Connect Edge1 to PC with a USB-C cable.

Quickly press the Function key 3 times in 2 seconds, then release the key. You will see the Power LED (Blue) blink for about 3 seconds.

After the Power LED (Red) turns OFF, this indicates that the board is in Upgrade Mode (Maskrom Mode).

Power on Edge1.

Long press the POWER key without releasing it.

Short press the Reset key and release it.

Count for 2 to 3 seconds, then release the POWER key to enter into Upgrade Mode. You will see the sys-led turn ON when you’ve entered Upgrade Mode.

Connect Edge1 to PC with a USB-C cable.

Refer to Setup Serial Tool to setup your Serial Tool for Edge1.

Once again, make sure you’ve done the correct connections and setup.

Hit SPACE on your keyboard at the moment of bootup to stop autoboot. This step will let Edge1 boot into U-Boot command line.

Type run update in the terminal of U-Boot. The Sys LED (White) will turn ON when you’ve entered Upgrade Mode.

Type run maskrom on the terminal of U-Boot as below, and you will enter Maskrom Mode.

Refer to this guide to setup your serial tool for Edge.

Once again, make sure you’ve done the correct connections and setup.

Boot into Android or Linux command line.

For Linux, execute sudo reboot loader. For Android, execute su and reboot loader. The system will reboot and enter Upgrade Mode. You will see the sys-led turn ON when you’ve entered Upgrade Mode (Loader Mode).

Power-on Edge.

Use a tweezer to short-circuit the two pads of M register, then without releasing.

Short press the Reset key and release it to boot into Upgrade Mode (Maskrom Mode).