install attempt on olimex a64 sd card

First of all, I picked the "generic" image from armbsd.org
and wrote it to an SD card.

Then I tried writing the u-boot image specific to the board.
dd complains about /dev/rsd0 being an invalid argument, but
seems to write to it anyway which, is ... weird - bug in
-current? So I wrote it to the on-filesystem image instead.

Plug in the board with HDMI connected to a DVI adapter.
u-boot shows its display then loads the NetBSD boot loader.
Everything seems fine. Then the NetBSD boot loader disappears
and the screen turns off, never turning back on.

What's going on? I have console=fb set, NetBSD should be
using the framebuffer.