What is bootloader
Bootloader is a piece of code that tells your Android device’s operating system how to boot up. It is usually locked because your manufacturer want you to stick to their Android OS version, which is specifically designed for your device. With the bootloader locked, you can’t customize your deice (e.g. flash a Custom ROM).
- Charge the battery minimum 30%.
- Back up your device.
- The most important: Android SDK must be installed on your computer.
Unlock your Bootloader
Warning: Unlocking bootloader voids your warranty. It also completely wipes (formats) your Android phone’s internal memory including applications, contacts, text messages, pictures and so on.
1. Enable USB debugging on your device. (Guide in here)
2. Connect your device to your computer via a USB cable. If you are the first time to do so, you will get a pop-up asking for permission.
3. Open the terminal on your computer (press Win+R, type cmd and hit Enter), change the folder to Platform Tools in the Android SDK. Typically, it looks something like this, but you have to find the exact path where you installed the Android SDK on your computer:
To change the folder path, you need to put “cd” in front of it, so the whole command would look like so:
cd C:/Android SDK/adt-bundle-windows-x86_64-20131030/sdk/platform-tools/
4. Then please type the following command line to boot the device into fastboot mode:
adb reboot bootloader
5. Once your device is in fastboot mode, type following command line:
6. Now you can see your device serial number. If you can’t see your serial number, and instead see “<waiting for device>”, install the “Android SDK.
7. Then type following command line and press Enter key:
fastboot oem unlock
8. A disclaimer will display on your device that must be accepted. Use the volume keys to choose the option “Yes”, and press power button to confirm selection.
9. If the device doesn’t automatically reboot, reboot it from the menu.
Congratulations, you device is now unlocked.
As Android is an open source OS and is available on many different hardware, every manufacturer has their own version of bootloader. Many of them provide methods to help you unlock the bootloader on their website.
- Motorola bootloader unlock program
- HTC unlock bootloader page
- Sony’s unlocking the bootloader instructions.
Some manufacturers and carriers don’t allow bootloader unlocking, but you can often find a way around that in the XDA Developers forum.