Date: Wed, 24 Sep 1997 16:56:31 -0700 (PDT)
Message-Id: <199709242356.QAA22538@adit.ap.net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
To: Larry Swanson <laswanson AT mwci DOT net>, djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: NASM + DJGPP newbie problem
Precedence: bulk

At 07:52  9/17/1997 -0500, Larry Swanson wrote:
>
>Hello
>
>I recently decided to learn how to program in assembly using NASM and
>DJGPP.  I'm having a problem trying to get the following code to work.
>(I usually get a message like 'access denied') that appears to be when I
>push something on the stack.
Perhaps try single-stepping it with a debugger. Then you may be able to
determine which instruction causes the invalid memory access.
>
>Also I have a few questions
>I know that  SS=stack selector,  CS = code selector, DS= data selector
>and that ES is extra selector. My question is, what are fs and gs? can I
>put a selector for the LFB there and leave it there or does DJGPP use it
>for anything?
FS and GS are two extra selector registers. I think the official word is
that you shouldn't count on having them be preserved across calls to library
functions.

Nate Eldredge
eldredge AT ap DOT net