I completely wiped my hard drive on an HP initially set up with windows uefi boot. The wipe also deleted default windows bootx64.efi. Right now my fat32 partition flagged as boot is mounted on /boot/efi.
Going in /boot/efi/EFI, the only folder, naturally, is ubuntu with grubx64.efi, shimx64.efi etc.
When I boot, the BIOS OS Selector naturally doesn't recognize any OS to boot (it only recognizes bootx64.efi right?). This answer explains how to set grub as the default bootloader over default windows boot. Should I do something similar and create a Boot folder inside /boot/efi/EFI with grubx64.efi copied in it, renamed as bootx64.efi? The above mentioned answer refers to the path: /EFI/BOOT/BOOTX64.EFI, but generally the bootloader should be in the path where boot partition is mounted, so in my case path /boot/efi/EFI is correct?
EDIT: Using HP Z-book 15. I currently have to manually select efi file when booting. BIOS allows "boot from efi file". I then select /EFI/ubuntu/grubx64.efi and boot starts.