From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261396AbUL2TPx (ORCPT ); Wed, 29 Dec 2004 14:15:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261398AbUL2TPx (ORCPT ); Wed, 29 Dec 2004 14:15:53 -0500 Received: from dialin-166-233.tor.primus.ca ([216.254.166.233]:10112 "EHLO node1.opengeometry.net") by vger.kernel.org with ESMTP id S261396AbUL2TPl (ORCPT ); Wed, 29 Dec 2004 14:15:41 -0500 Date: Wed, 29 Dec 2004 14:15:25 -0500 From: William Park To: Paulo Marques Cc: Jesper Juhl , linux-kernel@vger.kernel.org, Andreas Unterkircher Subject: Re: waiting 10s before mounting root filesystem? Message-ID: <20041229191525.GA2597@node1.opengeometry.net> Mail-Followup-To: Paulo Marques , Jesper Juhl , linux-kernel@vger.kernel.org, Andreas Unterkircher References: <20041227195645.GA2282@node1.opengeometry.net> <20041227201015.GB18911@sweep.bur.st> <41D07D56.7020702@netshadow.at> <20041229005922.GA2520@node1.opengeometry.net> <20041229015622.GA2817@node1.opengeometry.net> <41D2A7BE.2030806@grupopie.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41D2A7BE.2030806@grupopie.com> User-Agent: Mutt/1.4.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 29, 2004 at 12:49:02PM +0000, Paulo Marques wrote: > William Park wrote: > >[...] > > > >Ideally, motherboard should support booting from USB key drive > >directly. I'm told that most modern motherboards do support usbboot, > >but my machine doesn't. So, I trying to load the kernel from floppy > >(harddisk for testing purpose). This is part of my attempt to build > >Linux thin-client out of mini-ITX type of computer (Via CLE266 > >chipset, Via C3 cpu). > > > >Now, I need to find a machine that actually can do usbboot... > > You will have the same problem even if the BIOS supports booting from > USB. The BIOS will load the bootloader and map the USB drive as if it > were a regular disk, so that the INTxx calls (can't say the number > from memory) that LILO (or another bootloader) uses to load the kernel > and initrd into memory will work. > > After that, the kernel boots the same way as if it were loaded from a > floppy. It still needs to discover the USB drive to mount the root > filesystem, and that will still take the 5 seconds you were > complaining about. Ah, right. > > As Trent Lloyd already mentioned, you could solve this using a small > initrd and a "nash" script, instead of patching the kernel, although > I'm in favor of a patch of this sort getting into mainline. I read Documentation/initrd.txt and I don't understand it. If I understand it right, I have to build a complete root filesystem with all the stuffs necessary for mounting the second (real) root filesystem. If I'm loading the kernel from floppy, then I only have 200k to work with. I'll try initrd.txt, step by step over the holidays. > > After all, what is the use of kernel saying "Panic, can not mount the > root filesystem" instead of saying "humm... no root file system there. > Let me try again in a second or so and see if anything as come up..."? -- William Park Open Geometry Consulting, Toronto, Canada Linux solution for data processing.