Re: That horrible hack from hell called A20

H. Peter Anvin
2000-12-06T18:08:13Z

Alan Cox wrote:
>
> > INT 15-2401 disable A20
> > INT 15-2402 query status A20
> > INT 15-2403 query A20 support (kdb or port 92)
> >
> > IBM classifies these functions as optional, but it is enabled on a lot
> > of
> > new BIOS, no know conflicts, thus we can call this function to enable
> > A20,
> > check the result and only after failure we can try the old methods.
>
> I trust Linus over BIOS vendors, every single time.
>

The problem here is Linus doing things right, and the BIOS vendors not...
and the BIOS getting confused. If INT 15:24xx is supported, we might
actually want to use it, under the assumption that if it works, the BIOS
Suspend-to-Foo routines probably won't get too confused.

-hpa

--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."