I have a soekris SBC with OpenBSD 3.9, configured so that
it boots with tty00 acting as serial console.
# cat /etc/boot.conf
stty com0 9600
set tty com0

That is fine, when I need to have access to the console to fix
something, but in an unattended reboot I want to free up the serial port
to use it with a GPS reference clock. So I need a way to disable the
getty once I have verified that I have access to the net. Killing it
is not useful as init respawns it.

I suppose I could unconfigure the console, and just use command line
boot arguments to enable when required, but if there is another
solution I would prefer it.

Anyone know how to do this?

Thanks

mike <michael.no.spam.cook@wanadoo.fr> wrote:
> I have a soekris SBC with OpenBSD 3.9, configured so that
> it boots with tty00 acting as serial console.
> # cat /etc/boot.conf
> stty com0 9600
> set tty com0
>
> That is fine, when I need to have access to the console to fix
> something, but in an unattended reboot I want to free up the serial port
> to use it with a GPS reference clock. So I need a way to disable the
> getty once I have verified that I have access to the net. Killing it
> is not useful as init respawns it.
>
> I suppose I could unconfigure the console, and just use command line
> boot arguments to enable when required, but if there is another
> solution I would prefer it.
>
> Anyone know how to do this?

I don't think this is a very good idea; Soekrises are notoriously bad
timekeeping devices, and while adding a GPS clock will help, I'm fairly
certain that attaching the clock to a host that does reasonable
timekeeping on its own and then synchronizing the Soekris to that will,
at the very least, not degrade accuracy. Plus, a serial console is your
last straw, all complexity you can remove from this part of the system
is good.

If you are willing to deal with the possibility that the system fails to
enter multiuser mode, you could start getty from /etc/rc. This would
allow it to be killed as usual, I suppose, but would - as noted - have
the disadvantage that it simply wouldn't come up if a filesystem got
damaged beyond repear, or somesuch.

Joachim