freebsd-dev/sys/dev/nmdm
Julian Elischer 737a128622 Do it right this time. Give it a better name and place
CVSrepo deletion of the previous attempt will be requested:

--original message--
Add the 'virtual nulmodem driver'
Particularly useful for debuging kernels using vmware.

If your name is Bruce evans and you are a WIZ at tty interfaces,
then you should probably rip this to shreds and offer lots of suggestions and
patches. I've been using this since 4.0-CURRENT and it's never caused
problems but I'm sure I got something wrong. This is similar to the pty/cty
device driver except that both sides are ttys. Even minor numbers
are side A and odd minor numbers are side B.
Work needs to be done regarding what happens to the other side when you
close a node.

to use with vmware, configure vmware to redirect COM2 out to side A of one
of these and boot a kernel with teh gdb remote port set to sio1.
AFTER dropping into the gdb kernel debugger in your test kernel,
fire up gdb with it's remote port pointing at the appropriate side B.

To catch all console output, you can boot the vmware kernel with a serial
console, (COM1) similarly redirected to a nulmodem, and use 'tip' to observe it.

This is practically unaltered since pre 4.0 days except for
changes made along the way needed to make it compile, so any suggestions
or offers of total rewrites will be listenned to :-)
2001-02-27 16:39:54 +00:00
..
nmdm.c Do it right this time. Give it a better name and place 2001-02-27 16:39:54 +00:00