IN  PDEVICE_OBJECT DeviceObject,
  IN  ULONG SectorSize,
  IN  ULONG MBRTypeIdentifier,
  OUT PVOID *Buffer

Routine Description:

    Given a master boot record type (MBR - the zero'th sector on the disk),
    read the master boot record of a disk.  If the MBR is found to be of that
    type, allocate a structure whose layout is dependant upon that partition
    type, fill with the appropriate values, and return a pointer to that buffer
    in the output parameter.

    The best example for a use of this routine is to support Ontrack
    systems DiskManager software.  Ontrack software lays down a special
    partition describing the entire drive.  The special partition type
    (0x54) will be recognized and a couple of longwords of data will
    be passed back in a buffer for a disk driver to act upon.


    DeviceObject - The device object describing the entire drive.

    SectorSize - The minimum number of bytes that an IO operation can

    MBRIndentifier - A value that will be searched for in the
                     in the MBR.  This routine will understand
                     the semantics implied by this value.

    Buffer - Pointer to a buffer that returns data according to the
             type of MBR searched for.  If the MBR is not of the
             type asked for, the buffer will not be allocated and this
             pointer will be NULL.  It is the responsibility of the
             caller of HalExamineMBR to deallocate the buffer.  The
             caller should deallocate the memory ASAP.

Return Value: