Re: vesafb on archs !ia32 [Re: Calling VESA BIOS routines from

Khimenko Victor (khim@sch57.msk.ru)
Mon, 13 Dec 1999 07:16:09 +0300 (MSK)


In <Pine.LNX.4.10.9912130021370.5629-100000@alpha.random> Andrea Arcangeli (andrea@suse.de) wrote:
> On Sun, 12 Dec 1999, Gerd Knorr wrote:

>>Other options are: play tricks with vm86. Use a cpu emulator. XFree86 4.0
>>does the later to boot secondary vga's for multiheaded displays and initialize
>>vga boards on !ia32 hardware.

> Should I implement an IA32 emulator in the kernel in order to use the
> vesafb video driver with my PC card I have on the alpha?

Yes in 99% cases. If you really want _VESA_fb ...

> Wasn't vesa just a framebuffer mode that should work all over the place?

Yes. As long as "all places" support iX86 real mode...

> I don't care about palette/powersaving and so on. At boot I only want to
> tell the card "switch to graphic mode 778 and allow me write my data to the
> framebuffer".

And VESA standard only supports such thing from iX86 real mode.

> I can't believe I'll have to write an IA32 emulator into the kernel to do
> that (on sane hardware I would achieve the switch with a pair of writel() in
> the MMIO I think).

Correct. But if you want use VESAfb you should play by VESA rules. And VESA
rules (as of VESA 2.0) are simple: the ONLY way to select video mode is to
call specific int from real mode. Sometimes you should even load DOS's driver
to have such ability.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/