Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!asuvax!ncar!ico!rcd
From: rcd@ico.isc.com (Dick Dunn)
Newsgroups: comp.unix.sysv386
Subject: Re: Why can't elves cough? (terminology)
Summary: BCS vs ABI, SVID, etc. clarification
Message-ID: <1991Mar14.001906.29397@ico.isc.com>
Date: 14 Mar 91 00:19:06 GMT
References: <6405@unix386.Convergent.COM> <10719@scolex.sco.COM> <1991Mar13.095416.7172@kithrup.COM>
Organization: Interactive Systems Corporation, Boulder, CO
Lines: 26

To clarify some points which seemed confused in the discussion between Sean
Fagan and Mike Burg:  The terms "BCS" and "ABI" refer to different animals,
although they're both of the same species (a definition of a "system inter-
face for compiled application programs").

Background: SVID == System V Interface Definition - definition of the
programs, system calls, libraries, etc.

BCS == Binary Compatibility Specification:  This is the V.3.2 animal; it
refers to SVID 2nd edition; COFF spoken here.  COFF == Common Object File
Format.  BCS is undergoing extensive revision (mostly extension) to cover
things not present in the original version.  You'll hear this work called
"BCS2".

ABI == Application Binary Interface:  This is the V.4 animal; it refers to
SVID 3rd edition; ELF is a part of it.  ELF == Executable and Linking
Format.  However, note that V.4 will provide support for BCS (and there-
fore can run COFF programs).  I don't know, but I would not expect support
for ELF on V.3.2 systems--why retrofit it, rather than just go to V.4?

Summary:
	BCS	V.3.2	COFF	SVID 2
	ABI	V.4	ELF	SVID 3
-- 
Dick Dunn     rcd@ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
   ...But is it art?