Date:	Tue, 4 May 1999 11:15:45 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	Shawn <NRLax27 AT aol DOT com>
cc:	djgpp AT delorie DOT com
Subject:	Re: Operating System Development
In-Reply-To:	<372e19b7.0@oit.umass.edu>
Message-ID:	<Pine.SUN.3.91.990504111527.16899P-100000@is>
MIME-Version:	1.0
Reply-To:	djgpp AT delorie DOT com
X-Mailing-List:	djgpp AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On Mon, 3 May 1999, Shawn wrote:

> it appears that DJGPP outputs DOS dependant code.  Is there anyway
> around this?

The code emitted by the DJGPP port of GCC is *not* DOS-dependent, it
is 32-bit x86 machine code that assumes flat address space (i.e., the
segment registers are NOT reloaded by the emitted code).

What *is* DOS-dependent are the library functions and the run-time
environment.  These are separate pieces of software that are generally
either linked with (the library) or prepended to (the stub loader) the
object code emitted by the compiler.

If you want to retarget the development environment, you will need to
do several things:

  - reconfigure and rebuild the Binutils package (only if you want to
    use object file format other than COFF);
  - rewrite large portions of the library that issue DOS calls;
  - write your own startup code.

- Raw text -