grub-reboot
Set the default boot entry for GRUB, for the next boot only. tldr-pages
On Linux
Linux
Set the default boot entry to an entry number, name, or identifier for the next boot
sudo grub-reboot entry_numberIdentifySet the default boot entry to an entry number, name, or identifier for an alternative boot directory for the next boot
sudo grub-reboot --boot-directory /path/to/boot_directory entry_numberIdentify