Adding Support for DNA Valokuitu Plus EX400

The DNA Valokuitu Plus EX400 is a router sold at least in Finland by ISP DNA and in some shops also. The device is a white label product made by Inteno and the firmware is based on OpenWrt (Reboot) fork.


  • Device: DNA Valokuitu Plus EX400
  • SoC: MT7621A
  • Flash: 256MB NAND
  • RAM: 256MB
  • Ethernet: Built-in, 2 x 1GbE
  • Wifi: MT7603 2.4 GHz, MT7615 5 GHz (4x internal antennas)
  • USB: 1x 3.0
  • LED: 1x green/red, 1x green
  • Buttons: Reset

What I am looking for is a solution to using an overlay filesystem that is based on a writable folder rather than a separate mtd partition. It seems to work with the vendor firmware but fails with current openwrt.

The u-boot expects the kernel and the device tree to be under folder /boot on currently chosen firmware slot. I have yet to find a way to add way to add them to rootfs for this image only, not all targets of the mt7621 platform.

Wifi radios get their MACs from an uknown location but they seem to be preserved. I would like to understand where do they get them.

If there are any people with answers to the questions above or who wish to contribute by doing a review they are welcome to do so at the PR.

Thanks already in advance.