From owner-freebsd-amd64@FreeBSD.ORG Sat Apr 8 08:15:17 2006 Return-Path: X-Original-To: freebsd-amd64@freebsd.org Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2E4B416A400 for ; Sat, 8 Apr 2006 08:15:17 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) Received: from cs1.cs.huji.ac.il (cs1.cs.huji.ac.il [132.65.16.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id 99F1143D55 for ; Sat, 8 Apr 2006 08:15:16 +0000 (GMT) (envelope-from danny@cs.huji.ac.il) Received: from pampa.cs.huji.ac.il ([132.65.80.32]) by cs1.cs.huji.ac.il with esmtp id 1FS8bD-000OjG-2i; Sat, 08 Apr 2006 11:15:15 +0300 X-Mailer: exmh version 2.7.0 06/18/2004 with nmh-1.0.4 To: Astrodog In-Reply-To: Message from Astrodog of "Fri, 07 Apr 2006 21:38:19 +0800." <2fd864e0604070638n11ff30f1pa9ad3fe5ac669ea7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Date: Sat, 08 Apr 2006 11:15:15 +0300 From: Danny Braniss Message-ID: Cc: freebsd-amd64@freebsd.org Subject: Re: safe way to build i386 arch makeworld on amd64 arch? X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 08 Apr 2006 08:15:17 -0000 > On 4/7/06, Danny Braniss wrote: > > > hello list, > > > > > > is there a save way to 'downgrade' an amd64 build system by using '= make world' ? > > > > > > e.g. just remove the CPUTYPE=3Dopteron from the make.conf file and = do a > > > build world/kernels install world/kernels ? > > > > > > of do we need to do some more for this? > > > > > > thanks in advance > > > > > > Regards > > > patrick > > > > = > To downgrade? Not realistically. > = > > you can, i do: > > export MAKEOBJDIRPREFIX=3D/somwhersafe-i386 > > make TARGET_ARCH=3Di386 buildworld > > same for buildkernel, installworld/installkernel, and also you can sp= ecify > > a different DESTDIR=3D > > > > danny > > > = > That would certainly allow him to crosscompile an i386 kernel, and > world, but wouldn't have much effect on downgrading from AMD64 to > i386, since you run into a chicken or the egg problem with the kernel, > and world. (a 64-bit kernel does not play nice on a 32-bit world, > without some hacking around, and a 32-bit kernel does not play nice on > a 64-bit world), which makes it impossible to actually do both steps. > = > If you install the 32-bit kernel first, and reboot, the kernel won't > be able to run the 64-bit binaries. If you install the 32-bit world > first, the 64-bit kernel will become very, very sad, and won't let the > installation complete. > = > If you try to install the kernel, then the world without a reboot, you > have the same problem as installing the 32-bit world first, since even > with a 32-bit kernel installed, you're still RUNNING the 64-bit kernel > until you reboot. > = > There are actually ways to do this, but its almost always a bad idea. > Not to mention this will break any packages, or ports you're using > too, with the exception, perhaps, of Linux Compat. You are of course correct, but then again, I did mention DESTDIR=3D and MAKEOBJDIRPREFIX. personaly, machines that are not diskless, i tend to have 2 root slices (it only needs some 500 Mgb), and install on a non active slice/partition= , then i do 'boot0cfg -sn device'. When that fails i do have to go to the consol= e and reboot from the old partition :-(, this is nice if the console is walking distance away ... danny