Message-Id: <199512070126.TAA08745@ozzy>
To: Ty Sarna <tsarna@endicor.com>
Cc: port-i386@NetBSD.ORG
Subject: Re: ELF and Multiboot questions 
In-Reply-To: Your message of "Wed, 06 Dec 1995 13:50:21 CST."
             <199512061950.NAA16532@fezzik.endicor.com> 
Date: Wed, 06 Dec 1995 19:26:46 -0600
From: "Erik M. Theisen" <etheisen@teclink.net>
Sender: owner-port-i386@NetBSD.ORG
Precedence: list

>I just don't buy this. For things like nm, simply provide a different ELF
>version. (Which you'd need to write anyway if we went ELF cold-turkey.)
>Let usr.bin/nm/Makefile look at MACHINE or MACHINE_ARCH (or even
>MACHINE_OMF) and decide whether to built usr.bin/nm/aout/ or
>usr.bin/nm/elf/. The assembler and linker might be a little bit more
>difficult. Blatant hackery? No. No worse than having a zillion little
>elf-to-whatever convertes and such spread out in the different port's
>directories to convert to their native format (some of these exist
>already as a.out-to-whatever... why rewrite them?).

The tools are the least of the problems.  The system interfaces is were things
pick up steam.  The various interfaces are differnt enough to cause problems. 

>Face it, just like there are platforms that need ELF, there are
>platforms that need a.out.  It's going to have to stay in the toolchain.
>Further, sticking with a.out has advantges on many of the supported
>platforms, especially wrt binary backward compatibility (right now
>NetBSD 1.1 can be used to generate binaries for 1.0 without TOO much
>hassle... it'd be a lot more work if the 1.1 toolchain knew only ELF)
>and cross-OS emulation.

Backwards compatible is almost always evil ;-)!

>Besides, something else WILL come along to replace ELF one day, and then
>we'll have to go through all this again. Better to bite the bullet now
>and figure out how to reasonably support different formats on different
>platforms.

No doubt something will, but, ELF is expandable enough to support new platforms,
whereas a.out isn't. 

erik