[mirror_edk2.git] / MdeModulePkg / Universal / Disk / PartitionDxe / Mbr.c

/** @file\r
  Decode a hard disk partitioned with the legacy MBR found on most PC's\r
\r
  MBR - Master Boot Record is in the first sector of a partitioned hard disk.\r
        The MBR supports four partitions per disk. The MBR also contains legacy\r
        code that is not run on an EFI system. The legacy code reads the \r
        first sector of the active partition into memory and \r
\r
  BPB - BIOS Parameter Block is in the first sector of a FAT file system. \r
        The BPB contains information about the FAT file system. The BPB is \r
        always on the first sector of a media. The first sector also contains\r
        the legacy boot strap code.\r
\r
Copyright (c) 2014, Hewlett-Packard Development Company, L.P.<BR>\r
Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include "Partition.h"\r
\r
/**\r
  Test to see if the Mbr buffer is a valid MBR.\r
\r
  @param  Mbr         Parent Handle.\r
  @param  LastLba     Last Lba address on the device.\r
   \r
  @retval TRUE        Mbr is a Valid MBR.\r
  @retval FALSE       Mbr is not a Valid MBR.\r
\r
**/\r
BOOLEAN\r
PartitionValidMbr (\r
  IN  MASTER_BOOT_RECORD      *Mbr,\r
  IN  EFI_LBA                 LastLba\r
  )\r
{\r
  UINT32  StartingLBA;\r
  UINT32  EndingLBA;\r
  UINT32  NewEndingLBA;\r
  INTN    Index1;\r
  INTN    Index2;\r
  BOOLEAN MbrValid;\r
\r
  if (Mbr->Signature != MBR_SIGNATURE) {\r
    return FALSE;\r
  }\r
  //\r
  // The BPB also has this signature, so it can not be used alone.\r
  //\r
  MbrValid = FALSE;\r
  for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
    if (Mbr->Partition[Index1].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
      continue;\r
    }\r
\r
    MbrValid    = TRUE;\r
    StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
    EndingLBA   = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
    if (EndingLBA > LastLba) {\r
      //\r
      // Compatibility Errata:\r
      //  Some systems try to hide drive space with their INT 13h driver\r
      //  This does not hide space from the OS driver. This means the MBR\r
      //  that gets created from DOS is smaller than the MBR created from\r
      //  a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
      //  wrong on some systems FDISKed by the OS.\r
      //\r
      // return FALSE since no block devices on a system are implemented\r
      // with INT 13h\r
      //\r
    \r
      DEBUG((EFI_D_INFO, "PartitionValidMbr: Bad MBR partition size EndingLBA(%1x) > LastLBA(%1x)\n", EndingLBA, LastLba));\r
\r
      return FALSE;\r
    }\r
\r
    for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
      if (Mbr->Partition[Index2].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
        continue;\r
      }\r
\r
      NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
      if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
        //\r
        // This region overlaps with the Index1'th region\r
        //\r
        return FALSE;\r
      }\r
    }\r
  }\r
  //\r
  // None of the regions overlapped so MBR is O.K.\r
  //\r
  return MbrValid;\r
}\r
\r
\r
/**\r
  Install child handles if the Handle supports MBR format.\r
\r
  @param[in]  This              Calling context.\r
  @param[in]  Handle            Parent Handle.\r
  @param[in]  DiskIo            Parent DiskIo interface.\r
  @param[in]  DiskIo2           Parent DiskIo2 interface.\r
  @param[in]  BlockIo           Parent BlockIo interface.\r
  @param[in]  BlockIo2          Parent BlockIo2 interface.\r
  @param[in]  DevicePath        Parent Device Path.\r
   \r
  @retval EFI_SUCCESS       A child handle was added.\r
  @retval EFI_MEDIA_CHANGED Media change was detected.\r
  @retval Others            MBR partition was not found.\r
\r
**/\r
EFI_STATUS\r
PartitionInstallMbrChildHandles (\r
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,\r
  IN  EFI_HANDLE                   Handle,\r
  IN  EFI_DISK_IO_PROTOCOL         *DiskIo,\r
  IN  EFI_DISK_IO2_PROTOCOL        *DiskIo2,\r
  IN  EFI_BLOCK_IO_PROTOCOL        *BlockIo,\r
  IN  EFI_BLOCK_IO2_PROTOCOL       *BlockIo2,\r
  IN  EFI_DEVICE_PATH_PROTOCOL     *DevicePath\r
  )\r
{\r
  EFI_STATUS                Status;\r
  MASTER_BOOT_RECORD        *Mbr;\r
  UINT32                    ExtMbrStartingLba;\r
