ubuntu@ubuntu:~$ grub-mkimage -o bootx64.efi -p /efi/boot -O x86_64-efi  fat iso9660 part_gpt part_msdos  normal boot linux configfile loopback chain  efifwsetup efi_gop efi_uga  ls search search_label search_fs_uuid search_fs_file  gfxterm gfxterm_background gfxterm_menu test all_video loadenv  exfat ext2 ntfs btrfs hfsplus udf
grub-mkimage: errore: cannot stat /usr/lib/grub/x86_64-efi/gfxterm_background.mod.