[A83] Re: microcode

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: microcode
From: "Henk Poley" <HPoley@DDS.nl>
Date: Tue, 18 Sep 2001 21:09:40 +0200
Reply-To: assembly-83@lists.ticalc.org


> Van: Olle Hedman <alh@home.se>
> 
> At 20:44 2001-09-18, you wrote:
> >Updating microcode is probably a complex process, that cannot be easily
> >done by software running on said processor.  The worst I've heard of is
one
> >that flashes your BIOS with garbage, then reboots.  The only way I can
> >think of that a processor could contro lthe operation to recode itself
> >wouldbe if there were two processors, and most people aren't that rich .
 .
> 
> It could also have a small and simple "bootstrap" that loads itself with 
> new microcode.
> It would be very possible construct it to put a memory adress in a
register 
> and call a certain instruction or something.

Oh yes, they probably have some fixed adress where to place the new code,
and it's then transfered via some special instruction(s).

> Doesn't feel likly it is done like that though, to much safety problems
:)
> I didn't know about this new capability of new Intel processors. Sounds 
> very interesting.

Uhm, what if they overwrite the microcode-ROM with zero's ?

	Henk Poley <><