When Xiaomi launched the Redmi Note 3, the device's bootloader was locked "in order to protect user data safety". The company announced later on that it made the decision to lock the bootloader of all of its Mi devices, including the Mi4c and Mi Note Pro.
It is not uncommon for manufacturers to lock the bootloader, even if the device is clearly designed for the developer community.
Doing so makes sense to a degree as it improves security significantly. Xiaomi made the decision after facing issues with bootleggers who sold fake Mi phones or Mi phones with unofficial Roms that contained bloatware or even worse, malware.
The change impacts users in several ways. After upgrading to MIUI 6.1.14 or later, the following changes take effect:
- Root is disabled even if it was enabled before. Root can only be enabled if the bootloader is unlocked.
- Updating using Recovery Mode is only possible if the Mi PC Suite is used.
- Locked bootloader devices can not be updated using MiFlash. Users need to unlock the bootloader if they want to flash Fastboot Rooms.
The locked bootloader won't affect OTA updates.
One could say that this is for the good of the customer, and it is certainly true to a degree. The main issue however is that Xiaomi designed an insane unlock process for customers who want to unlock the bootloader of their device.
The first hurdle is a Chinese-only site that Xiaomi created for the process. You do need to sign in with a Mi account, and fill out a request form afterwards.
The form asks for your forum username, country mobile phone number and a reason. All requests are processed manually according to Xiaomi, and it is unclear right now if the company will refuse to provide an unlock code if it things the request is unreasonable.
One issue that non-Chinese owners of Xiaomi devices will run into is that the request form accepts only Chinese and no other language.
A user in the official forum was kind enough to offer a translated reason which you can copy and paste into the form.
Once you have checked the box to accept the agreement, you are taken to the next page where you are asked to enter a SMS verification code that is sent to the number you entered on the first page.
You have five minutes to enter it, so make sure you are quick. The button on the right of the form where you enter the code in reads resend. You can use it to get a new SMS if the first did not arrive or expired.
The last page displays a confirmation message that the "application has been successfully submitted", and that you will receive a SMS notification once the request has been approved.
Users on the XDA forum who completed the application process had to wait between 3 to 21 days before the request was approved by Xiaomi.
So, not only are you required to fill out a form in Chinese, the actual unlocking takes up to three weeks on top of that provided that the reason that you gave is accepted and not rejected.
When you receive the approval SMS to your device, start the Mi Flash Unlock Tool and follow the instructions on this page.