$ dd if=/dev/zero of=boot.img bs=1M count=512 $ sudo mkfs.vfat boot.img
By default, EFI firmwares boot a specific file under /efi/boot/. The name of
such file depends on the architecture: for example, on 64 bit x86 systems it is
bootx64.efi, while on ARM it is bootaa64.efi.
Copy /usr/lib/grub/x86_64-efi/monolithic/grubx64.efi from package
grub-efi-amd64-bin to /efi/boot/bootx64.efi on the boot image, and that
should be enough to start GRUB.
