I've been looking all over for this, it must be possible but the closest answer i could find is this one:
How can I get grub2 to boot a different option only on the next boot?
This is for a laptop that has Ubuntu and another, lesser known OS installed. It's mostly used for music/audio capture and processing, so it's normally running the realtime kernel - sometimes however i need to use the generic one for running virtual machines, because trying to load VirtualBox's kernel modules on realtime kernel (at least on a AMD cpu) currently crashes the whole system. I'd also like to be able to run the other OS from Ubuntu's GRUB but the OS probing process when running 'update-grub' doesn't recognize it.
The main problem however is that i can't just tell grub to boot "another item" from its list, since all available kernels for a specific OS install are under "special options for (that install)" and therefore don't have their own entry in the top-level list.
...so, how do i do this, preferably without relying on changes to config files that might get overwritten by future updates? Thanks for any assistance!
