IN  PMDL SourceMdlChain,
  IN  ULONG SourceOffset,
  IN  PVOID DestinationBuffer,
  IN  ULONG DestinationOffset,
  IN  ULONG DestinationBufferSize,
  OUT PULONG BytesCopied

Routine Description:

    This routine copies data described by the source MDL chain starting at
    the source offset, into a flat buffer specified by the SVA starting at
    the destination offset.  A maximum of DestinationBufferSize bytes can
    be copied.  The actual number of bytes copied is returned in BytesCopied.


    SourceMdlChain - Pointer to a chain of MDLs describing the source data.

    SourceOffset - Number of bytes to skip in the source data.

    DestinationBuffer - Pointer to a flat buffer to copy the data to.

    DestinationOffset - Number of leading bytes to skip in the destination buffer.

    DestinationBufferSize - Size of the output buffer, including the offset.

    BytesCopied - Pointer to a longword where the actual number of bytes
        transferred will be returned.

Return Value:

    NTSTATUS - status of operation.