Bootloader unlock policies - phhusson/treble_experimentations GitHub Wiki

Unlocking bootloader can be more or less complicated based on the OEM. There is a note associated /5. 0 means it's impossible to unlock, 5/5 means it's as simple as oem unlock => fastboot oem unlock

Google Pixels 5/5

OnePlus 5/5

Xiaomi Global 1.5/5

Xiaomi's unlock policy is pretty annoying. You'll always be able to unlock your bootloader, but you can't know ahead of time how much time it will take. It can be anything between 3 days and 2 months.

Also it requires a Xiaomi tool. You'll need to run it at least twice: Once to mark the date of the start of the unlock, and the other one to make the actual unlock. Xiaomi's tool is Windows-only, however there are alternatives: https://www.xiaomitool.com/V2/

Unlocking is limited to one per user-account per month.

It is possible that the wait-time changes during the wait itself.

The service is however pretty reliable.

Xiaomi China 1/5

All of those applies, but in addition, there is a monthly quota of devices that can be unlocked.

Asus 4/5

On Asus devices, you just need to find the developer app (it is specific to the device), install it on your device, launch it, and you'll be able to unlock your device.

However, the developer app isn't usually available day one, and the service isn't totally reliable.

Moto 4/5

You need to register on Moto's website, give your device's S/N, and it'll send you back a fastboot unlock code.

Huawei 0.1/5

Some devices have exploits available.

Samsung 4/5

There is no fastboot on Samsung. Heimdall is available on Linux/Mac, but you'll most likely need Windows to run Odin every now and then. Unlocking usually is instant, though it requires to connect the device to WiFi, and maybe also a Google or Samsung account to appear legit. Sometimes, it can take up to one week to have the Enable OEM Unlock option to appear.