Extensible Firmware Interface Boot Manager; Figure C-1. Efi Boot Sequence - HP Integrity rx4640 User's & Service Manual

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.
EFI and Pre-OS System Environment (POSSE) are similar. EFI is an Intel specification,
NOTE
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
Platform
Init
Standard
firmware
platform
initialization
Application Program
Interface (API) specified
162
EFI
Application
EFI Image
Load
Drivers and
application
loaded
iteratively
Boot manager
EFI
Bootcode
Retry
Failure
EFI
OS Loader
Load
Boot from
ordered list
of EFI OS
loaders
Value add implementation
EFI transfers
OS Loader
EFI API
Boot Services
Terminate
Operation
handed off to
OS Loader
Appendix C