boot0 via serial console

[Ulrich Spörlein <uqs@xxxxxxxxxxxxx>]

Hi,

installed 2.4.1 inside a VM and would like to run it headless, therefore
I did "the usual" to get the boot output on COM1, but this is not quite
working.

I put -Dh in /boot.config and removed the Booteasy manager. Upon boot I
see (on vidconsole!)

loader: not a directory.
No /boot/loader

BTX loader 1.00 ... the usual
. ..

So I set console=comconsole in /boot/loader.conf and at least the loader
shows up on my serial console, but what about earlier boot stages?

Then I tried installing boot0sio, which also fails

dragonfly# boot0cfg -b /boot/boot0sio ad0
boot0cfg: /dev/ad0: unknown or incompatible boot code

The disk looks like this:

dragonfly# fdisk -s ad0
/dev/ad0: 520 cyl 256 hd 63 sec
Part        Start        Size Type Flags
   1:          63     8386497 0xa5 0x80
dragonfly# mount
ROOT on / (hammer, local)
devfs on /dev (devfs, local)
/dev/serno/VB5bd93a73-736207b9.s1a on /boot (ufs, local)
/pfs/@@-1:00001 on /var (null, local)
/pfs/@@-1:00002 on /tmp (null, local)
/pfs/@@-1:00003 on /usr (null, local)
/pfs/@@-1:00004 on /home (null, local)
/pfs/@@-1:00005 on /usr/obj (null, local)
/pfs/@@-1:00006 on /var/crash (null, local)
/pfs/@@-1:00007 on /var/tmp (null, local)

Regards,
Uli