Over the past few years, a suspicious number of companies have started to "take care of your data", aka block/strictly limit your ability to unlock the bootloader on your *own* devices.
While this may not affect you directly, it sets a bad precedent and it might be a good idea to keep track of companies and workarounds.
In the past, Huawei allowed you to unlock with a special code you get by submitting some information to emui.com (IMEI, serial, model, and product ID), but in 2018 "corporate values have changed" and the site went down. <br/>
I don't recommend paid methods due to general sketchiness. I have used one of these tools a while ago, it was okay.<br/>
Through HCU-client (Not everything is supported + incredible prices https://hcu-client.com/buy/) or DC-Unlocker (Same problems as HCU https://www.dc-unlocker.com/buy)
In the flaming pile of HMD's "great" decisions to improve Nokia, one stands out more than others: They decided to follow the fresh "lock the bootloader" trend.<br/>
The most annoying part about them is that you *can* unlock your bootloader, but only if you can enter fastboot. And guess what? They locked fastboot with an RSA key!<br/>
As per Realme, they decided that segregating people by ~~race~~ their phone's region is cool. If you didn't buy your phone in China or India, chances are you won't be unlocking anything anytime soon.
In April-May 2023 you could unlock any Realme phone using this script https://github.com/turistu/rmx3474-rooting, but on May 26th Realme posted this joke of an announcement on their forum https://c.realme.com/in/post-details/1661960232244367360 <br/>
Older MTK-based models can use the [mtkclient method](https://github.com/melontini/bootloader-unlock-wall-of-shame#mediatek). There *might* be a Unisoc method, but I've never seen it.
Seeing how easily Realme dropped the ball on their global users, I personally would be worried about their future plans.
For now you can use any of the guides here https://c.realme.com/in/post-details/1248075024070344704 (They're just copy-pasting the same info as the unlock process didn't change much at all)
If you need DeepTesting, try this: https://forum.xda-developers.com/t/unlock-bootloader-help.4425415/post-86777721
### 2. Samsung (Exynos)
If you have an Exynos-based Samsung, you can unlock your phone, but this will permanently trip Knox. As a result *any* Knox based features will be broken *even if you re-lock*. This includes, but not limited to: Samsung Pay, Pass, Flow, Health, Secure Folder, Secure Wi-Fi, Smart View. Can you be denied warranty? Probably...
Some of those features can be fixed with this LsPosed module https://github.com/BlackMesa123/KnoxPatch and this Magisk Module https://github.com/BlackMesa123/KnoxPatch#knoxpatch-enhancer.
What? OnePlus? Aren't their phones super easy to unlock? - yes, but... <br/>
You probably heard about the OnePlus X OPPO os merger and while it did get called off, both companies started sharing a "unified codebase". You can probably see where I'm going.
If one day OnePlus decides to practice racism like Realme or go nuclear like OPPO/Vivo, they'll have those "unified" tools at their disposal.
### 4. Xiaomi/Redmi/POCO
Currently, Xiaomi allows everyone to unlock, well, that is, if you have a SIM card, internet connection, a MI account, can set up their unlock tool and have 7 days (or more) at your disposal. <br/>
The problem is that their unlock process is similar to that of OPPO, where you have accounts, verifications, RSA keys and more. And while it doesn't seem like they're going to change their policy anytime soon, but if they do, they can just break the unlock tool/block you with that MI account.
