From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 18 Sep 2002 05:50:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 18 Sep 2002 05:50:05 -0400 Received: from 62-190-218-52.pdu.pipex.net ([62.190.218.52]:54283 "EHLO darkstar.example.net") by vger.kernel.org with ESMTP id ; Wed, 18 Sep 2002 05:50:05 -0400 From: jbradford@dial.pipex.com Message-Id: <200209181002.g8IA2w52001416@darkstar.example.net> Subject: Re: Question about the dd command To: tcheer@gmx.de (Eric Tchepannou) Date: Wed, 18 Sep 2002 11:02:58 +0100 (BST) Cc: linux-kernel@vger.kernel.org In-Reply-To: <18955.1032342092@www26.gmx.net> from "Eric Tchepannou" at Sep 18, 2002 11:41:32 AM X-Mailer: ELM [version 2.5 PL6] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, > I am trying to build a boot image in order to boot from a CD device. I have > already created all the parts ( Kernel, Lilo and Rootfs ) and try to bring > them together. I first copied it on a floppy in order to see wether I could > boot from it and it worked. In the Linux-Bootdisk-HOWTO It is said that on > should transfer the rootfs with the following command > > dd if=rootfs of=/dev/fd0 bs=1k seek=KERNEL_BLOCKS > > I calculated the KERNEL_BLOCK value in my case and applied the command. It > is supposed to transfer the rootfs file into the same floppy containing the > kernel. I am surprised to see that with a ls-command the rootfs.gz is invisible > on the floppy, though the boot process from floppy works properly. Later i > created an image of the floppy ( dd if=/dev/fd0 of=boot.img bs=10k count=144 > as in the Linux-Bootdisk-HOWTO ), created an iso file from it with mkisofs and > copied it on CD. Now I can't boot the image from this CD! I'm assuming that you're trying to create a bootable CD for an X86 machine. In that case, this is not how bootable CDs work. You need to look up the 'El-Torito' bootable CD specs, and take it from there. John.