Re: Forcing a serial console for the kernel

[buhrow%lothlorien.nfbcal.org@localhost (Brian Buhrow)]

        Hello.  The easiest and most reliable way to get a serial console is
to use the installboot(8) program with the -o option.  This method has
worked as long as I remember, and that's been quite a long time.
Steps:

1.  cd /usr/mdec on the target machine

2.  installboot -v -o console=com0 /dev/rwd0d /boot bootxx_ffsv1

        The above command line assumes you want serial on com0, i.e. pc port
com1, that the boot disk is wd0 and that you're using an ffsV1 filesystem.

Then, when you reboot, the boot prompt will come up on the serial port, and
you can boot single user, multi-user, with or without acpi, etc.
You shouldn't need to use any of the consdev options in the kernel config.
The kernel will take the console direction from the boot loader.

Hope that helps.

-thanks
-Brian

P.S.  PC port com1 is IO addr 0x3f8, irq 4, if you want historical port
references.

-Brian