NdisMapFile (Compact 2013)

3/26/2014

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

Syntax

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

Parameters

• Status
  A pointer 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 the NdisUnmapFile function is called.
  • NDIS_STATUS_ALREADY_MAPPED
    The caller cannot access the file contents at this time.

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

• FileHandle
  The handle that was returned by a previous call to the NdisOpenFile function.

Return Value

None.

Remarks

NdisMapFile associates (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. Therefore, a successful caller is given exclusive access to the file data until NdisUnmapFile or the NdisCloseFile function is called.

A miniport 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 deallocates the buffer that contains the file contents.

A miniport driver can call NdisMapFile only during initialization.

Requirements

Header	ndis.h
Library	ndis.dll

See Also

Reference

NDIS File Interface
MiniportInitializeEx
NdisCloseFile
NdisOpenFile
NdisUnmapFile