[Treble-Enabled Device Guides, News, & Discussion] edufpaz:
This guide is for flashing GSI on Umidigi A7 Pro device, which was released in 2020 with Android 10. This device supports Project Treble and comes with a super partition that contains system, product and vendor partitions. I tried flashing the GSI by the unofficial TWRP and it was not possible. TWRP couldn't break the encryption and I couldn't see the system partition to finally flash the GSI image.

So the only way I was able to flash the GSI was through adb/fastboot. There are several guides on the internet but all with some erroneous command suggestion. The best guide was found in a Telegram channel and it worked for me and which I successfully adapted in the flash of the GSI AOSP of the PHH, version 411 (system-squeak-arm64-ab-vndklite-gapps-secure.img).

You who have this model and want to venture into custom Android, follow below the instructions I used successfully.

Warning

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VERY IMPORTANT: Before trying to make any changes to your device, keep in mind the high risk this entails. It takes knowledge and experience to succeed. I am not responsible for bricking your device and do so at your own risk if you wish. I'm narrating what I did to successfully install Android 12 on my device. Before succeeding, I failed miserably in 5 attempts, resulting in a brick, but with the right tools, I was able to get my Stock ROM back to life. Have the tools you need to recover your device at hand.

Also, be aware that a GSI (any of them) is made by Goggle for development testing by application developers and is not 100% usable on a daily basis. They are adapted by the developers themselves and all have some problem or failure to use the device.

For example: fingerprint to unlock does not work.

Even a Custom ROM that is different from GSI has its limitations, as they are not developed by the device manufacturer, but by Android enthusiasts.

My advice, research and study about Android, about your Android device, about your device's ROM and about ROM customization. Watch videos on Youtube and learn about Android on XDA Forums.

That said, whether you feel free to move on or not, read and reread this guide carefully. If in doubt or with fears: DO NOT GO AHEAD!!!

Tools Needed to flash only on Umidigi A7 pro

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1. Stock ROM official:

https://community.umidigi.com/forum.php?mod=viewthread&tid=20976&extra=page%3D1

2. Adb and fastboot tool, choose for your Windows or Linux platform, it must already be installed before GSI flash:

SDK Platform Tools release notes | Android Studio | Android Developers

Android SDK Platform-Tools is a component for the Android SDK.

developer.android.com

3. Umidigi USB Drivers for Windows users, must already be installed before flashing GSI:

https://community.umidigi.com/forum.php?mod=viewthread&tid=4916&extra=page%3D1

4. Notice: TWRP recovery has on Android 12 version, it should not be flashed. And for this GSI flash we are not going to use TWRP recovery. Also because it is not possible to flash .img file in TWRP for Umidigi A7 pro.

5. Download any GSI PHH and choose the version that suits you best. I tested Vanilla (without Google apps), Gogapps (slim version of Google apps) and Gapps-secure (normal version of Google apps and to install Magisk), extract the file before installing:

Release AOSP 12.1 v411 · phhusson/treble_experimentations

Fixes boot on some devices (notably Mediatek but probably others as well) Fixes gapps variant' launcher Fixes floss' variant webview Fix setup wizard on gapps variant Fix fingerprint on some oplus ...

github.com

6. Download the product.img which will replace the product.img from the Stock ROM. This partition must not be deleted.

https://xdaforums.com/t/tutorial-ma...with-dynamic-partition.4311045/#post-85390677

7. To flash the GSI, the device must have the bootloader unlocked. The bootloader unlock process has the same result as factory reset, erases all user data and restores the ROM as if you turned on the device for the first time. So backup your data before starting. Another thing, your device must have the updated Stock ROM (UMIDIGI A7 PRO V1.4_20211115 ROM - SPFT + OTA release, the link is in item 1 above) and cannot be rooted.

8. This guide is for flashing GSI on Umidigi A7 pro, bootloader must already be unlocked. For unlocking bootloader or flashing root Magisk is another guide. Save this guide to your PC and use it to help you install the GSI.

9- Create a folder on your computer's Desktop to save the downloaded files. Install the drivers if it's Windows and install the ADB/FASTBOOT Platform. Test to connect your device to the PC and test ADB/FASTBOOT with the following command:

Let's start flashing on Umidigi A7 pro:

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10- Connect the connected device to the PC, open a CMD (Windows) or Terminal (Linux) with Administrator privileges.

11- Run the command to verify the connection with ADB:

adb devices

12- Run the command to enter Bootloader mode:

adb reboot bootloader

13- Run the command to unlock the system boot:

fastboot --disable-verification flash vbmeta vbmeta.img

14- Run the command to enter FASTBOOTD mode:

fastboot reboot fastboot

15- Run the command to confirm that you are in FASTBOOTD mode, if yes it is in FASTBOOTD mode:

fastboot getvar is-userspace

16- Run the command to flash the new product partition:

fastboot flash product product.img

17- Run the command to wipe the Data partition:

fastboot -w

18- Run the command to delete the system partition:

fastboot erase system

19- Run the command for flash system:

fastboot flash system <arquivo da GSI que você baixou no item 5>.img

20- Run the command to resize the system partition:

fastboot resize-logical-partition system 2952790016

21- Now you can start your smartphone with the new GSI. There are two ways to start:

21-1 Holding the VOLUME DOWN button + POWER button and wait for the device to restart

or

21-2 Run the command to start Recovery and press the POWER button with the option "Reboot system now":

fastboot reboot recovery

Credits:

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@kusti420 and @Allexwin50 - [Tutorial] Magisk on GSI on devices with dynamic partition

https://xdaforums.com/t/tutorial-ma...with-dynamic-partition.4311045/#post-85390677

@D34thstroke and @Kenzomusik - channel Telegram Umidigi A7 Pro Chat - https://web.telegram.org/z/#-1311986347

See below a mirror of my flash successfully: