Re: [RFT] x86 acpi: normalize segment descriptor register on resume

H. Peter Anvin
2008-07-13T20:24:29Z

Andi Kleen wrote:
>
> Hmm, but the change was not supposed to break the s3 bios. Something
> fishy is going on. It sounds like the s3 bios relies on some earlier
> segment register setup.
>
> If true this means the segment register reset would need to be moved
> later after S3 bios ran. Saving/restoring is unfortunately not possible
> because we cannot save/restore the hidden state loaded from the GDT earlier.
>

That really doesn't make sense, though. The VESA BIOS has to be entered
in clean real mode; it's designed to be entered from reset, after all.
There is definitely something fishy going on, but I don't think this
particular aspect is it.

What's *really* odd is that this was required with the old code but
doesn't work at all with the new code. The former is understandable,
the latter is not.

-hpa