DeviceIoControl

DeviceIoControl sends a control code directly to a specified file system driver, causing the corresponding device to perform the specified operation.

Syntax

Copy

BOOL DeviceIoControl(
    [in]                       HANDLE hDevice,
    [in]                       DWORD IoControlCode,
    [in, optional]             LPVOID lpInBuffer,
    [in]                       DWORD nInBufferSize,
    [out, optional]            LPVOID lpOutBuffer,
    [in]                       DWORD nOutBufferSize,
    [out, optional]            LPDWORD lpBytesReturned,
    [in, out, optional]        LPOVERLAPPED lpOverlapped
);

Parameters

[in] hDevice

A handle to the device that is to perform the operation. Call GetLastError to obtain a device handle.

[in] IoControlCode

The control code for the operation. This value identifies the specific operation to be performed and the type of device on which the operation is to be performed. The following values are defined:

Value	Definition
IOCTL_DISK_CHECK_VERIFY	Obsolete. Use IOCTL_STORAGE_CHECK_VERIFY.
IOCTL_DISK_EJECT_MEDIA	Obsolete. Use IOCTL_STORAGE_EJECT_MEDIA.
IOCTL_DISK_FORMAT_TRACKS	Formats a contiguous set of disk tracks.
IOCTL_DISK_GET_DRIVE_GEOMETRY	Obtains information on the physical disk's geometry.
IOCTL_DISK_GET_DRIVE_LAYOUT	Provides information about each partition on a disk.
IOCTL_DISK_GET_MEDIA_TYPES	Obsolete. Use IOCTL_STORAGE_GET_MEDIA_TYPES.
IOCTL_DISK_GET_PARTITION_INFO	Obtains disk partition information.
IOCTL_DISK_LOAD_MEDIA	Obsolete. Use IOCTL_STORAGE_LOAD_MEDIA.
IOCTL_DISK_MEDIA_REMOVAL	Obsolete. Use IOCTL_STORAGE_MEDIA_REMOVAL.
IOCTL_DISK_PERFORMANCE	Provides disk performance information.
IOCTL_DISK_REASSIGN_BLOCKS	Maps disk blocks to spare-block pool.
IOCTL_DISK_SET_DRIVE_LAYOUT	Partitions a disk.
IOCTL_DISK_SET_PARTITION_INFO	Sets the disk partition type.
IOCTL_DISK_VERIFY	Performs logical format of a disk extent.
IOCTL_SERIAL_LSRMST_INSERT	Enables or disables placement of a line and modem status data into the data stream.
IOCTL_DISK_STORAGE_CHECK_VERIFY	Checks for change in a removable-media device.
IOCTL_DISK_STORAGE_EJECT_MEDIA	Ejects media from a SCSI device.
IOCTL_DISK_STORAGE_GET_MEDIA_TYPES	Obtains information about media support.
IOCTL_DISK_STORAGE_LOAD_MEDIA	Loads media into a device.
IOCTL_DISK_STORAGE_MEDIA_REMOVAL	Enables or disables the media eject mechanism.

For more detailed information on each control code, see its topic in the Microsoft documentation. Each topic provides details on the usage of the lpInBuffer, nInBufferSize, lpOutBuffer, nOutBufferSize, and lpBytesReturned parameters.

[in, optional] lpInBuffer

A pointer to a buffer that contains the data required to perform the operation.

This parameter can be NULL if the IoControlCode parameter specifies an operation that does not require input data.

[in] nInBufferSize

The size, in bytes, of the buffer pointed to by lpInBuffer.

[out, optional] lpOutBuffer

A pointer to a buffer that receives the operation's output data.

This parameter can be NULL if the IoControlCode parameter specifies an operation that does not produce output data.

[in] nOutBufferSize

The size, in bytes, of the buffer pointed to by lpOutBuffer.

[out, optional] lpBytesReturned

A pointer to a variable that receives the size, in bytes, of the data stored into the buffer pointed to by lpOutBuffer.

[in, out, optional] lpOverlapped

Ignored. This parameter should be set to NULL.

Return Value

If the function succeeds, it returns TRUE. If the function fails, it returns FALSE. Call GetLastError to get extended error information.

Requirements

Minimum supported version	Header	Library
wRTOS 1.0 SDK	windows.h	wRTOS_rtss.lib