How to mount the android img file under linux? [closed]

Question

Recently, I'm interest in the android rom, I want to change and rebuild them.
So, I did some test on my XOOM, it's very easy to flash something into the machine.
I got some ROM from MOTOROLA (http://developer.motorola.com/products/software/), they are some img file, and I want to know what's inside, I hope to unpack them.

I tried the unyaffs, it said broken img file.
I try to mount them, it works great on the system.img, and I can get the file inside.

When I want to mount userdata.img by mount -o loop userdata.img /mnt/userdata (the same as system.img), it tells me mount: you must specify the filesystem type so I try the mount -t ext2 -o loop userdata.img /mnt/userdata, it said mount: wrong fs type, bad option, bad superblock on...

So, how to get the file from the inside of userdata.img?

Answer 1

See the answer at: http://omappedia.org/wiki/Android_eMMC_Booting#Modifying_.IMG_Files

First you need to "uncompress" userdata.img with simg2img, then you can mount it via the loop device.

Answer 2

I have found a simple solution: http://andwise.net/?p=403

Quote

(with slight adjustments for better readability)

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This is for all who want to unpack and modify the original system.img that you can flash using recovery. system.img (which you get from the google factory images for example) represents a sparse ext4 loop mounted file system. It is mounted into /system of your device. Note that this tutorial is for ext4 file system. You may have system image which is yaffs2, for example.

The way it is mounted on Galaxy Nexus:

/dev/block/platform/omap/omap_hsmmc.0/by-name/system /system ext4 ro,relatime,barrier=1,data=ordered 0 0 

Prerequisites:

• Linux box or virtual machine
• simg2img and make_ext4fs binaries, which can be downloaded from the linux package android-tools-fsutils

Procedure:

Place your system.img and the 2 binaries in one directory, and make sure the binaries have exec permission.

Part 1 – mount the file-system

mkdir sys ./simg2img system.img sys.raw sudo mount -t ext4 -o loop sys.raw sys/ 

Then you have your system partition mounted in ‘sys/’ and you can modify whatever you want in ‘sys/’. For example de-odex apks and framework jars.

Part 2 – create a new flashable system image

sudo ./make_ext4fs -s -l 512M -a system new.img sys/ sudo umount sys rm -fr sys 

Now you can simply type:

fastboot flash system new.img 

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