Firefly RK3399 “Invalid device tree, expect boot to fail” (openbsd-current)

Hello,

I am trying to boot and install openbsd on my Firefly RK3399 ARM SoC.

With the latest packages I get the following error :
WARNING: Invalid device tree, expect boot to fail
(line n° 152 in the full output https://pastebin.com/5gsrd5Jz)

And the boot indeed fails.
This is very strange, given that using the same method and dtb file
a few years ago circa 2019, at the time when obsd support was minimal,
I managed to boot and install it on the very same card.
What could have gone wrong ?

The incrimined file is 
/usr/local/share/dtb/arm64/rockchip/rk3399-firefly.dtb
provided by the dtb package : https://openports.pl/path/sysutils/dtb

I also mailed the openbsd-arm mailing list earlier when trying to boot
from SD card and am now stuck there
https://marc.info/?l=openbsd-arm&m=170836038500353&w=2

Thank you
-- 
Sylvain Saboua
www.saboua.xyz