From: alaric AT abwillms DOT demon DOT co DOT uk (Alaric B. Williams)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Interrupt Handling in C
Date: Fri, 13 Dec 1996 18:01:15 GMT
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Message-ID: <850500059.16055.0@abwillms.demon.co.uk>
References: <Pine DOT SGI DOT 3 DOT 91 DOT 961211110523 DOT 10278A-100000 AT chinook DOT physics DOT utoronto DOT ca>
NNTP-Posting-Host: abwillms.demon.co.uk
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Peter Berdeklis <peter AT atmosp DOT physics DOT utoronto DOT ca> wrote:


>The DJGPP FAQ suggest that "bullet proof" interrupt handlers must be 
>written in ASM.  What is it that prevents DJGPP from outputing bullet 
>proof code in C?  Could someone give me some hints.  

>As you can probably guess I want to write an interrupt handler in C.  I 
>could certainly modify the gcc -S output if necessary, but what traps 
>should I be looking for.

>Does someone have a DJGPP hardware/interrupt programing FAQ I could look at?

Kerching!

Browse around "http://www.abwillms.demon.co.uk/prog/"

There's a tutorial on the theory I wrote, which contains a simple
hardware library I wrote. When you're read that, I'd recommend
downloading the wizz-bang libhw library from the same page, which does
quite a few useful things.

I've based the security of the interrupt handlers around a cunning
method of marking stuff as locked, which requires the removal of a gcc
bug. Patched versions of the executables cc1.exe and cc1plus.exe are
gettable from the page - select the appropriate one for your version
of DJGPP (v2 or v2.01)

>Thank you.

The pleasure is all mine!

>---------------
>Peter Berdeklis
>Dept. of Physics, Univ. of Toronto

Hmmm - what's a physicist want with interrupt handlers? I'd be well
proud if libhw were used to control a data logging device or something
cool like that :-)


ABW
--

"Simply drag your mother in law's cellphone number from the
Address Book to the Laser Satellite icon, and the Targeting
Wizard will locate her. Then follow the onscreen prompts for
gigawattage and dispersion pattern..."

(Windows for Early Warning and Defence User's manual P385)

Alaric B. Williams Internet : alaric AT abwillms DOT demon DOT co DOT uk
<A HREF="http://www.abwillms.demon.co.uk/">Hello :-)</A>