From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 18 Mar 2007 02:05:28 +0000 (GMT) Received: from rwcrmhc14.comcast.net ([204.127.192.84]:25569 "EHLO rwcrmhc14.comcast.net") by ftp.linux-mips.org with ESMTP id S20022880AbXCRCF0 (ORCPT ); Sun, 18 Mar 2007 02:05:26 +0000 Received: from [192.168.1.4] (c-68-34-70-207.hsd1.md.comcast.net[68.34.70.207]) by comcast.net (rwcrmhc14) with ESMTP id <20070318020441m1400iqsrbe>; Sun, 18 Mar 2007 02:04:42 +0000 Message-ID: <45FC9E39.7010506@gentoo.org> Date: Sat, 17 Mar 2007 22:04:41 -0400 From: Kumba User-Agent: Thunderbird 2.0b2 (Windows/20070116) MIME-Version: 1.0 To: Linux MIPS List CC: Arnaud Giersch Subject: Re: IP32 prom crashes due to __pa() funkiness References: <45D8B070.7070405@gentoo.org> <45FC46F0.3070300@gentoo.org> <87irczzglc.fsf@groumpf.homeip.net> In-Reply-To: <87irczzglc.fsf@groumpf.homeip.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 14525 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: kumba@gentoo.org Precedence: bulk X-list: linux-mips Arnaud Giersch wrote: > > I don't know if it is the RightWay(TM), but I am running here a fresh > IP32 kernel (l.m.o git updated yesterday). It was compiled with > CONFIG_BUILD_ELF64=n, and I am using vmlinux. > > $ file /boot/vmlinux-2.6.21-rc3-g839fd555 > /boot/vmlinux-2.6.21-rc3-g839fd555: ELF 64-bit MSB executable, MIPS, MIPS-IV version 1 (SYSV), statically linked, not stripped > > If it makes a difference, I am using arcboot. I suppose then the question is, which is better for IP32? CONFIG_BUILD_ELF64=y or CONFIG_BUILD_ELF64=n. The reason the o64 hack used to exist, if my memory serves me correctly, was that someone once said that when built and run as a pure 64bit binary converted to 32bit via objcopy, 6 extra insns were run every cycle (I think), introducing unneeded slowdown. This changed to 2 insns by going the o64 route, which involved CONFIG_BUILD_ELF64=n. So 4 less insns technically resulted in a quicker kernel, though the layman might not notice such. I believe that all changed at some point, which is why CONFIG_BUILD_ELF64=y was an A-OK thing prior to the __pa() introduction. Now I guess we're back to CONFIG_BUILD_ELF64=n? I guess the real question is, which way is the OneWay(TM), RightWay(TM) and OnlyWay(TM)? Cheers, --Kumba -- Gentoo/MIPS Team Lead "Such is oft the course of deeds that move the wheels of the world: small hands do them because they must, while the eyes of the great are elsewhere." --Elrond