Date: Tue, 12 Dec 2000 23:38:38 -0800 From: Mike Smith <msmith@freebsd.org> To: arch@FreeBSD.ORG Subject: Re: Proposed bus address typedef. Message-ID: <200012130738.eBD7cc307071@mass.osd.bsdi.com> In-Reply-To: Your message of "Tue, 12 Dec 2000 23:24:57 PST." <20001212232457.X16205@fw.wintelcom.net>
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> * Mike Smith <msmith@FreeBSD.ORG> [001212 23:20] wrote:
> >
> > I'd like to propose some changes to the way we represent bus addresses, to
> > deal with situations where u_long (IMO not a good choice to begin with)
> > is too small.
>
> Sure sounds like a nescessary change.
It's only "necessary" really in this one case, although I'd like to step
away from "u_long" just because it's so vague.
> > Specifically, I'd like to be able to deal with x86 systems in PAE mode,
> > where physical addresses are 36 bits in size.
>
> Er, don't PAE machines use segmentation registers? There's no
> 64bit registers are there?
There are no 64-bit registers, no.
> If that's not true, any chance on it becoming a complile time option
> to save cycles on non PAE machines?
That would definitely be a worthwhile optimisation, although it would
lead to nasty binary compatibility issues between PAE and non-PAE driver
modules, for example.
--
... every activity meets with opposition, everyone who acts has his
rivals and unfortunately opponents also. But not because people want
to be opponents, rather because the tasks and relationships force
people to take different points of view. [Dr. Fritz Todt]
V I C T O R Y N O T V E N G E A N C E
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