From owner-freebsd-arch@FreeBSD.ORG Mon Oct 22 11:38:22 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 B5ABE16A418 for ; Mon, 22 Oct 2007 11:38:22 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from mrout3.yahoo.com (mrout3.yahoo.com [216.145.54.173]) by mx1.freebsd.org (Postfix) with ESMTP id A315D13C4DA for ; Mon, 22 Oct 2007 11:38:22 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from minion.local.neville-neil.com (proxy8.corp.yahoo.com [216.145.48.13]) by mrout3.yahoo.com (8.13.6/8.13.6/y.out) with ESMTP id l9MBRW59096524; Mon, 22 Oct 2007 04:27:33 -0700 (PDT) Date: Mon, 22 Oct 2007 19:27:25 +0800 Message-ID: From: gnn@freebsd.org To: "Kip Macy" In-Reply-To: References: User-Agent: Wanderlust/2.15.5 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.8 (=?ISO-8859-4?Q?Shij=F2?=) APEL/10.7 Emacs/22.1 (i386-apple-darwin8.9.1) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII 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 11:38:22 -0000 At Sun, 21 Oct 2007 20:56:35 -0700, Kip Macy wrote: > > 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 > If most of the bits will be shared, then lets share them, that is, use the second proposal. I couldn't find a good example in the tree for a precedent, though the powerpc might come close, with its powermac and powerpc sub-directories. > 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 > > > 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. Yes, this makes sense too. Thanks, George