Plug the USB-A to Type-C cable to ROCK 5B Type-C port, the other side to PC.To boot ROCK 5B to Maskrom mode is simple: Please check this guide, Install rockchip flash tools under Windows/Linux/MacOS PC. We use the rkdeveloptool in Linux/macOS and the RKDevTool under Windows.
The PC tools we use to communicate with rock 5 in Maskrom mode are the rkdeveloptool and RKDevTool. Rock 5 supports Maskrom mode, which is a special operation mode for CPU to wait for USB OTG port command. 1 Install the image to eMMC from USB port.