Warning ⚠️
I)DO NOT DOWNDRADE TO OxygenOS 13 AFTER UNLOCKING BOOTLOADER
II)BEFORE LOCKING BOOTLOADER MAKE SURE TO UNROOT IT
Items Required:
- Working Brain
- PC/Laptop with Platform tools, ADB and Fastboot Drivers
- Device with OOS 14 or above(Only if Bootloader is available in above updates)
On to the steps:
- Make sure to backup your file (use PC/ SDcard/ Google backup/Swift Backupor whatever you wish) as unlocking or locking will erase internal storage.
- Enable the 'USB-debugging' and 'Allow Bootloader Unlock' options from the Developers option in additional settings and connect the device to the PC with USB.Info! To enable the developer option, open settings>about phone>version> tap version no. 7-8 times.
- Download latest SDK-Platform-tools and extract it in PC. Now open the extracted folder and open an elevated cmd/powershell window here using shift + right click>Open in the terminal.
- Use the command in the terminal
If a pop-up appears on the phone, then click on allow.adb devices
Again, use the same command you should see serial number of your device. This means the device is connected to the ADB interface successfully. - Now follow the below commands:
adb reboot bootloader
Extra! You can also enter Bootloader/Fastboot Mode by pressing and holding all keys: volume +, volume - & power button.
To check that the device is connected, it will show its serial no.fastboot devices
To unlock bootloaderfastboot flashing unlock
OR
To lock bootloaderfastboot flashing lock
Info! Two options will appear on the phone to unlock/lock or not Using the volume keys, select Unlock/Lock and press the power button to confirm.
To reboot devicefastboot reboot
Extra! I) You may need these while relocking.
II) To check current slot- fastboot getvar current-slot
III) To change slots- fastboot --set-active=a write b in place of a if you want to flash in b slot instead of a. - Done
Success!
Enjoy bootloader will unlock now.
Video Tutorial for unlocking
Video Tutorial for locking
Credit: NordCE3 Community
Pranish