[Qemu-devel] Question about user mode emulation

[Qemu-devel] Question about user mode emulation

[Laurent DESNOGUES]

Just as a note, I finally did not find the answer to my question.

If I understand correctly, user mode emulation relies completely
on the guest OS for memory allocation, and does not use any kind
of memory mapping.  Am I right?

If so, that means I can't use Qemu as is for my project...

Of course using virtual addresses for user emulation would slow
down things due to memory copying, but I think this may still
be very interesting for some developments.

What do people think about that?


Laurent



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Re: [Qemu-devel] Question about user mode emulation

[Ishwar Rattan]

On Thu, 24 Jun 2004, Laurent DESNOGUES wrote:

> Just as a note, I finally did not find the answer to my question.
What was the question?

>
> If I understand correctly, user mode emulation relies completely
> on the guest OS for memory allocation, and does not use any kind
> of memory mapping.  Am I right?
That is correct, as most emulated systems have to be at the mercy
of hosting OS fro access to hardware resources.

>
> If so, that means I can't use Qemu as is for my project...
What is your project?

-ishwar

Re: [Qemu-devel] Question about user mode emulation

[Laurent DESNOGUES]

> What was the question?

Question about the implementation of sigprocmask syscall in
Qemu which made no sense (given that I thought Qemu was doing
some virtual address mapping).

> > If I understand correctly, user mode emulation relies completely
> > on the guest OS for memory allocation, and does not use any kind
> > of memory mapping.  Am I right?
> That is correct, as most emulated systems have to be at the mercy
> of hosting OS fro access to hardware resources.

This does not prevent from using target virtual addresses,
though it can be slow and a pain to implement...

> What is your project?

PS2 Linux user mode emulation to port new binutils/gcc/glibc
toolchain to PS2.


Laurent