Flash the Radxa CM5

On Ubuntu 22.10 or newer, and current Debian:

sudo apt install rkdeveloptool

On older distributions the package may not exist, in which case build it from source:

sudo apt install -y libudev-dev libusb-1.0-0-dev dh-autoreconf pkg-config build-essential git
git clone https://github.com/rockchip-linux/rkdeveloptool
cd rkdeveloptool && autoreconf -i && ./configure && make -j"$(nproc)"
sudo cp rkdeveloptool /usr/local/sbin/

Check it worked:

rkdeveloptool -V

No driver is needed. You will need sudo for the flashing commands.

Install via Homebrew — no compiling required:

brew tap IgorKha/rkdeveloptool
brew install rkdeveloptool

If you encounter an untrusted tap error:

Error: Refusing to load formula igorkha/rkdeveloptool/rkdeveloptool from untrusted tap igorkha/rkdeveloptool

Fix it via the recovery instructions and run:

brew trust igorkha/rkdeveloptool

Check it worked:

rkdeveloptool -V

If the tap is unavailable, build from source instead:

# We must use g++ on MacOS when building
brew install automake autoconf libusb pkg-config gcc@15
# Clone and build
git clone https://github.com/rockchip-linux/rkdeveloptool
cd rkdeveloptool && autoreconf -i && CXX=/opt/homebrew/bin/g++-15 ./configure && make

Windows uses RKDevTool, a graphical tool, plus a USB driver. Both come from Radxa:

1. Download and extract DriverAssistant v5.14, then run DriverInstall.exe as administrator. Without this driver Windows will not recognise the board.
2. Download and extract RKDevTool v2.96, then launch RKDevTool.exe.
3. You will also need 7-Zip to decompress the .img.xz image into a plain .img before flashing.

The commands in Write the Image below are for macOS and Linux. For the RKDevTool click-through, follow Radxa's RKDevTool guide — with the board in MaskROM mode it will show “Found One MASKROM Device”, and you write the loader and image from there.

If you have access to a Mac or Linux machine, we recommend using it — that is the path we test against.

rkdeveloptool db rk3588_spl_loader.bin
# You should see: Downloading bootloader succeeded.

xz -dk asimov-rpu-<version>.img.xz

rkdeveloptool wl 0 asimov-rpu-<version>.img
# The write process will begin. After a few minutes it will reach:
# Write LBA from file (100%)

rkdeveloptool rd
# You should see: Reset Device OK.

On Linux these need sudo. The xz -dk line decompresses the image and keeps the original; the write itself needs the plain .img.

In RKDevTool, with the board showing “Found One MASKROM Device”, load rk3588_spl_loader.bin as the loader and the decompressed asimov-rpu-<version>.img as the image, then start the write. Step-by-step screens are in Radxa's RKDevTool guide.

Decompress the .img.xz with 7-Zip first — RKDevTool cannot read the compressed file.