How to install a Boot-debuggable image

On this page, you can learn how to install a boot-debuggable image to get root access during startup time within the ADB developer tools.

Back to the downloads page

This process is for advanced users only. The boot-debuggable kernel is only meant for low-level development on the phone. If you just want to update your phone, please use the Standard Package instead. Be sure to backup all important data before you proceed!
  1. Download the boot-debuggable image to a new folder on your computer. In this example, I've named it "debug-image".
  2. Turn off your phone
  3. Press both the Power and Volume Up buttons at the same time1
  4. You'll should see "Fastboot mode" on the screen of your phone.
  5. On your computer, you'll need to have the "ADB and Fastboot" tools installed. Install these using the awesome guide from XDA Developers
  6. Once you have the fastboot tools installed, navigate to the "debug-image" folder. Open a Command Prompt (Windows) or Terminal (MacOS / Linux) in this folder
  7. Type the following in the prompt window:
    fastboot devices

    It should list your device. If it does not detect your device, make sure you have installed the appropriate "ADB drivers" for your device (Google should be your friend to get these)

  8. To begin installing the image (flashing), you'll need to unlock the device's bootloader. To do so, type the following command in the command prompt or terminal:
    fastboot oem unlock
  9. Confirm the operation. The phone will reboot now, but you'll need to turn it of and reboot it back into Fastboot Mode (see steps 2 and 3)
  10. Once back in fastboot mode, it's time to install the boot-deuggable image:

    Type the following command with the correct file name in the command prompt or terminal:

    fastboot flash boot <NAME_OF_THE_BOOT_DEBUGGABLE_IMAGE>.img
  11. If you are not going to make any unofficial modifications to your phone (such as rooting), it's time to re-lock the bootloader. This ensures all apps keep working (some apps refuse to work if the bootloader is unlocked)

    To re-lock the bootloader, type the following command in the command prompt or terminal:

    fastboot oem lock
  12. Finally, it's time to reboot your phone.

    To reboot your phone, type the following command in the command prompt or terminal:

    fastboot reboot
  13. Congratulations, your phone should now be running the boot-debuggable kernel software!
1 If you have a ZUK Z1, you'll need to press both the Power, Volume Down and Volume Up buttons to access Fastboot Mode.