Need help with Serial port communication

[shashi]

I am trying to implement the following
-> Capability to interact with server during boot via serial port
-> Cause server to crash (TOC) on command.

The setup is we are managing many servers, and remotely rebooting and
configuring the servers, when rebooting we would like to control the
booting process (intel machine).

For non Intel machine (HP-UX to be specific) we can do that using GSP
(Telnet).

Need help or ideas how it could be done on intel machines (Linux &
Windows) using serial port.

Thank you.
shashi