how to dual boot? (was Re: adding boostrap code to boot system)

[walt]

Jeremy C. Reed wrote:
> (I changed subject line in the attempt to get more interest :)
> 
> On Fri, 3 Mar 2006, Jeremy C. Reed wrote:
>>> 	set currdev=disk0s4a
>>> 	unload
>>> 	boot /kernel -s
>> Danke. This worked fine.
> 
> Strange. But it only works for me when I use the "-s".
> 
> I have tried setting currdev and rootdev.

Really?  I'm working from memory now (my DFly box is busy compiling
gnome for the third time in ten days, so I can't reboot it just now)
but I recall that trying to set the rootdev gives me an error message
in both DFly and FreeBSD.

> And if I do not use the -s it 
> boots the kernel from harddisk but then still loads the LiveCD's 
> configuration...

Again I am working from memory -- I hope I'm not confusing *BSD
with the linux kernel -- maybe it would be worth a try to compile
a new DragonFly kernel (even a generic kernel) to see if the name
of the rootdev is compiled into the new kernel.  I seem to recall
that each kernel remembers the name of the rootdev it was compiled
on.  (But I may be thinking of linux.)

Try grepping in /boot/loader.conf for 'root' and see if that gives
you any ideas.

And thanks for all your hard work for us DFliers!