Microsoft Overhauls Longhorn Drivers for Usability, ConnectivityBy David Morgenstern | Print
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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 FRANCISCOMicrosoft Corp. clued in hardware makers at the semiannual Intel Developer Forum here to the company's 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."
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 don't 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] doesn't 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 don't 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, there's 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.
Part of Microsoft's driver initiative includes advances in the Plug & Play specification, first released in 1995. Jaff said the group went back to the original architects for their suggestions.
Currently, there are different programming models for backplane-connected devices, mostly storage interfaces, and for protocol- and bus-connected devices, using USB, FireWire and IP networking. What is needed, Jaff said, is a common user interface, and common protocols for developers.
The new direction will provide a common programming model and driver framework as well as a new common interface to all of these connections for the user.
The plan will rely on a number of technologies, including PnP-X, which lets networked devices appear and function as if they were local devices; the Function Discovery API, which gives developers a way to find and use devices on a network that support the UPnP (Universal Plug & Play) protocol and WSD (Web Services for Devices).
In a demonstration of the new technologies, a wireless picture frame was discovered on the network and a slideshow was served to the device from a laptop. The process employed a "Found New Hardware" wizard that found the device and loaded a driver, an authentication routine, and the WS-Discovery specification released in February.
The Web Services for Devices API will be in Longhorn, according to the presentation slides shown. This particular point was underlined.
PnP-X devices will appear to the user as locally connected devices, including in the Device Manager, and peripheral vendors will be able to install device-specific software on the user's machine.
Jaff said Longhorn will also see a "fixed" SSDP (Simple Service Discovery Protocol) for Universal Plug & Play devices, which has received past criticisms for performance and security.
Developers were upbeat about new connectivity features, although most said they are only now just considering development of 64-bit drivers, something that was mentioned as an aside at the end of the presentation.
"It was good to see them finally address the PnP issues. This has been a long time coming," said Dan Watley, product manager with ICTV Inc. of Los Gatos, Calif. The company develops HeadendWare, server-side software that lets set-top boxes support interactive rich-media.
"If it works, it will be great," observed Gary Stroud, director of client systems at Gracenote LLC of Emeryville, Calif. The company's music-identification system is behind the DDB compact disc database service supported by a number of consumer products, including Apple Computer Inc.'s iTunes and iPod combination.