1. Using AndroidToool.

Download AndroidTool_v2.65.rar and DriverAssitant_v4.5.rar

Android 7.1：

https://github.com/ADVANTECH-Rockchip/rk3399_tools/tree/android_7.1.2_ks

Debian 9.x ：

https://github.com/ADVANTECH-Rockchip/linux_tools/tree/rk3399_linux_v231_risc

Android 10.0

https://github.com/ADVANTECH-Rockchip/rk3399_tools/tree/rk3399-androidQ10

Step1 Connect with the OTG port and PC.

Step2 Double click DriverInstall.

Step3 Enter into MASKROM mode .

There are two ways to enter MASKROM .

1. Hardware way to enter MASKROM

TBD

2. Software way to enter MASKROM

When the device boot up to android or debian, you can use ADB or Debug console, send command "reboot loader" .

Or Press "ctrl + c" key when booting into uboot, until get the following information on debug console : 

Android 7.1：

Hit any key to stop autoboot: 0
rkboot # <INTERRUPT>
rkboot # loader

Debian 9.x：

Hit any key to stop autoboot: 0
rkboot # <INTERRUPT>
rkboot # rbrom

Click "Advantech Function" , then "Enter MASHROM" button to enter MASHROM mode .

Step4 Select the image path.

Step5 Finish the update