• Introducing XDA Computing: Discussion zones for Hardware, Software, and more!    Check it out!
  • Fill out your device list and let everyone know which phones you have!    Edit Your Device Inventory

How To Guide [GUIDE][UNLOCK][ROOT] Picture guide unlock bootloader, flash custom ROMs & root Xiaomi Poco X3 Pro

Search This thread

wertguygywe

Member
Jun 9, 2021
25
1
Does this mean my device is unlocked?


[[email protected] ~]$ sudo fastboot flashing get_unlock_ability
(bootloader) get_unlock_ability: 1
OKAY [ 0.002s]
Finished. Total time: 0.002s


EDIT: No, it is not unlocked.


[[email protected] ~]$ sudo fastboot oem device-info
(bootloader) Verity mode: true
(bootloader) Device unlocked: false
(bootloader) Device critical unlocked: false
(bootloader) Charger screen enabled: false
OKAY [ 0.005s]
Finished. Total time: 0.005s

[[email protected] ~]$ sudo fastboot oem unlock
FAILED (remote: Token verification failed, reboot the device)
finished. total time: 0.035s
 
Last edited:

pl1992aw

Senior Member
Apr 5, 2019
949
554
I have the latest arrow os on poco x3 pro now. But magisk failed to be installed.
It rebooted fastboot mode repeatedly after flashing magisk_patched_[random_strings].img.
If I flash original boot.img, it can be rebooted to system.

Below are some error in magisk install log I think:
cp: can't preserve ownership of 'busybox': Operation not permitted
cp: can't preserve ownership of 'magisk32': Operation not permitted
cp: can't preserve ownership of 'magisk64': Operation not permitted
cp: can't preserve ownership of 'magiskboot': Operation not permitted
cp: can't preserve ownership of 'magiskinit': Operation not permitted
Read Clean Flash custom ROMs step 8 carefully.

You did not follow my post, so you get errors.

This picture is in step 8 clearly.

The Notes already tell you the answer.
1621354930726-png.5313123
 
Last edited:

pl1992aw

Senior Member
Apr 5, 2019
949
554
My phone is detected on the Windows PC, and even is detected in fastbbot. But the official unlocker app does not notice it.

Unplug, then replug USB cable.
The driver may take some time (few minutes) to install.

If that does not work, reboot when the phone is in fastboot and connected to PC.

Close the unlocker program and then open it again.
 

onoakino

Senior Member
Sep 25, 2015
259
54
Manila
I have a question on step 6. It said to turn off wifi and turn on mobile data. Does that mean that I cannot use the phone's wifi for seven days? What will happen if I don't turn off my wifi, or if I turn it off and then turn it on again even if the 7 day waiting period is not done?
 

pl1992aw

Senior Member
Apr 5, 2019
949
554
I have a question on step 6. It said to turn off wifi and turn on mobile data. Does that mean that I cannot use the phone's wifi for seven days? What will happen if I don't turn off my wifi, or if I turn it off and then turn it on again even if the 7 day waiting period is not done?

Only during step 6 you turn off WIFI and turn on mobile data.

If you did not turn off WIFI during step 6, MIUI will tell you to do that and turn on mobile data. This is MIUI built-in requirement.

You can do whatever you want to WIFI and mobile data anytime before and after step 6. There's no restriction other than step 6.
 
  • Like
Reactions: onoakino

pl1992aw

Senior Member
Apr 5, 2019
949
554
Last edited:

pl1992aw

Senior Member
Apr 5, 2019
949
554
Reply redirect from https://forum.xda-developers.com/t/4267263/post-85196877
So if if i try to flash a rom older than the version installed on the phone i brick it right? This is the part it scary me, since i have no idea if my phone firmware match this rom and where to check this part.

Not always. So far this phone doesn't have that restriction yet, so we can still downgrade. (MIUI 12.5.1.0 can downgrade to 12.0.6.0~12.0.1.0)

Check the Anti version just in case.

This restriction only affect MIUI, the Xiaomi official ROM.

Other custom ROMs should not have ARB things.

Right, this is the easiest part. The tool work on my pc.

ps: But i need to keep the phone powered on for 7 whole days with mobile data active? Is a huge cost since i have a base subscription with my operator (1,5 eur/day). If i can do this just the first time i can handle this.

Can i at least switch it off or the timer reset and it need to stay connected 24/7?

Read Unlock boot loader step 7.

