Update Redmi Note 9 Pro (joyeuse/miatoll) to MIUI 12.5 (Android 11) preserving your data

TLTR (Too Long To Read) 😉

After reading the title you could ask: "What will I found here? Isn't this suppposed to be the default behavior with MIUI updates?"
Well... sadly, no.

Android 10 --> 11 OTA updates were blocked by Xiaomi a long time ago, due to a "suspicious" issue with WhatsApp app.
An official statement was never released, but there are some posts on MIUI forum (here and here) to confirm it.

The only "official" way to update to Android 11 is to use MiFlash+FastBoot ROM... but this will completely reset your phone and make you loose your data, apps, personal stuff...

This blog post describes the steps I've done to "forcibly" update my Redmi Note 9 Pro from 12.0.3 to 12.5.7 preserving my config, user data and apps.
The same procedure should work for all Redmi Note 9 versions (at least Qualcomm versions AKA miatoll: Curtana, Joyeuse, Excalibur and Gram).

I was able to update my phone without any issue (even WhatsApp works flawlessly, no problems with it).

Why can't I update my Redmi with the bundled Updater app?

XIAOMI released MIUI 12.5.x for RN9 at the end of Oct 2021.
A few weeks ago, devs were reported about some issues with WhatsApp app like notifications not shown and attachments not being correctly managed.

Due to this, they decided to stop OTA updates from 12.0.x to 12.5.x till the issue is fixed.
Well, the issue is still there (if it ever existed, no "official" declarations, only some forum posts, see above) and the "cautious" people like me that did not immediately upgrade were stuck on A10 and (12.0.x).

Manually downloading the 12.5 update zip file and forcibly installing with the bundled Updater app fails with misleading errors like "Can't install this stable version" and "Can't flash this stable ROM".

The only "official" way to jump to A11 is to download the fastboot version of the 12.5 ROM (5GB!) and flash it through MiFlash... but this will erase all of your data, apps, config, fingerprints.
Ok ok, if you have a backup you could reinstall everything but... that's a PITA, isn't it?

Below you'll find the steps I've followed to forcibly upgrade my 12.0.3 RN9Pro (Joyeuse) to 12.5.7 using the great OrangeFox recovery and preserving everything: configuration, user data and apps.

Warnings

Although I was able to complete these steps without issues, it doesn't mean you'll be able too!

• Please read all of the steps before starting the upgrade to have a full picture of what you're going to do, then double check you have no doubt about any of the steps.
  If so, please do not start the upgrade and search for help.
• Please backup all of your sensitive data before the upgrade to be able to reinstall everything from scratch in case of any disaster 😉

Prerequisites

• This steps were tested personally on a Xiaomi Redmi Note 9 Pro Global (joyeuse), but they should work on any miatoll device (since they share the same OrangeFox recovery image)
• Unlocked bootloader (no root required though)
• phone USB debug mode must be enabled, see here for details
• download latest OrangeFox recovery ROM ([email protected]_2.zip at the time of writing, see here)
• download latest zip MIUI update for your phone (mine is joyeuse, so I've downloaded this one miui_JOYEUSEGlobal_V12.5.7.0.RJZMIXM_48f0898fc9_11.0.zip), then copy it on the phone (internal storage is the best place)
• Check you have a working adb.exe and fastboot.exe tool (or adb/fastboot if you're on *nix system), see here for details.
  You must be "confortable" with them (as well as OrangeFox).
  If not, please read some documentation and watch some videos to improve your knowledge 😉.

Upgrade steps

If you've read all of the warnings and precautions above, you're ready to upgrade your phone.

AGAIN: please read all of the steps before starting the upgrade, to have a full picture of what you're going to do. In case of any doubt, please stop and ask for help before doing anything on your phone.
I'M NOT RESPONSIBLE OF ANY ISSUE ON YOUR PHONE. YOU AGREE THAT THESE STEPS COULD BE DANGEROUS AND COULD BRICK YOUR PHONE!

1. attach your phone (turned on) to the PC, open a command prompt and check if adb can connect to it
   
   adb devices
   
   You must see one attached device; if not, check on phone display and confirm connection
2. shutdown the phone, then press POWER + Volume - buttons together to get to fastboot mode
   you must now see a black screen with "FASTBOOT" (please note it must be FASTBOOT and not FASTBOOTD, no trailing "D")
3. you can now install OrangeFox recovery (replacing the bundled MIUI recovery) or only boot it temporarily...
   I've followed the latter so let's only boot OrangeFox without installing it.
4. Extract recovery.img from OrangeFox .zip file and boot it
   
   fastboot boot recovery.img
   
   (command prompt current dir must be the same you've extracted recovery.img into)
5. Once OrangeFox has started, it asks for your phone password (or sequence). You must insert it correctly to let it access your /data partition and preserve your internal data.
6. The FileManager icon (the first one at the bottom of the screen) should be already selected (otherwise click it).
   Navigate to the folder you've saved the MIUI zip update into, then select the zip file.
   OrangeFox is now ready to flash the zip file... swipe to right the button at the bottom of the screen and wait patiently...
7. At the end of the upgrade you'll be prompted to Wipe cache and dalvik, confirm it
8. You can now finally reboot your phone and, again, wait patiently for it to come up with the updated MIUI (it could require several minutes, depending on how much apps you've installed)
9. Your phone is now updated to MIUI 12.5.x.x + Android 11, and it still has your installed apps and data

Final thought

I hope you've been be able to complete the steps and can now enjoy your "brand new" Redmi phone.

Even if I could understand the caution of MIUI devs who blocked updates (because of a possible WhatsApp issue) to save users from disasters... but letting them behind to Mar-2021 (release date of latest 12.0.x version) and forgetting them was not acceptable.
Again, the "brave" users who updated immediately to 12.5 were able to get latest updates, while the other are locked... that's not good, Xiaomi 👎