HP Integrity Server rx4640 manual Extensible Firmware Interface Boot Manager

Utilities

Extensible Firmware Interface Boot Manager

Extensible Firmware Interface Boot Manager

Extensible Firmware Interface (EFI) is an OS and platform-independent boot and pre-boot interface. EFI resides between the OS and platform firmware. This allows the OS to boot without having details about the underlying hardware and firmware. EFI supports boot devices; uses a flat memory model; and hides platform and firmware details from the OS.

NOTE	EFI and Pre-OS System Environment (POSSE) are similar. EFI is an Intel specification,
	whereas POSSE is the HP implementation that aids HP support.

EFI consolidates boot utilities similar to those found in PA-RISC based servers, such as the Boot Console Handler (BCH), and platform firmware into a single platform firmware. EFI allows the selection of any EFI OS loader from any boot medium that is supported by EFI boot services. An EFI OS loader supports multiple options on the user interface.

EFI supports booting from media that contain an EFI OS loader or an EFI-defined server partition. An EFI-defined server partition is required by EFI to boot from a block device.

Figure C-1 EFI Boot Sequence

EFI

Driver

EFI

Application

EFI

Bootcode

OS Loader

						Retry		EFI API
								Failure
Platform		EFI Image				EFI		Boot Services
					OS Loader
Init			Load					Terminate
						Load
Standard		Drivers and			Boot from			Operation
firmware		application			ordered list			handed off to
platform		loaded			of EFI OS			OS Loader
initialization		iteratively			loaders
	Application Program					Value add implementation
	Interface (API) specified
				Boot manager			EFI transfers

162 Appendix C