Jeff Flowers <jeffrey@orsiros.dyndns.org> writes:
> During the install, I was asked to choose between serial and normal
> bootblocks. I used normal bootblocks but can anyone tell me what
> serial bootblocks are and why I might wish to make use of them?

Serial boot blocks output console boot messages to a system serial
port instead of to video. They are often combined with a kernel option
that says "please set the system console to the serial port".

If you had a machine sitting without a console in a machine room,
serial boot blocks and serial console in the kernel would let you
remote manage a machine using a terminal server or similar mechanism,
whereas it is a lot harder to extend VGA a few hundred or thousand
miles. That's why they're used.

However, they're at best a partial solution -- the BIOS itself will
generally not cooperate with serial console management, so you can't
set BIOS parameters that way, and it is hard to hard reboot a machine
without some sort of hardware assist.

If one really is paranoid about remote serial management, the right
thing is something like the PC Weasel (see http://www.realweasel.com/)
serial management board from Middle Digital, which (among other
things), redirects VGA to serial, redirects serial input to the
keyboard port, and has a watchdog timer and remote hardware reset
system.

I've used them and they're quite nice things.

--
Perry E. Metzger		perry@wasabisystems.com
--
NetBSD: The right OS for your embedded design. http://www.wasabisystems.com/