How to enable PC-Console on boot

[Matthias Petermann <mp%petermann-it.de@localhost>]

Hello all,

I have the following entry in my Xen boot.cfg:

```
menu=Boot Xen:load /netbsd-XEN3_DOM0.gz root=NAME=root;multiboot /xen.gz 
dom0_mem=512M dom0_max_vcpus=1 dom0_vcpus_pin console=pc
```

Xen domain 0 boots with this without any obvious errors and is 
addressable over the network (SSH).

What I am missing, however, is a usable console output on the VGA 
display. Serial console is not an option on the device (intel NUC5 
without external serial port) - or at least I wouldn't know where to 
connect it and how.

When I boot with my boot.cfg, I briefly see the spinning dash and the 
memory addresses written out, then the screen goes black and stays that way.

The device boots in EFI mode, so it seems to use a graphical console 
(I'm not sure if this has anything to do with DRM/KMS). When I boot a 
normal NetBSD kernel without Xen, a very small font appears.

I have already tried various combinations, but come on no green branch. 
Does anyone know how to do this correctly or can refer me to the 
appropriate documentation?

Kind regards
Matthias