PowerPC Emulator

[mol-general@lists.maconlinux.org]

On Sat, Sep 14, 2002 at 02:37:11AM +0900, Tomoyuki Ueda wrote:
> Hello.
> 
> The FAQ page mentions adding a PowerPC emulator to MOL,
> but as I skimmed through the archive of the list, I conjecture
> making that kind of emulator is difficult.

It is not trivial, no :-). I believe it is possible though. However, 
the emulator would have to be extremely fast. In practice, this means that
the one has to translate of PowerPC instructions into x86 ones and 
use some kind of register scheduler.

I have a fair idea how to implement this (and have done some proof
of concept tests). The really though part is the MMU though. One could
go for a MMU-less implementation but that would be kind of limited
(it would be impossible to boot MacOS X or Linux, and possibly also 
MacOS 9).

Another alternative is adding support for the MMU emulation 
in the kernel. There are problems with this approach too
(for instance, the emulator must live in the same virtual
address space as the emulated PowerPC).

> I found the following page:
> http://www.microlib.org/
> they seem to have PPC emulator running(though not fully functional).
> I'd love to see MOL running on x86 PC!

Not really. MOL needs high performance emulation. Most PowerPC emulators
are not really written for this kind of thing but are rather simulators
intended for design and research.

/Samuel