>Kevin Lawton wrote:
>>
>> The guest driver has to access the memory via normal data
>> access instructions. So unless you want to get fancy and
>> either make the guest OS map in some extra video memory
>> beyond where the OS thinks memory stops, or do some bank
>> switching interface, the special driver framebuffer
>> has to be part of normal memory.
>
>I was wondering, in the "real" world, does the physical memory have to
>be continuus? (ie, can isa/pci extension boards provide "extra" physical
>memory somewhere?)
It is very unusual nowadays, though there's nothing against it in principle.
Some old computers have a memory hole between 15MB-16MB.
I'm not 100% sure how SDL works, so I'll ask this question: when you set up
the SDL framebuffer, do you supply a buffer address to SDL or does SDL supply
the address of the framebuffer to you ? In the latter case it is essential,
that we can directly map the SDL framebuffer as guest physical memory, in
order to avoid data copying. In the first case, we can simply use
"existing" memory.
Adding an IOCTL call to map memory shouldn't be very difficult; I'm willing to
implement this (but could you publish your SDL plugin source so I have something
to test it with ?)
-- Ramon