  UINTN                     Index;\r
  HARDDRIVE_DEVICE_PATH     HdDev;\r
  HARDDRIVE_DEVICE_PATH     ParentHdDev;\r
  EFI_STATUS                Found;\r
  UINT32                    PartitionNumber;\r
  EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode;\r
  EFI_DEVICE_PATH_PROTOCOL  *LastDevicePathNode;\r
  UINT32                    BlockSize;\r
  UINT32                    MediaId;\r
  EFI_LBA                   LastBlock;\r
\r
  Found           = EFI_NOT_FOUND;\r
\r
  BlockSize = BlockIo->Media->BlockSize;\r
  MediaId   = BlockIo->Media->MediaId;\r
  LastBlock = BlockIo->Media->LastBlock;\r
\r
  Mbr = AllocatePool (BlockSize);\r
  if (Mbr == NULL) {\r
    return Found;\r
  }\r
\r
  Status = DiskIo->ReadDisk (\r
                     DiskIo,\r
                     MediaId,\r
                     0,\r
                     BlockSize,\r
                     Mbr\r
                     );\r
  if (EFI_ERROR (Status)) {\r
    Found = Status;\r
    goto Done;\r
  }\r
  if (!PartitionValidMbr (Mbr, LastBlock)) {\r
    goto Done;\r
  }\r
  //\r
  // We have a valid mbr - add each partition\r
  //\r
  //\r
  // Get starting and ending LBA of the parent block device.\r
  //\r
  LastDevicePathNode = NULL;\r
  ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
  DevicePathNode = DevicePath;\r
  while (!IsDevicePathEnd (DevicePathNode)) {\r
    LastDevicePathNode  = DevicePathNode;\r
    DevicePathNode      = NextDevicePathNode (DevicePathNode);\r
  }\r
\r
  if (LastDevicePathNode != NULL) {\r
    if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
        DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
        ) {\r
      CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
    } else {\r
      LastDevicePathNode = NULL;\r
    }\r
  }\r
\r
  PartitionNumber = 1;\r
\r
  ZeroMem (&HdDev, sizeof (HdDev));\r
  HdDev.Header.Type     = MEDIA_DEVICE_PATH;\r
  HdDev.Header.SubType  = MEDIA_HARDDRIVE_DP;\r
  SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
  HdDev.MBRType         = MBR_TYPE_PCAT;\r
  HdDev.SignatureType   = SIGNATURE_TYPE_MBR;\r
\r
  if (LastDevicePathNode == NULL) {\r
    //\r
    // This is a MBR, add each partition\r
    //\r
    for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
      if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
        //\r
        // Don't use null MBR entries\r
        //\r
        continue;\r
      }\r
\r
      if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
        //\r
        // This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
        //  We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
        //  this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
        //  that corrupted the GPT partition. \r
        //\r
        continue;\r
      }\r
\r
      HdDev.PartitionNumber = PartitionNumber ++;\r
      HdDev.PartitionStart  = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
      HdDev.PartitionSize   = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
      CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (Mbr->UniqueMbrSignature));\r
\r
      Status = PartitionInstallChildHandle (\r
                This,\r
                Handle,\r
                DiskIo,\r
                DiskIo2,\r
                BlockIo,\r
                BlockIo2,\r
                DevicePath,\r
                (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
                HdDev.PartitionStart,\r
                HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
                MBR_SIZE,\r
                (BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
                );\r
\r
      if (!EFI_ERROR (Status)) {\r
        Found = EFI_SUCCESS;\r
      }\r
    }\r
  } else {\r
    //\r
    // It's an extended partition. Follow the extended partition\r
    // chain to get all the logical drives\r
    //\r
    ExtMbrStartingLba = 0;\r
\r
    do {\r
\r
      Status = DiskIo->ReadDisk (\r
                         DiskIo,\r
                         MediaId,\r
                         MultU64x32 (ExtMbrStartingLba, BlockSize),\r
                         BlockSize,\r
                         Mbr\r
                         );\r
      if (EFI_ERROR (Status)) {\r
        Found = Status;\r
        goto Done;\r
      }\r
\r
