Serial Console oddness

[rob holland <rob@ereet.co.uk>]

I've setup a machine to boot using com0 as the console by using: set tty 
com0 in /etc/boot.conf and it boots up fine and displays the dmesg stuff 
over the serial port and then displays the login: prompt and works fine as 
a terminal. (hurray)

However, if I take the disk and put it in another machine (which has no 
keyboard/graphics card) it doesn't use the serial port for the console for 
some reason, and I can't figure out why.

In the dmesg of the first machine it has a line which says something like:

found pccom0 at isa0
pccom0 is console

Or words to that effect.

On the second machine the dmesg says:

found pccom0 at isa0

Then carries on and doesn't include the line about the console.

Any idea why, when it has detected the com0 fine, it then doesn't use it as 
the console?

Might it be something to do with the probe thing before openbsd boots?

On the machine that I can plug a monitor into the bootloader says something 
like:

probe apm apci com0 [other stuff here]

Of course I can't check if that appears on the second machine :(

Does anyone have any ideas?

If it is something to do witht the bootloader, can I tell it where to find 
the com0?

Full dmesgs can be provided from both boxes, although I'm not sure they 
hold any clue so I haven't posted them.

The box is running GENERIC 3.0 (from the cd, not cvs updated).

Regards,

Rob

-
rob holland