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Mail Archives: djgpp-workers/1998/01/07/08:19:16

Sender: vheyndri AT rug DOT ac DOT be
Message-Id: <34B380C7.21B7@rug.ac.be>
Date: Wed, 07 Jan 1998 14:19:04 +0100
From: Vik Heyndrickx <Vik DOT Heyndrickx AT rug DOT ac DOT be>
Mime-Version: 1.0
To: DJ Delorie <dj AT delorie DOT com>
Cc: djgpp-workers AT delorie DOT com
Subject: Re: djgpp v2.02 alpha 980101
References: <199801071311 DOT IAA14152 AT delorie DOT com>

DJ Delorie wrote:
> 
> > You should make it 0x10FFFF. Please read my previous email which
> > explains why. The reason it works under DOS is simply because CS has
> > more brains than other DPMI implementors.
> 
> I *can't* make it 0x10ffff.  The 80386 CPU chip doesn't have that much
> resolution.  The size of segments larger than 64k must be multiples of
> 4K.  The closest 4k to 0x10ffff is 0x110000.

You *can*. You even cannot do otherwise.
You are right but the resolution for 20+ bits addresses, but a segment
which has a size of N has a limit of N-1. The guys who wrote the DPMI
spec's required (not in that many words, IIRC) you should pass the limit
with the 12 LSbits set. Under CWSDPMI this causes the actual limit to be
4K more than you intended it to be, i.e 0x110FFF.

Please read my previous email on...

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