In order to root a new device, I try to follow the tutorial to port CWM for an unrooted device. When I do dump_image boot/sdcard/boot.img I got dump_image: permission denied. How can I resolve this? does it means I need to root it first before I can dump the boot image?

2 Answers 2


What is your final goal? You can try to root it using towelroot (its an apk that just roots the device). Or something else. Exploit roots are nice, as they are not changing your boot partition and let you clone the original one later on.

I never used the command you mentioned, i always used dd.

adb shell su dd if=/dev/block/platform/..../by-name/boot of=/data/local/tmp/oboot.img chmod 777 /data/local/tmp/oboot.img exit exit adb pull /data/local/tmp/oboot.img

There is another option: Download the official firmware from the net, unzip and untar it and you will have all your partition images ready. This is an example for Samsung devices: http://samsung-updates.com/

If you would tell us more about the device you are using, we could help you much better. (device name, hardware tag/number like gt-i9505, android and firmware version)

Good luck!

  • it require su, which I do not have. I order to have su, I need to root. In order to root, I need to port CWM to my new device. In order to port CWM I need to dump the boot.img. In order to dump or dd I need su .......
    – Wang
    Sep 10, 2014 at 20:30
  • @Wang i just edited the answer and added two new hints Sep 10, 2014 at 20:47
  • My device is not samsung. But I did manage to get a factory restore rom by contact the device provider. And extracted the boot.img from it. Thanks a lot! Now I am porting :D
    – Wang
    Sep 19, 2014 at 18:20

Just root your device and type su and but the dump_image binary to any of these /cache/create new folder,/data/create new folder,or /system/create new folder hope it helps.

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