I've looked and looked without finding..
with lilo, I can do this:
lilo -R SunOS && init 6
which will reboot my PC on Solaris, provided that lilo.conf has a
"SunOS" label somewhere, of course.
This is quite usefull for unattended reboots "one-shot" (meaning that
the next reboot while using Solaris will use the default image as
defined in Lilo).
I couldn't find a way to do so with grub. I thought of doing a small
script that manipulate grub's menu.lst, but I find the idea totally
unelegant; there must be a way, is there ?