NdisMapFile (Windows Embedded CE 6.0)

1/6/2010

This function maps an already open file into a caller-accessible buffer if the file is currently unmapped.

Syntax

            VOID NdisMapFile(
            PNDIS_STATUS
            Status
            ,
            PVOID* 
            MappedBuffer
            ,
            NDIS_HANDLE
            FileHandle
            );
        

Parameters

• Status
  [out] Points to a caller-supplied variable in which this function returns the status of the mapping operation, which can be one of the following:

  • NDIS_STATUS_SUCCESS
    The caller has exclusive access to the file contents until NdisUnmapFile is called.
  • NDIS_STATUS_ALREADY_MAPPED
    The caller cannot access the file contents at this time.

• MappedBuffer
  [out] Points to a caller-supplied variable in which this function returns the base virtual address of the mapped file contents or NULL.

• FileHandle
  [in] Specifies the handle returned by a preceding call to NdisOpenFile.

Return Value

None.

Remarks

NdisMapFile associates or maps a virtual address range with an opened file so the driver can access the file contents. NdisMapFile allows only one mapping of a particular file to be outstanding at any time. Consequently, a successful caller is given exclusive access to the file data until NdisUnmapFile or NdisCloseFile is called.

A NIC driver can map and unmap such an open file as necessary, using alternating calls to NdisMapFile and NdisUnmapFile. A call to NdisCloseFile releases the FileHandle and de-allocates the buffer containing the file contents.

A NIC driver can call NdisMapFile only during initialization.

Requirements

See Also

Reference

NDIS Library Functions
NdisCloseFile
NdisOpenFile
NdisUnmapFile