Tutorial #18: Unlocking the bootloader on Redmi Note 3

As I had mentioned in my review of the Redmi Note 3, it was good value for money. However, MIUI proved to be a hindrance for the target user because of which I had switched the device to LineageOS while not rooting it and keeping the bootloader locked. However, with the phone now back in my hands, it was time to break the shackles for good.

To Xiaomi's credit, they have an official process in place for unlocking the bootloader. However, it has its quirks and more often than not following the official guide results in the process being stuck at 50% due to incompatibilities. This was the case with my first attempt and hence I decided to proceed with it unofficially.

As always, I headed to XDA to quickly gather the process for this device. However, the process seems to be a bit outdated and perhaps a bit difficult to follow for the uninitiated, so I have listed the steps undertaken by me. There could be other ROM versions or files you can use but I have mainly picked up the ones from the XDA thread linked above which you might visit in case you need visual reference.

Note: Prior to starting with the flashing process or even after flashing the MIUI ROM in Step 4, make sure you have the 'OEM unlocking' option selected under Developer Options, without which the fastboot unlocking will fail.

Step 1: Download and extract/install the following:
1. MIUI Global ROM v7.2.5.0 (You will have to extract the file twice to get the folder contents)
2. Mi Flash Tool (Official MI tool to flash ROMs - used v2017.7.20.0 at the time of writing)
3. Unlocked emmc_appsboot file (Primary file needed to unlock bootloader)
4. EDL Fastboot (To enter emergency download mode)
5. Minimal ADB and Fastboot (Installs necessary ADB and fastboot drivers)
5. TWRP Recovery (Gateway to flashing anything on the device)

Step 2:
Browse to the 'images' folder within the extract ROM folder (kenzo_global_images_V7.2.5.0.LHOMIDA_20160129.0000.14_5.1_global) and replace the emmc_appsboot.mbn file in that folder with the downloaded one.


Step 3:
After installing the Minimal ADB and Fastboot drivers, connect the phone and run 'edl.cmd' from within the extracted 'fastboot_edl' folder to boot the phone to the emergency download (EDL) mode. If you don't, then the Mi Flash tool may give a 'tz error'. This mode can be recognised by the flashing red LED on the device.


Step 4:
Run the Mi Flash tool using 'XiaoMiFlash.exe' and select the folder containing the extracted ROM files (kenzo_global_images_V7.2.5.0.LHOMIDA_20160129.0000.14_5.1_global). Clicking on 'Refresh' should list the device and then subsequently, click on 'Flash'. The process will take 4-5 minutes to complete after which you will be able to see the 'success' status.

Step 5:
Boot the phone to the normal fastboot mode using the Volume Down + Power button. Open a command prompt window and browse to the 'Minimal ADB and Fastboot' folder. Here, execute the following command:
fastboot oem device-info
It should indicate 'Device unlocked: false', following which execute the command:
fastboot oem unlock-go
Running the 'fastboot oem device-info' command once again should now indicate 'Device unlocked: true'. That's it, your device now has an unlocked bootloader.

Step 6:
While not part of the bootloader unlocking process, a follow-up step should be to flash the TWRP recovery which opens a whole window of opportunities. This can be done by copying the 'twrp-3.1.1-0-kenzo' (latest file at the time of writing) to the 'Minimal ADB and Fastboot' folder and running the following command from the cmd window:
fastboot flash recovery twrp-3.1.1-0-kenzo.img
Following this, you will have complete freedom to tinker with the device in any way you deem apt. Oreo, anyone?

5 comments:

Unknown said...

Hey, that post was really helpful , but now I reciveid that message : FAILED (remote: oem unlock is not allowed) after I execute the command:
fastboot oem unlock-go. What should I do to unlock the device ? Thanks

Mat Urb said...
This comment has been removed by the author.
Sa Ma said...

Hello, that error usually results when the 'OEM Unlocking' or similar option is not enabled in the 'Developer Options' prior to starting this process. I guess I should have mentioned this as well in the tutorial rather than assuming the same.

Mat Urb said...

I'm in a bind now because my redmi is now brick and can not unlock the oem since I have no rom. Is there a way to OEM Unlock from the fastboot or edl mode menu ?

Sa Ma said...

You should be able to flash a ROM in EDL mode and then start the bootloader unlocking process from scratch. Although a bit old now, the following tutorial should still be helpful.
http://en.miui.com/thread-235865-1-1.html