Intel-based Macs and virtual Windows

On Mar 16, 2006, at 11:48 AM, keith025 wrote:

> Schofield wants to run Windows natively and say he will not be able
> to. Unfortunately the article emphasises "Windows will not run on
> Intel-based iMacs" thereby ignoring virtual use. Does the issue of
> dropping EFI hold any problems for virtual Windows on Intel based
> Macs?

No, it's unlikely to cause any problem. Any virtual environment is
either going to bypass the need for BIOS entirely (WINE) or will
emulate a PC, complete with BIOS and whatever else is necessary to
run the virtual machines (Virtual PC, VMWare).

--Nik

Quoting keith025 <keithvalperga.demon.co.uk>:

> R. Movin in TidBITS#820/13-Mar-06 says

> Schofield wants to run Windows natively and say he will not be able
> to. Unfortunately the article emphasises "Windows will not run on
> Intel-based iMacs" thereby ignoring virtual use. Does the issue of
> dropping EFI hold any problems for virtual Windows on Intel based
> Macs?

Virtual PC has to emulate a BIOS in order for XP to be able to run in it.

Virtual PC already has to do this on the PowerPC machines because they use
OpenFirmware (also not supported by Microsoft, even on 64-bit OS) instead of
BIOS. Virtual PC for Windows ALSO emulates a BIOS, even on regular PC's.

The benefit of moving Virtual PC from Power PC to Intel is that it no longer
needs to translate x86 machine code in to Power PC machine code. It
will still
need to provide the virtualized hardware (BIOS, video card, IDE, USB, etc....)
for the Guest OS to run.

Virtual PC on Intel Mac should be of comparable speed to Virtual PC on
Windows.
VPC on Windows is usable as long as you aren't trying to do heavy graphics or
CPU intensive operations.

Windows XP doesn't currently run on Mac Intel hardware because of EFI, this
doesn't apply to emulated hardware -- you can just emulate what you
need. BTW I
think a method for booting XP on Mac has been found. I saw some reports about
that today.

At 10:48 AM -0800 2006/03/16, keith025 wrote:
>Unfortunately the article emphasises "Windows will not run on
>Intel-based iMacs" thereby ignoring virtual use. Does the issue of
>dropping EFI hold any problems for virtual Windows on Intel based
>Macs?

        Yes. It makes it much more complicated, but a workaround for
XP has been posted. Presumably Vista will work too, with a different
procedure.

        Note that this doesn't have as much impact on virtualization,
such as Virtual PC (is MS backpedaling on their commitment here?) &
VMware (they're working on it), because there Windows boots inside a
virtual machine, which is provided by the virtualization software.
Guest operating systems have no access to the real underlying
hardware.

http://nak.journalspace.com/
http://wiki.onmac.net/index.php/HOWTO


                                                Chris
--
Chris Pepper: <http://www.reppep.com/~pepper/>
Rockefeller University: <http://www.rockefeller.edu/>

keith025 wrote:

> Schofield wants to run Windows natively and say he will not
> be able to. Unfortunately the article emphasises "Windows
> will not run on Intel-based iMacs" thereby ignoring virtual
> use. Does the issue of dropping EFI hold any problems for
> virtual Windows on Intel based Macs?

Why would it be a problem? If a virtual machine running on a PowerPC Mac
can emulate Intel hardware (including BIOS), then a virtual machine
running on an Intel Mac should be able to do this as well.

And it looks like Windows XP can boot on an Intel Mac, now:

<http://onmac.net/> has ended its competition.
The process is listed here:
<http://wiki.onmac.net/index.php/HOWTO>

Harro de Jong

At 9:08 AM -0800 2006/03/17, Chris Pepper wrote:
>At 10:48 AM -0800 2006/03/16, keith025 wrote:
>>Unfortunately the article emphasises "Windows will not run on
>>Intel-based iMacs" thereby ignoring virtual use. Does the issue of
>>dropping EFI hold any problems for virtual Windows on Intel based
>>Macs?
>
> Yes. It makes it much more complicated, but a workaround for
>XP has been posted. Presumably Vista will work too, with a different
>procedure.
>
> Note that this doesn't have as much impact on virtualization,
>such as Virtual PC (is MS backpedaling on their commitment here?) &
>VMware (they're working on it), because there Windows boots inside a
>virtual machine, which is provided by the virtualization software.
>Guest operating systems have no access to the real underlying
>hardware.

        Correcting myself -- I misread. Lack of EFI does not affect
classic virtualization (VMware & VPC). I don't know if it would
affect "paravirtualization" like Xen, since that's closer to the
hardware, and they're trying pretty hard to avoid emulation as much
as possible -- more intercepting hardware requests from guest OSes
and then allowing/denying and queueing them. There are a couple
articles about Xen linked from onmac.net.

        Note that Xen is apparently up and running with Windows &
Linux on Intel Macs, but Mac OS X won't yet run on Xen...


                                                Chris
--
Chris Pepper: <http://www.reppep.com/~pepper/>
Rockefeller University: <http://www.rockefeller.edu/>

Quoting Nik <gerberinik.net>:

> No, it's unlikely to cause any problem. Any virtual environment is
> either going to bypass the need for BIOS entirely (WINE) or will
> emulate a PC, complete with BIOS and whatever else is necessary to
> run the virtual machines (Virtual PC, VMWare).

BTW, WINE stands for Wine Is Not an Emulator. And it isn't. It implements the
Windows API's in unix. It doesn't emulate any hardware or software.

http://www.winehq.com/site/myths#slow

Anything that needs to talk to a real BIOS won't run under WINE. However this
should not be a problem as very few apps actually need to talk to a real BIOS,
instead letting the OS handle that. A bigger hurdle for Mac users will be that
WINE runs under X.

Le 06-03-16 à 13:48, keith025 a écrit :

> Does the issue of dropping EFI hold any problems for virtual
> Windows on Intel based Macs?

Not for running Windows in emulation (ala Virtual PC). I just wrote
up my experiences on this very thing a couple of days ago - I spent
some time getting Windows XP to run under the "Q" open source emulator.

<http://www.beatnikpad.com/archives/2006/03/20/windows-mac-q>

Speed is adequate for basic stuff (browser testing and such), and
most things seem to work well. It's not as fast as Virtual PC, but
apparently there's work being done on a kernel extension which will
enable Q to run in virtualization mode. If I understand this
correctly, on Intel macs virtualization will mean near-native
performance.

Neil
--
Slumming at the BeatnikPad : http://www.beatnikpad.com/
The person you love is 72.8% water.

On 21 Mar 2006, at 09:17 , kevinvanhaaren.net wrote:
> A bigger hurdle for Mac users will be that WINE runs under X.

And realistically, this makes it a non-starter. I mean, seriously,
this is simply not a realistic solution for the vast majority of users.

--
Spontaneity has its time and place.

On Mar 21, 2006, at 1:51 PM, Google Kreme wrote:

> On 21 Mar 2006, at 09:17 , kevinvanhaaren.net wrote:
>> A bigger hurdle for Mac users will be that WINE runs under X.
>
> And realistically, this makes it a non-starter. I mean, seriously,
> this is simply not a realistic solution for the vast majority of
> users.

But we're discussing a smallish subset of the vast majority of users--
those who need to and are willing to run Windows. That subset should
be put off less by X-Windows (interesting naming that long predated
both Mac OS X and Windows) than would the whole of the vast majority
of users.

Whether it's enough less or not, I don't know.

   --John