From owner-freebsd-arch@FreeBSD.ORG Wed Jan 28 21:51:28 2009 Return-Path: Delivered-To: arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 74F2C106570F; Wed, 28 Jan 2009 21:51:28 +0000 (UTC) (envelope-from gad@FreeBSD.org) Received: from smtp6.server.rpi.edu (smtp6.server.rpi.edu [128.113.2.226]) by mx1.freebsd.org (Postfix) with ESMTP id EABDA8FC08; Wed, 28 Jan 2009 21:51:27 +0000 (UTC) (envelope-from gad@FreeBSD.org) Received: from [128.113.24.47] (gilead.netel.rpi.edu [128.113.24.47]) by smtp6.server.rpi.edu (8.13.1/8.13.1) with ESMTP id n0SLpHwv004811; Wed, 28 Jan 2009 16:51:17 -0500 Mime-Version: 1.0 Message-Id: In-Reply-To: <200901281540.30546.jhb@freebsd.org> References: <200901260947.32870.jhb@freebsd.org> <20090128.122411.1626285557.imp@bsdimp.com> <200901281540.30546.jhb@freebsd.org> Date: Wed, 28 Jan 2009 16:51:16 -0500 To: John Baldwin , "M. Warner Losh" From: Garance A Drosehn Content-Type: text/plain; charset="us-ascii" ; format="flowed" X-Bayes-Prob: 0.0001 (Score 0) X-RPI-SA-Score: 0.70 () [Hold at 20.00] COMBINED_FROM,J_CHICKENPOX_65 X-CanItPRO-Stream: outgoing X-Canit-Stats-ID: Bayes signature not available X-Scanned-By: CanIt (www . roaringpenguin . com) on 128.113.2.226 Cc: arch@FreeBSD.org, gad@FreeBSD.org Subject: Re: Trimming the default /boot/device.hints 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: Wed, 28 Jan 2009 21:51:29 -0000 At 3:40 PM -0500 1/28/09, John Baldwin wrote: >On Wednesday 28 January 2009 2:24:11 pm M. Warner Losh wrote: > > In message: > > Garance A Drosehn writes: > > : >> : We could even install the LEGACY.hints file as /boot/legacy.hints, >> : and then if someone has a problem we can say "go into the boot >> : loader, and type 'include /boot/legacy.hints'. If that doesn't >> : solve your problem, then your problem is not related to this big >> : change to /boot/device.hints". And if it *does* solve their problem, >> : they can just look at 'dmesg' after they boot up, and get a good idea >> : of what lines they need to add to /boot/device.hints. >> : >> : I don't see how this would cost us much (compared to *not* having a >> : legacy.hints file), and yet it might make things much easier if it >> : turns out that too many hints had been removed. >> >> Actually, that's a very clever idea you've stumbled into. The boot >> loader already know if acpi is involved, and could trivially be >> augmented to know if there's PNP data. If neither of them are in >> place, it could automatically load legacy.hints... >> >> But the cheap 'get the file there' is a good idea. > >What I'm worried about I guess is how long we have to maintain this. Also, >why do we have hints for ed0 but not ex0? That is, the current list is >rather arbitrary and only caters to certain rare hardware and not to other >rare hardware. I'd rather just do a simple clean break and drop all of the >rare hardware. I don't really think there will be anyone who actually >_needs_ to include /boot/legacy.hints, but we will be stuck with this very >arbitrary file forever. I don't see why we would be stuck with it forever. The only way the user will *use* the file is if they explicitly type "include /boot/legacy.hints" before 'boot' while in the boot loader. Every time they boot, they will have to go through these extra steps. Nothing will automatically use the file for them. The proposal is to remove a lot of lines. You then say "if this *does* cause a problem, they can always type in the 5 lines of hints that they need" -- assuming they know exactly which hints they need to type as they reboot into 8.0-RELEASE for the first time (which is when we are the most likely to see this hit non-developer users). Once a non- developer is in that situation, do you want to talk them through figuring out which hints they need, and then having them type in those lines? Or do you want to say: "Huh. I'm not sure what your problem is, but trying typing in this one line to the boot loader. If that works, then we can figure out what lines need to be added to your personal device.hints file for your specific hardware --- and you will never again have to type in 'include /boot/legacy.hints'". I'm not saying we keep installing the legacy.hints file forever. But it might be awfully convenient to have it there for 8.0-release and maybe 8.1-release (since we know many people won't really install 8.x-stable until 8.1-release). After that, we simply stop installing the file. And if we do have this convenient file there, then we can justify removing even more lines from default device.hints file, the one which is always automatically sourced for all users. A legacy.hints file just seems to be an extremely low-cost safety measure as we make the transition. Btw, I do very much like the idea of making device.hints smaller. -- Garance Alistair Drosehn = drosehn@rpi.edu Senior Systems Programmer or gad@FreeBSD.org Rensselaer Polytechnic Institute; Troy, NY; USA