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From: "John S. Dyson" <toor@dyson.iquest.net>
Message-Id: <199706010255.VAA06402@dyson.iquest.net>
Subject: Re: Binaries
In-Reply-To: <199705311936.NAA18541@obie.softweyr.ml.org> from Wes Peters at "May 31, 97 01:36:08 pm"
To: softweyr@xmission.com (Wes Peters)
Date: Sat, 31 May 1997 21:55:06 -0500 (EST)
Cc: psd@worldaccess.nl, questions@FreeBSD.ORG
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> pauld@mail.dotcom.fr writes:
>  > Which binary format does FreeBSD use? (I looked into a file but it wasn't
>  > ELF like linux uses and I don't know if it's still a.out but that wouldn't
>  > be that great I think (adress space, that's why linux uses ELF))
> 
> FreeBSD uses a.out because there aren't any good reasons to change.
> I'm not sure why Linux ended up with so many problems in their a.out
> format, and won't speculate to avoid starting a flame war.  ;^)
> 
> ELF does not grant any larger address space than a.out, the address
> space is pretty much dictated by the adressing model of the MMU.  As far
> as I know, both Linux and FreeBSD use the i386 32-bit flat memory model,
> which yeilds a virtual address space of 2^32 bytes.
> 
> FreeBSD does support Linux ELF binaries if you load the Linux emulator.
> 
One more thing, FreeBSD does have native ELF support available.  We have
intentionally decided not to make it standard yet.  The scales haven't
tipped in the ELF direction yet, but may someday.  There are a few
problems with a.out, but those aren't normally apparent...  ELF just isn't
the solution to every binary format problem.

ELF vs. a.out isn't generally a reason to choose an OS.

John