From owner-svn-src-head@FreeBSD.ORG Tue Sep 29 12:04:07 2009 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 AFD061065696; Tue, 29 Sep 2009 12:04:07 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 8232A8FC20; Tue, 29 Sep 2009 12:04:07 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 10CD246B06; Tue, 29 Sep 2009 08:04:07 -0400 (EDT) Received: from jhbbsd.hudson-trading.com (unknown [209.249.190.8]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 67F898A024; Tue, 29 Sep 2009 08:04:06 -0400 (EDT) From: John Baldwin To: Marcel Moolenaar Date: Tue, 29 Sep 2009 07:49:07 -0400 User-Agent: KMail/1.9.7 References: <200909282352.n8SNql1n069970@svn.freebsd.org> In-Reply-To: <200909282352.n8SNql1n069970@svn.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200909290749.08764.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Tue, 29 Sep 2009 08:04:06 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00,RDNS_NONE autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r197608 - head/sys/geom/part 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: Tue, 29 Sep 2009 12:04:07 -0000 On Monday 28 September 2009 7:52:47 pm Marcel Moolenaar wrote: > Author: marcel > Date: Mon Sep 28 23:52:47 2009 > New Revision: 197608 > URL: http://svn.freebsd.org/changeset/base/197608 > > Log: > The first 96 bytes may not be zeroes. It can contain trivial boot > code that merely emits an error and waits for a key press before > rebooting. The error being that extended partitions are not > bootable. The origin is presumed to be Windows 2000; Windows XP > does not do this... > > For now, ignore the first 96 bytes when checking that the EBR is > (for the most part) all zeroes. > > Tested by: Mario Lobo > MFC after: 1 week > > Modified: > head/sys/geom/part/g_part_ebr.c Why do you check for zeros at all? AFAIK, the only real check is for AA55 at the end of the sector (and having an MBR or other Extended MBR partition entry point at the sector in question). The '96' thing seems rather arbitrary in the code, and I think the zero's check is overly restrictive. -- John Baldwin