From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Sun, 9 Jul 2000 13:57:41 -0700 Received: from u-73.karlsruhe.ipdial.viaginterkom.de ([62.180.21.73]:63492 "EHLO u-73.karlsruhe.ipdial.viaginterkom.de") by oss.sgi.com with ESMTP id ; Sun, 9 Jul 2000 13:57:18 -0700 Received: (ralf@lappi) by lappi.waldorf-gmbh.de id ; Sun, 9 Jul 2000 06:29:28 +0200 Date: Sun, 9 Jul 2000 06:29:28 +0200 From: Ralf Baechle To: "J. Scott Kasten" Cc: linux-mips@oss.sgi.com, linux-mips@fnet.fr, linux-mips@vger.rutgers.edu Subject: Re: Kernel boot tips. Message-ID: <20000709062927.A5609@bacchus.dhis.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: ; from jsk@tetracon-eng.net on Fri, Jul 07, 2000 at 10:10:59AM -0300 X-Accept-Language: de,en,fr Sender: owner-linux-mips@oss.sgi.com Precedence: bulk Return-Path: X-Orcpt: rfc822;linux-mips-outgoing On Fri, Jul 07, 2000 at 10:10:59AM -0300, J. Scott Kasten wrote: > I learned 3 slick booting tips for booting an Indy from disk without a > regular Linux boot loader that might be useful to some of the newbies. > > First off, there are two ways to trick the prom into booting the kernel > image like the normal Irix kerenel from disk. If you have an EFS or XFS > bootable file system on the drive, and have Irix up at some point, you can > put the linux kernel in the file system as /unix in place of an Irix > kernel. When booting, sash will look for that particular file and > bootstrap it. Another way to accomplish this trick if you don't want any > Irix partitions on your drive at all is to use the volume header itself. > Sash is located there, and the boot prom will load and execute sash as > part of the boot process. Under Irix, you can use dvhtool to replace sash > with the linux kernel itself. Then when the system tries to boot, the > prom will load "sash" like normal, but will end up boot straping the linux > kernel for you. (I think this will require a coff image though.) > > The third trick I learned will help those that cannot afford the spare > change to keep around extra SCSI drives so that they have a bootable Irix > image to use for accomplishing these feats. If you use fx to initially > prepare your linux disk, use the expert option and resize the volume > header partition. Make it big, like 25 Meg or so. Shrink the efs/xfs > root partition down very small, but don't delete it. Keep the swap > partition as well, but again, rather small. On the Irix CD, you'll find > the directory /dist/miniroot, and inside there, the Irix kernel miniroot > images. Pick the one named for your machine arch, such as unix.IP22. > When I set up my volume header, I put sash in there like normal, but also > put the miniroot image in there as well, and put the linux kernel as /unix > in the vestigal efs/xfs root partition. Now from the prom, I can enter > the command "miniroot" and get the Irix kernel up with a handful of > utilities to manage the disk. It has fx, dvhtool, and others. On top of > that, you can ifconfig your ethernet device and use rcp to pull over your > linux kernel from the network to install it on the efx/xfs root or in the > volume header as you choose. You can even mount cdroms and so forth. > Basicly, this is the next best thing to having a full blown Irix install > somewhere. I've finally commited my rewrite of dvhtool into the CVS archive on oss. It's not yet complete but hackers may be interested in taking a look at it. One of my next projects will be a standalone libc which can be used to write reasonably portable standalone tools like a sash equivalent. Ralf