Just do a regular Linux install on a desktop machine with an IDE disk, install
a Cobalt kernel with /vmlinux.gz being a sym-link to the kernel (NB my kernel
patch for Cobalt changes the link proceedure to just gzip -9 the kernel
instead of making a zImage - a zImage is not supported by the BIOS).
As the Cobalt boot process is totally different from the boot process for a
desktop machine (the Cobalt BIOS loads /vmlinux.gz and does not support boot
sectors etc) you can have a hard disk configured for both booting a Cobalt
machine and booting a desktop machine - this is really handy in case you mess
things up. ;)
The Cobalt machines don't have a virtual console so you only want a getty running on /dev/ttyS0. You need a Cobalt patched kernel as a regular kernel will not work. Also the Cobalt machines use 486 class CPUs. I suspect that recent releases of Fedora won't work on them because of this but haven't got around to testing.
The Cobalt BIOS images that I have tried have had some bugs. The latest
version I tried did not boot a Qube. New ROM images are available on
Sourceforge. The
version I use is here.
The ROM source is based on Linux kernel source and has the same bugs. The
ROM version I use (because the later versions I tried didn't work properly)
doesn't support booting from an ext3 file system with XATTRs on sym-links (IE
SE Linux file labels). I used to create a /boot file system on a machine
without SE Linux to avoid the labels and use dd to copy it in, but this is
a gross hack. So now I have converted one of my Cobalt machines to XFS
which works without any problems. I will soon convert the other machine to
XFS and recommend that you only use XFS on Cobalt machines to avoid these
issues.