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Mail Archives: djgpp/1999/05/04/13:19:40

From: "Christopher Nelson" <paradox AT gye DOT satnet DOT net>
To: <djgpp AT delorie DOT com>
Subject: Re: Operating System Development
Date: Tue, 4 May 1999 09:09:42 -0600
Message-ID: <01be9640$232ede20$LocalHost@thendren>
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Reply-To: djgpp AT delorie DOT com

>I'm beginning to work on a new operating system for Intel 80386 or higher.
>I had planned to use DJGPP and NASM to do this, but it appears that DJGPP
>outputs DOS dependant code.  Is there anyway around this?  Is there another
>C compiler to use?


DJGPP doesn't output DOS-dependent code, what it outputs is 32-bit,
protected mode instruction.  ld links that code with a stub, thus making the
executable DOS-dependant.

there are two very important things to note here:

 #1 if you are writing a bootloader it must be 16-bit.  it must also by a
flat image.  if you don't know what those two things mean/are you need to do
a bit of research.

#2 the code image is inside the .o files produced from gcc -c -o <output>
<source>.  if you wish to get to them you must either write your own program
to do it (it's not hard) or get JLOC from John Fine's page.  i forget the
exact URL.  you CAN do it with ld, but it's a major pain.  it's easier to do
it with JLOC or even write your own.

please remember that you cannot use libc until you port the low-level
functions to your operating system.

    -={C}=-

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