From: "Alexei A. Frounze" <alex DOT fru AT mtu-net DOT ru>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Interrupt wrapper (was Re: keyboard interrupt)
Date: Tue, 28 Mar 2000 18:10:41 +0400
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

Jonathan Meunier wrote:
> 
> In this case, wouldn't the _go32_dpmi_allocate_iret_wrapper() wrapper
> take care of this? I don't see why it shouldn't work...

I do not know. Btw, as a programmer that works with low-level stuff, I
like clear stuff just like typical IRQ ISR. I.e. with saving registers,
loading segments, performing I/O, acknowleging IRQ, returning back via
IRET(D).


> 
> (and to merge your other post)..
> As for your wrapper source code you posted, I would like some
> clarification.. What is ___djgpp_ds_alias? is it just some sort of
> pointer to the data segment?

Yes, it's a variable where program's data selector is stored.

> 
> But what exactly is a wrapper; why do we need one?

I already answered this question... Since, DJGPP/GCC doesn't support
definitions of Interrupt Service Routines (using "interrupt" reserved
word or something similar) with register save/load, ... and IRET(D), we
should do this with ASM. Clear?

Alexei A. Frounze
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