IN  PVOID SourceBuffer,
  IN  ULONG SourceOffset,
  IN  ULONG SourceBytesToCopy,
  IN  PMDL DestinationMdlChain,
  IN  ULONG DestinationOffset,
  IN  PULONG BytesCopied

Routine Description:

    This routine copies data described by the source buffer to the MDL chain
    described by the DestinationMdlChain. The


    SourceBuffer - pointer to the source buffer

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

    SourceBytesToCopy - number of bytes to copy from the source buffer

    DestinationMdlChain - Pointer to a chain of MDLs describing the
            destination buffers.

    DestinationOffset - Number of bytes to skip in the destination data.

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

Return Value:

    NTSTATUS - status of operation.