Yes, that is unforntunately a big problem. The linux kernel 2.6.16 has gone through some major changes in the file structure for powerpc which prevents mkvmlinuz from working out of the box. I'm sure there are work being done to be able to use mkvmlinuz with kernels 2.6.16+, Sven can probably answer that better. Debian has the same problem but they are not using the 2.6.16 kernel yet so. (Yes, Ubuntu has a 2.6.15 kernel, but is has taken a lot of patches from the 2.6.16 kernel, including the changes for powerpc.)
I tried to use the object files from a vanilla 2.6.15 kernel from kernel.org but it didn't work with the default kernel in Ubuntu anyway. The problem was that the kernel became to big, I tried to recompile the Ubuntu kernel with some modules removed and it worked. But as soon as I added them again the kernel was unbootable.
I then talked to Sven about the to big kernel proble and he gave me some suggestions about how to make a big kernel boot in the firmware on the Pegasos, but it didn't work for me.
So, what I'm doing now is to use
GRUB2. A binary which works on the Pegasos can be found at
http://www.blastware.org/grub2/index.html
Just copy the files to your boot partition. You then need to edit the file grub.cfg, mine looks like:
Code:
timeout 10
title linux 2.6.15-20
linux (hd,5)/boot/vmlinux-2.6.15-20-powerpc root=/dev/hda6 quiet splash
initrd (hd,5)/boot/initrd.img-2.6.15-20-powerpc
title linux 2.6.15-19
linux (hd,5)/boot/vmlinux-2.6.15-19-powerpc root=/dev/hda6 quiet splash
initrd (hd,5)/boot/initrd.img-2.6.15-19-powerpc
title Linux 2.6.12
linux (hd,5)/boot/vmlinux-2.6.12-10-powerpc root=/dev/hda6 quiet splash
initrd (hd,5)/boot/initrd.img-2.6.12-10-powerpc
My root is /dev/hda6 so the harddrive number is the same as in OF.
Then in OF I boot the system with:
Code:
boot hd:5 boot/grub/grubof.modules prefix=(hd,5)/boot/grub
The prefix is neccesary for GRUB2 to automatically find the config file. If you do not specify the prefix you will get a prompt in GRUB2. It is also possible to load the configfile from inside the GRUB2 prompt with:
Code:
configfile (hd,5)/boot/grub/grub.cfg
But it's better to have the menu shown automatically
You of also cource need to change (hd,5) and h:5 to the number of your partition.
The wiki for GRUB2 also has some information about GRUB2 and PowerPC,
http://grub.enbug.org/TestingOnPowerPC