1623938887835.png


Right, so i go into developer menù and enable usb debug, then connect the phone to my pc using ptp option, then i flash via adb command line the twrp, then i copy the arrowos rom into download folder in the phone (or any of these folders shared and visible on my pc).

Reboot, volume down and power, enter TWRP, then install arrowos.

Fine.

Volume down and power : to get into Fastboot.

Enter TWRP with
fastboot boot TWRP-3.5.1-vayu-Nebrassy-1.img

Well, these passages are super easy, but my only issue is the part you mentioned above regarding roll back restrictions, will post my phone specifications when arrive, maybe i need to restore a certain version of the MIUI before doing all those parts to match the rom one?

So far it seems you can directly flash ArrowOS right after you unlock bootloader.

Seems to work with any MIUI firmware.

Just remember to format data before you boot into system.
uQ0QCVS.jpg


I can use this tool, no problem.

So, if i have understand correctly, once i flashed the ArrowOS i can avoid this issue right? Twrp will be permament and no need to reinstall everytime.

ArrowOS can have TWRP permanent in recovery partition.
 
Last edited:
  • Like
Reactions: kd276

kd276

Senior Member
Jun 14, 2021
156
15
Read Unlock boot loader step 7.

View attachment 5340519

Volume down and power : to get into Fastboot.

Enter TWRP with
fastboot boot TWRP-3.5.1-vayu-Nebrassy-1.img

Ah ok, so i do not need to install the TWRP into my phone at this point, but execute it from my pc while the device is in fasboot mode using the command above from CMD.

So, cmd> fastboot boot e:\TWRP-3.5.1-vayu-Nebrassy-1.img

Since i put the file into my pc partition E.

I guess i need to install TWRP after installed the Arrowos to have it permanent right?

So far it seems you can directly flash ArrowOS right after you unlock bootloader.

Seems to work with any MIUI firmware.

My phone arrive tomorrow, i got just now a message from the carrier. Since i need anyway to wait a week i'll post all the info here to be 100% sure and safe.

Just remember to format data before you boot into system.
uQ0QCVS.jpg
[/quote]

Absolutely.

ArrowOS can have TWRP permanent in recovery partition.

This is perfect, i wont bother you anymore, you already were so kind to help me till this point, will just post tomorrow screenshoots of my device, then i will follow your procedure after the week passed (thank god i can switch the phone off and do not keep it active to internet 24/7). :D
 
Last edited:

AmirHXe

New member
Jan 30, 2019
2
0
Thanks for the well-put post
I have one question
What will happen if my PC gets shut down during the unlock process? (due to a power outage for example)
 

pl1992aw

Senior Member
Apr 5, 2019
949
554
Thanks for the well-put post
I have one question
What will happen if my PC gets shut down during the unlock process? (due to a power outage for example)

The actual unlock process is fast, about 3~5 seconds during step 20.

In case it really does, unlock is interrupted, so bootloader remain locked. Just repeat step 20 or repeat from step 16.

If you ever flash recovery or boot.img for Magisk in other phone, it's similar process.

Xiaomi official unlock tool
  1. first pass command to phone (almost instant) [fastboot oem unlock *****]
  2. then sends unlock file (this is what likely took 3~5 seconds) [sideload]
After that unlock will progress on phone itself without the need of PC.

If this happens and phone cannot boot up, find Xiaomi official repair center to fix it. Technically the bootloader is locked, so definitely have warranty coverage.
 
Last edited:
  • Like
Reactions: AmirHXe

kd276

Senior Member
Jun 14, 2021
156
15
Sudden carrier strike in my zone, delivery of my device delayed on monday, it can't be helped, have a nice week-end everyone. :cool:

ps: About unrooting and installing twrp, i also found this guide while surfing some reviews, pretty detailed like yours and pratically the same, and splitted into different parts, for people who prefer videos over text.
 
Last edited:

Top Liked Posts

  • 1
    I made a big error after unlocking my device. I was on 12.5.3 India but I flashed the fw_12.5.2.0_GLOBAL in error before flashing the ROM. Now I am able to boot into fastboot and recovery but not able to flash stock rom iin fastboot. And in recovery I cant access my storage. How can I fix this error?

    Download latest TWRP if you were using TWRP.

    Format data with recovery, then reboot to recovery.

    After rebooted to recovery, flash ROM in recovery.

    Format data again after flashing ROM.

    USB OTG or microSD can also be used.
    1
    And when I try to flash it in Fastboot it shows error:Writing 'crclist'.

