From: J DOT J DOT vanderHeijden AT student DOT utwente DOT nl (J.J. van der Heijden)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: cross-compiling: FROM linux TO msdos
Date: Sun, 17 Nov 1996 12:57:22 GMT
Organization: University of Twente, Enschede, The Netherlands
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Message-ID: <328f09db.1399130@news.student.utwente.nl>
References: <56lkks$gpg AT agate DOT berkeley DOT edu>
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To: djgpp AT delorie DOT com
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On 17 Nov 1996 00:01:32 GMT, cdamond AT uclink2 DOT berkeley DOT edu wrote:

>I'm trying to compile a C cross-compiler out of the gcc sources.  I want
>it run with an i486-unknown-linux host and i486-unknown-msdos target, and
>I'm compiling it on an i486-unknown-linux (host==server).  Thus, this is
>sort of the inverse of djgpp.
>
>So far, following the directions, I've managed to successfully compile
>gcc-2.7.2.1 with i486-unknown-linux -> i486-unknown-linux, but when I try
>to specify the target as msdos, it says that that configuration is not
>supported, when it is specifically mentioned in the docs as a supported
>target. I know I also need cross-compiled binutils eventually (the
>instructions don't seem to indicate that I don't need them yet) but the
>directions on building them for a cross-compiler are much worse than
>gcc's.
>
>So, a few questions for someone who's done this before (or someone smart
>who hasn't):
>

I did this; you can download the complete toolchain from you nearest
SunSite linux mirror, directory is devel/msdos.

It's still v2.0 though (didn't bother to upgrade yet)

>+Why does the gcc configuration utility not acknowledge the valid target
> msdos?

You have to edit `config.sub' and add -go32* to list of supported OS's

>
>+Is there an easier way to do this, since I know the processor is the same
> (and thus the assmbler code should be, shouldn't it?)
>
No. Linux uses ELF object format, DJGPP uses COFF.

>+How do you build the binutils for a cross-compiler?  Do I need to, given
> that they are intended to produce code for the same processor?
>
./configure --host=i486-linux --target=i386-go32 --build=i486-linux

*BUT* you need some patches to change the default object format from
coff-i386 to coff-go32

>+Is there anything else besides gcc and binutils I need (special msdos
> libraries or headers for example) to set up a cross-compiler?

You need a C-library, which is basically djdevXXX.zip with the header
files converted to UNIX text format.

/janjaap