From owner-freebsd-questions@FreeBSD.ORG Wed Nov 21 08:42:58 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 238B9556 for ; Wed, 21 Nov 2012 08:42:58 +0000 (UTC) (envelope-from freebsd@qeng-ho.org) Received: from blue.qeng-ho.org (blue.qeng-ho.org [217.155.128.241]) by mx1.freebsd.org (Postfix) with ESMTP id A094B8FC14 for ; Wed, 21 Nov 2012 08:42:57 +0000 (UTC) Received: from fileserver.home.qeng-ho.org (localhost [127.0.0.1]) by fileserver.home.qeng-ho.org (8.14.5/8.14.5) with ESMTP id qAL8gnQ2082826; Wed, 21 Nov 2012 08:42:50 GMT (envelope-from freebsd@qeng-ho.org) Message-ID: <50AC9409.1030609@qeng-ho.org> Date: Wed, 21 Nov 2012 08:42:49 +0000 From: Arthur Chance User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2 MIME-Version: 1.0 To: Warren Block Subject: gpt booting (Was: Re: boot problem after freebsd-update from 9.1-RC2 to 9.1-RC3) References: <50ABE97B.5030408@johnea.net> <50AC041A.7050607@dreamchaser.org> <50AC3116.6010600@johnea.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Nov 2012 08:42:58 -0000 On 11/21/12 05:11, Warren Block wrote: > gptboot looks for the first UFS partition. Maybe /boot/boot can be > modified to do that also. It's a little more complicated than that Warren. AIUI gptboot first looks (in partition order) for partitions with both the bootme and bootonce attributes set. If it doesn't find any, or if they all failed to boot it then tries booting partitions with just the bootme attribute. It only boots the first UFS partition if no partitions have the bootme attribute set, and IIRC that is for compatibility with the 8.x gptboot which didn't know the boot* attributes. Confusingly, there's no manual page for gptboot to document this. It's sort of implicit in the gpart manual page, in the section on ATTRIBUTES for GPT, but the best way to understand it is to read the code for gptfind in /usr/src/sys/boot/common/gpt.c