>From: Paul Mackerras <paulus@cs.anu.edu.au>
>
>I was able to boot by putting a copy of vmlinux.coff on a mac format
>floppy, and setting OF variables (using Boot Variables) like this:
>
>boot-device     fd:vmlinux.coff
>boot-file        root=/dev/sda7
>
>(the space before root= is significant).
 
Note you still need a partition (/dev/sda7 in the example) with a linux
filesystem and command set on it.
 
jonh@cs.dartmouth.edu
 
There are also vmlinux.coff files around that contained compressed ram-
disk images that allow you to boot from floppy and use the ram-disk as
the root device.  In this case the boot-file would be " root=/dev/ram"
These are usually made for a special purpose, but you can create your
own by setting up a ram disk with the stuff you want, then creating a
compressed image of it in linux-pmac/arch/ppc/pmac/boot called
ramdisk.image.gz, then in that directory do "make vmlinux.coff.initrd"
 
#mke2fs /dev/ram				This makes an ext2 filesystem on the ramdisk
#mount /dev/ram /ramdisk		Mounts it - assumes /ramdisk is a valid directory
#mkdir /ramdisk/bin
#cp /bin/bash /ramdisk/bin/sh	Make sure there is a shell to run
 
add whatever else you like, but remember it's got to fit on a floppy
with the linux kernel too!
 
#cd ~/linux-pmac/arch/ppc/pmac/boot    Assumes the source tree is at ~/
#dd if=/dev/ram of=ramdisk.image
#gzip ramdisk.image
#make vmlinux.coff.initrd
 
Viola!  Now just copy that to a floppy, rename it to vmlinux.coff and
you're ready to go.
 
		 haceeaton@aplcomm.jhuapl.edu