    Some way to deal with that:
    1
    I have TWRP installed and boot in and out but cant flash stock rom in fastboot and not able to access storage in TWRP. Will try fastboot boot twrp_file_name.img and see if that helps. Thanks a mil.

    Can try ADB sideload and flash in TWRP:
  • 1
    Tsk, I was digging high and low for the driver and only to read this thread to learn that it is only available in chinese version of mi unlocker >.<

    No, the driver is also in the latest English version.

    Because Xiaomi did not update their link, so many people didn't find it.

    Read here:
    https://forum.xda-developers.com/t/4288121/post-85207525
    1
    Thanks, well, flashing back the whole MIUI again for the baseband and vendor update is indeed a pain in the ass, with my old N4 just needed to install the zipped baseband (packed by a XDA user) and worked, hopefully this is the case here too.

    Today I did the firmware only update which was around 100MB zip file and wipe cache/dalvik, it successfully booted.

    So it's possible to only update the firmware in ArrowOS.

    Though the vendor was not included in that firmware.
    1
    So you updated the firmare from a "non-global" to global? Believe wasn't a good thing to do so.

    Try and error. It works though. Until encountering an issue, then I'll clean flash.

    When seeing MIUI updates, apart from China ROMs, which this phone doesn't have, the Global ROMs got the first updates. Then other regions got their updates.

    So the ROMs in other regions and countries seems to base on Global ROMs. The firmware may be same in all those release later.
    1
    Once you update the firmware you can't roll back on your previous version right?

    You can roll back. MIUI can be downgraded, firmware is included in official MIUI ROMs, so firmware can be roll back alongside with flashing previous ROMs as long as ARB is not triggered.

    Is firmware necessary to be updated if you phone have no issues at all?

    Think of it as drivers. You get updates of drivers.
    1
    Well, that was easy. You'll never see me again MIUI. :poop:
  • 20
    Thanks for @urbanman2004 guide for Poco X3 Pro. Some sentences still needed, so keeping it similar.

    This guide provides photos & screenshots.

    Simulate
    all process and reduce misunderstanding.

    * May loose warranty after unlock according to Xiaomi policy of the country you bought phone from. Check it yourself.
    * We are not responsible for anything that may happen to your phone by installing any custom ROMs and/or kernels.
    * You do it at your own risk and take the responsibility upon yourself and you are not to blame us or XDA and its respected users.

    Section 1: Unlock bootloader
    (Works for most Xiaomi/Redmi/Poco phones)

    • Keep phone with more than 60% battery.
    1. Register Xiaomi account on PC or Phone doesn't matter. (Use same account in all steps)

    Might ask SMS verification. Keep phone number for this Mi Account until all unlock done and successfully booted into MIUI after step 21.

    2. On phone, sign in your Mi Account from setting. (Use same account in all steps)
    hy4DkTF.jpg


    XZxCz5k.jpg

    3. Turn on Developer option:
    Settings –> About Phone (My Device) –> tap on MIUI version (For POCO) until it says Developer options enabled at the bottom.
    Gofn6XG.jpg


    CBgWSaD.jpg

    4. Turn ON "Find my device"
    nHTZ435.jpg

    XRqUPyb.jpg

    s2VCqJQ.jpg
    QndBFlT.jpg


    5. Back out to Settings, Additional Settings –> Developer options –> Mi Unlock status.
    iaolVCD.jpg


    UW3tU1B.jpg

    02wK1vG.jpg


    6.
    1i6frr5.jpg


    PNofSGL.jpg


    DON'T DO STEP 6 ANYMORE after done it ONCE. Will reset countdown timer if you do that.

    • SIM card inside phone with mobile data doesn't need to be the one linked to Mi-account. Can put a different SIM card as long as it can use mobile data.
    • Only during step 6 you turn off WIFI and turn on mobile data.
      Can do whatever you want to WIFI and mobile data anytime before and after step 6. There's no restriction other than step 6.
    • Can remove your SIM card once step 6 was done. But you still need the number linked to Mi-Account accessible to receive SMS if Mi-Account ask for verification.

