From owner-svn-src-all@FreeBSD.ORG Tue Dec 2 21:15:08 2008 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D89E1106576E; Tue, 2 Dec 2008 21:15:08 +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 B42208FC0C; Tue, 2 Dec 2008 21:15:07 +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 mB2LEsxJ011443; Tue, 2 Dec 2008 16:15:01 -0500 (EST) (envelope-from jhb@freebsd.org) From: John Baldwin To: Luigi Rizzo Date: Tue, 2 Dec 2008 14:24:58 -0500 User-Agent: KMail/1.9.7 References: <200812021457.mB2Evmha063418@svn.freebsd.org> In-Reply-To: <200812021457.mB2Evmha063418@svn.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200812021425.00173.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [IPv6:::1]); Tue, 02 Dec 2008 16:15:01 -0500 (EST) X-Virus-Scanned: ClamAV 0.93.1/8712/Tue Dec 2 12:14:43 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: r185562 - head/sys/boot/i386/boot0 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 Dec 2008 21:15:09 -0000 On Tuesday 02 December 2008 09:57:48 am Luigi Rizzo wrote: > Author: luigi > Date: Tue Dec 2 14:57:48 2008 > New Revision: 185562 > URL: http://svn.freebsd.org/changeset/base/185562 > > Log: > This commits brings in a lot of documentation and some enhancement > of the boot0.S code, with a number of compile-time selectable options, > the most interesting one being the ability to select PXE booting. > > The code is completely compatible with the previous one, and with > the boot0cfg program. Even the actual code is largely unmodified, > with only minor rearrangements or fixes to make room for the new > features. > > The behaviour of the standard build differs from the previous > version in the following, minor things: > > + 'noupdate' is the default, which means the code does not > write back the selection to disk. You can enable the feature > at runtime with boot0cfg, or changing the flags in the Makefile. > > + a drive number of 0x00 (floppy, or USB in floppy emulation) is > now accepted as valid. Previously, it was overridden with 0x80, > meaning that the partition table coming from the media was > used to access sectors on a possibly different media. > You can revert to the previous mode building with -DCHECK_DRIVE, > and you can always use the 'setdrv' option in boot0cfg I would flip this back to the original default. This was there to workaround certain broken BIOSes that incorrectly specified a drive of 0x00 when you booted from the hard drive (at least according to the comments). On such systems they will now fail to boot. MBR's aren't really supported on floppies, so you shouldn't ever have a legitmate %dl of 0x00. In the rare case that you do you could use the 'setdrv' option to boot0cfg. -- John Baldwin