From owner-freebsd-arch@FreeBSD.ORG Mon Oct 22 12:08:14 2007 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C938616A417 for ; Mon, 22 Oct 2007 12:08:14 +0000 (UTC) (envelope-from des@des.no) Received: from tim.des.no (tim.des.no [194.63.250.121]) by mx1.freebsd.org (Postfix) with ESMTP id 857FB13C48E for ; Mon, 22 Oct 2007 12:08:14 +0000 (UTC) (envelope-from des@des.no) Received: from tim.des.no (localhost [127.0.0.1]) by spam.des.no (Postfix) with ESMTP id 01C2420A0; Mon, 22 Oct 2007 13:50:28 +0200 (CEST) X-Spam-Tests: AWL X-Spam-Learn: disabled X-Spam-Score: -0.0/3.0 X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on tim.des.no Received: from ds4.des.no (des.no [80.203.243.180]) by smtp.des.no (Postfix) with ESMTP id E2EDA209F; Mon, 22 Oct 2007 13:50:27 +0200 (CEST) Received: by ds4.des.no (Postfix, from userid 1001) id A0C048448C; Mon, 22 Oct 2007 13:50:26 +0200 (CEST) From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= To: "Kip Macy" References: Date: Mon, 22 Oct 2007 13:50:26 +0200 In-Reply-To: (Kip Macy's message of "Sun\, 21 Oct 2007 20\:56\:35 -0700") Message-ID: <86lk9ve5bx.fsf@ds4.des.no> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.1 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-arch@freebsd.org Subject: Re: Should Xen be a sub-arch or a build option? X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Oct 2007 12:08:14 -0000 "Kip Macy" writes: > Let me say in advance that this is not an invitation to discuss the > technical merits of xen. This is purely a request to discuss how one > would structure the tree were one to import it into CVS. > > Hypothetically speaking, if one were to import Xen support into CVS > what would be the best way to go about it? > > There are a number of choices when doing it as a sub-arch: > - A separate directory for i386 and amd64 > - sys/xen-i386 > - sys/xen-amd64 > - A shared directory as most of the bits will be shared: > - sys/xen - common bits > - sys/xen/i386 - i386 specific bits > - sys/xen/amd64 - amd64 specific bits > > It could, in principle, also be done as a build option. I'm not sure > how well it would mesh with the existing build tools as there are a > number of files that I would not want to compile in (e.g. code that > talked directly to the BIOS) that is normally built by default. In > that case I would structure it: > > - sys/i386/xen - xen specific bits for i386 > - sys/amd64/xen - xen specific bits for amd64 I'd say a kernel option would be the best choice; code that isn't relevant for Xen but is otherwise compiled by default can be bracketed with #ifndef XEN. > There is also a question of where the drivers should be put. I propose > that they would be put under sys/dev/xen, so you would have e.g. > sys/dev/xen/xennet, sys/dev/xen/xenblk etc. Sounds reasonable. DES --=20 Dag-Erling Sm=C3=B8rgrav - des@des.no