    7. Wait for 7 days (Day 1). DO NOT LOG OUT your Mi-Account on your phone.
    • Try not to use phone too much as later will do factory reset and loose all data.
    • Or backup manually. Not gonna write how to backup.
      • No need to connect internet (mobile data and WIFI) all the time.
      • Can use your phone
      • Can even power off phone in the meantime. (Thanks for @kamild_ answer)
    8. Wait for 7 days (Day 2). DO NOT LOG OUT your Mi-Account on your phone.
    9. Wait for 7 days (Day 3). DO NOT LOG OUT your Mi-Account on your phone.
    10. Wait for 7 days (Day 4). DO NOT LOG OUT your Mi-Account on your phone.
    11. Wait for 7 days (Day 5). DO NOT LOG OUT your Mi-Account on your phone.
    12. Wait for 7 days (Day 6). DO NOT LOG OUT your Mi-Account on your phone.
    13. Wait for 7 days (Day 7). DO NOT LOG OUT your Mi-Account on your phone.

    14. Download Xiaomi Unlock tool for Windows PC.
    Direct download link (English Version 5.5.224.55)
    BkIy4OO.png

    NOrWLD6.png


    15. Extract all files into short-named folder. Go into folder and double click on miflash_unlock.exe
    5bJ8Fdv.png


    Different versions, double click on batch_unlock.exe
    rcJT9UI.png

    16. Sign in your Mi Account. (Use same account in all steps)
    EQawftl.png


    xL1xj9n.png

    17. Connect phone with official USB cable to PC. Check on PC if see device.
    S9taFjD.png


    • Turn OFF all locks (screen lock, face lock, fingerprint, pin, bluetooth lock.)
    • Turn ON "Find my device"
    • Logout Google

    If not detected, do as in spoiler:
    1. Double click on MiUsbDriver.exe
      1624109364083-png.5342061
    2. Should see your phone now.
    3. Reboot your PC.

    Backup your data from your phone now. You will loose ALL your data on your phone after step 20.

    18. Shut down/ Power off phone normally manually.

    When screen turn all black for about 30 seconds, hold Vol down + Power button together to enter Fastboot mode.
    yLfgdEo.png

    (Picture from GSMarena)

    Should see Fastboot on phone screen
    zlWsVJQ.png

    19. Connect your phone with official USB cable to PC. Should see on PC a device listed. (Locked)
    KM5WvMu.jpg

    If not detected, do as in spoiler:
    1. Double click on MiUsbDriver.exe
      1624109364083-png.5342061
    2. Connect phone to computer via official USB cable, and confirm your phone shows up recognized as "Android Bootloader Interface" (in Device Manager)
      1624108585394.png
    3. Reboot your PC.

    WARNING !!! From the step later, you will loose ALL your data on your phone. Backup your data from your phone.
    Take out microSD card from device in case something went wrong and destroy microSD card.

    20. Press Unlock, Unlock, Unlock anyway, Unlock anyway. (If you are worried of what it's warning you, don't unlock and don't think of custom Roms or root.)
    NoplT0J.jpg

    Dxtff64.png


    iJGGJXt.png


    BSBepWd.png

    CY0DiNG.png


    If see this or some hours left, wait for remaining countdown hours.
    RpSJX8m.png

    kHzrUEg.png


    Wait until times up (count it yourself) and start from step 17 again.

    Exit Fastboot mode:
    Unplug phone from PC and hold power button until screen turns black. Will boot into MIUI.

    21. Wait phone boot up, or press Reboot phone if it did not reboot itself.

    If you see this after boot up, use Wifi or insert SIM card with mobile data access and enter your Mi Account password.
    5FcpZ4J.jpg

    RD5Ulwg.jpg


    ##End of Unlock Bootloader process
    17
    • Unlock bootloader to do the followings.
    • Keep phone with more than 60% battery.

    Section 2: Clean Flash custom ROMs
    Make it simple using program mentioned in INDEX thread.

    XiaomiADBFastbootTools (Java)
    https://github.com/Szaki/XiaomiADBFastbootTools

    If you don't trust the tools or link below,
    1. Download here:
    https://github.com/Szaki/XiaomiADBFastbootTools/releases
    iqkvbpF.png

    2. For this program to work, install Oracle Java or OpenJDK (Mentioned in Readme)
    Jd5uCwe.png

    Here use Windows to do demo.

    Oracle Java download here or here (Choose either one to install)
    LwXsj8W.png

    Double click and install that on your Windows.