      if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {\r
        break;\r
      }\r
\r
      if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) ||\r
          (Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
        ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
        continue;\r
      }\r
      HdDev.PartitionNumber = PartitionNumber ++;\r
      HdDev.PartitionStart  = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
      HdDev.PartitionSize   = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
      if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) ||\r
          (HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
        break;\r
      }\r
\r
      //\r
      // The signature in EBR(Extended Boot Record) should always be 0.\r
      //\r
      *((UINT32 *) &HdDev.Signature[0]) = 0;\r
\r
      Status = PartitionInstallChildHandle (\r
                 This,\r
                 Handle,\r
                 DiskIo,\r
                 DiskIo2,\r
                 BlockIo,\r
                 BlockIo2,\r
                 DevicePath,\r
                 (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
                 HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
                 HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
                 MBR_SIZE,\r
                 (BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
                 );\r
      if (!EFI_ERROR (Status)) {\r
        Found = EFI_SUCCESS;\r
      }\r
\r
      if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
          (Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
          ) {\r
        break;\r
      }\r
\r
      ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
      //\r
      // Don't allow partition to be self referencing\r
      //\r
      if (ExtMbrStartingLba == 0) {\r
        break;\r
      }\r
    } while (ExtMbrStartingLba  < ParentHdDev.PartitionSize);\r
  }\r
\r
Done:\r
  FreePool (Mbr);\r
\r
  return Found;\r
}\r
Commit	Line	Data
f42be642	1	/** @file\r
adbcbf8f	2	Decode a hard disk partitioned with the legacy MBR found on most PC's\r
	3	\r
	4	MBR - Master Boot Record is in the first sector of a partitioned hard disk.\r
	5	The MBR supports four partitions per disk. The MBR also contains legacy\r
	6	code that is not run on an EFI system. The legacy code reads the \r
	7	first sector of the active partition into memory and \r
	8	\r
48557c65	9	BPB - BIOS Parameter Block is in the first sector of a FAT file system. \r
adbcbf8f	10	The BPB contains information about the FAT file system. The BPB is \r
	11	always on the first sector of a media. The first sector also contains\r
	12	the legacy boot strap code.\r
	13	\r
01331951	14	Copyright (c) 2014, Hewlett-Packard Development Company, L.P.<BR>\r
493d8e3a	15	Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>\r
e5eed7d3	16	This program and the accompanying materials\r
f42be642	17	are licensed and made available under the terms and conditions of the BSD License\r
	18	which accompanies this distribution. The full text of the license may be found at\r
	19	http://opensource.org/licenses/bsd-license.php\r
	20	\r
	21	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	22	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	23	\r
	24	**/\r
adbcbf8f	25	\r
	26	#include "Partition.h"\r
	27	\r
a8d0c20e	28	/**\r
	29	Test to see if the Mbr buffer is a valid MBR.\r
	30	\r
	31	@param Mbr Parent Handle.\r
	32	@param LastLba Last Lba address on the device.\r
	33	\r
	34	@retval TRUE Mbr is a Valid MBR.\r
	35	@retval FALSE Mbr is not a Valid MBR.\r
	36	\r
	37	**/\r
adbcbf8f	38	BOOLEAN\r
	39	PartitionValidMbr (\r
	40	IN MASTER_BOOT_RECORD *Mbr,\r
	41	IN EFI_LBA LastLba\r
	42	)\r
adbcbf8f	43	{\r
	44	UINT32 StartingLBA;\r
	45	UINT32 EndingLBA;\r
	46	UINT32 NewEndingLBA;\r
	47	INTN Index1;\r
	48	INTN Index2;\r
	49	BOOLEAN MbrValid;\r
	50	\r
	51	if (Mbr->Signature != MBR_SIGNATURE) {\r
	52	return FALSE;\r
	53	}\r
	54	//\r
	55	// The BPB also has this signature, so it can not be used alone.\r
	56	//\r
	57	MbrValid = FALSE;\r
	58	for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
	59	if (Mbr->Partition[Index1].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
	60	continue;\r
	61	}\r
	62	\r
	63	MbrValid = TRUE;\r
	64	StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
