[OpenBIOS] Faulty Qemu SPARC64 IDE emulation?
igor.v.kovalenko at gmail.com
Wed Dec 16 23:32:24 CET 2009
On Sun, Dec 13, 2009 at 9:29 PM, Igor Kovalenko
<igor.v.kovalenko at gmail.com> wrote:
> On Sun, Dec 13, 2009 at 9:07 PM, Tarl Neustaedter
> <Tarl.Neustaedter at sun.com> wrote:
>> Igor Kovalenko wrote:
>>> We also need to find out how memory mappings are laid out
>>> preparing to run client code. It is not clear from of1275 docs.
>> Generally, OF is placed in high memory, and memory allocations are from low
> That is how memory layout looks like now, if we look at 32bits of physical
> address space. The only difference seems to be with low 16m being used
> for both pci memory, i/o space and actual memory. It's getting mapped 1:1
> into virtual address space used by openbios code.
> What is really confusing is how exactly we need to claim and map memory
> for client program. Some client programs appear to be happy with read-write
> privileged mapping, some may expect global translation, and docs are
> basically silent in this regard. Can we do 4M page mappings?
>> But there are several address spaces, which it sounds like are being
>> overlapped here:
> Right, that's the issue we have at the moment; both qemu and openbios
> are to be changed.
>> 1) Actual memory
>> 2) PCI memory space
>> 3) PCI IO space
>> They are each independent address spaces. Zero in any one of them is
>> independent from zero in all the others.
Just thought this needs more words to clarify.
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