its a virtual machine...
I've downloaded the Darwin x86 8.0.1 ISO from Apple and pointed the VM's CD drive to that image, and while the boot loader seems to start the mach kernel, after a few seconds the display resolution adjusts to 1024x768 (I think) and just hangs on an empty black screen with no indication of CD drive activity.
I get the exact same symptoms when I try to install Darwin x86... it appears as though its about to work just fine, you get to the boot options screen... then when you boot, black screen.
Parallels provides a list of OS's that are supported. If Darwin x86 is not on that list you should not expect it to install and run. I don't recall seeing it on the list.
Well... NetBSD isn't on that "supported" list... and it runs like the wind! Also, Plan 9 isn't there (why would it be?) and, as far as I can tell, it works pretty good too. I thought it might have to do with funky mach kernel stuff, but
OpenStep works, too, and it uses the mach kernel.
I'm not saying Parallels should support every OS that runs on x86... but hey... if OpenStep and FreeBSD work, Darwin x86 ought to work too (I'm not interested in running OS X virtualized, btw... but I am very interested in test driving Darwin x86 before I commit to dedicating a real machine to it).
Come to think of it... Parallels should be ported to run on Darwin x86 (not much work involved there... if it already runs on OS X). How cool would it be to be able to seamlessly migrate an entire office from Windows to Darwin via running Parallels on top of Darwin with a Windows vm? Let me give you a hint... very very cool.
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edited
I'm getting different behavior with some different settings.
At the boot menu,
if you use -F (to ignore the boot file) the screen changes to the OS X splash screen (screen with an Apple)!
if you use -f (for safe boot, don't load drivers), a mad amount of stuff goes across the screen, looks like files being loaded.
and I got a white screen of death (instead of the black one) when I tried something more complex: boot: platform=X86PC rd=disk1s0 -f "Graphics Mode"="640x480x16"
Also, here's a thought...
Since its possible to
install Darwin x86 with other emulator software, do that, then
convert the vm to Parallels. I haven't tried this, but I will once I give up on a straight install.