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Message-ID: <4058F337.1080703@bellard.org>
Date: Thu, 18 Mar 2004 01:54:15 +0100
From: Fabrice Bellard <fabrice@bellard.org>
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Subject: Re: [Qemu-devel] qemu and OS/2
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To: gwa@alumni.cmu.edu, qemu-devel@nongnu.org

Greg Alexander wrote:
> 
> 
> Fabrice Bellard wrote:
> 
>> Hi,
>>
>> Can you try the CVS ? I made a specific VGA fix for the OS/2 install 
>> (you can see the OS/2 & IBM logo), but there are still problems after.
>>
>> If OS/2 does not rely on segment limit checks or weird FPU exceptions, 
>> then there is a chance that QEMU can launch it soon.
> 
> 
> If I remember correctly, at least the early versions of OS/2 DID rely on 
> segment limit checks.  This allowed it to do multitaking on 286 
> processors, and a lot of that mechanism was still used in the 386 code.

It is possible and easy to add full segment limit and right checks in 
QEMU with a runtime selectable option. It would impact mostly 16 bit 
code and the slowdown would be small: because QEMU is a dynamic 
translator, some tests can be done at translation time.

Unfortunately it is not yet on the top on my TODO list :-(

Fabrice.