	65	EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
	66	if (EndingLBA > LastLba) {\r
	67	//\r
	68	// Compatibility Errata:\r
	69	// Some systems try to hide drive space with their INT 13h driver\r
	70	// This does not hide space from the OS driver. This means the MBR\r
	71	// that gets created from DOS is smaller than the MBR created from\r
	72	// a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
	73	// wrong on some systems FDISKed by the OS.\r
	74	//\r
	75	// return FALSE since no block devices on a system are implemented\r
	76	// with INT 13h\r
	77	//\r
01331951 SEHM	78	\r
	79	DEBUG((EFI_D_INFO, "PartitionValidMbr: Bad MBR partition size EndingLBA(%1x) > LastLBA(%1x)\n", EndingLBA, LastLba));\r
	80	\r
adbcbf8f	81	return FALSE;\r
	82	}\r
	83	\r
	84	for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
	85	if (Mbr->Partition[Index2].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
	86	continue;\r
	87	}\r
	88	\r
	89	NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
	90	if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
	91	//\r
	92	// This region overlaps with the Index1'th region\r
	93	//\r
	94	return FALSE;\r
	95	}\r
	96	}\r
	97	}\r
	98	//\r
ea7cb08c	99	// None of the regions overlapped so MBR is O.K.\r
adbcbf8f	100	//\r
	101	return MbrValid;\r
	102	}\r
	103	\r
a8d0c20e	104	\r
	105	/**\r
	106	Install child handles if the Handle supports MBR format.\r
	107	\r
490b5ea1	108	@param[in] This Calling context.\r
	109	@param[in] Handle Parent Handle.\r
	110	@param[in] DiskIo Parent DiskIo interface.\r
493d8e3a	111	@param[in] DiskIo2 Parent DiskIo2 interface.\r
490b5ea1	112	@param[in] BlockIo Parent BlockIo interface.\r
	113	@param[in] BlockIo2 Parent BlockIo2 interface.\r
	114	@param[in] DevicePath Parent Device Path.\r
a8d0c20e	115	\r
	116	@retval EFI_SUCCESS A child handle was added.\r
	117	@retval EFI_MEDIA_CHANGED Media change was detected.\r
	118	@retval Others MBR partition was not found.\r
	119	\r
	120	**/\r
adbcbf8f	121	EFI_STATUS\r
	122	PartitionInstallMbrChildHandles (\r
	123	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	124	IN EFI_HANDLE Handle,\r
	125	IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
493d8e3a	126	IN EFI_DISK_IO2_PROTOCOL *DiskIo2,\r
adbcbf8f	127	IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
490b5ea1	128	IN EFI_BLOCK_IO2_PROTOCOL *BlockIo2,\r
adbcbf8f	129	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
adbcbf8f	130	)\r
adbcbf8f	131	{\r
	132	EFI_STATUS Status;\r
	133	MASTER_BOOT_RECORD *Mbr;\r
	134	UINT32 ExtMbrStartingLba;\r
	135	UINTN Index;\r
	136	HARDDRIVE_DEVICE_PATH HdDev;\r
	137	HARDDRIVE_DEVICE_PATH ParentHdDev;\r
	138	EFI_STATUS Found;\r
	139	UINT32 PartitionNumber;\r
	140	EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
	141	EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
490b5ea1	142	UINT32 BlockSize;\r
	143	UINT32 MediaId;\r
	144	EFI_LBA LastBlock;\r
adbcbf8f	145	\r
adbcbf8f	146	Found = EFI_NOT_FOUND;\r
adbcbf8f	147	\r
490b5ea1	148	BlockSize = BlockIo->Media->BlockSize;\r
	149	MediaId = BlockIo->Media->MediaId;\r
	150	LastBlock = BlockIo->Media->LastBlock;\r
	151	\r
	152	Mbr = AllocatePool (BlockSize);\r
adbcbf8f	153	if (Mbr == NULL) {\r
737dfc36	154	return Found;\r
adbcbf8f	155	}\r
adbcbf8f	156	\r
96f99e1d	157	Status = DiskIo->ReadDisk (\r
96f99e1d	158	DiskIo,\r
490b5ea1	159	MediaId,\r
96f99e1d	160	0,\r
490b5ea1	161	BlockSize,\r
96f99e1d	162	Mbr\r
96f99e1d	163	);\r
adbcbf8f	164	if (EFI_ERROR (Status)) {\r
	165	Found = Status;\r
	166	goto Done;\r
	167	}\r
490b5ea1	168	if (!PartitionValidMbr (Mbr, LastBlock)) {\r
adbcbf8f	169	goto Done;\r
	170	}\r
	171	//\r
	172	// We have a valid mbr - add each partition\r
	173	//\r
	174	//\r
	175	// Get starting and ending LBA of the parent block device.\r
	176	//\r
	177	LastDevicePathNode = NULL;\r
	178	ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
	179	DevicePathNode = DevicePath;\r
1232b214	180	while (!IsDevicePathEnd (DevicePathNode)) {\r
adbcbf8f	181	LastDevicePathNode = DevicePathNode;\r
1232b214	182	DevicePathNode = NextDevicePathNode (DevicePathNode);\r
adbcbf8f	183	}\r
	184	\r
	185	if (LastDevicePathNode != NULL) {\r
	186	if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
	187	DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
	188	) {\r
