Emulating OS4

[HenryCase]

Looking for ways to get OS4 out of its current bad situation.

I know others have tried this before, but I would like a discussion on suitable Virtual Machine (VM) platforms for OS4, and the work required to build an OS4 VM.

PowerPC emulation is a must. Here are some VM platforms that can emulate PowerPC:
QEMU
PearPC
GXemul

PearColator may be of some use (has PPC support I believe):
http://sourceforge.net/projects/pearcolator/

Also, PowerPC support is being worked on for Xen, but currently work is only being done on PPC970, which AFAIK we can't use:
http://wiki.xensource.com/xenwiki/XenPPC/

Out of all the options currently listed, I think GXemul looks the most promising, as it's an active project, emulates PowerPC and has been able to run unmodified operating systems:
http://en.wikipedia.org/wiki/GXemul

Points I'd like to discuss:
1. Any other options missed?
2. What is needed to build a VM for OS4?
3. Value in the project?

Any thoughts?

[HenryCase]

@downix
Thanks man, helpful as always.

AmigaOne Boot ROM?
http://www.hyperion-entertainment.biz:8080/amiga/frameset_html?func=download

Kickstart 3.1
http://www.amigaforever.com/

m68k emulator
I take it this is necessary for OS4 Classic rather than OS4 A1? QEMU has m68k support in user emulation (not sure what that means). Would that be enough?
http://fabrice.bellard.free.fr/qemu/qemu-doc.html#SEC2

[HenryCase]

Gwion wrote:
UAE under morphOS maby?

There is already an OS4 emulator for MorphOS...
http://amigazeux.net/os4emu/
Interesting thread about it:
http://tinyurl.com/2y3g7w

I suppose we should concentrate on OS4 Classic so that more people would feel comfortable running it emulated. Does anyone know how much access to the m68k processor OS4 Classic needs on boot? If nobody knows, can someone with a suitable hardware setup do some investigating please?

Methuselas wrote:
Isn't there also a RISC emulator? :idea:

Which flavour of RISC?

[HenryCase]

Methuselas wrote:

HenryCase wrote:
Which flavour of RISC?

Acorn, I believe??  :-?

OIC, so it emulates ARM processors. I'm not sure how similar PPC and ARM are, even though they are both RISC architectures. Thanks for mentioning it though, I'm sure plenty of people will find ARM emulation useful (GBA emulator anyone? :-)).

I noticed in the 'Amiga OS4 on old (PPC) Macs' thread that beakster2 was working on an OS4 emulation solution using PearPC. Fingers crossed that works out. (Beakster2, if you are reading this, well done for taking some initiative).

Can anyone explain how virtual machines do their job? Do you have to create an exact copy of hardware in software, or will approximations work?