VideoPortZeroMemory function (video.h)

The VideoPortZeroMemory function fills a block of system memory with zeros.

Syntax

VIDEOPORT_API VOID VideoPortZeroMemory(
  [out] PVOID Destination,
        ULONG Length
);

Parameters

[out] Destination

Specifies the starting address of the block of memory. This value must be in a mapped logical range returned by VideoPortGetDeviceBase.

Length

Specifies the size, in bytes, of the block.

Return value

None

Remarks

Miniport drivers' DriverEntry functions generally call VideoPortZeroMemory to initialize the VIDEO_HW_INITIALIZATION_DATA structure with zeros.

The given Destination must be in a mapped logical range returned by VideoPortGetDeviceBase and/or a system space RAM address, such as an address on the stack. Use VideoPortZeroDeviceMemory to fill any device-memory block, such as a frame buffer, with zeros.

A miniport driver's HwVidInterrupt or HwVidSynchronizeExecutionCallback function can call VideoPortZeroMemory.

Callers of VideoPortZeroMemory can be running at any IRQL if the memory pointed to by the Destination parameter is in nonpaged pool. Otherwise, the caller must be running at IRQL < DISPATCH_LEVEL.

Requirements

See also

DriverEntry

HwVidInterrupt

HwVidSynchronizeExecutionCallback

VIDEO_HW_INITIALIZATION_DATA

VideoPortCompareMemory

VideoPortMoveMemory

VideoPortZeroDeviceMemory