initial grub menu over ethernet

[zchen]

i would say your best bet is to have a hardware/firmware solution that
can ensure resetting/rebooting the machine whenever you want to (Intel,
Tyan and Asus all have motherboards that allow power up, power down and
resetting of the machines from a serial port, some can even be rebooted
from an ethernet card).  on top of that have a boot loader that can
interact with a boot server.