Re: [Qemu-devel] PCI: Memory mapped / ROM resources

[Gianni Tedesco]

On Wed, 2004-05-26 at 21:21, Fabrice Bellard wrote:
> Hi,
> 
> Gianni Tedesco wrote:
> > I'm writing some qemu PCI devices and i'd like to know if it's possible
> > to register memory mapped I/O regions and also I'd like to be able to
> > map in a ROM device, but I guess this is missing for the same reason
> > memory mapped resources aren't currently supported. Is that to do with
> > the qemu CPU/MMU code?
> 
> Memory mapped resources are fully supported. ROM devices are not 
> supported, but it is very easy to add.

Yeah, i figred that just after I hit send my last post. (isnt that
always the way).

> > Is this going to be implemented any time soon, what are the issues if
> > any? I don't mind doing the monkey work to get it implemented, if i'm
> > pointed in the right direction. I haven't even looked at how the CPU
> > emulation parts work yet.
> 
> Which hardware do you want to add ? I can add ROM devices if it is 
> really necessary.

I'm adding a host PCI proxy layer that works under Linux, ie: make host
PCI devices appear within the emulator. Similar to 'pcidev' on bochs,
but without a custom kernel module, and some minor performance
enhancements. I ought to have a patch ready by tomorrow evening.

It's not amazingly urgent really, don't kill yourself over it, I'll
probably get around to adding it later myself.

PS. I am using mmap() on /proc/pci/bus/XX/YY.Z nodes to map PCI
registers, probably there is a nice way to allow the code generator to
generate accesses directly on to these vmas? It's probably not that much
of a win in any case, but interesting.

-- 
// Gianni Tedesco (gianni at scaramanga dot co dot uk)
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