On Wed, Jan 8, 2014 at 3:48 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Wednesday 08 January 2014, Geert Uytterhoeven wrote:
>> VGA is special, in that it uses "ISA memory space". This is not a subset of
>> "PCI memory space", but something different. Some PCI host bridges
>> (IIRC, e.g. on Mac) do not allow access to this space.
>> Most other "PC I/O" use ISA I/O space, which is a subset of PCI I/O space.
>
> Right, but they often go together, and I think vgacon actually requires
> both, doesn't it? I'm not aware of anything else requiring access to the
Yes, VGA uses both.
> 0xa0000-0xfffff or the 0xf00000-0xffffff ISA memory windows except VGA,
> but I could be missing some less common devices. These are often not
> available on non-x86 systems, which prevents VGA from working even if
> low I/O space addresses are routed to PCI.
And MDA, for mdacon.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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