[Oppo Reno Ace Questions & Answers] falsewind:
So... Hey guys,

I just wanted to let everyone know that I was actually able to flash the GSI from the link below on my OPPO Reno Ace:

https://xdaforums.com/project-treble/trebleenabled-device-development/aosp-10-0-quack-phh-treble-t3992559

I am super new to all this, but I decided to take the risk anyways because I really wanted to get away from ColorOS. Luckily it worked out to the point that the phone seems functional so far (just flashed it as of writing this).

Disclaimer: Do this at your own risk! I am not responsible for what happens to your phone for following what I did. Please think twice before trying! Also remember to back-up your phone first!

Before I continue on how I got it to work, I got the Reno Ace Gundam edition. Not sure if that makes a difference but I thought this should be mentioned. Also since I couldn't find a version of TWRP for the Reno Ace; I followed the instructions on how to flash without it.

Here are all the main links I used:

Walkthrough for Deep Test app: https://xdaforums.com/find-X/how-to/guide-how-to-apply-deep-testing-pafm00-t3888013

GSI: https://xdaforums.com/project-treble/trebleenabled-device-development/aosp-10-0-quack-phh-treble-t3992559

Flashing Instructions and "vbmeta.img": https://www.xda-developers.com/flash-generic-system-image-project-treble-device/

Extra Links in case of weird trouble. Hopefully you won't need it:

Google Usb Driver: https://developer.android.com/studio/run/oem-usb#InstallingDriver

How to manually install Google USB Driver: https://visualgdb.com/KB/usbdebug-manual/

Useful Key Word: Kedacom USB Device

*** Backup your phone before going forward.

Getting the Deep Testing app:

Now first, you do need to sign-up for an OPPO account. The link from the OP will take you to their site and you can sign-up from there.

- You will be required to login to your OPPO account in order to use the app.

- The file you download is named "Reno Ace深度测试.apk".

- Add ".apk" to the end of the filename if it's not already there. DO NOT rename the file.

- Once logged into your OPPO account on your phone, you stay logged in so you don't need to worry about actively logging in everyday.

- Next, follow the instructions on how to use the app from the Deep Test thread.

- Keep trying until your submission gets accepted, then the hardest part begins: you...wait...

- Once approved, it took ~2 days for me to be able unlock.

Make sure you have ADB ready on your computer:

- There are plenty of guides on it, so I'll just leave a link here; honestly I forgot the specifics already: https://www.xda-developers.com/install-adb-windows-macos-linux/

Steps:

- Prepare your GSI: You can look for other GSI(s), but from my research it seems safest to get it from here first; before trying others: GSI thread

- This link explains what GSI are and how to choose which one to get.

- *Make sure to extract the ".img" file from the ".img.xz" zip file.*

- Download "vbmeta.img" from "Troubleshooting Tips" of the "Flash GSI without TWRP" section of the How to Flash GSI Guide.

-After you've extracted the ADB folder, keep the files (.img files) you intend to flash within the "platform-tools" folder.

*Noob tip lol: Clicking on the folder address and typing "cmd" is the quick way to open command prompt within the directory.*

- *** There are some unique steps for the Reno Ace, if not all OPPO phones, due to the Deep Testing app. ***

- After you get your approval, note that if you press the "Start Deep Testing" text you will be immediately put into fastboot mode. SO DO NOT PRESS IT NOW.

- Make sure you have OEM Unlock and USB Debugging enabled within Developer Options. Then connect your phone to your PC and set it to transfer files.

- On computer, open command prompt within the "platform- tools" folder. Enter the command "adb devices", when you see your device ID and "device" next to it, this means the phone has been connected. (If a prompt on your phone pop-ups, tap the "Always allow this computer to USB Debug" and "Allow". This is just what I did, not sure if it's necessary).

- Now go into the Deep Testing app on your phone, tap on "Queue status" and then "Start Deep Testing".

- You should see the images from this Oppo Find X tutorial, on your phone. Landing on the screen with the big green "Start" on top.

- Once you're here, enter "fastboot flashing unlock" into ADB and you'll move on to the next screen where you select "Unlock the Bootloader".

- After confirming, your phone will factory reset itself, and reboot into ColorOS again.

- Check to make sure your phone is connected to adb.

- From here on you follow "Flash GSI without TWRP" part of the How to Flash GSI Guide starting at step 2. If you have your ".img" files in the "platform-tools" folder then you can skip step 3.

- Before step 5 you need to flash the vbmeta: fastboot flash vbmeta name_of_vbmeta.img

Then flash the GSI ".img" file with fastboot -w flash system name_of_system.img.

(The comments there mentions that the "-u" is incorrect and should be "-w", which worked for me.)

* Important: without flashing "vbmeta.img" you'll be stuck in a boot loop because the phone prevents you from booting into the GSI. If this does happen, hold down Volume Down and Power until the phone vibrates to boot back into "fastboot mode". Enter "fastboot device" in ADB to confirm the phone is connected, and start over from step 4 in the How to Flash GSI Guide. *

- Once you finish step 6 your phone should boot into the GSI.

Hopefully this proves useful. I'm no expert, I simply found my way around things.

I honestly have no idea where to go from here, Magisk? LineageOS? If anyone can give me some pointers, that would be very much appreciated.

Things that are not working for me:

- Can't setup In-screen Fingerprint sensor