EFIBOOTBOOTX64EFI

EFIBOOTbootx64efi is a commonly used way to refer to the 64-bit UEFI boot loader binary used in EFI boot processes. In the UEFI firmware architecture, the system firmware loads an EFI executable from the EFI System Partition (ESP) to start the operating system. The 64-bit variant used on x86-64 systems is typically named BOOTX64.EFI and located under the EFI/BOOT directory.

BOOTX64.EFI serves as a fallback or minimal boot loader. When no specific boot entry is configured or when booting from removable media, the firmware attempts to load /EFI/BOOT/BOOTX64.EFI. This binary then loads the actual bootloader for the operating system, such as Windows Boot Manager (bootmgfw.efi), GRUB, or systemd-boot.

On many installations, the ESP contains multiple entries with different paths, for example /EFI/Microsoft/Boot/bootmgfw.efi for Windows, /EFI/ubuntu/grubx64.efi or /EFI/opensuse/grubx64.efi for Linux, and loader.efi for systemd-boot. The security of these binaries is commonly governed by UEFI Secure Boot, which requires signatures from trusted keys.

Management of EFI boot entries is commonly performed with tools such as efibootmgr on Linux or bcdedit on Windows. These tools can create, delete, or reorder Boot#### entries and set the default boot option. Understanding the boot path and its naming is important for dual-boot configurations, recovery scenarios, and ensuring reliable startup across different hardware.