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SubjectRe: SVGA kernel chipset drivers.


On Fri, 31 May 1996, Albert Cahalan wrote:
> > Unlikely. The difference between a library driver running with
> > video ram mmap()'d (ie direct access) and io port access and a
> > kernel driver is probably that the kernel driver is slower due
> > to syscall overhead.
>
> Nope, the kernel can provide a framebuffer device in /dev that
> programs can mmap. IO port access is less critical.
>
> The real reasons for such a driver are reliability and security.

Could we PLEASE stop this framebuffer nonsense?

It's not going to happen. There are LOTS of cards that don't even _have_
framebuffers (and they are usually the really high-end ones, the ones
that people will want support for in the future). If they _do_ have a
framebuffer, then SVGAlib can do the mapping itself.

Finally, IO port acccess is not at all less critical. As far as I know,
there are _no_ PC graphics cards that you can really program without
using IO ports. Stuff like colourmaps etc are almost invariably done with
IO port access on PC's.

Linus


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