For now everything seems to work.
Widevine Security Level is L3. But i think that was also the case on the original K20 12.1.2 CN rom. I think it changed since Android 11 or MIUI 12. I seem to remember that the K20 had at a time Widevine Security Level L1
Now to my flashing sequence. Things that may need few extra steps or are important in bold.
Many steps are taken and condensed from this post
https://xiaomi.eu/community/threads...ctly-miui-11-on-mi9t-9-9-26-to-20-1-21.52539/
Preparation steps:
For ease of use i used this TWRP package
http://www.mediafire.com/file/xqf8k1c80qzn3d6/twrp-3.3.1-2-davinci-fix.zip/ file from
https://xiaomi.eu/community/threads...ctly-miui-11-on-mi9t-9-9-26-to-20-1-21.52539/ . From the extracted package i exchanged the "TWRP.img" with the latest stable TWRP (3.9.2) for my phone from
https://twrp.me/xiaomi/xiaomimi9t.html
You can look them up here
https://xiaomi.eu/community/threads/miui-12-0-12-1-12-2-12-5-stable-release.56191/
- Remember your Wifi password for first boot after Bootloader Unlock/Factory Reset. Needed to log into Mi Account (After Bootloader Unlock double check if it is really unlocked).
- Check that MiAccount is binded with the currently used phone number. Seems to be needed for the second half of Unlocking the bootloader.
- make a backup/copy of all your important data to another harddrive/pc
1.
Bootloader unlock
- Recheck that my MI Account is available and set in the phone.
- Have an active SIM card with data/internet available that can access the xiaomi servers. Damn coup
- have active Developer Options for the following substeps
- activate "USB-Debugging", "OEM-Unlock" and add your active logged in Mi-Account by "Add Account and device" in "Mi Unlock Status"
- Here Little Stumble block. Got some error message that i can't exactly remember. Somewhat like Error: Can't add account try again in a few Minutes. -> In my case i needed to logout and relogin the Mi Account on my Phone. Then i could finish this step.
- Check that you have a current backup of all your Data and "USB-Debugging" is active
- Start miflash unlocker (in my case miflash_unlock-en-5.5.224.24) on your PC
- Reboot phone into fastboot mode (Press and hold Volume down and Power button) and then connect to PC with "mi unlocker"
- double check again that you have made a current backup of all your important files and EndToEnd encrypted device bounded chats(For example signal, viber)
- miunlocker should show a device with a "locked" text in a column. Next step will "Factory Reset" the Phone if there is no waiting time like in my case. Press Unlock button or F6 to start Unlocking without warning. In my case it was immediately. Maybe since i was using my Mi Account for a longer time with the phone already? Afterwards i got a factory resetted Phone that is showing the first setup infos in chinese.
- Reenter minimal first Setup details. Wifi is needed to connect Mi Account.
- You are going to see a chinese message from Xiaomi with 2 options "Activate this device" (first button) and "WI-FI settings" (second button) .
- First enter wifi details after selecting the second button
- Second enter Mi Account passwort. (In my case the Mi account seems to be detected by the Sim card phone number and the user/MiAccount can not be changed)
- You should be inside the fresh MIUI system and can input minimal infos (Language selection and so on). I skipped most steps. Reactivate Developer Options
- activate "USB-Debugging", "OEM-Unlock" inside Developer Options
- double check that Mi Unlock Status is displaying Unlocked state in the Developer Options. Everytime during Boot/Reboot you will now see an unlocked icon at the top middle part of the phone screen. When it is showing the "Redmi" name just before the MIUI Logo
2. Flash TWRP (further helpful tips on
https://miui.blog/redmi-k20/flash-xiaomi-eu-rom-redmi-k20-pro-mi-9t-pro/ )
and install Rom
- go into fastboot mode and flash TWRP
- In my case extracted "twrp-3.3.1-2-davinci-fix.zip" into a root folder of the pc
- exchanged twrp.img with the latest stable TWRP (renamed to twrp.img)
- connect phone (in fastboot mode) with pc
- run "Flash_TWRP.bat" (right click and run it as administrator. optional? Just wanted to be sure that nothing interferes)
- follow the comments. After continuing two times this is finished. Should run only for a few seconds each
- reboot into recovery mode and TWRP should load (but has no writeaccess to the original old encrypted MIUI data partition. So no backup of data partition possible. But this is uninteresting after a factory reset. Normal reboot into system is not possible for now. Will always reboot into TWRP)
- directly after booting into TWRP
- activate modification access "Swipe to allow system modification"
- click on "Wipe" than on "Format Data" to gain write access on the data partition. No advanced wipe or any other wipe needed.
- going back to "main menu" and reboot into recovery/TWRP. (Reboot optional?)
- optional make a backup of everything else besides Data partition. Maybe helpful in case some future custom rom/twrp flash is making some bigger errors.
- From "main menu" - "Backup" - select all partition and make backup
- If not still connected, connect phone with PC and copy the xiaomi.eu rom ("xiaomi.eu_multi_HMK20MI9T_V12.1.2.0.RFJCNXM_v12-11.zip") onto the device. (Without previous "Format Data" we would not have write access. Maybe TWRP has an option to decrypt and mount the data partition, but data wipe was easier)
- while connected you can copy your optional TWRP backup.
- Go back to Main Menu and select Install. Select the copied rom zip file. Confirm by swiping "Swipe to confirm flash"
- Go back to Main menu and reboot into System. (Seems like there was no need for a wipe of cache/dalvik)
Be happy with a freshly installed Xiaomi.EU system. The first boot took about ~5 minutes for me and it seemed stuck on the "MIUI" Logo. So no worries on the first slow boot.
Now you can setup your initial system with your google account and mi account. The rest is just your usual android app installation and optionally copying your important files back. If available your EndToEnd encrypted Chat backups can now also be reimported.
Just read about safetynet again. Installed GooglePay and at least on starting i am not getting any notification about anything failing. Seems that safetynet is working for stable rom versions despite unlocked bootloader and without magisk and no rooting for now
