Subject: Re: port-i386/26007
To: None <gavan@netbsd.org, gnats-admin@netbsd.org, netbsd-bugs@netbsd.org>
From: Gavan Fantom <gavan@coolfactor.org>
List: netbsd-bugs
Date: 10/28/2005 18:55:01
The following reply was made to PR port-i386/26007; it has been noted by GNATS.
From: Gavan Fantom <gavan@coolfactor.org>
To: gnats-bugs@netbsd.org
Cc:
Subject: Re: port-i386/26007
Date: Fri, 28 Oct 2005 19:54:32 +0100
David Laight wrote:
> The following reply was made to PR port-i386/26007; it has been noted by GNATS.
>
> From: David Laight <david@l8s.co.uk>
> To: gnats-bugs@netbsd.org
> Cc:
> Subject: Re: port-i386/26007
> Date: Fri, 28 Oct 2005 17:40:19 +0100
>
> On Fri, Oct 28, 2005 at 12:08:02PM +0000, Gavan Fantom wrote:
> >
> > I had speculated that this may be a CPU bug. I'm now starting to wonder
> > whether the BIOS is enabling more caches than we're expecting.
>
> One difference between the 1.6 bootcode and the current copy is that
> prot_to_real used to do an immediate ljmp having just written to the
> code to patch the instruction. I changed it to do an indirect longjump.
>
> I don't think anyone has tried reverting that change.
> (Nor the other subtle changes required to get the correct address mode
> and bound bits set in the segment descriptor - IIRC especially SS)
Does any other OS do it the way we currently do?
--
Gillette - the best a man can forget