[haiku-development] Re: Virtual 8086 mode support

  • From: "Axel Dörfler" <axeld@xxxxxxxxxxxxxxxx>
  • To: haiku-development@xxxxxxxxxxxxx
  • Date: Mon, 21 Apr 2008 13:45:18 +0200 CEST

Jan Klötzke <jan.kloetzke@xxxxxxxxxx> wrote:
> > That sounds indeed like the best solution. It probably wouldn't
> > even
> > hurt to keep the area around - we might want to have a similar
> > solution
> > for APM; at least it seems to help some buggy implementations to
> > make
> > that address range available.
> Ok, I'm about to revise my patch to provide a vm86() kernel function.
> I have
> an idea on how to implement it but it will take some time...

Great, thanks!
About keeping the area around, as I proposed above: that might not be a
good idea after all, since at least accessing the first page should
always lead to a page fault if possible.

> To make area/mapping stuff more clear let me summarize the
> requirements:
>   * A private area on 0x000--0x502 with the real values copied from
> the
>     physical RAM
>   * Most propably another private area in the 640kb range for some
> enry/exit
>     code and stack
>   * A identity mapping of the 0xA0000--0xFFFFF range

Sounds fine to me.


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