From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1LakSf-0003T4-Mt for mharc-grub-devel@gnu.org; Sat, 21 Feb 2009 00:31:37 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LakSd-0003Sq-Ie for grub-devel@gnu.org; Sat, 21 Feb 2009 00:31:35 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LakSZ-0003Se-1i for grub-devel@gnu.org; Sat, 21 Feb 2009 00:31:33 -0500 Received: from [199.232.76.173] (port=38985 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LakSY-0003Sb-SS for grub-devel@gnu.org; Sat, 21 Feb 2009 00:31:30 -0500 Received: from mail-in-02.arcor-online.net ([151.189.21.42]:46866) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LakSY-0004tR-Cg for grub-devel@gnu.org; Sat, 21 Feb 2009 00:31:30 -0500 Received: from mail-in-17-z2.arcor-online.net (mail-in-17-z2.arcor-online.net [151.189.8.34]) by mx.arcor.de (Postfix) with ESMTP id 7166C3FE678 for ; Sat, 21 Feb 2009 06:31:27 +0100 (CET) Received: from mail-in-15.arcor-online.net (mail-in-15.arcor-online.net [151.189.21.55]) by mail-in-17-z2.arcor-online.net (Postfix) with ESMTP id 5FAA245C041 for ; Sat, 21 Feb 2009 06:31:27 +0100 (CET) Received: from cerberus.olympus (dslb-088-074-227-229.pools.arcor-ip.net [88.74.227.229]) (Authenticated sender: blubberdiblub@arcor.de) by mail-in-15.arcor-online.net (Postfix) with ESMTPSA id 2CC6835EC65 for ; Sat, 21 Feb 2009 06:31:27 +0100 (CET) X-DKIM: Sendmail DKIM Filter v2.6.0 mail-in-15.arcor-online.net 2CC6835EC65 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arcor.de; s=mail-in; t=1235194287; bh=Np/Ij/Stdy75dMCr37wM0GjQcvmHi/nTf0i0k8G1/Xc=; h=From:To:Subject:Date:References:In-Reply-To:MIME-Version: Content-Type:Content-Transfer-Encoding:Message-Id; b=JRPcWIE5BsDbt bJcXjmnXga+epKAa38J57J9cArxVj39JqvX1CyOJeKxMKjtXhYk4XwTVyz9/v3QMYJn 32VkKHPcjffkBDwWUKQOHZXj8kNHwCkawuqsdShKxQ012ddw80LIMRvhZA1DgwT83K7 q5JVlFMAAlF52wYFkHB7XyeQ= Received: from cerberus.olympus ([192.168.1.3] ident=foobar) by cerberus.olympus with esmtp (Exim 4.69) (envelope-from ) id 1LakSU-0001MF-J0 for grub-devel@gnu.org; Sat, 21 Feb 2009 06:31:26 +0100 From: Niels =?utf-8?q?B=C3=B6hm?= To: The development of GRUB 2 Date: Sat, 21 Feb 2009 06:31:25 +0100 User-Agent: KMail/1.9.9 References: <499F04F2.7040302@earthlink.net> In-Reply-To: <499F04F2.7040302@earthlink.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200902210631.26175.bitbucket@arcor.de> X-Virus-Scanned: ClamAV 0.94.2/9018/Fri Feb 20 20:07:43 2009 on mail-in-15.arcor-online.net X-Virus-Status: Clean X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) Subject: Re: Writing to superblock? X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Feb 2009 05:31:35 -0000 On Friday 20 February 2009, BandiPat wrote: > > Anyway, the writer of the script ask me a question I have not been able > to find anything about, so I thought I would come straight to you guys! > I already know that Grub2 will work with XFS and will write to the > MBR, but he is asking about Superblocks also when using XFS. Will it? If I understand you correctly, you talk about writing GRUB to a root sector= of=20 a partition that contains a XFS filesystem (which happens to coincide with= =20 the start of the superblock of XFS' first allocation group), right? I mean the traditional way to execute raw boot code from a partition is to= =20 chainload its first sector and jump to its first byte, which means there ha= s=20 to be boot code at this place or at the very least a jump instruction that= =20 points to the real boot code. But I don't think this is possible with XFS since it has its magic number i= n=20 the first 4 bytes. It looks like this: 00000000 58 46 53 42 00 00 10 00 00 00 00 00 00 20 00 00 |XFSB......... = =2E.| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |..............= =2E.| 00000020 19 c5 80 51 80 34 4a c9 b6 aa c5 44 0b 16 c7 7b |...Q.4J....D..= =2E{| etc. =46or this, also have a peek at=20 http://xfs.org/index.php/XFS_FAQ#Q:_Does_LILO_work_with_XFS.3F The alternative would be to find another unused cave with stable location i= n=20 XFS' metadata, although I doubt there is one. But you may want to check mor= e=20 deeply at http://oss.sgi.com/projects/xfs/papers/xfs_filesystem_structure.p= df Regards, Niels B=C3=B6hm