[HOWTO] Flashing ‘yakju’ firmware image on Galaxy Nexus (maguro) shipped with ‘yakjuxw’ firmware

UPDATE: Got the OTA of Android 4.1.1 on my Galaxy Nexus. Had an issue because of which the update failed initially. Head over to this post to find out more.

I bought a Samsung Galaxy Nexus over at eBay a month back (Check out my un-boxing and first impression post and video here https://atlocalhost.wordpress.com/2012/04/27/google-samsung-galaxy-nexus-unboxing/). By then Google had already rolled out the 4.0.4 version of Android and I still hadn’t got the OTA update. I checked online and figured that only the products with firmware ‘yakju’ would get the updates directly from Google.

Galaxy Nexus phones loaded with other firmwares (such as mine `yakjuxw’) are localized for specific countries and would get the updates directly from Samsung after they are verified. I then looked around on the web and figured that to get Android 4.0.4 right away, I had to flash the `yakju’ firmware manually and be able to get future updates instantly. Thus I compiled this post after I successfully updated my Galaxy Nexus with the `yakju’ firmware, to list out the steps I followed in the process, so that anyone else owning a Galaxy Nexus with `yakjuxw’ or similar firmwares might find it helpful.

WARNING: The following procedure will involve unlocking the boot loader. This will result in complete loss of data, hence I suggest that a backup of the existing data be made before proceeding further. This procedure may not void the warranty of the phone, however if anything goes wrong I may not be held responsible. Please proceed at your own risk. 🙂

Download the necessary files:

Extract all the files downloaded into one directory (C:\galaxy_nexus_404). Note that the image file downloaded is of type tgz. You could use 7-zip to extract all the files. Once the content is extracted, a file by name `image-yakju-imm76d.zip’ is found. Extract the contents of this zip file into the same directory. Once this is done, the directory should contain files shown in the picture below.

Follow the steps below to unlock the boot loader:

  • Reboot the phone into boot loader mode. To do this, first power off the phone and then hold the Volume Up and Volume Down keys simultaneously and press the power button until the phone boots up into boot loader mode.

  • Take a note of the bottom most line which should say “LOCK STATE – LOCKED”. This indicates that the boot loader locked. We will have to unlock the boot loader to proceed further. To do this, first connect the phone through USB and wait for Windows to finish installing the drivers. If the installation fails, point windows to the location where the driver files were downloaded above. (My Computer (Right Click) -> Manage -> Device Manager; right click on the device and select `Update Driver Software’, then follow the prompts to install the downloaded drivers). If all has gone well, Device Manager should show the phone as Galaxy Nexus.

  • Now open a command window (Start -> Run -> type `cmd’ or Windows Key + R and type `cmd’) and cd to the directory create above.

    cd \
    cd galaxy_nexus_404

    Verify if the device is connected properly by typing the following command.

    fastboot devices

    Now unlock the boot loader by typing the following command. (Note that this will completely wipe all the data on your phone. Make sure to have taken backup of any important data). Answer `Yes’ to the prompt on the phone screen.

    fastboot oem unlock

    Now reboot the boot loader

    fastboot reboot-bootloader

Flash the `yakju’ firmware:

  • Once the phone has rebooted back into the boot loader mode, verify that the connection is intact and execute the following commands in the same command windows opened above at the same location in the given order.

    fastboot flash system system.img
    fastboot flash userdata userdata.img
    fastboot flash boot boot.img
    fastboot flash recovery recovery.img
    fastboot erase cache
  • Optionally you could also try to lock the boot loader back. This isn’t mandatory but it is safe to do so.

    fastboot oem lock
  • Finally, reboot your phone.

    fastboot reboot

The first time the phone boots, it takes a few seconds longer as the Dalvik cache has to be rebuilt. Once that’s done, your Nexus should be running with the new firmware. Hope this post is informative enough.


UPDATE: I have heard that flashing the `yakju’ firmware using the procedure above causes problems while installing the Jelly Bean update. I found this xda-developers thread http://forum.xda-developers.com/showpost.php?p=28690833&postcount=1522 which says that flashing the phone with the latest radio solves the problem. The radio file can be downloaded from here: http://forum.xda-developers.com/showpost.php?p=20569003&postcount=2. Thanks everyone for the comments to point that out.

DISCLAIMER: This post is inspired by various other bloggers and special thanks to members of the xda-developers. I made a few changes here and there which I find to be more convenient. I take no credit for discovering the original procedure intended for the purpose.



  1. Thank you. Finally a guide that just worked.

    1. Worked like a charm. Thanks

      1. Hello. After doing this I received 4.1 OTA update but won’t install corectly. I goes about a quarter of progress bar and after that it shows android logo with a red triangle. What is the problem?

      2. The reason the OTA 4.1 update didn’t work is because this guide forgot to flash the updated radio.
        refer to this site; http://forum.xda-developers.com/showthread.php?p=28692651

  2. TheGreatStatic · · Reply

    This worked perfectly. Thanks for the guide.

  3. I used this method and installed takju instead of yakju, the advantage is that takju includes the updated radio XXLF1 and did not have to flash it.
    I like this method as it does not use CWM at all.

  4. Hi!

    I got this error, what happend and how to solve it?

    C:\Android>fastboot flash system system.img
    erasing ‘system’…
    OKAY [ 0.117s]
    sending ‘system’ (425775 KB)…
    FAILED (remote: Exceed Buffer Size (0x16400000))
    finished. total time: 0.134s

    Thanks in advance

    1. I haven’t seen that error before. I have to check on this. Will get back to you when I find something.

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