Deploying UEFI‐Aware Operating Systems on Dell™ PowerEdge™ Servers By Anand Joshi, Bill Munger, Mark Shutt, Thomas Cantwell, and John Sieber
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Table of Contents History ........................................................................................................................................................................... 2 What is UEFI? ................................................................................................................................................................. 2 What UEFI has to Offer ............................................................................................................
History In the mid‐1990s during the development of Intel’s Itanium‐based system, PC BIOS limitations (for example, 16‐bit processor mode, 1 MB addressable space, PC AT hardware dependencies, etc.) hindered platform development for Itanium. While the Itanium chip was not well received, the development exposed significant limitations to the original PC firmware architecture that led to the development of a new framework, called Extensible Firmware Interface (EFI).
What UEFI has to Offer The primary goal of UEFI is to define an architecture that can scale with time and to offer structured coding environment allowing easy enablement of new technology. The main characteristics of UEFI are: • • Abstraction for the Operation System. The UEFI specification provides an interface between the platform firmware and the operating system. The interfaces/API/protocols mark a clear boundary between the firmware and the operating system and the operating system loader.
Differences between BIOS and UEFI Boot Modes The following table highlights the differences between the boot modes. Feature Operating System Support BIOS POST Boot Manager Hot Key Boot Order Control USB Emulation Default Boot Order Boot Options Boot Mode BIOS UEFI Compatible with operating systems Must support UEFI that do not support UEFI. All the current and legacy operation systems can be installed in this boot mode.
UEFI Boot Manager The UEFI Boot Manager is entered by pressing during the pre‐boot phase of system startup. In UEFI boot mode, it replaces both the BIOS Boot Manager and the boot configuration options in the BIOS Setup Utility . When the Boot Mode is set to UEFI the BIOS Setup Utility fields, Boot Sequence and USB Flash Drive Emulation Type are grayed out, replaced by enhanced options in the UEFI Boot Manager.
Deploying a UEFI‐Aware Operating System Once the hardware and firmware support UEFI, the operating system needs to be redesigned to support UEFI. UEFI is still an emerging technology and standard, so there are only a few operating systems that have full support. Dell offers both legacy BIOS‐mode and UEFI‐mode. Operating Systems that support UEFI ‐ 1) Microsoft® Windows ®Vista, SP1 and Windows Server® 2008 – X64 versions only.
Once the operating system is installed, you can install applications and use the system normally with a few caveats. There are applications that may try to interact with the hard drive directly (imaging tools) – these may not work as expected. Dell recommends that you contact your application vendors for all mission‐critical applications to ensure they work in the UEFI environment.