Microsoft Reverses UEFI Plans

Firmware dropped from Vista launch.

Microsoft has pushed back its plans to support a new type of PC firmware, called UEFI, or Unified Extensible Firmware Interface, which has begun working its way into the PC market.

Company officials said in a presentation during the Intel Developer Forum in San Francisco in early March that Microsoft would support UEFI in its Longhorn Server operating system, due next year. But, reversing its earlier plans, Microsoft also said at IDF that it will not support the new firmware in the first version of Windows Vista, its next PC operating system, slated for wide availability in November.

Instead, Microsoft plans to add UEFI support to "subsequent 64-bit client releases" of Vista, said Andrew Ritz, development manager at the Redmond, Wash., company.

Microsoft had planned to support UEFI in Vista and Longhorn Server at launch. The firmware, sometimes referred to as EFI for short, was created for Itanium-based servers and then repurposed as an alternative for PC BIOS software.

UEFI isnt the first landmark feature Microsoft has dropped from Vista. It dropped WinFS (Windows File System) in August 2004 in an effort to get Vista out by the end of this year.

UEFI is the first revision of PC firmware since the inception of the IBM PC clone market and is designed to help make PCs more stable and manageable.

Given that, Microsofts move to drop support for UEFI in the initial Vista release reflects as much about its outlook for 64-bit software on the desktop as it does about getting Vista to market, company officials argued.

Several factors led the company to change its priorities, they said.

Among the issues that officials cited were smaller-than-expected numbers of systems using the interface at the time of Vistas arrival and the advent of a new UEFI 2.0 standard. UEFI 2.0 was created by the Unified EFI Forum, a body that took over stewardship of the interface from Intel.

Microsoft officials also said that computer makers priorities were more focused on servers, where UEFI can provide benefits such as allowing larger numbers of add-in cards and reducing card-to-card conflicts.

"As part of our ongoing testing and work with the Unified EFI Forum, we came to the realization that there would not be enough systems with EFI support enabled by the time Windows Vista launches," a Microsoft spokesperson said in an e-mail to eWEEK.

"We are continuing to work closely with the Unified EFI Forum and with our industry partners to ensure that we can ultimately provide a high-quality, standards-based EFI solution that works across the many different platforms on which Windows runs," the spokesperson said.

The Unified EFI Forum, ironically, supports the Microsoft plan. The firmware was designed to work with both 32- and 64-bit operating systems and be backward-compatible with operating systems designed for BIOS. UEFI systems can employ a special software compatibility module to emulate BIOS functions and thus boot operating systems, such as Windows XP, which were designed to work with BIOS.

Because of UEFIs ability to work with BIOS-based operating systems via compatibility modules, the Unified EFI Forum, whose members include Microsoft, Intel, Advanced Micro Devices, PC makers and BIOS developers, put its efforts behind driving 64-bit UEFI 2.0 implementations in PCs. Indeed, Microsoft said in the IDF presentation that it will not support 32-bit UEFI at all.

Building PCs with UEFI and compatibility modules offers the most logical path to supporting the widest variety of operating systems, including Windows XP, Vista and Linux, said Mike Richmond, manager of platform software for Intels Core Software Division, a segment of the Santa Clara, Calif., companys Software and Solutions Group.

"Nobody is going to build a system that just boots [using] EFI for a long time," Richmond said. "If somebody buys a PC to run Windows, they want the option to be able to run older versions. That leads to the decision that most OEMs are going to make that they will include some sort of BIOS backward compatibility."

Basing a machine on 64-bit UEFI and including a compatibility module would allow it to ship with XP or Vista but still give companies the option to load older operating systems or to use Linux. Then, following the arrival of Vista with UEFI support, that version of the operating system would run natively on top of the machines UEFI firmware.

Given that it hasnt shipped Vista yet, Microsoft has not said when follow-ons to the operating system—such as a Vista Service Pack 1 that might contain UEFI support—could arrive. It took about a year for the company to deliver XP SP1. Vista R2, the next full-fledged version of Vista, isnt expected until 2008.

At any rate, Microsoft is taking the long view. Despite anticipation of UEFI by PC makers, "This is about reinvesting in an area of the [PC] platform that hasnt been invested in in a long time," Richmond said. "If it takes a little longer [to get to market], it takes a little longer."

Meanwhile, since it contends Vista will deliver a host of improvements in stability and manageability, the lack of immediate UEFI support should not have a major effect on the PC industry or on IT managers, the company maintains.

"In the meantime, Windows Vista already is engineered for better manageability from the ground up," the Microsoft spokesperson said in the e-mail.

Among improvements Microsoft added to Vista are more complete control over system settings, better-quality information about system behavior and the ability to better locate problematic areas inside systems.

Additional reporting by Microsoft Watch Editor Mary Jo Foley