Boot the rockpi4 into OTG flash mode

Install image to eMMC from USB OTG port

ROCK Pi 4 supports Maskrom mode, which is a special operation mode for CPU to wait for USB OTG port command. The Linux/macOS PC tool we use to communicate with ROCK Pi 4 in Maskrom mode are the rkdeveloptool and RKDevTool. We use tool rkdeveloptool in Linux/macOS and RKDevTool tool under Windows.


  • ROCK Pi 4 mainboard
    • ROCK Pi 4A
    • ROCK Pi 4A Plus
    • ROCK Pi 4B
    • ROCK Pi 4B Plus
    • ROCK Pi 4C
  • eMMC on board or eMMC module
  • Power adapter
  • USB Male A to Male A cable(important) USB C to USB A cable does not working on all PCs

Install Tools&Drivers

Please check this guide, Install rockchip flash tools, rkdeveloptool/RKDevTool, under Windows/Linux/MacOS PC.

Boot the board to maskrom mode

To boot ROCK Pi 4 into maskrom mode is simple:

    1. Power off the board
    1. Short-circuit SPI Nor Flash if there is one SPI Nor Flash on board.

Spi clk gnd.jpg

    1. Remove microSD card
    1. Insert removable eMMC module ( Skip this when there in one eMMC on board)
    1. Plug the USB Male A to Male A cable to ROCK Pi 4 OTG port(the upper USB3 port), the other side to PC
    1. Press and hold the Maskrom key if your board is Plus version with soldered eMMC (1: Reset 2: Maskrom 3: Recovery)