    3. Keep PC connected to internet, find XiaomiADBFastbootTools.jar downloaded and double click on it.
    UeY3VjI.png

    4. Will automatically download SDK Platform Tools.
    5aUkO48.png


    5. Turn ON USB debugging in Developer options (access mentioned in Unlock bootloader step 5)
    L62Yk2A.jpg
    • Logout Mi Account, Google, all accounts.
    • Remove all fingerprint, PIN, password, picture password.
    • Turn OFF Find My Device function.
    • Backup your data from your phone.

    6. Connect phone to PC, swipe down notification on phone and tap MTP/ File transfers
    ttJuPmX.jpg


    5sfr8jb.png

    Or
    p4kdYyB.jpg

    If it's your first time doing this, should see this screen. Choose "Always allow from this computer" and press OK.
    i2VYYuq.jpg


    7. Confirm on PC to see information of your device.
    cvlakl1.png


    8. Find custom ROM and read all reply and original thread. Sometimes firmware requirement and updated info is in replies.
    (Step 8, 9 and 12 and links are POCO x3 pro specific)
    ArrowOS as example: Download on PC Official ArrowOS -vayu ROM for POCO X3 Pro [direct link here].

    Check the date and version as well.
    1623983625978.png
    1625875073908.png


    If phone is not on MIUI version for required firmware, do additional as spoiler:
    Download on PC official MIUI Recovery ROM or MIUI by Xiaomi.eu ROM ZIP (2~3GB) of POCO x3 pro.

    • EEA is official ROM
    • Xiaomi.eu is custom ROM
    u8Ro01H.png


    9. Download recovery TWRP from here by Nebrassy for POCO x3 pro.
    Q6qKzh4.png


    10. On PC, press "Device" -> "Reboot to" -> "Fastboot"
    RyKJwK4.png


    Should see Fastboot on phone
    zlWsVJQ.png

    11. Program on PC should jump to Fastboot tab
    pqFHbhw.png


    If it did not jump to that tab,
    click on Fastboot tab and choose "Option" -> "Reload device"
    wkcpQW4.png

    Warning !!! Look at the Anti version:
    This is important for Xiaomi/Redmi/Poco phones.

    4sRmk1k.png

    • Only official MIUI may have ARB index.
    • Customs ROMs should not have ARB index.

    If your device is Anti version: 2,

    1) you can flash Rom with Anti Roll Back (ARB) index: 3, 4, 5, 6... etc. and the Anti version will become 3, 4, 5, 6... etc.

    2) you can flash Rom with ARB index 2, and the Anti version will remain 2.

    3) you CANNOT flash Rom with ARB index 1. Don't use that ROM in anyway, flashing through custom recovery will likely brick your phone.

    4) If ARB index is 0, that means no ARB of that ROM. It will not check or change your device Anti version.

    Make sure look at ARB index of MIUI ROM and Anti version of your phone. I don't have your phone. You decide to flash.

    How to check ROM ARB index is written in the Source.

    Source:
    https://www.xda-developers.com/xiaomi-anti-rollback-protection-brick-phone/

    12. Assume confirm MIUI ROM safe from ARB, click
    X1UdfgK.png


    Choose
    Q6qKzh4.png
    for Poco X3 pro.

    Change next drop down menu to "recovery".
    • Do not choose wrong option, or may be in BIG trouble.
    vehUX5s.png


    Press Flash Image (Some device cannot do this step, check at your device XDA tutorial)
    Confirm at the Status " Writing 'recovery' Okay "
    1cIvhXE.png


    13. Boot to TWRP
    jABmbYR.png


    Phone should boot into TWRP.
    eCcSjvX.png

    14. Copy or Drag MIUI and custom Rom zip into phone Download folder for easy finding.
    Pc2xAPp.png

    qshpGr2.png


    If PC did not see anything in "My Computer" or "This PC",
    unplug USB cable and then plug back again, so PC can read it correctly.
    r6bhhMb.png

    15. In TWRP on phone, tap Install
    aB0IU74.png

    If Firmware did not meet needs of custom ROM, do additional in spoiler
    Choose Download folder, then tap on MIUI ROM zip.
    XAy3ieb.png


    Swipe to confirm Flash
    RAKAUr6.png


    After it's done, press back.

    In Download folder, tap on custom ROM zip.
    60Dp38A.png


    Swipe to confirm Flash
    rg9sO9k.png

    Wait until it's done

    16. Press back, back, until you see Wipe, tap it and then tap Format Data.
    uQ0QCVS.jpg


    Type yes, press enter.
    mlssVLp.png


    17. Press Reboot System. Wait for like 10~15 minutes until initialization setup shows.
    u1oSf0O.png


    ## End of Clean Custom Rom flashing.

    Dirty Flash / ROM update
    Do this only when developer or users said it can.

