From owner-freebsd-hackers Wed Feb 17 10:44:41 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from stephens.ml.org (cm2081634025.ponderosa.ispchannel.com [208.163.40.25]) by hub.freebsd.org (Postfix) with ESMTP id D0F70113CE for ; Wed, 17 Feb 1999 10:44:39 -0800 (PST) (envelope-from tas@stephens.ml.org) Received: from stephens.ml.org (localhost.loc [127.0.0.1] (may be forged)) by stephens.ml.org (8.9.1/8.9.1) with ESMTP id SAA24903; Wed, 17 Feb 1999 18:44:38 GMT (envelope-from tas@stephens.ml.org) Message-Id: <199902171844.SAA24903@stephens.ml.org> To: freebsd-hackers@FreeBSD.ORG Cc: Thomas Stephens From: Thomas Stephens Subject: ELF, System V and multiple ABIs Date: Wed, 17 Feb 1999 10:44:38 -0800 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I recently noticed a potential ELF issue, and didn't find any references to it in the FreeBSD list archives, so am bringing it up here. I was looking over the latest System V ABI draft, and noticed there is an update (dated April 1998) which includes modifications to the ELF format. Significantly, the usage of the e_ident array in the ElfXX_Ehdr structure has changed slightly, in order to allow for multiple ABIs on each hardware platform. While the ELF format defined in the previous draft only used the first seven bytes of e_ident, with byte eight (EI_PAD) representing the start of padding, the current one adds two new values to support an OS/ABI identifier number followed by a version. As a side-effect, EI_PAD has been redefined: EI_OSABI 7 (OS/ABI identifier) EI_ABIVERSION 8 (OS/ABI version) EI_PAD 9 This new version of ELF currently defines EI_OSABI values for System V, HP-UX and stand-alone (embedded) applications, but it seems to me it would make things much easier if all ELF-compatible systems were to adopt it. The URL for the System V spec update is: http://www.sco.com/developer/gabi/contents.html One way or the other, this change means SCO binaries will be incompatible with FreeBSD's branding scheme. Assuming a move to IA-64, it would also affect potential compatibility with HP and IBM binaries. I'd be interested in any comments with regard to adopting this change in FreeBSD, as well as an idea the likelihood of Linux, NetBSD, etc. adopting it. Thomas Stephens tas@stephens.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message