Is it possible to select which system to boot before rebooting, on a multi-boot UEFI system?

Solution 1:

Your question itself contains some possible answers. Another one is to manipulate the EFI's BootNext parameter. This sets a one-time boot to the specified target boot program. This can be done in Linux via the efibootmgr utility:

1. Type efibootmgr (or efibootmgr -v to get more detail) as root or using sudo. This will display a list of your boot options.
2. Identify the boot option you want to boot. For instance, to boot straight to Windows, you probably want the option entitled Windows Boot Manager. (Note, however, that these names are sometimes deceptive. You may need to experiment and figure out the details for your system.)
3. Type efibootmgr -n #### as root or using sudo to tell the system to boot to Boot#### next, where #### is the number of the entry you want to boot.

I believe you can do something similar with EasyUEFI in Windows, but that's a GUI tool and so may not be useful for the scenario you describe. Perhaps bcdedit could do the trick, but I've not looked into it.