From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 4 Dec 2001 19:50:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 4 Dec 2001 19:49:55 -0500 Received: from ziggy.one-eyed-alien.net ([64.169.228.100]:63751 "EHLO ziggy.one-eyed-alien.net") by vger.kernel.org with ESMTP id ; Tue, 4 Dec 2001 19:49:46 -0500 Date: Tue, 4 Dec 2001 16:49:41 -0800 From: Matthew Dharm To: "H. Peter Anvin" Cc: Ingo Oeser , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Endianness-aware mkcramfs Message-ID: <20011204164941.A29968@one-eyed-alien.net> Mail-Followup-To: "H. Peter Anvin" , Ingo Oeser , linux-kernel@vger.kernel.org In-Reply-To: <3C0BD8FD.F9F94BE0@mvista.com> <3C0CB59B.EEA251AB@lightning.ch> <9uj5fb$1fm$1@cesium.transmeta.com> <20011205013630.C717@nightmaster.csn.tu-chemnitz.de> <3C0D6CB6.7000905@zytor.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3C0D6CB6.7000905@zytor.com>; from hpa@zytor.com on Tue, Dec 04, 2001 at 04:39:18PM -0800 Organization: One Eyed Alien Networks X-Copyright: (C) 2001 Matthew Dharm, all rights reserved. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable There is another argument for supporting both endiannesses.... Consider an embedded system which can be run in either endianness. Sounds silly? MIPS processors can run big or little endian, and many people routinely switch between them. Matt On Tue, Dec 04, 2001 at 04:39:18PM -0800, H. Peter Anvin wrote: > Ingo Oeser wrote: >=20 > >=20 > > Yes, from a CS point of view.=20 > >=20 > > But practically cramfs is created once to contain some kind of > > ROM for embedded devices. So if we never modify these data again, > > why not creating it in the required byte order?=20 > >=20 > > Why wasting kernel cycles for le<->be conversion? Just because > > it's more general? For writable general purpose file systems it > > makes sense, but to none of romfs, cramfs etc. > >=20 >=20 >=20 > Because otherwise you far too easily end up in a situation where every > system suddenly need to be able to support *BOTH* endianisms, at which > point you're really screwed; supporting dual endianism is significantly > more expensive than supporting the "wrong" endianism, and it affects all > systems. >=20 > Nip this one in the bud. >=20 > -hpa >=20 >=20 > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ --=20 Matthew Dharm Home: mdharm-usb@one-eyed-alien.= net=20 Maintainer, Linux USB Mass Storage Driver M: No, Windows doesn't have any nag screens. C: Then what are those blue and white screens I get every day? -- Mike and Cobb User Friendly, 1/4/1999 --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE8DW8lz64nssGU+ykRAuFAAKDYjdcFn0R/2fSyZfT36yIfN3dhzACeMPRZ pNWppLlrw8i2BtiO8O2QoPA= =oqd1 -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd--