[ros-kernel] Mapping of page table

[Eric Kohl]

"Vizzini" <vizzini at plasmic.com> wrote:


> I'd also like to discuss moving the kernel/hal back down to 0x80000000
> while we're discussing this.  Forcing /3GB has the effect of depriving
> the cache manager of virtual memory, which on big configurations may be
> a bad thing.  What does everyone else think?

I think that's a good idea. AFAIR, Sven Schreiber wrote in his book
'Undocumented Windows 2000 Secrets' that the layout looks like this:

  0x80000000 - 0x8000FFFF (64KB) Mapped IVT, BIOS data, etc.
  0x80010000 - 0x800FFFFF Hal
  0x80100000              Ntoskrnl

I think mapping the lowest 64k of real mode memory (IVT, BIOS data, etc)
into kernel space could be useful for BIOS calls, especially for the VGA
driver.


Eric