From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1NzVzJ-0005ev-Ar for mharc-grub-devel@gnu.org; Wed, 07 Apr 2010 10:12:13 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NzVzH-0005eK-Kh for grub-devel@gnu.org; Wed, 07 Apr 2010 10:12:11 -0400 Received: from [140.186.70.92] (port=46260 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NzVzE-0005cX-I5 for grub-devel@gnu.org; Wed, 07 Apr 2010 10:12:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1NzVzC-0003aa-Q3 for grub-devel@gnu.org; Wed, 07 Apr 2010 10:12:08 -0400 Received: from mail.gmx.net ([213.165.64.20]:46470) by eggs.gnu.org with smtp (Exim 4.69) (envelope-from ) id 1NzVzC-0003a0-Ax for grub-devel@gnu.org; Wed, 07 Apr 2010 10:12:06 -0400 Received: (qmail invoked by alias); 07 Apr 2010 14:11:58 -0000 Received: from 165.126.46.212.adsl.ncore.de (HELO 192.168.2.69) [212.46.126.165] by mail.gmx.net (mp005) with SMTP; 07 Apr 2010 16:11:58 +0200 X-Authenticated: #2145628 X-Provags-ID: V01U2FsdGVkX18FMvpI5aQFTrZyyVlvjTals5feVYYm0Q2/qqevc8 ebfnQ+b7IhYEbj Date: Wed, 07 Apr 2010 16:11:12 +0200 From: "Thomas Schmitt" To: grub-devel@gnu.org References: <4BBC7EC7.7010501@gmail.com> In-Reply-To: <4BBC7EC7.7010501@gmail.com> Message-Id: <105865055614914@192.168.2.69> X-Y-GMX-Trusted: 0 X-FuHaFi: 0.53000000000000003 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Subject: Re: How to prepare an ISO 9660 CD for booting via GRUB ? 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: Wed, 07 Apr 2010 14:12:12 -0000 Hi, > > Are there other media types [...] ? > Floppy. (supported for image sizes smaller than 1.44 MiB) > [...] > We probably need a way to choose a subset of modules for floppies If i squeeze out the overhead, then xorriso writes 754 * 2048 bytes rather than 757 * 2048 by grub-mkisofs. At the end of grub-mkrescue i have now: ## prog=grub-mkisofs prog="xorriso -as mkisofs -no-emul-boot -no-pad" # This creates an image without multi-session/Blu-ray overhead # by hiding the random access capability of the target file. $prog ${grub_mkisofs_arguments} --protective-msdos-label -r ${iso9660_dir} ${source} | cat > ${output_image} (Possibly the 3 blocks difference comes from obsolete RockRidge "RR" entries written by mkisofs.) ------------------------------------------------ A first tarball is available with the necessary program enhancements: http://www.gnu.org/software/xorriso/xorriso-0.5.3.tar.gz For overall info see http://www.gnu.org/software/xorriso/xorriso_eng.html Build: ./configure ; make Installation is not mandatory. One may use it by the absolute path of ./xorriso/xorriso . E.g.: prog="/home/thomas/xorriso-0.5.3/xorriso/xorriso -as mkisofs -no-emul-boot -no-pad" There is still no support for option --modification-date= and option -r is still ignored. (I will implement "reasonable Rock Ridge" soon. Although it is an odd thing.) ------------------------------------------------ > > Is it worth to sacrifice multi-session history > > capabilities in order to save 64 kB ? > Perhaps as an option, not as default. It turned out that writing to a recognizable random-access file or block device brings an overhead of 64 kB to 126 kB. Normally not a problem with contemporary media. But if floppies are of interest ... Have a nice day :) Thomas