My homelab has long been powered by Mikrotik hardware (with the exception of my WiFi access points), and I’ve been quite satisfied with their capabilities. Lately, however, I wanted to experiment with running a pure Debian router.

The device I chose was the Radxa E52C, a small board computer with 2 2.5G ethernet ports, built-in EMMC for storage and a relatively powerful RK3582 chip (2xA76 and 4xA55 cores).

I won’t cover its configuration or how it will fit in my current network setup as I’m still considering multiple options, and I hope I’ll write them here one day.

Instead, I’ll focus more on how I managed to flash a clean Armbian installation instead of using their provided Debian or OpenWRT image. I didn’t want to spend time auditing their repos and their packages and this is why I decided to try installing a vendor-neutral image instead. Also, the absence of readily available instructions for installing official Debian on this specific board is why I decided to go with an Armbian image instead.

So, let’s begin by downloading the our Armbian image.

You can download and flash the image for the Radxa Rock 5C, since they share a similar SOC.

You will also need the bootloader from the Radxa website, located here

Finally, download or build rkdeveloptool from their website. We need this tool to write to the device bootloader and EMMC.

The next step is to boot the board into Maskrom mode. This involves pressing and holding the Maskrom button (it is located inside a small hole) on the side of the device (a clip is necessary) during the power-on process. Once the device has power, you can release the button.

Then, plug a USB cable to the USB port next to the Maskrom button and to your computer and let’s focus on the fun part.

# Check that the device is recognized
sudo ./rkdeveloptool ld

# Flash the bootloader
sudo ./rkdeveloptool db ~/Downloads/rk3588_spl_loader_v1.15.113.bin

# Flash armbian
sudo ./rkdeveloptool wl 0 ~/Downloads/Armbian_25.2.1_Rock-5c_bookworm_vendor_6.1.99_minimal.img

# Reboot the device
sudo ./rkdeveloptool rd

After the flashing finishes, you can use minicom to open a serial connection to the device. You will also need to plug a USB cable to the DEBUG port of the board.

Run

sudo minicom -w -t xterm -l -R UTF-8 -b 1500000 -8 -D /dev/ttyUSB0

You should see the board booting or the login page (depending on how fast you plugged the cable). If you don’t see anything try pressing Enter, or see if you miss the drivers for the ch341-uart chip that the board uses.

The board should work correctly except the obvious missing feature that I noticed immediately, the non-working WAN port.

To fix this, we will need to change the device tree file to point to the correct board, instead of the 5C we used earlier (probably this is because 5C has only one ethernet port)

To do this, open the /boot/armbianEnv.txt file with nano, or you can install vim. Then we will need to edit the line that starts with fdtfile. Change the value it currently has with rockchip/rk3588s-radxa-e52c.dtb, so that you will end up with something like this

fdtfile=rockchip/rk3588s-radxa-e52c.dtb

Then reboot and you should have both NICs working.

With the Armbian image successfully flashed onto the Radxa E52C and the fix for the second network interface implemented, the board is now ready for its role as a Debian router. Getting a clean Armbian image up and running on the Radxa E52C certainly involved a few more steps than simply flashing a provided image. I’m excited to experiment with different configurations and see what this little Debian machine can do, something I intend to share in a future update.