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.
efibootmgr. I set ubuntu as first boot but that didn't help (could be because I'm using an HP). I then read what boot repair does and it's basically doing the same thing I've seen so many times, that is copygrubx64.efiand put inEFI/Boot/renamed asbootx64.efi. I just tried this and now at least OS selector recognizes bootx64.efi and loads grub. Problem is it acts weird: sometimes the purple screen stays on forever, other times grub load and other times it goes directly in ubuntu boot. Will explore more options later on. – wraithie Jan 25 '16 at 23:55