
fastboot oem format
From the android build these are the binaries that go into each partition:
Sector# Size Name Binary
256 128K xloader MLO
512 256K bootloader u-boot.bin
2048 8M recovery recovery.img
18432 8M boot boot.img
34816 512M system system.img
1083392 256M cache cache.img
1607680 512M userdata userdata.img
2656256 2183M media none
File locations
- MLO --> x-loader/MLO
- u-boot --> u-boot/u-boot.bin
- boot.img --> need to create using zImage + ramdisk.img
- recovery.img ---> need to create using zImage + ramdisk-recovery.img
- system.img --> $mydroid/out/target/product/<platform>/system.img
- cache.img -->
- userdata.img --> $mydroid/out/target/product/<platform>/userdata.img
All these partitions can be flashed with the given binary using fastboot.
fastboot flash <name> <binary>
Example flashing of all partitions
fastboot flash xloader MLO
fastboot flash bootloader u-boot.bin
fastboot flash recovery recovery.img
fastboot flash boot boot.img
fastboot flash system system.img
fastboot flash cache cache.img
fastboot flash userdata userdata.img
[edit] Modifying .IMG Files
Typically when you want to modify any of the partitions,you would need to unzip-modify-rezip and then fastboot flash.
Following section talks about how to do that for each partition
BOOT.IMG
boot.img = zImage + ramdisk.img
zImage = kernel image
ramdisk.img = out/target/product/blaze/root/
%./out/host/linux-x86/bin/mkbootimg
--kernel zImage
--ramdisk ramdisk.img
--base 0x80000000
--cmdline "console=ttyO2,115200n8 mem=456M@0x80000000 mem=512M@0xA0000000 init=/init vram=10M omapfb.vram=0:4M androidboot.console=ttyO2"
--board omap4
-o boot.img.new
Output: boot.img.new
**Note: bootarg is passed to kernel via --cmdline option above
**Note：For Pandaboard ES,--cmdline should be mmodified as "console=ttyO2,115200n8 mem=456M@0x80000000 mem=512M@0xA0000000 init=/init vram=32M omapfb.vram=0:16M androidboot.console=ttyO2"
To "just" boot boot.img (before flashing) you can use:
%fastboot boot boot.img
RAMDISK.IMG
%mkdir root
%cd root
%gunzip -c ../ramdisk.img | cpio -i
<make changes to root/ contents...>
%./out/host/linux-x86/bin/mkbootfs root/ | ./out/host/linux-x86/bin/minigzip >ramdisk.img.new
#output: ramdisk.img.new
** Note: any init.rc changes will need to use this method
RECOVERY.IMG
Is just like boot.img.
recovery.img = zImage + ramdisk-recovery.img
*Follow the same steps as boot.img for packing/unpacking
SYSTEM.IMG
#uncompress
%./out/host/linux-x86/bin/simg2img system.img system.img.raw
#mount to directory mnt-point/
%mkdir mnt-point
%sudo mount -t ext4 -o loop system.img.raw mnt-point/
#modify any .so or apk in the mnt-point/ directory
#rezip
(till Android-L) %sudo out/host/linux-x86/bin/make_ext4fs -s -l 512M -a system system.img.new mnt-point/
(from Android-M) %sudo out/host/linux-x86/bin/make_ext4fs -s -T -1 -S file_contexts -L system -l 512M -a system system.img.new mnt-point/
%sudo umount mnt-point/
Output: system.img.new
Instead of having to reflash the whole big system.img, one can selective update any binary in /system folder on running target
%adb remount
%adb push <local> <remote>
Eg:
%adb remount
%adb push out/target/product/blaze/obj/lib/overlay.omap4.so /system/lib/hw/overlay.omap4.so
%adb sync
USERDATA.IMG
#uncompress
%./out/host/linux-x86/bin/simg2img userdata.img userdata.img.raw
#mount to directory mnt-point/
%mkdir mnt-point
%sudo mount -t ext4 -o loop userdata.img.raw mnt-point/
#modify any .so or apk in the mnt-point/ directory
#rezip
#%sudo ./out/host/linux-x86/bin/make_ext4fs -s -l 512M -a userdata userdata.img.new mnt-point/
# Above command won't work on GB/HC. For GB/HC, please use the following updated command
%sudo ./out/host/linux-x86/bin/make_ext4fs -s -l 512M -a data userdata.img.new mnt-point/
%sudo umount mnt-point/
Output: userdata.img.new
CACHE.IMG
#This is empty ext4 fs image
%mkdir mnt-point/
%sudo ./make_ext4fs -s -l 256M -a cache cache.img mnt-point/
Output: cache.img
[edit] TI Android build setup
Copy kernel zImage, u-boot.bin and MLO for your board in folder device/ti/blaze/boot/.
Rename as:
%mv MLO MLO_es2.2_emu
or
%mv MLO MLO_es2.2_gp
(based on your board being GP or EMU)
Next start standard android build and all img files are generated in:
out/target/product/blaze/*.img
A script is introduced in TI Android release to make this flashing process easier: device/ti/blaze/boot/fastboot.sh
Usage:
cd device/ti/blaze/boot/
%fastboot.sh --emu
or
%fastboot.sh --gp
Running this script will flash whole android system on your board.
