Android - How to re-lock Android bootloader?
You'll need to use fastboot
, which is provided in the CF-Auto-Root zip file, and also available standalone and packaged with lots of other software. It's part of the Android SDK Tools / Platform Tools, which can be installed on Windows, OSX, or Linux.
Note: If you've installed a custom ROM or kernel on top of rooting, you'll want to flash the necessary stock versions from the Nexus 5 stock image with fastboot or possibly through TWRP/ClockWorkMod Recovery.
In order to re-lock the bootloader:
- Reboot your phone to Bootloader Mode
- Connect the USB Cable to your computer.
- Open a Command Prompt (Terminal on Linux or OSX)
- Navigate to the
platform-tools
directory inside the unzipped CF-Auto-Root directory. Use the following command, depending on your OS.
- Linux:
./fastboot-linux oem lock
- OSX:
./fastboot-mac oem lock
- Windows:
fastboot-windows.exe oem lock
- Linux:
On a rooted device, you can use BootUnlocker to re-lock the bootloader without using fastboot. You can also use it to unlock the bootloader again without wiping data. I use it to keep my bootloader locked most of the time, but unlock it prior to installing a system update or doing anything else that might require re-rooting via fastboot flash.