[haiku-development] Re: Virtual 8086 mode support

Ingo Weinhold <ingo_weinhold@xxxxxx> wrote:
> I would simply reserve a small piece of the required address space 
> and do the 
> vm86 stuff fully in the kernel (i.e. available to userland via an 
> ioctl() 
> only). When the driver needs to execute vm86 code, an area with the 
> code to 
> execute and the stack are mapped into the reserved region (cloned or 
> copied 
> -- whatever makes sense), the code is executed, and when done the 
> area is 
> unmapped again. That's not high-performance, but for stuff like 
> resolution 
> changes, it should be totally sufficient.

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.

Bye,
   Axel.

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