I think your last option is the best, with a slight modification from the former options. If you use a boot loader, you can probably find one that will let you specify the root device at runtime. Then, have it access the FS on CD, load kernel, etc.; or have it load a kernel with an initrd, and do as you suggest. Luke On Mon, 3 Mar 2003, Karl Dahlke wrote: > This is long, but definitely "on topic", so please read. > > You may have noticed that the newest computers don't have floppy drives. > They boot from CD rom. > Therefore, we need talking rescue CDs. > > Yes, there are some out there, but let's say we want to build our own, > with our adapters, our utilities, etc. > How can this be accomplished? > I'm looking for advice/ideas. > Here are the options as I see them. > Some of these may not even be possible; I don't know. > > (A) Place your mini distribution, with adapter and utilities etc, > into a ram disk or a loop-accessible file. > Use lilo to replace the first 512 bytes, thus creating a boot disk > that is also a Linux disk. > Then burn this out to a CD. > I know this works with floppies, but don't know about CDs. > Can you make a bootable linux file system this way? > Does the file system have to cover the entire CD, or can it be smaller? > My system, that makes me happy, is 80 meg, > so it's a shame to have to manipulate and burn all 670 megs. > And, how do you set the root device, since some CDs are on hdc > while others are on hdd. > Guess wrong, and Linux doesn't come up at all. > Also, some CD players require weird drivers that might not be on my distro. > > (B) put a bzImage at the base of the CD so LInux boots > directly, no boot loaders involved. > It then sucks in a large ramdisk. > Maybe it's 30 or 40 meg. > Today's computers can handle that. > You've got all your utilities, everything you need, > in memory. > You don't have to keep the CD spinning, in fact you can take it out completely. > Now mount your hard drives and go to work. > Also, no need to copy and remount directories in tmpfs, > like /tmp and /etc and /home, so they can be writable. > Everything is writable, because it's all in memory, and no longer on CD. > And I don't have to set the root device. > I like this approach, but if you have an older computer with less then 64 meg, > it's probably not going to work for you. > That's the only down side I guess. > Other than that, it's very simple and convenient. > > (C) A hybrid. > Put bzImage at the base and suck in a modest initrd, just a few megs. > It wakes up, looks around, figures out where the CD is, > loads the necessary drivers, mounts the CD, > say under /usr, and gives you access to the rest of the utilities that don't > fit in memory. > This is the most complicated of the three, but the most general and flexible. > Is it possible, btw, to have a linux file system on a CD, > that you can mount, that doesn't start at the beginning? > It would have to start past the bzImage and past the initrd image - > and I don't know if that can be done. > > And perhaps there are other ways to implement this that I haven't thought of. > > Please give me your ideas. > If you can give a detailed procedure on how to make such a disk, > that's even better; > though you might want to mail that to me off line, eklhad@comcast.net, > so as not to clog up this list too much. > > Thank you, > Karl > > > > _______________________________________________ > > Blinux-list@redhat.com > https://listman.redhat.com/mailman/listinfo/blinux-list > _______________________________________________ Blinux-list@redhat.com https://listman.redhat.com/mailman/listinfo/blinux-list