Microsoft Overhauls Longhorn Drivers for Usability, Connectivity

In a demonstration to developers, Microsoft pointed to an overhaul of device driver APIs and user interfaces for the forthcoming Windows Longhorn. The new capabilities include a desktop that will give equal weight to remote and local devices.

SAN FRANCISCO—Microsoft Corp. clued in hardware makers at the semiannual Intel Developer Forum here to the companys Windows Longhorn developer to-do list for connectivity and drivers. The initiatives will entail a major overhaul of Windows device driver technology for both programmers and users.

During a Tuesday session on forthcoming driver issues, Microsoft focused on a range of programming and user interfaces, including the first major rewrites to several key features introduced with Windows 95, such as WDM (Windows Driver Model) and PnP (Plug & Play) protocol.

According to Kosar Jaff, product unit manager of the Windows device experience group, the new device connectivity represents the "platformization and virtualization of the PC."

Jaff pointed to two underlying principles with the changes: the transition from wired connections to a PC to new wireless protocols; and the vision of a so-called "smart" network featuring a large number of interoperable devices. These connections will drive a new "ecosystem" of computing as well as a new business model for device manufacturers and software developers.

"Applications writers dont need to know if devices are near or far. When we get to the new world, expect to see a massive scale of interoperable devices," he said.

However, these moves will be complex, Jaff admitted, and could tax developers trying to decide where to put programming resources, as well as users, who expect a certain level of performance and reliability from devices. "These ease-of-use issues will be overwhelming if we dont get ahead of them," he warned the audience.

Longhorn will introduce a new driver architecture, Jaff said, called the Windows Driver Foundation. While the current Windows Driver Model has served since 1996, "the fundamental model is broken," he said. Microsoft estimates that some 30,000 drivers have been developed under the old model, with new entries arriving daily.

The new foundation divides drivers into two modes: one low-level as in the current practice and a more abstracted "user-mode framework." Many IP network drivers will take advantage of the higher, user-mode framework, while other devices, such as those for video, for example, will stay with the low-level framework.

"[Windows Driver Model] doesnt go away; WDF is a nice abstraction," Jaff said. Microsoft will also make available a number of internal tools for driver verification, he added.

Also due with Windows Longhorn will be a variety of new user interfaces for connecting devices to a system or discovering devices on the network.

Drivers installation issues continue to be a problem for users and for developers supporting those customers.

"Consumers dont know anything about hardware first and software second," Jaff said. He pointed out that current Windows drivers go through a "ritual" that can include "whacking the registry," leading to unexpected side effects for uninstalls or with other drivers.

"Consistent device installation" is an expected feature for Longhorn, he said. The new interface, which was given a demonstration to the developers, requires the user to give permission for a core device installation. "It was a free-for-all before; this ensures rollback."

However, if the installer request is from a trusted source, theres no need for any user interface at all, Jaff said. "An admin can install a driver on every seat in an enterprise with just one click."

Next Page: Advances in PnP.