Downgrading to Android 9
Hello together. Some days ago a realized that the MI A2 now is one of the best supported newer UT devices. I decided to get one, it came with Android 10.
Hey, what a hard way to go forward. I am not an expert an I'd wish people like me could find some more simple informations what else to do - on this site.
First I had some trouble to unlock the bootloader. I have read something about creating an account and a rather complicated unlocking procedure. But I then followed a YT video and could unlock it with the "OEM unlock" setting only using a web connection. Perhaps there are several versions out in the market? No detailed informations about this... But, ok, it's done.
I then installed Lineage 18.1. first to do some tests with Android apps. I wanted an ungoogled device for this. I also installed the Device Info HW app via Aurora to check the panel. As far as I can see I do not have the JDI panel.
But now I have found another problem when starting the installer: I have to go back to Android 9. Heavens! Can someone help me to do that? I tried the image link in the installer but the downgrading fails: "no android info-text".
@odo If you managed to install Lineage 18.1 (which is Android 11 btw.), you should also be able to flash Lineage 16, which is based on Android 9. The procedure should be similar.
Regarding the downloadable stock-android9 zip file from the installer:
- How did you flash it?
@luksus Lineage 16 for the MI A2 is not available. But ok, I got it. I have Android 9 on the phone. I used the Lineage recovery but I had error messages: downgrade not allowed. I ignored this.
In the next step I will try the UT installer.
@odo yeah let us know if ubports installer worked. Sometimes you have to try multiple times. I know with my nexus 6p i had to install original android it came with then with twrp format it so its empty then i used the installer and on my operating system manjaro. I had to be in sudo even tho they dont recommend that. Try everything u can think of and patients is virtue good luck
The installer did not work! Now I have serious problems with the device. I can easily switch into fastboot mode, but it's a pain running the recovery. After flashing the recovery new it works once, but afterwards I cannot come back to it. It's like being in a loop then. I can flash a new image, when the recovery works, but the phone did not boot. Before using the installer this worked.
I now try to flash the stock Rom with the MI flash tool. Great problem as well. I am away from windows for years and had to reanimate an old Win 8.1 HDD. I updated a long time, installed the USB drivers but the flash tool still fails. Great disaster.
Do you have the Android 9 stock rom? I believe it can be fastboot flashed on linux.
"Tip: Xiaomi users when reverting to the stock MiUi ROM use the Mi Flash Tool. This requires a windows PC. Linux users can try an alternate method to flash the stock ROM. They can unzip the ROM file and run the flash-all.sh file from a console screen."
I've done this for stock roms on another type of phone and it's dead easy. Extract the rom and check to see if it's packed with a flashall file.
If yes, then open a terminal in that folder, put phone in fastboot mode and connect to pc. Check you are connected with "fastboot devices" then run "./flash-all.sh" (or whatever exactly the flashall is called)
It should reboot automatically, so disconnect and wait for it to happen!
Hope this helps
@chrisrg I can't see the flashall file...
Ok, I tried another thing. As said above flashing an image is still possible. I tried the A9 image of the installers link. The phone doesn't start but I ignored this and tried the installer again. The installer worked - success, I thought. I could also boot into the recovery. Nothing strange here, the recovery says halium 9. But I am a bit confused because the recovery shows the Lineage logo. I think, this is normal (?). After continuing the procedure I can see the device busy with preparing - but in the end it still does not boot. I see the android one screen, and then the message that the bootloader is unlocked etc, then the "android one" again and so one. After some loops the "unlocked" message disappears - end of action. No UT screen.
I tried another computer - the same. Another thing I realised very late is also confusing: the installer says automatically "jasmine", not jasmine_sprout. What's this?! The jasmine is a ZTE device...
@odo try to switch an active slot or flash android 9 image to both slots.
e.g. switch to A:
Installer says: "Your device must be running a specific android 9 build before installing Ubuntu Touch. You can use the link below to download it. You can use either use stock recovery or TWRP recovery to flash it. Flash it to both slots to be safe."
The thing about "jasmine" vs. "jasmine_sprout": When you connect the device from running android with USB debugging On, it's detected as "jasmine_sprout" and installer knows it. When you connect the device from fastboot, it's detected as "jasmine" and therefore it's unknown. I don't know why.
I don't know what happened. Very curious. I flashed TWRP and than the Android 9 image new, and the device worked again.
Then I flashed the other slot too and gave the installer another try. In the beginning everything was ok. Then I could not reboot into recovery. What's this again. My only idea was installing the TWRP manually and continue with the installer. This worked but in the end I got the message "connection to the device lost" and a error message on the phone.
I think this was it. I'll try to install Lineage again or perhaps e-OS. Thanks very much to all.
New day, new luck. Success!!! Unbelievable!
Today I did the same as yesterday: Flashing mechanically recoveries and images, well, always the same files. I installed in both slots, but I have already done this yesterday.
Android did still not start, and I decided to try the installer for the very last time. And then, I could boot into recovery again, the process continued - and in the end I saw the UT screen. How great is this! I'm very happy!
Man, you need a lot of patience to come to a good end with this phone. Hope, the installation does not crash again.
Does anybody have an explanation why this device is so tricky, I'd like to say capricious? Or is it just my sample?
@odo Great news, congratulation!