EngDeviceIoControl function (winddi.h)

Article
02/22/2024

The EngDeviceIoControl function sends a control code to the specified video miniport driver, causing the device to perform the specified operation.

Syntax

ENGAPI DWORD EngDeviceIoControl(
  [in]            HANDLE  hDevice,
  [in]            DWORD   dwIoControlCode,
  [in, optional]  LPVOID  lpInBuffer,
  [in]            DWORD   nInBufferSize,
  [out, optional] LPVOID  lpOutBuffer,
  [in]            DWORD   nOutBufferSize,
  [out]           LPDWORD lpBytesReturned
);

Parameters

[in] hDevice

Handle to the device that is to perform the operation.

[in] dwIoControlCode

Specifies the control code for the operation. The I/O controls are listed and described in full in Video Miniport Driver I/O Control Codes.

[in, optional] lpInBuffer

Pointer to a buffer containing data required to perform the operation. This parameter can be NULL if the control code specifies an operation that does not require input data.

[in] nInBufferSize

Specifies the size, in bytes, of lpInBuffer.

[out, optional] lpOutBuffer

Pointer to a buffer in which the operation's output data is returned. This parameter can be NULL if the control code specifies an operation that does not produce output data.

[in] nOutBufferSize

Specifies the size, in bytes, of lpOutBuffer.

[out] lpBytesReturned

Pointer to a DWORD that specifies the actual size, in bytes, of the data returned in lpOutBuffer.

Return value

The return value is a 32-bit Win32 API-defined error code.

Remarks

EngDeviceIoControl is used by a display driver to communicate I/O requests to its corresponding miniport driver. This function provides the only communication channel between a display and video miniport driver.

Requirements

Requirement	Value
Minimum supported client	Available in Windows 2000 and later versions of the Windows operating systems.
Target Platform	Universal
Header	winddi.h (include Winddi.h)
Library	Win32k.lib
DLL	Win32k.sys