Kernel-Mode Multimedia Drivers

Kernel-mode multimedia drivers executing under Windows NT have the following characteristics:

• They execute in kernel mode.

• They export kernel-mode driver entry points that are called by the Windows NT Executive for performing I/O operations requested by user-mode multimedia drivers.

• They are implemented as services under the control of the Windows NT Service Control Manager.

• They communicate with device hardware by calling functions in the Windows NT Executive. The I/O Manager and the Hardware Abstraction Layer (HAL), both of which are parts of the Windows NT Executive, provide driver compatibility across the various hardware platforms supported by Windows NT.

  Kernel-mode drivers often do not call Windows NT Executive functions directly. Instead, they might call functions in support libraries, which in turn call the Executive functions. The support libraries are described in the chapters discussing the various driver types. The chapters are listed in Types of Multimedia Devices.

For information about designing a kernel-mode multimedia driver, see Designing a Kernel-Mode Multimedia Driver.