If you like to mod your Nexus devices but you're also a fan of tight security, you probably already know BootUnlocker. It's a simple app that allows rooted devices to lock and unlock the bootloader without wiping user data. The developer, segv11, is back with v1.5.1 of this handy little utility. The latest update adds support for the WiFi (flo) and LTE (deb) variants of the 2013 Nexus 7 and the ability to set the tamper flag on the Nexus 4 (mako) and Nexus 5 (hammerhead).


Prior to this update, BootUnlocker supported every Nexus device since the Galaxy Nexus with the notable exception of both generations of the Nexus 7. It is known that the original Tegra-based version from 2012 will probably never be directly supported due to technical limitations, it's great to see the Qualcomm-based 2013 Nexus 7 variants joining the list.

A new feature to BootUnlocker is the ability to toggle the tamper flag. In a recent OTA, the Nexus 4 and Nexus 5 began setting this flag if the bootloader were unlocked and "tampered with." Just like locking and unlocking the bootloader, this is achieved by modifying a byte of data stored in the param or misc partition. While it's unlikely that Google or LG are denying warranty claims on these devices, it doesn't hurt to play it safe in the event you have to return a device for a physical defect.

BootLocker is freely available from the Play Store, just hit the widget below. You can also pick up the source code from Google Code if you're interested in seeing how it works. Happy flashing!

Source: XDA

Cody Toombs
Cody is a Software Engineer and Writer with a mildly overwhelming obsession with smartphones and the mobile world. If he’s been pulled away from the computer for any length of time, you might find him talking about cocktails and movies, sometimes resulting in the consumption of both.

  • SAI

    So does this mean I can unlock my N7 2013 and root it all without losing any of my data?

    • silver_arrow

      "... allows rooted devices to lock and unlock the bootloader without wiping user data"

      So it doesn't look like it.

      • SAI

        Must've missed that...oh well...thanks

    • Open1Your1Eyes0

      Root first, then unlock via this app.

    • http://www.androidpolice.com/author/cody-toombs/ Cody Toombs

      If a rooting method comes along that doesn't relay on having an unlocked bootloader, then you could do this. Otherwise, you have to first unlock, root, then re-lock with this app. It's not completely ideal, but you can use the backup utility in adb to save your data, then go through the rooting steps, and then restore your data.

    • asdfasdfasdf

      Actually, you might be able to use Cydia Impactor to root without loss of data and then unlock bootloader using this app. I'm not sure if cydia impactor works on kitkat, but it's worth a shot.

  • Spasillium

    Yay no more padlock icon that shows under Google (until a temp bootloader unlock that is)

  • duse

    Does the tamper flag need reset even if you flash the factory image before sending the device in for a warranty claim? Or does the factory image cover every last byte on the device, including the tamper flag? Just wondering if Google is trying to implement a permanent watermark of tampering, even if you factory restore it.

    • http://www.androidpolice.com/author/cody-toombs/ Cody Toombs

      I can't actually test it right now, but I'm almost positive the tamper flag persists through a full factory restore. We know that restoring a factory images does not inherently re-lock the device, and the tamper flag lives on the same partition as the lock flag, so it seems extremely likely that the tamper flag will be unaffected by a factory restore. Besides, the point of a tamper flag is only to show that a phone has been modified at some point in history, not to show that it has been returned to stock.

      • duse

        So if the tamper flag and unlock state both survive a restore, but if the bootloader is relockable by design but the tamper flag is not, then the tamper flag is meant to be a permanent watermark of modification. I wonder if Google has an issue with this app, or plans to make the tamper flag not so easily writable in the future. I love Google's policy of putting no obstacles in the way of getting full access to your device, I just wish they'd be more upfront about how it affects your warranty.

        • osm0sis

          Bingo! :)
          I was very pleased to be able to crack N7 2013 support for us all over the holidays here. Thanks for the link to my N7 2012 thread as well Cody.

          • http://www.androidpolice.com/author/cody-toombs/ Cody Toombs

            Thanks for the hard work!

    • Milind Shah

      No flashing the factory image doesn't make the tamper flag say untampered...you either have to use this app, or a script which sets it back to untampered... I had to RMA my device and I had to use the script before I sent it for replacement :-)

  • https://play.google.com/store/apps/developer?id=iWizard Bikram Agarwal

    I just found a good use of "Wishlist" in play store. Apps that I might find useful in future but not right now. "Add to wishlist". So, it acts like a bookmark, so that when I actually need it, I don't have to go all "What was the name of that app again...".

    • hh

      Isnt that the sole purpose of wishlists on any website?

      • https://play.google.com/store/apps/developer?id=iWizard Bikram Agarwal

        When "Wishlist" was introduced, users were expecting that we'll be able to keep track of those apps; like price drops, major updates etc. But turned out it didn't do any of that. So, I never used it. Until today as bookmark.

        • http://www.androidpolice.com/author/cody-toombs/ Cody Toombs

          There were also a lot of people expecting the wishlist feature would eventually allow other people to purchase apps for you as a gift, much like Amazon's wishlist. I'm not sure how much use it would have had outside of parents buying games for their kids, but it still seems like something that should have happened.

          • http://k3rnel.net Juan Rodriguez

            My fiancee is against putting her card data on Google, but I'd love to be able to either "gift her" apps, or money.
            Before you mention Play Store cards, they don't work in Mexico.