26-07-2017, 02:47 PM
Unlike in some other devices, you don't necessarily need to unlock the bootloader to flash a custom ROM to your Mediatek (MTK), Spreadtrum (SPD) Android phone. You don't even need bootloader (fastboot) to flash a custom recovery since Mediatek has SP Flash tool and Spreadtrum has Research / Upgrade download tool amidst several Chinese boxes. There are however certain scenarios where fastboot is the only feasible way to get a custom recovery loaded to your device from which you can then root, backup or install a custom ROM. This guide will explain how to unlock the Bootloader on a Mediatek (MTK), Spreadtrum (SPD) or Qualcomm (QLM) Android phone, an important prerequisite for flashing a custom recovery via fastboot.
Requirements
- Setup ADB-Fastboot on your PC. For Spreadtrum devices, follow this guide (in order to enable adb detect your device)
- Enable USB Debugging and OEM Unlocking (if available)
How to unlock a Mediatek, Spreadtrum or Qualcomm Android phone's Bootloader via fastboot
Follow the steps below to unlock the Bootloader of an Android device
See the video tutorial below or @ https://youtu.be/DL5NMR-n4_Q- Open the adb folder
- Hold Shift (on the keyboard) then right-click on a blank space in the folder > Select Open Command window here
- Command prompt screen (adb) should now be open
- Connect the phone to PC (via USB cord) while ON then run the command below (by "run", I mean type then press Enter
Code:adb devices
- If you've setup everything right, the device should get detected under List of devices attached
- Run the command below to get the phone into Bootloader (fastboot)
Code:adb reboot-bootloader
if that fails
Code:adb shell reboot fastboot
- The phone should now boot into fastboot
- In fastboot, test detection / connection to the device using
Code:fastboot devices
- If fastboot is set up right, you should see its ID printed out
- Now, check the phone's Bootloader status using either of the two commands below (if its locked or unlocked)
Code:fastboot oem device-info
fastboot getvar unlocked
- If you use the fastboot oem device-info command and the result is false then your bootloader is locked but if the result is true then the bootloader is unlocked
- If you use the fastboot getvar unlocked command and the result is no then your bootloader is locked but if the result is yes then the bootloader is unlocked
- If you use the fastboot oem device-info command and the result is false then your bootloader is locked but if the result is true then the bootloader is unlocked
- If you've confirmed your bootloader is locked, then run the command below to unlock Bootloader
Code:fastboot oem unlock
- If that doesn't work then try either of the two commands below
Code:fastboot oem unlock-go
fastboot flashing unlock
fastboot flash unlocking
fastboot bbk unlock_vivo
- Note that some devices require you to also run
Code:fastboot flashing unlock_critical
- You should get a prompt (on the phone) asking you to press Volume up to confirm or Volume down to cancel. Press Volume up on the phone (for some phones its actually the opposite; Volume down would confirm while up would cancel or do nothing)
- Once Bootloader is unlocked, reboot the phone using
Code:fastboot reboot
- The phone might take a while to boot up (since its a first boot) so be patient
Important Notice
- This guide isn't guaranteed to work on all (Mediatek, Spreadtrum, Qualcomm, Exynos, Hisilicon, Intel etc) Android phones
- Ensure to backup your important stuff because unlocking your Bootloader wipes your phone's data (/userdata)
- Unlocking the bootloader bricks some devices so ensure to relock or flash the firmware if you find yourself in such a situation
- If you successfully installed ADB / fastboot and your device still isn't detect then its most likely due to old ADB, fix it using the guide here
Note!
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