From: "Edmund Horner" <edmund1 AT geocities DOT com>
To: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Cc: <djgpp AT delorie DOT com>
Subject: RE: DXEs and other OSes
Date: Wed, 26 Jul 2000 01:40:57 +1200
Message-ID: <000001bff63d$f661b660$fc9260cb@morgoth>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0
Importance: Normal
In-Reply-To: <Pine.SUN.3.91.1000725153302.24883C-100000@is>
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
Reply-To: djgpp AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

A quick test in Linux resulted in a program that will correctly load and
execute the DXE test file compiled by DJGPP.  Of course this was an
extremely simple case...

Surely, though, the DXE mechanism involves nothing more than loading a piece
of machine code into memory and CALLing it.  Doesn't this mean that as long
as the instruction set doesn't change(*), a DXE will be binary portable?  (*
I actually expect the function calling mechanism, etc., would have to remain
the same, too.)

DXE modules have a hard time using any DOS or DPMI functions, they tend to
rely on the calling program for that...

Anyway, I thank you for your reasoning.

Edmund.

> > Considering a compiled DXE is virtually no more than pure machine code,
> > would a DXE compiled with DJGPP run fine with a program under Linux
> > (assuming the DXE mechanism was ported to linux, of course).
>
> Probably not.
>
> > That is, is the only difference between DJGPP and gcc for Linux the
> > libraries?
>
> No, that's not the only difference.  DJGPP uses a different object code
> format (COFF as opposed to ELF).  In addition, a DXE may, depending on
> what's in it, call DOS or DPMI functions which, of course, won't work on
> Linux.