Re: Next round of console patches

Gerd Knorr (kraxel@goldbach.isdn.cs.tu-berlin.de)
Tue, 1 Sep 1998 20:13:25 +0200 (CEST)


On Tue, 1 Sep 1998, Alan Cox wrote:

> > vesafb does _not_ lookup the framebuffer base address and size in PCI
> > space, but uses the value returned by the VBE 2.0 BIOS calls.
>
> And where does the vesafb spec say the frame buffer area may be write
> gathered or that the palette callback will not flip a bit that puts mmio
> where the video memory was and flip it back thus write gathering...

The vesa specs suggests to use ports (not mmio) for the protected mode
interface. mmio is currently not supported by vesafb, it will disable the
usage of the protected mode interface if mmio is requested (which might
break 256 color modes).

And if a board wants to use mmio for the protected mode interface, it has
to tell where the mmio area is. A descriptor is needed for the mmio area.
The VESA BIOS expects the selector for the mmio area in %es.

Gerd

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