plex86 ported to NetBSD/i386

hubertf writes "plex86 is now works on a second Open Source operating system. So far plex86 only supported Linux as host platform, and thanks to Frank van der Linden of Wasabi Systems, it now also works on the i386 port of the NetBSD multi-platform operating system. Tested operating systems include FreeDOS beta 4, MS-DOS 6.22, Red Hat 6 Linux and NetBSD 1.5. See the NetBSD site for more information.

Comments

Re:Trend in free software....

[Baki]

Any decently written application for a UNIX variant (including Linux here) should run with very little effort on any UNIX variant.

Alas there are more and more bad programs that use Linux peculiarities, making the port unnecessary hard (and thus sinning against the common UNIX philosophy).

The longer a program is isolated on one UNIX variant, the bigger chances are that it will be hard to port afterwards, that it will rely upon non-standard API's i.e. bad design. Thus it is good for the program to be ported ASAP.

Re:What about Darwin?

[maggard]

Er - things are getting a bit jumbled here...

Darwin is the core of Apple's Mac OS X but it's Open Source, BSD-compatible & runs on x86 as well as PowerPC. Indeed Apple has made special effort to release Darwin for x86, it's not just by happenstance.

Thus the original very cogent point that Plex86 could be ported to Darwin running on x86. No where was mentioned MacOS X or PowerPC (though they've been brought up many times in other places recently.)

I agree that this would indeed be very interesting, if only for the surrealism.

Who could have predicted 5 years ago that Jobs would return to Apple, have a coup & take over the company, then have Apple buy Next, Open Source the core of their OS, build in BSD-compatibility, make it backwards-compatible with the notoriously idiosyncratic MacOS then release it. To then put an emultor on top of this whole series of suprises would be frosting*.

Please folks, before you invest the effort into posting please read what the original poster says & not what you guessed from a quick scan.

* Yes there's VirtualPC etc. but they're MacOS-only and just not as neat as Plex86 though they're arguably more stable & more polished, as well as technically much more sophisticated.

What about Darwin?

[levendis]

I would love to see plex86, bochs, or even VMware support Apple's Intel version of Darwin (aka OS X). I haven't been able to get it running on any CPU emulators or physical machines. It seems to me that these emulators would find quite a niche in the OS development market.

Can anybody explain, exactly, why some OS/emulator combinations don't work? I assume it has to do with unsupported hardware (i.e. Darwin only work with Intel PIIX IDE controllers, and maybe all the emulators emulate a VIA controller)

Re:What about Darwin?

[israfil_kamana]

Plex86 is a virtualization system, not a full emulation system (or at least it contains an emulation system, but the point is virtualization.)

The point of this is that instructions do not have to be emulated because an x86 instruction on FreeBSD, say, is the same machine code instruction on Windows. It's the APIs that are different. So rather than emulating hardware, Plex86 "passes-through" the machine instructions to the hardware unchanged, achieving very low drag on performance.

So what you want is Bochs, pure and simple. I do hope that Bochs development doesn't permanently stall now that it's creator is working on Plex86. It's a good product, and frankly, I'd love to run x86 apps on OpenBSD on an Alpha. ;)

VMWare will almost certainly port their stuff to the MacOSX, though probably not Darwin. I'll bet that Bochs is ported to Darwin soon, as it runs on three other BSD's

Re:What about Darwin?

[levendis]

Right, but plex86 still has to virtualize the peripheral hardware, just not the instructions. For example, if the "guest" OS makes a BIOS INT 13 call, the emulated BIOS inside plex86 is what actually handles the call. I find it kind of odd that none of the emulators handle the right hardware combination to allow Darwin to boot (of course, Darwin is notoriously picky about such things on Intel hardware)

Degrees of porting difficulty

[DickBreath]

The classic "hello world" program in C can be ported to any OS. (Mac, Windows, etc.)

I generally agree with your remark about unix software being easily ported to other unix-alikes. At least for user-space things. For the most part.

Kernel space things may be much more difficult to port. You may be dealing with totally different API's. Or even different concepts, for an extreme example, such as kernel loadable modules, vs. VXD's, vs. Mac OS "Extensions", etc. (Using the term "kernel space" very loosly here.)

A bad program may, as you say, be unnecessarily be difficult to port. But a program difficult to port is not necessarily bad.

The question that has not been asked here is: how much of Plex86 is user-space? Doesn't it involve some Kernel trickery in order to achieve the virtualization? I got that impression from Kevin Lawton's paper here: http://www.plex86.org/research/paper.txt