How can I get to display the boot menu in serial console?

[Ottavio Caruso <ottavio2006-usenet2012%yahoo.com@localhost>]

Hi,

I'm booting a NetBSD 9.0_RC1 VM in qemu (Linux host).

For various reasons (one being that qemu VGA rendering of text mode is
crap), I need to boot the image over an emulated serial console:

$ cat opt/bin/boot-netbsd-virtio
#!/bin/sh
qemu-system-x86_64 \
-drive if=virtio,file=/home/oc/VM/img/netbsd.image,index=0,media=disk \
-M q35,accel=kvm -m 400M -cpu host -smp $(nproc) \
-nic user,hostfwd=tcp::6665-:22,model=virtio-net-pci,ipv6=off -nographic

In the guest, I have:

$ cat /boot.cfg
menu=Boot Serial:rndseed /var/db/entropy-file;consdev com0;boot netbsd
menu=Boot normally:rndseed /var/db/entropy-file;boot netbsd
menu=Boot single user:rndseed /var/db/entropy-file;boot netbsd -s
menu=Disable ACPI:rndseed /var/db/entropy-file;boot netbsd -2
menu=Disable ACPI and SMP:rndseed /var/db/entropy-file;boot netbsd -12
menu=Drop to boot prompt:prompt
default=1
timeout=5
clear=1

I can see the boot menu if I boot in VGA mode, but not over serial console.

The system boots fine; I just can't select any other option.

Is there anything I can do or is it a limitation of how NetBSD sees
serial consoles?

As a term of comparison, I have a similar setup for a FreeBSD guest
and I can indeed see the FreeBSD boot menu.

Thanks



-- 
Ottavio Caruso