From owner-svn-src-head@FreeBSD.ORG Mon Dec 1 19:32:40 2008 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8FD96106576F; Mon, 1 Dec 2008 19:32:40 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id 0DACB8FC1F; Mon, 1 Dec 2008 19:32:39 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [IPv6:::1]) (authenticated bits=0) by server.baldwin.cx (8.14.3/8.14.3) with ESMTP id mB1JW7SX099801; Mon, 1 Dec 2008 14:32:33 -0500 (EST) (envelope-from jhb@freebsd.org) From: John Baldwin To: Luigi Rizzo Date: Mon, 1 Dec 2008 13:58:15 -0500 User-Agent: KMail/1.9.7 References: <200811261801.mAQI1LRp062260@svn.freebsd.org> In-Reply-To: <200811261801.mAQI1LRp062260@svn.freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200812011358.15430.jhb@freebsd.org> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [IPv6:::1]); Mon, 01 Dec 2008 14:32:34 -0500 (EST) X-Virus-Scanned: ClamAV 0.93.1/8704/Mon Dec 1 11:39:36 2008 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=4.2 tests=AWL,BAYES_00,NO_RELAYS autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r185339 - head/sys/boot/i386/boot0 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Dec 2008 19:32:40 -0000 On Wednesday 26 November 2008 01:01:21 pm Luigi Rizzo wrote: > Author: luigi > Date: Wed Nov 26 18:01:21 2008 > New Revision: 185339 > URL: http://svn.freebsd.org/changeset/base/185339 > > Log: > Pass the pointer to the selected partition in %si to the next stage > boot code. The bug was introduced in rev.1.13, and went unnoticed > because FreeBSD's boot1 does not use it, but other systems might. > > (I have been struggling for almost a full day trying to figure out > why a syslinux'ed partition would not boot when started with the > FreeBSD /boot/boot0, only to realize that the bug was ours!) > > The space for the two extra bytes (push %si and pop %si) is reclaimed > by removing an extra CRLF that is printed before booting. > > The bug is not a major one but if there is time it might be a good > thing to merge it into the upcoming releases. Note that there is nothing (no standard, etc.) that requires any MBR boot loader to pass anything besides %dl (boot device ID) to other loaders. However, we did used to do this and had an 'XXX: what does %si carry?' comment that 1.13 removed. I would suggest adding a more expanded comment about '%si' in the block comment above this code where the old 'XXX' comment was detailing why %si is preserved. -- John Baldwin