12 Oct
2007
12 Oct
'07
8:57 p.m.
Jules writes:
I suppose real computers have a separate service
processor for this
kind of
thing, so it's easy to put things right even if something does go
wrong (plus
of course the update can *only* be done from the service processor -
not from
some rogue code running on the main CPU)
Not a service processor, but Alpha has a built in "failsafe loader"
that allows you to rewrite the console firmware if something happens.
It also has hardware lockdown of the PROM.
I don't think I'd consider a separate service processor always a good
thing, though - I've just been looking at the docs for the Sun E10k and
if you loose the SSP you're pretty much hosed unless you can get Sun to
make a new one up that matches your machine. Aren't IBM mainframes and
their ThinkPads in roughly the same boat? There, though, I think it's
easier to recover if you have a backup - I got the feeling that the
E10k's unit was somehow hardware-locked to that machine.