serial=0,9600n8 append="console=tty0 console=ttyS0,9600"
cd /dev rm -f console tty0 mknod -m 622 console c 5 1 mknod -m 622 tty0 c 4 0 rm -f /etc/ioctl.save
S0:12345:respawn:/sbin/getty ttyS0 DT9600 vt100
ttyS0
URL of this page: http://lcdx00.wm.lc.ehu.es/~svet/beowulf/serialcon.html