I am not responsible if you damage, brick, or willingly alter your phone in any way shape or form blah blah blah, you get the point.
I did not fully test with 100 certainty these GSI-A roms below. Even the ones below that I did test have many bugs/issues. The ones below were the ones that booted correctly for me. Test at your own discretion. Some of these roms wont have SU & GAPPS.
Make sure you have an unlocked bootloader.
Make sure your phone has, TWRP installed.
Make sure you have drivers installed, here.
Fastboot & ADB tools, here.
Rom's I've tested & boot on Armor 6:
1. (AOSP) Android 10 by phhusson
2. PixelExperience 10.0 BETA by ExpressLuke
3. Havoc OS 3.0 by ExpressLuke
4. Resurrection Remix by phhusson
Any other GSI-A roms being supported can be found here, feel free to try out your own if you feel like it.
1. Place your device in, "Fastboot mode"
2. Open up command prompt (cmd) on your computer, cd into the folder where fastboot & adb is in, and type, "fastboot erase system"
3. Now flash the GSI-A image to your Armor 6 system partition. "fastboot flash system (what ever your system name).img"
4. This following command will format userdata & cache. "fastboot -w"
5. Last but not least step using fastboot, is to reboot your device. "fastboot reboot"
Now, pay attention.
When you flash the system image to your device, it only flashes the minimum data size that comes with the image. You have to reboot into TWRP, Resize /data partition & format to EXT4 to get the full 128GB partition size.
6. Boot into TWRP. To do this, power off the device and press both the, "Power button + Volume up button" at the same time during which you should see the bootloader menu. To move between options to have to press the volume up, until you are hovering over, "recovery" option. Then press volume down, to select recovery and boot into it.
7. Select the, "wipe" option.
8. Select & check mark, "Data" first, then secondly, select, "Repair or change file system."
9. Resize the data partition.
10. Now change the file system format, to, "EXT4"
Now reboot the phone
That's all there's to it. Not all GSI-A images will work, if they don't work, the developer of that GSI-A has to make it so. Good luck.