Re: [Qemu-devel] Running PPC Mac OS X Tiger Apps via Qemu on El Capitan

[Paolo Bonzini]

On 27/01/2016 15:52, Gabriel Diggs wrote:
> I’m trying to get my head around running a PPC App created to run on OS
> X 10.4 Tiger on El Capitan 10.11.3. I came across Qemu as a possible
> solution. The app in question is Traktor DJ Studio 3. It’s a Midi and
> Audio intensive app so latency has to be very low and it needs to be
> able to communicate seamlessly with a USB linked midi controller. Is it
> possible to wrap the app in a Tiger flavored Qemu similar to wrapping a
> Windows app in Wine in El Capitan? If so can you direct me to easy to
> read instructions to get everything setup?

tl;dr: It's not possible.

First of all, the two usecases are very different.  In the PPC case, the
OS is the same but the processor is different.  In the Wine case, the OS
is different but the processor is the same.

QEMU has two emulation modes for other processors, but unfortunately
neither is good for you.

The first mode is system emulation, which emulates a whole system (e.g.
a PowerMac) but it slows down execution substantially so the latency
bounds are probably not good enough for you.

The second mode is user-mode emulation, which _would_ be exactly what
you want but doesn't support Darwin (Mac OS X's kernel), only *BSD and
Linux.  The reason for this is that the Darwin user-kernel interface is
undocumented and changes enough across OS X releases that it would not
be practical to maintain it.  It _might_ be practical to maintain it
only for PPC Darwin, since it's dead, but someone has to do the work to
resurrect it.

Sorry for the bad news,

Paolo