	189	CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
	190	} else {\r
	191	LastDevicePathNode = NULL;\r
	192	}\r
	193	}\r
	194	\r
	195	PartitionNumber = 1;\r
	196	\r
	197	ZeroMem (&HdDev, sizeof (HdDev));\r
	198	HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
	199	HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
	200	SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
	201	HdDev.MBRType = MBR_TYPE_PCAT;\r
	202	HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
	203	\r
	204	if (LastDevicePathNode == NULL) {\r
	205	//\r
	206	// This is a MBR, add each partition\r
	207	//\r
	208	for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
	209	if (Mbr->Partition[Index].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
	210	//\r
	211	// Don't use null MBR entries\r
	212	//\r
	213	continue;\r
	214	}\r
	215	\r
	216	if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
	217	//\r
	218	// This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
	219	// We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
	220	// this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
	221	// that corrupted the GPT partition. \r
	222	//\r
	223	continue;\r
	224	}\r
	225	\r
	226	HdDev.PartitionNumber = PartitionNumber ++;\r
	227	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
	228	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
48557c65	229	CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (Mbr->UniqueMbrSignature));\r
adbcbf8f	230	\r
	231	Status = PartitionInstallChildHandle (\r
	232	This,\r
	233	Handle,\r
	234	DiskIo,\r
493d8e3a	235	DiskIo2,\r
adbcbf8f	236	BlockIo,\r
490b5ea1	237	BlockIo2,\r
adbcbf8f	238	DevicePath,\r
	239	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	240	HdDev.PartitionStart,\r
	241	HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	242	MBR_SIZE,\r
	243	(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
	244	);\r
	245	\r
	246	if (!EFI_ERROR (Status)) {\r
	247	Found = EFI_SUCCESS;\r
	248	}\r
	249	}\r
	250	} else {\r
	251	//\r
	252	// It's an extended partition. Follow the extended partition\r
	253	// chain to get all the logical drives\r
	254	//\r
	255	ExtMbrStartingLba = 0;\r
	256	\r
	257	do {\r
	258	\r
96f99e1d	259	Status = DiskIo->ReadDisk (\r
96f99e1d	260	DiskIo,\r
490b5ea1	261	MediaId,\r
	262	MultU64x32 (ExtMbrStartingLba, BlockSize),\r
	263	BlockSize,\r
96f99e1d	264	Mbr\r
96f99e1d	265	);\r
adbcbf8f	266	if (EFI_ERROR (Status)) {\r
	267	Found = Status;\r
	268	goto Done;\r
	269	}\r
	270	\r
c63cd426	271	if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {\r
adbcbf8f	272	break;\r
	273	}\r
	274	\r
	275	if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) \|\|\r
	276	(Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
	277	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
	278	continue;\r
	279	}\r
	280	HdDev.PartitionNumber = PartitionNumber ++;\r
	281	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
	282	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
	283	if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) \|\|\r
	284	(HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
	285	break;\r
	286	}\r
	287	\r
	288	//\r
	289	// The signature in EBR(Extended Boot Record) should always be 0.\r
	290	//\r
	291	((UINT32 ) &HdDev.Signature[0]) = 0;\r
	292	\r
	293	Status = PartitionInstallChildHandle (\r
490b5ea1	294	This,\r
	295	Handle,\r
	296	DiskIo,\r
493d8e3a	297	DiskIo2,\r
490b5ea1	298	BlockIo,\r
	299	BlockIo2,\r
	300	DevicePath,\r
	301	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	302	HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
	303	HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	304	MBR_SIZE,\r
	305	(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
	306	);\r
adbcbf8f	307	if (!EFI_ERROR (Status)) {\r
	308	Found = EFI_SUCCESS;\r
	309	}\r
	310	\r
	311	if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
	312	(Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
	313	) {\r
	314	break;\r
	315	}\r
	316	\r
	317	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
	318	//\r
	319	// Don't allow partition to be self referencing\r
	320	//\r
	321	if (ExtMbrStartingLba == 0) {\r
	322	break;\r
	323	}\r
	324	} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
	325	}\r
	326	\r
	327	Done:\r
	328	FreePool (Mbr);\r
	329	\r
	330	return Found;\r
	331	}\r