From: Karl Rasmussen <karl AT vvm DOT com>
Newsgroups: comp.os.msdos.djgpp,gnu.gcc.help
Subject: embedded 16 bit, real mode, x86 target for gcc?
Date: Wed, 03 May 2000 10:14:58 -0500
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

I am writing some low level IO code (essentially BIOS equivalent) for an
embedded project. If possible, C would be prefered to assembly language
(goal: 90% C, 10% assembly or better). We need some code to be 16 bit
compatible for legacy interface requirements. For other parts, 32 bit is
fine, though not required.

I was hoping to find a gcc back end for this. If it would look like a 16
bit x86 cross compiler, that would be great. Our development environment
is 32 bit x86, Linux or Win 9x, NT 4. 

I was excited to find DJGPP, but from the FAQ I get the message this is
not what DJGPP is. Nor did any of the other gcc builds or compilers seem
to claim to do this. Did I miss something? Is there any gcc based
solution? Or do I need to get an old Borland or MS 16 bit compiler?

The DJGPP solution with dpmi services is quite clever, but I can't use
that trick. The code I'm writing is already at the level that is
supposed to be implementing those functions for real.

(Yes, I tried to push back the 16 bit requirement and see if we could go
all 32 bit, and we are stuck with the 16 bit requirement.)

Any pointers or ideas will be appreciated.

Thanks,

Karl Rasmussen
karl AT vvm DOT com