I have two identical phones. On one of them I've managed to corrupt the system partition and it won't boot. I have fastboot, root (on the one that boots), but I don't have ClockworkMod --- my phone isn't supported. Instead I have the world's most unhelpful vendor recovery, which supports update.zip and nothing else.

I'm trying to copy the system partition from the working phone to the non-working one via fastboot. But I cannot successfully reflash the partition. I always get a failure, and the only message is 'flash write failure'. I've tried erasing it first.

My suspicion is that I'm somehow not taking the image from the working phone correctly and the OOB data is incorrect.

I'm using busybox's nanddump to do this:

nanddump -f /sdcard/backup/mtd7 /dev/mtd/mtd7

Is this correct? The resulting image is larger than an image taken with dd, so it does appear to contain the OOB data, but fastboot won't flash it. Does fastboot require images in some exotic format?

  • Out of curiosity, how much RAM is in the non-booting device and how big is the system image you get from nanddump? I know on the Kindle Fire, for instance, flashing the system partition can be problematic because an image pulled by hand is too big to fit in RAM, so fastboot balks when you try to flash it (no idea if that's the case here, just a shot in the dark). Apr 4, 2012 at 13:39
  • ...good question. MemTotal from /proc/cpuinfo shows 152784kB, and the flash image is 129MB, so it could be running out of memory. OTOH the minimal diagnostics I'm getting say that it is transferring correctly, and is only failing when it tries to write it. Apr 4, 2012 at 13:46
  • What device do you have? Apr 4, 2012 at 19:37
  • One of these: flickr.com/photos/elurstoidi/4626364634/in/… The actual model reported varies depending where you look. I think it's vaguely Z71ish inside. If I want ClockworkMod, I'd have to port it myself! Apr 4, 2012 at 21:51

2 Answers 2


Take the image of the phone that's working by the following code

  • First find out the dev block of the system partition

cat /proc/mounts

  • Search for the system partitions and note down the corresponding /dev/block/ partition
  • For example for my phone it is /dev/block/mmcblk0p12

  • Now make the exact copy of the partition using dd command

dd if=/dev/block/***** of=/sdcard/system.img

  • Copy this system.img from your phone to PC
  • Connect your other phone in fastboot mode
  • Run the following command

fastboot flash system <path-to-system.img>


Depending on the device you have, the android version it runs and the phones manufacturer, you may not be able to do what you want. Copying the /system partition is unlikely to work anyhow as your working device has assigned the ESN to the crucial system files already and it may not be allowed to flash because of dmverity checking. Your best bet is to find a stock image of the devices ROM and use your manufacturers flashing program (ie.. Samsung uses Odin, Sony has their program, etc...), or dump an OTA update.zip and flash that in your stock recovery.

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