Installation

Download Dumbdroid

Warning: Dumbdroid is under active development, and comes with bugs and missing features. Use at your own risk!

Builds updated on October 14, 2025. Make sure to unpack first!

Dumbdroid variant	Qin F21 Pro	Doov R77 Pro, Qin F22 Pro
Google apps	gapps30	gapps31
Vanilla (microg)	vanilla30	vanilla31

Necessary tools

• mtkclient
• fastboot and ADB

Unlock the bootloader

This will factory reset your phone!

Open Settings->About phone. Tap on “Build Number” until you unlock the Developer mode. Go into Settings->System->Developer options, and enable “USB debugging” and “OEM Unlocking”. Turn off the phone.

Use the following commands to unlock the bootloader:

mtk e metadata,userdata,md_udc
mtk da seccfg unlock

Make a backup

It is of utmost importance to back up the original software on your phone. This way if anything goes wrong, you can easily go back and start from scratch. You’ll need about 5 GB of free space on your hard drive.

mkdir f21_stock_rom
mtk rl --skip userdata f21_stock_rom

Flash the new system

Turn on your phone and enable “USB debugging” in the settings again. Reboot into fastboot mode:

adb reboot fastboot

Erase user data if you are upgrading from the stock ROM. Updating Dumbdroid doesn’t require this step, unless you are downgrading from GApps to Vanilla.

fastboot erase userdata
fastboot erase metadata

Flash Dumbdroid. Make sure you unpack the zip archive first!!!

fastboot flash system dumbdroid_???.img # replace ??? with the actual filename

If you get errors that the system partition doesn’t exist, make sure that you are in the proper fastboot mode (use the ‘adb reboot fastboot’ command or enter fastboot mode from recovery). You should see “Fastbootd” written at the top of the screen on the phone.

If you get errors that the system partition is too small or can’t be resized, try flashing the vanilla dumbdroid and switch to g-apps afterwards through Settings->System->Updates.

fastboot reboot

Booting the system for the first time might take 5-10 minutes.

Recover from backup

mtk wl f21_stock_rom