HP Vectra VE 5/xx hp desktop pcs, plug and play for Microsoft Windows 2000 (Mi - Page 6

server computers that include ACPI system boards. In addition, Plug and Play device driver support for many device classes is provided by the Microsoft Win32® Driver Model (WDM), which also supports power management and other new capabilities that can be configured and controlled by the operating system. UurÃXvq D€ƒyr€r‡h‡v‚ To incorporate Plug and Play support into Windows 2000, a native Plug and Play implementation was integrated into the existing Windows code base. This results in the following changes for developers who previously created drivers under the Windows NT 4.0 device driver model: • Bus drivers are now separate from the HAL. Bus drivers control an I/O bus, including per-slot functionality that is device-independent. In the new architecture, bus drivers have moved out of the hardware abstraction layer (HAL) to coordinate with changes and extensions made to existing kernel-mode components, such as the Executive, device drivers, and the HAL. Bus drivers are generally provided by Microsoft. • New methods and capabilities are available to support device installation and configuration. The new design includes changes and extensions to existing user-mode components, such as the Spooler, class installers, Control Panel applications, and Setup. In addition, new kernel-mode and user-mode Plug and Play-enabled components have been added. • New Plug and Play APIs are used to read and write information from the registry. For the new design, changes and extensions were made to the registry structure. This structure supports Plug and Play and allows the registry to be enhanced in future versions of Windows, while also providing backward compatibility. Windows 2000 supports legacy Windows NT drivers, but these have no Plug and Play and power management functionality. Manufacturers who want to support complete Plug and Play capabilities for their devices and who want the same drivers to function on both Windows NT and Windows operating systems need to develop new drivers that integrate the latest Plug and Play and power management functionality. This white paper provides a brief overview of the architecture and design direction for Plug and Play under Windows 2000. The beta releases of the Windows 2000 DDK document the actual driver modifications required to allow current drivers to work in a Windows 2000 Plug and Play system. Windows 2000 White Paper 2