    First disable all Magisk module and reboot to prevent issues.

    Do Section 2 step 13, 14, 15 with the update custom ROM zip file.

    When done, replace step 16 to following:
    vZUxquq.png


    Then Reboot System.

    ## End of Dirty flashing.
    8
    • Unlock bootloader to do the followings.
    • Keep phone with more than 60% battery.

    Section 3: Install Magisk (Root)
    Install steps and methods are written by topjohnwu (Magisk author) here, but will still put picture guide for POCO x3 Pro.

    1. Download Magisk from official github on you phone, click and install.
    G7CW0Fq.png


    NdDMz1w.png


    vhNT4N6.png


    GbMwdYG.png


    V83aknF.png

    Or find this and tap it once
    yYCd56B.png
    UuBmApN.png


    2. Choose boot.img and extract from your custom Rom/MIUI Rom on PC which you already had.
    8A4l635.png


    Connect phone to PC and copy that boot.img into phone Download folder.
    qshpGr2.png


    3. In Magisk app, click Install. Select and Patch a file.
    KtQvnqg.png


    fL6Rwpz.png


    gXYDNqI.png


    ubTrvW2.png


    5efZqa5.png

    4. Copy the patched file to PC somewhere easy to find.
    czpwKgp.png


    5. Open PC program XiaomiADBFastbootTools
    1) Select image magisk_patched-*****_*****.img
    2) confirm selecting the patched image file name
    3) choose boot partition in next drop down menu
    4) Flash Image into boot partition, Yes.
    RctQ9KS.png


    Wait for "Writing 'boot' OKAY"
    PRpEgVn.png


    6. Reboot to system
    BoyuP1z.png


    7. Go into Magisk app and check if it's installed.
    GKlFRxt.png

    8. Voila... or can do something more (Didn't feel the difference, though it said Recommended)
    WGSE6il.png


    r1MfGuQ.png


    9. Reboot. Voila! Enjoy Magisk 😃

    ##End of Magisk (Root) installation.
    5
    Reserved... Maybe for troubleshoot

    Q. Why not use Mi-Flash?
    A. Because one may easily accidently Clean All and Lock with different region MIUI and brick the device.
    Go Xiaomi Poco F3 / Xiaomi Mi 11X / Redmi K40 and see how many users brick their device using Mi-Flash.
    Be sure to check ARB index of MIUI.

    Q. Why flash MIUI with TWRP not Fastboot?
    A. To check you actually had unlocked bootloader. Without unlocked bootloader, you shouldn't be able to boot into TWRP.

    Q. Widevine issues?
    A. Read threads in spoiler:
    You can have Widevine L1 on custom Roms.
    https://forum.xda-developers.com/t/4267263/page-2#post-84919939

    You can lost Widevine L1 on official MIUI Roms even without unlocking or root.
    https://forum.xda-developers.com/t/4281695/
    Devices supporting Widevine L1 certificate renewal officially:

    POCO X3 Pro (vayu) [Stable V12.5.1.0.RJUMIXM+]

    * Cetain devices have been losing Widevine L1 certificate randomly. The reason is unknown to us.
    * Certificate renewal is done via Settings -> Passwords & security -> Fingerprint unlock -> Fingerprint payments -> Widevine (L1)
    https://xiaomi.eu/community/threads/info-widevine-l1-support.61064/

    If your device haven't officially receive MIUI update to 12.5.1.0, try Xiaomi.eu

    Read also:
    https://xiaomi.eu/community/threads/info-widevine-l1-support.61064/#post-606155
    2
    Did you lose anything by unlocking bootloader? Like Widevine or something. Also, any special partition or file one should backup before unlocking (Not counting user data)? In Sony phones user have to backup TA partition or they will lose some features.

    Thanks in advance

    Loss from Unlocking bootloader is written in above tutorial.

    Partition backup is generally not needed if you do things correctly. For now, even if you have full backup of qcn, maybe can't even restore.
    Read here: https://forum.xda-developers.com/t/4276823/post-85014473

    Widevine issue, Read both:

    You can have Widevine L1 on custom Roms.
    https://forum.xda-developers.com/t/4267263/page-2#post-84919939

    You can lost Widevine L1 on official MIUI Roms even without unlocking or root.
    https://forum.xda-developers.com/t/4281695/