Side note, android's 'reboot' cmd can take an argument,
fastboot' or 'reboot recovery'.. that might be one of the few features
from android worth copying ;-)
I'm still missing something simliar to "lilo -R <cmdline>" in the
of modern boot loaders. This used to set the lilo command line for the
next boot. lilo command line is boot entry name plus additional kernel
parameters. So you say ...
"lilo -R default single && reboot"
... for a single user boot. Or ...
"lilo -R testkernel && reboot"
... to boot a different kernel once.
Seems at least for the second use case some out-of-tree grub2 patches
are floating around, adding a --once switch to grub-set-default. Some
linux systems have it, some don't ...