load kernel from different media

[Chris Whitehouse]

Hi all,

I cannot boot my motherboard with the default kernel on 7.2-RELEASE (or 
any other iso's I have tried). It panics if device sbp is in the kernel. 
So far I've got things working by putting the hard disk in another 
machine, installed the OS and rebuilt a kernel without sbp, then 
returned the disk to my computer. That's ok for a one off install but 
this machine is supposed to be for messing around.

Can I load a kernel from some other media? Eg boot from an install CD, 
interrupt the boot, load a modified kernel from a usb stick or installed 
hard drive and continue booting from the CD.

At the boot prompt I can list disks with lsdev and I can load and unload 
a kernel from the media I booted from (obviously) but I can't see how to 
load a kernel from another disk.

I checked man 8 loader and man 8 boot but couldn't see what I wanted, 
hopefully I didn't just miss it. If the answer is in there I would 
really appreciate a pointer.

Thanks

Chris