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

Header	ndis.h
Library	ndis.dll
Windows Embedded CE	Windows CE .NET 4.0 and later

See Also

Reference

NDIS Library Functions
NdisCloseFile
NdisOpenFile
NdisUnmapFile