TF101 Android: Image block device via adb

Question

I have an Asus TF101 tablet running Android ICS. I am trying to image the entire internal flash file system onto my desktop via adb. The problem is that the image I am obtaining appears to be corrupted:

On my desktop I am using Ubuntu 12.10:

adt-bundle-linux-x86-20131030/sdk/platform-tools/adb shell su -c "dd if=/dev/block/mmcblk0" | pv > mmcblk0.raw

I am then trying to use this image with:

testdisk mmcblk0.raw

Unfortunately testdisk finds only nonsensical partition data even using a deep search. Attempting to list any of the files contained in these admittedly non-sensical partition results in a corrupt filesystem error.

Even when trying to read out only a single partition, e.g.

adt-bundle-linux-x86-20131030/sdk/platform-tools/adb shell su -c "dd if=/dev/block/mmcblk0p7" | pv > mmcblk0p7.raw

the resulting partition image seems corrupted. Trying to mount via a loop device fails with corrupt filesystem errors. Running fsck on the image floods me with non-ending file-system errors.

Any hint on what I am doing wrong here?

Answer 1

I know this topic is old, but this could help someone: If you can install a modded recovery it would be very useful, dumping with system on is not always a good idea. Then try this:

adb shell "dd if=/dev/block/mmcblk0" | dd of=mmcblk0

The filesystem should be unmounted when executing a dump for best results.

Answer 2

For one thing, the shell on the Android side is converting LF to CR-LF -- hex 0A to 0D 0A. Various workarounds are to undo the change by streaming through sed or perl, processing the file after, or installing stty on the Android device and using stty raw as part of the adb shell command.

Answer 3

Must to use twin quotes. (With Gingerbread 2.3.4)

adb shell 'su -c "dd if=/dev/block/mmcblk0"' | dd of=data.raw