Login to serial port (not console)

[tlaronde%polynum.com@localhost]

Hello,

With NetBSD systems without an attached display, I set the console to
the serial line, from the boot sequence. No problem.

With a system with a display, I had a hardware failure of the monitor,
so I'd like now, if this happens again, to _add_ the possibility to 
login also to one of the two serial ports (/dev/tty00 or /dev/tty01)
via tip(1)---the very same way one does via serial line with the
headless server.

But this is supplementary to the /dev/ttyE*.

Putting on, say /dev/tty00, in /etc/ttys does not work, whether with
"Pc", "std.9600" or a custom entry in gettytab.

I have browsed the net about this, but this more or less ends with
setting the console on the com port, while I'd like to add the login
capacity supplementary to this.

When launching getty (via /etc/ttys) on a serial port, ps(1) shows that
getty is not attached to any tty (not the, say, /dev/tty00). 

Is there some special permissions to be set on the devices for getty to
work?

Is there a connecting sequence between say tip and getty, at the 
beginning, some handshaking or whatever that is configured automatically
when the console is declared as com0 and has to be done when one does
this "by hand"?

What is the best way/tool to see what is going on (or what is _not_
going on) between the two serial ports connected by a null modem cable?

As should be clear, the dance between getty and the ttys are not very
clear for me.

Note: I have declared the console on the serial port for now. But I'd
like to let the console on ttyE0, and to have a login ability via the
serial port as a fallback.

Thanks in advance for tips, or links to documentation etc.

Cheers,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                      http://www.kergis.com/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89  250D 52B1 AE95 6006 F40C