IOCTL_SFFDISK_QUERY_DEVICE_PROTOCOL IOCTL (sffdisk.h)

User-mode applications use this IOCTL to retrieve a protocol value that identifies the card as either an SD card or an MMC card. For a description of this command, see the Secure Digital I/O (SDIO) specification.

To perform this operation, call the DeviceIoControl function (described in the Microsoft Windows SDK documentation) using the following parameters.

bRet = DeviceIoControl (
    (HANDLE)  hDevice, 
    (DWORD)  dwIoControlCode, 
    (PUCHAR)  lpInBuffer,
    (DWORD)  nInBufferSize, 
    (PUCHAR)  lpOutBuffer,
    (DWORD)  nOutBufferSize, 
    (LPDWORD)  lpBytesReturned,
    (LPOVERLAPPED)  lpOverlapped 
  );

Parameters

hDevice

The handle to a volume in the SD stack.

dwIoControlCode

Contains the control code for the operation. This value identifies the specific operation to be performed and the type of device on which to perform it. Use IOCTL_SFFDISK_QUERY_DEVICE_PROTOCOL for this operation.

lpInBuffer

Not used with this IOCTL. Caller should pass in a NULL.

nInBufferSize

Not used with this IOCTL. Caller should pass in a value of 0.

lpOutBuffer

Pointer to a SFFDISK_QUERY_DEVICE_PROTOCOL_DATA structure in a user-supplied buffer that contains the results data. The ProtocolGUID member of the SFFDISK_QUERY_DEVICE_PROTOCOL_DATA structure contains a GUID that identifies the card as either an SD card or an MMC card. If the operation fails and GetLastError returns the error code STATUS_BUFFER_TOO_SMALL, the output buffer was not large enough to hold the results data.

nOutBufferSize

Contains the size, in bytes, of the output buffer pointed to by the lpOutBuffer parameter.

lpBytesReturned

Pointer to a variable that receives the size, in bytes, of the results data stored in the buffer pointed to by lpOutBuffer.

If the output buffer is too small to hold the return data then it will contain a value of zero on output, the call will fail, and GetLastError will return the error code ERROR_INSUFFICIENT_BUFFER. In case.

If lpOverlapped is NULL (nonoverlapped I/O), caller cannot assign a NULL to lpBytesReturned parameter on input. If lpOverlapped is not NULL (overlapped I/O), caller can assign a NULL to the lpBytesReturned parameter.

If this is an overlapped operation, you can retrieve the number of bytes returned by calling the GetOverlappedResult function. If hDevice is associated with an I/O completion port, you can get the number of bytes returned by calling the GetQueuedCompletionStatus function. For a description of the GetOverlappedResult and GetQueuedCompletionStatus functions see the Windows SDK documentation.

lpOverlapped

Pointer to an OVERLAPPED structure, as described in the Windows SDK documentation.

If the caller opened the device with the FILE_FLAG_OVERLAPPED flag, lpOverlapped must point to a valid OVERLAPPED structure. In this case, the system executes DeviceIoControl as an overlapped, asynchronous operation. If the caller opened the device with the FILE_FLAG_OVERLAPPED flag, and lpOverlapped is NULL, the function fails in unpredictable ways.

If the caller opened the device without specifying the FILE_FLAG_OVERLAPPED flag, the system ignores the value in lpOverlapped, and the DeviceIoControl function does not return until the operation has been completed, or until an error occurs.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

TBD

Output buffer

TBD

Output buffer length

TBD

Input / Output buffer

TBD

Input / Output buffer length

TBD

Status block

If the operation succeeds, DeviceIoControl returns a nonzero value.

If the operation fails, DeviceIoControl returns zero. To get extended error information, call GetLastError.

Requirements