[lug] floppy install images

[Bear Giles]

Hugh Brown wrote:
> Does anyone know of a way to take the two floppy images, make them into
> one 2.88 image and put it on cdr (as the boot image)?

Yes, but not without a lot of work.

First some background... the first disk is a "boot" disk that 
loads the kernel -- and it has to be understood by the BIOS on the 
motherboard.  This often means that it's a FAT filesystem set up 
as a bootable floppy, but instead of MSDOS.SYS or the like there's 
a secondary bootloader that understands how to load the linux 
kernel and initrd (initial ramdisk) image.  The initrd is a cramfs 
image that can contain kernel modules, initialization scripts, and 
various utilities.  At a minimum it usually contains mount/umount, 
tar, gzip... and if you want a cheap rescue disk it will contain 
busybox and a script that allows you to run the system out of the 
initrd image.

The second disk is a "root" disk that, typically, is a minix 
filesystem containing a compressed tarball containing the entire 
filesystem that you'll see when you get a prompt.  The 'initrd' fs 
mentioned earlier will be nowhere in sight.

Finally, an "el Torito" bootable CD will treat a 1.44M or 2.88M 
section of the disk as a bootable floppy.  You can create a 
suitable image with mkisofs with the -b flag (iirc), but obviously 
the purpose of mkisofs is to create ISO9660 filesystems, not to 
provide burnable images with arbitary filesystems on them.

So at a minimum you need to have some way to

   1) convert the "root" image so that it is an ISO9660 FS on CD 
instead of a minix FS on 1.44M floppy,

   2) edit the "boot" image so that it knows to load the root 
image from /dev/scd0 instead of /dev/fd0, something that requires 
editing the linuxrc script in the initrd image in recent kernels, and

   3) verify that the kernel supports CD drives and ISO9660 file 
systems.

Not impossible, but it'll require some serious twiddling with some 
specialized tools (e.g., mkinitrd, mkcramfs, etc.)

Bear