Installing NetBSD on PINEBOOK Pro

[Marc Baudoin <babafou%babafou.eu.org@localhost>]

Hi,

I'd like to install NetBSD on my newly received PINEBOOK Pro but I
can't get it to boot from a micro SD card.

I followed the instructions from
https://wiki.netbsd.org/ports/evbarm/rockchip/:

dd if=arm64.img of=/dev/sd0d bs=1m conv=sync
dd if=/usr/pkg/share/u-boot/pinebook-pro/rksd_loader.img of=/dev/sd0d seek=64 conv=sync

(arm64.img is latest -CURRENT from cdn, /dev/sd0 is my micro SD
card)

but, when I power on the PINEBOOK Pro, the screen stays black and
the device powers off by itself.

What am I doing wrong?