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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!newsfeed.nacamar.de!fu-berlin.de!irz401!orion.sax.de!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: ELF? Date: 30 Apr 1997 21:52:46 GMT Organization: Private BSD site, Dresden Lines: 35 Message-ID: <5k8eve$8j@uriah.heep.sax.de> References: <cmott-2004971630470001@192.168.0.5> <5jooj9$9c8@uriah.heep.sax.de> <33609855.6725@desy.de> <29577CEB029DEE7D.15EB282B5ACE579C.9F4A01791A26A597@library-proxy.airnews.net> <3363BCCC.3DF5@desy.de> <87hggsm9d8.fsf@altair.franken.de> <y7z3esb5v7l.fsf@hzsbc259.nl.lucent.com> <sej9121qqzk.fsf@ethanol.gnu.ai.mit.edu> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.6 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:40069 Joel Ray Holveck <joelh@gnu.ai.mit.edu> wrote: > I don't design linkage formats, I just link. So, what's the > difference between a.out, b.out, ELF, and coff? I can't explain any and all differences (and i don't even know b.out), but in short: a.out: Oldest, and `classic' unix object format. Short and compact header, with a magic number at the beginning that's often used to characterize the format. Three loaded segments: .text, .data, and .bss, plus a symbol table and a string table in the file. COFF: SVR3 object format. The header now comprises a section table, so you can have more than just .text, .data, and .bss. IIRC, the section length values are 16-bit entities only. ELF: Successor of COFF. Multiple sections, and 32-bit or 64-bit numbers possible. Major drawback: ELF has been designed in the assumption that there will be only one ABI per architecture. There isn't actually, not even in the commercial SysV world (which has at least three ABIs: SVR4, Solaris, SCO). -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)