[GUIDE] How to unlock your bootloader (with photos)
Meizu MX4

This guide is based on the xda forum post but includes images to hopefully clear things up.

First of all, you need to download the files required for your phone here (same link as the one on XDA)
This archive includes all of files for unlocking the device. You still need to download the flymeOS 4.2.8.2A update.zip file from this very forum:
link

Step one should be the easiest step (and I won’t make any photos of it since I don’t want to downgrade my own phone):

Install flymeOS 4.2.8.2A, with full wipe. It has to be a fresh installation. You should therefore backup all of your files before wiping your phone. This is just the stock flymeOS, no modifications have been done yet. Why do you need to install an older version of flymeOS? Well, all other versions based on android 5 and above have fixed the exploit used to unlock the bootloader and therefore do not work. Don’t even try as you will brick your phone.

Step 2: On your computer, you have to get the unlock files ready. For this, you need the archive with the required files as well as the update you just installed on your phone (flymeOS 4.2.8.2A). I suggest putting the update.zip in the same folder as the unlock files. Also, this should be the moment when you extract the update.zip as you need to work with files within the archive.
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Step 3: Copy the patcher to the update folder and run it.
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It should look something like this:
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all you have to do is click on “patch” and wait until it says “Successfully partched!”
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Step 4: You should now have a new file within the update folder called uboot.img.BAK. This is the original uboot.img and is not needed. What you do need is the new one which has replaced the original one and is therefore called uboot.img
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Create a new folder outside of the update folder and call it “UNLOCK” (in capitals). Copy the uboot.img to this folder.
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Now you need to connect your phone to your computer and copy this UNLOCK folder to the root directory of your SDcard (aka phone storage, nothing fancy)
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You also need to copy the “gscript” folder to your phone:
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Now you need to do things on your phone. The first thing is to request root access in the normal settings (how to get root is in the general F.A.Q). Next up is installing a terminal emulator. You can either open the play store or meizu app store and search “terminal emulator”, or you can install the one provided with the unlock files. The APK is in the gscript folder. (I usually use the terminal emulator from the Play Store as I have always liked it and it has never let me down).
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Once you are ready, as in, once you have copied all the required files to your phone, got root access, and installed the terminal emulator, go ahead and open up the terminal emulator. Everything from now is command-line, meaning you have to type in specific commands to make things work. Don’t worry if you write in something wrong, in almost all cases, you will just get an error because its written wrong.
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The first command you have to type in is
su
This is the code to request root access (su=superuser). If you haven’t already allowed it, make sure that the root request is remembered by flyme security as it can be a pain to always allow root access.
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(I’m currently having trouble with root on my broken version of flyme :smile: )
the user account name should change once you are in root (for me, non root is u0_a139@mx4, in root, it should be su@mx4 or something similar)
After you are in root mode within the terminal, you can type in the final command
sh /sdcard/gscript/unlock.sh
This is the final command that flashes the modified uboot.img to your phone to unlock your bootloader.
It should be noted that this is at your own risk and can cause a complete brick if this fails for any reason!
And finally, wait 3 minutes (don’t rush it) before rebooting your phone. If your phone boots back up into flyme, congrats, you now have an unlocked bootloader. Have fun.

DO NOT INSTALL A NORMAL FLYME UPDATE VIA NORMAL UPDATE.ZIP. THIS WILL BRICK YOUR PHONE NOW. IF YOU WANT TO STAY ON FLYME WITH UNLOCKED BOOTLOADER, REFER TO THE XDA POST/THE FILES INCLUDED TO FLASH THE CORRESPONDING PATCHED STOCK RECOVERY OR FULLY CUSTOM RECOVERY VIA FASTBOOT.

AGAIN, ALL THIS IS AT YOUR OWN RISK, I HOLD NO RESPONSIBILITY FOR BROKEN PHONES, NOR DOES ANYBODY ELSE.

So how is the MX4 with custom ROM compared to stock in terms of performance and stability?

I have to admit that I’m kind of jealous. Flyme 5 on the PRO 5 is pretty good and all but nothing can beat a slim stock Android/custom ROM.

last edited by ShadowOfDeth
Meizu MX4

@ShadowOfDeth well to be honest, there is a lot of work to do to get custom ROMs to play nice with the phone, its mostly in the tweaking of the kernel (which is possible because we have the kernel source code). We just need somebody to set aside time to make the tweaks and modifications.

The main performance issue (which users also experience on test versions of flymeOS) is the fact that the big.little architecture refuses to enable all cores when required so the maximum performance you get is the 4 low powered cores along with 2 high powered cores. Obviously not 100%.

DO NOT INSTALL A NORMAL FLYME UPDATE VIA NORMAL UPDATE.ZIP. THIS WILL BRICK YOUR PHONE NOW. IF YOU WANT TO STAY ON FLYME WITH UNLOCKED BOOTLOADER, REFER TO THE XDA POST/THE FILES INCLUDED TO FLASH THE CORRESPONDING PATCHED STOCK RECOVERY OR FULLY CUSTOM RECOVERY VIA FASTBOOT.

AGAIN, ALL THIS IS AT YOUR OWN RISK, I HOLD NO RESPONSIBILITY FOR BROKEN PHONES, NOR DOES ANYBODY ELSE.

Really Weird…!!!
I updated from 4.2.2.2A to Flyme 5 ( meizu mx4 32GB unlocked ) without problem and my bootloader still unlocked.

Steps
1 - go to dialer and type ##3646633##
2- go to Simme Lock
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and select Unlock Permanently to all option
3- update

then I updated the phone… and whalaaaa my bootloader still unlocked.

last edited by zencacu
Meizu MX4

@zencacu This has nothing to do with the bootloader, this is just to lock/unlock the phone to a specific carrier

ok, But the weird thing is…!!!
if I upgrade, why the bootloader remain open…!!!

P.S. Nice tuto…!!!
Greetings…!!!

Meizu MX4

@zencacu the photos you posted are not the bootloader and have nothing to do with the bootloader. If you updated to flymeOS 5 without modifying the update.zip you would break your phone.

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