HP PC Commercial BIOS (UEFI) Setup Administration Guide For Business Notebook and Desktop 2015 Models - Technical whitepaper

May 2016

857394-002

HP PC Commercial BIOS (UEFI) Setup

8 Appendix 1 49

8 Appendix 1

8.1 What is UEFI?

Unified Extensible Firmware Interface (UEFI) defines the interface between the operating system and platform firmware

during the boot, or start-up process. Compared to BIOS, UEFI supports advanced pre-boot user interfaces.

The UEFI network stack enables implementation on a richer network-based OS deployment environment while still

supporting traditional PXE deployments. UEFI supports both IPv4 and IPv6 networks. In addition, features such as Secure

Boot enable platform vendors to implement an OS-agnostic approach to securing systems in the pre-boot environment.

The HP ROM-Based Setup Utility (RBSU) functionality is available from the UEFI interface along with additional configuration

options.

8.2 Introduction

The HP UEFI System Utilities are embedded in the system ROM. The UEFI System Utilities enable a wide range of

configuration activities, including:

 Configuring system devices and installed options.

 Enabling and disabling system features.

 Displaying system information.

 Selecting the primary boot controller or partition.

 Configuring memory options.

 Launching other pre-boot environments, such as the Embedded UEFI Shell and Intelligent Provisioning.

8.3 Benefits of UEFI

 Abstracts Platform from OS and Decouples development

 Includes modular driver model and CPU-independent option ROMs

 Modular and extensible and provides OS-Neutral value add

 OS loader can keep the same as underlying hardware change

 Supports larger drives over 2TB with GPT partition

8.4 Overview of UEFI Boot Process

The purpose of the UEFI interfaces is to define a common boot environment abstraction for use by loaded UEFI images,

which include UEFI drivers, UEFI applications, and UEFI OS loaders. UEFI allows the extension of platform firmware by

loading UEFI driver and UEFI application images. When UEFI drivers and UEFI applications are loaded they have access to all

UEFI-defined runtime and boot services.

There are two sets of services in UEFI:

 Boot Services - UEFI applications (including OS loaders) must use boot services functions to access devices and allocate

memory. These services are not available once the OS is running.

 Runtime Services - The primary purpose of runtime services is to abstract minor parts of the hardware implementation

of the platform from the OS.

These services are present when OS is running.