From owner-freebsd-current@freebsd.org Mon Jul 13 17:35:18 2015 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6337299B2A0 for ; Mon, 13 Jul 2015 17:35:18 +0000 (UTC) (envelope-from allanjude@freebsd.org) Received: from mx1.scaleengine.net (mx1.scaleengine.net [209.51.186.6]) by mx1.freebsd.org (Postfix) with ESMTP id 4080E199 for ; Mon, 13 Jul 2015 17:35:17 +0000 (UTC) (envelope-from allanjude@freebsd.org) Received: from [192.168.1.10] (unknown [192.168.1.10]) (Authenticated sender: allanjude.freebsd@scaleengine.com) by mx1.scaleengine.net (Postfix) with ESMTPSA id 01BC89769; Mon, 13 Jul 2015 17:35:16 +0000 (UTC) Message-ID: <55A3F6D2.70505@freebsd.org> Date: Mon, 13 Jul 2015 13:35:14 -0400 From: Allan Jude User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Adrian Chadd CC: Warren Block , Hans Ottevanger , "Andrey V. Elsukov" , freebsd-current Subject: Re: Lenovo BIOS boot fix References: <55A1FFD5.7080008@freebsd.org> <55A2030B.7010405@freebsd.org> <55A2835F.1030004@yandex.ru> <55A2ACDD.408@freebsd.org> <55A36FBE.1020206@beastielabs.net> <55A3D01E.40102@freebsd.org> <55A3DF26.5020602@freebsd.org> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Jul 2015 17:35:18 -0000 On 2015-07-13 13:19, Adrian Chadd wrote: > I'm really confused. Why is the active flag not set again? > > I thought that was the whole point of the active flag in the partition table. > > > -a > Not that it counts much, but windows does not set the active flag in its pMBR. I was under the impression the standard says that it should not be set, as anything actually examining the pMBR as if it were an MBR, obviously doesn't support GPT. I've heard reports that GPT partitions with the active flag set, will not boot properly under UEFI. At this point, I am not sure whether it should be set or not. This fix is for the Lenovo's with the broken BIOS. It moves the 0xee partition in the pMBR to the 2nd slot instead of the first. This does not seem to break any previously working hardware, and it makes the Lenovo's work. I have a patch: https://reviews.freebsd.org/D3065 that adds an option to gpart create to a pMBR with this fix applied. If this gets committed, I can add 'GPT + Lenovo Fix' as an option during the installer. I already plan to add 'GPT + Active' for people like Colin Percival, who have a Dell or HP that seems to complain if the active flag is missing. Windows avoids these issues by entirely refusing to boot from a GPT partitioned disk without UEFI, even though there is no such requirement. -- Allan Jude