A Headless machine (serial console needed)

Andrew F. Nelson (nelson@cs.umn.edu)
Wed, 2 Aug 1995 11:06:17 -0500 (CDT)

Hello all. I have a request. Has anyone set up the kernel for a
headless machine. When you boot other UNIX machines without a monitor
or keyboard, they redirect console output to the serial port. Now I
now you can set up a getty on the serial port, but it is not the same.
I want total control of my machine before it even comes up. It
probably wouldn't be that difficult to compile in. I am willing to do
some of the work if it hasn't been done, but I wouldn't know exactly
where to start.
- First choice: Is there any way to see if a monitor is connected. All
PC's I know about need a video card to boot. Basically if there is a
monitor console = /dev/console otherwise console = /dev/ttyS0 or
- Second choice: If the above won't work, just hardcode into your
kernel that the console messages are now sent to /dev/ttyS0.

>From the little I understand about the kernel, I would assume this
would mean that the serial driver or a portion of it would have to be
loaded first and then just don't set up the console (EGA/VGA) stuff.
I would love more input and if this has allready been done I would
love a HOWTO.
Andrew F. Nelson Systems Staff - University of Minnesota
Computer Science
"Murphy's Law isn't just a saying, it is a way of life!"