From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1OUPf6-0005gm-QA for mharc-grub-devel@gnu.org; Thu, 01 Jul 2010 15:43:04 -0400 Received: from [140.186.70.92] (port=51562 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OUPev-0005Tw-Px for grub-devel@gnu.org; Thu, 01 Jul 2010 15:43:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OUPep-0002Cw-Of for grub-devel@gnu.org; Thu, 01 Jul 2010 15:42:52 -0400 Received: from mail-bw0-f41.google.com ([209.85.214.41]:33426) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OUPep-0002CO-Dt for grub-devel@gnu.org; Thu, 01 Jul 2010 15:42:47 -0400 Received: by bwz9 with SMTP id 9so1432007bwz.0 for ; Thu, 01 Jul 2010 12:42:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :x-enigmail-version:content-type; bh=rBum9vrRjBzF76LbwyNpt6alv5h32syP4PZPjEQB+Xo=; b=WV+X5A4lVhUxULUQjanH/61Flw9BEIFOCg2Z8BVlAYZ8p2fzUHCZuJ5FCc4Qpmo3FD MFXBXPms9Cw2jld9F6v3tEf9UD83zRykuK7ZK9kQ/15ICCi0YBoiPd4ojH/B0IH/8fMB /GAR8EnCyKNUW34sEeKyDMpd+aQVbBxywmmNk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:x-enigmail-version:content-type; b=QXY5DzfDqQJAWxVrj4AW2Mp78QOUJLhsa/+yAhw8mzE3AkC16priRoZXkm4i505S7s xOItbHQhCAhq1XK6shj6q7xvdNSylT2yKBXE0b6YBCTFKTqvrWhmdzQ77rX2Y5npgsZ8 izyEJob4JCGc17NiuBnq0iUOJnxexcodbh+fQ= Received: by 10.204.126.142 with SMTP id c14mr5945120bks.16.1278013364913; Thu, 01 Jul 2010 12:42:44 -0700 (PDT) Received: from debian.bg45.phnet ([81.62.28.146]) by mx.google.com with ESMTPS id bi18sm13717441bkb.9.2010.07.01.12.42.43 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 01 Jul 2010 12:42:43 -0700 (PDT) Message-ID: <4C2CEFAB.8090308@gmail.com> Date: Thu, 01 Jul 2010 21:42:35 +0200 From: =?UTF-8?B?VmxhZGltaXIgJ8+GLWNvZGVyL3BoY29kZXInIFNlcmJpbmVua28=?= User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100515 Icedove/3.0.4 MIME-Version: 1.0 To: grub-devel@gnu.org References: <63A4C2F2B04E2948B033568534F6C9C578E3D737EE@GVW1095EXB.americas.hpqcorp.net> In-Reply-To: <63A4C2F2B04E2948B033568534F6C9C578E3D737EE@GVW1095EXB.americas.hpqcorp.net> X-Enigmail-Version: 1.0.1 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="------------enig55D65E453DC6E60AE1526037" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: Re: grub2 and hybrid MBR booting X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Jul 2010 19:43:02 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig55D65E453DC6E60AE1526037 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 06/29/2010 08:37 PM, Elliott, Robert (Server Storage) wrote: > I successfully ran ubuntu 10.04 (which uses grub2) on a 4 TB drive=20 > (presented by a RAID controller) on a system with legacy BIOS. The=20 > drive got partitioned as GPT; a BIOS boot partition was installed;=20 > and grub stage 1 contains the 8-byte LBA of the BIOS boot partition=20 > hardcoded into its 440 bytes of x86 boot code, so it can load the=20 > code in that BIOS boot partition. > > That works pretty well, but requires any program that moves the BIOS=20 > boot partition to know that grub is pointing to it and also adjust=20 > that 8-byte LBA value stored in LBA 0. > > =20 After moving of partitions containing it's recommended to reinstall bootloader > In the UEFI Working Group (which defines GPT) and the T13 (ATA) standar= ds=20 > bodies, we defined a slightly different method: the GPT partition reco= rd=20 > now includes a Legacy BIOS Bootable bit that can be set for a partition= =20 > like the BIOS boot partition, The algorithm is documented in=20 > T13 EDD-4 revision 2 and later (see > http://t13.org/Documents/MinutesDefault.aspx?DocumentType=3D4&DocumentS= tage=3D1). > > =20 At last. It's refreshing from the usual lie that you need EFI to boot from GPT-partitioned disk. But I don't see the need to standartise the interface between MBR code and the rest. Standartisation is good only for interoperability between different software. But in this case both parts are from the same bootloader so it will only reduce flexibility. > and the x86 boot code in LBA 0 can search=20 > through the GPT partition table for a partition with that bit set to 1 = > (rather than contain a hardcoded LBA). It's closedly modeled after msdos. It annihilates most of advantages of G= PT. I suppose you want to put filesystem on bootable partition too. When we added GPT support virtually unlimited embedding zone was the grea= t plus. Switching to msdos-like scheme would be a huge step backwards (es= pecially that you have no MBR gap). It's a repetion of old mistakes under= new sauce. MSDOS scheme already forced anti-patterns and any new scheme = must be based on saner pattern.=20 > Would grub2 consider switching to that modified algorithm? > > H Peter Anvin has implemented it in syslinux-4.00-pre48 (see > http://syslinux.zytor.com/wiki/index.php/The_Syslinux_Project).=20 > =20 Syslinux is known for hanging on the old protocol no matter the price. > The boot code=20 > doesn't have enough room to verify the GPT CRC and perform all the poss= ible=20 > GPT verification checks, but it can definitely walk through the structu= re=20 > and find the boot partition. > > =20 Which contradicts your spec. Unimplementable spec only forces devs to code undefined behaviour. --=20 Regards Vladimir '=CF=86-coder/phcoder' Serbinenko --------------enig55D65E453DC6E60AE1526037 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iF4EAREKAAYFAkws76sACgkQNak7dOguQglebwEAtu1OVboBFVPHo3pZjo7tEoqn wxNx3mMVdp7rdi970K0A/0BIhnBPsjcmjBPI6I/TvkmVgyvuozEeQj8iku9VUGzm =vgIh -----END PGP SIGNATURE----- --------------enig55D65E453DC6E60AE1526037--