[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) 2006 - 2011, 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
      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]  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_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
                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
                 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
490b5ea1	14	Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>\r
e5eed7d3	15	This program and the accompanying materials\r
f42be642	16	are licensed and made available under the terms and conditions of the BSD License\r
	17	which accompanies this distribution. The full text of the license may be found at\r
	18	http://opensource.org/licenses/bsd-license.php\r
	19	\r
	20	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	21	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	22	\r
	23	**/\r
adbcbf8f	24	\r
	25	#include "Partition.h"\r
	26	\r
a8d0c20e	27	/**\r
	28	Test to see if the Mbr buffer is a valid MBR.\r
	29	\r
	30	@param Mbr Parent Handle.\r
	31	@param LastLba Last Lba address on the device.\r
	32	\r
	33	@retval TRUE Mbr is a Valid MBR.\r
	34	@retval FALSE Mbr is not a Valid MBR.\r
	35	\r
	36	**/\r
adbcbf8f	37	BOOLEAN\r
	38	PartitionValidMbr (\r
	39	IN MASTER_BOOT_RECORD *Mbr,\r
	40	IN EFI_LBA LastLba\r
	41	)\r
adbcbf8f	42	{\r
	43	UINT32 StartingLBA;\r
	44	UINT32 EndingLBA;\r
	45	UINT32 NewEndingLBA;\r
	46	INTN Index1;\r
	47	INTN Index2;\r
	48	BOOLEAN MbrValid;\r
	49	\r
	50	if (Mbr->Signature != MBR_SIGNATURE) {\r
	51	return FALSE;\r
	52	}\r
	53	//\r
	54	// The BPB also has this signature, so it can not be used alone.\r
	55	//\r
	56	MbrValid = FALSE;\r
	57	for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
	58	if (Mbr->Partition[Index1].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
	59	continue;\r
	60	}\r
	61	\r
	62	MbrValid = TRUE;\r
	63	StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
	64	EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
	65	if (EndingLBA > LastLba) {\r
	66	//\r
	67	// Compatibility Errata:\r
	68	// Some systems try to hide drive space with their INT 13h driver\r
	69	// This does not hide space from the OS driver. This means the MBR\r
	70	// that gets created from DOS is smaller than the MBR created from\r
	71	// a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
	72	// wrong on some systems FDISKed by the OS.\r
	73	//\r
	74	// return FALSE since no block devices on a system are implemented\r
	75	// with INT 13h\r
	76	//\r
	77	return FALSE;\r
	78	}\r
	79	\r
	80	for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
	81	if (Mbr->Partition[Index2].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
	82	continue;\r
	83	}\r
	84	\r
	85	NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
	86	if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
	87	//\r
	88	// This region overlaps with the Index1'th region\r
	89	//\r
	90	return FALSE;\r
	91	}\r
	92	}\r
	93	}\r
	94	//\r
ea7cb08c	95	// None of the regions overlapped so MBR is O.K.\r
adbcbf8f	96	//\r
	97	return MbrValid;\r
	98	}\r
	99	\r
a8d0c20e	100	\r
	101	/**\r
	102	Install child handles if the Handle supports MBR format.\r
	103	\r
490b5ea1	104	@param[in] This Calling context.\r
	105	@param[in] Handle Parent Handle.\r
	106	@param[in] DiskIo Parent DiskIo interface.\r
	107	@param[in] BlockIo Parent BlockIo interface.\r
	108	@param[in] BlockIo2 Parent BlockIo2 interface.\r
	109	@param[in] DevicePath Parent Device Path.\r
a8d0c20e	110	\r
	111	@retval EFI_SUCCESS A child handle was added.\r
	112	@retval EFI_MEDIA_CHANGED Media change was detected.\r
	113	@retval Others MBR partition was not found.\r
	114	\r
	115	**/\r
adbcbf8f	116	EFI_STATUS\r
	117	PartitionInstallMbrChildHandles (\r
	118	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	119	IN EFI_HANDLE Handle,\r
	120	IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
	121	IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
490b5ea1	122	IN EFI_BLOCK_IO2_PROTOCOL *BlockIo2,\r
adbcbf8f	123	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
adbcbf8f	124	)\r
adbcbf8f	125	{\r
	126	EFI_STATUS Status;\r
	127	MASTER_BOOT_RECORD *Mbr;\r
	128	UINT32 ExtMbrStartingLba;\r
	129	UINTN Index;\r
	130	HARDDRIVE_DEVICE_PATH HdDev;\r
	131	HARDDRIVE_DEVICE_PATH ParentHdDev;\r
	132	EFI_STATUS Found;\r
	133	UINT32 PartitionNumber;\r
	134	EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
	135	EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
490b5ea1	136	UINT32 BlockSize;\r
	137	UINT32 MediaId;\r
	138	EFI_LBA LastBlock;\r
adbcbf8f	139	\r
adbcbf8f	140	Found = EFI_NOT_FOUND;\r
adbcbf8f	141	\r
490b5ea1	142	BlockSize = BlockIo->Media->BlockSize;\r
	143	MediaId = BlockIo->Media->MediaId;\r
	144	LastBlock = BlockIo->Media->LastBlock;\r
	145	\r
	146	Mbr = AllocatePool (BlockSize);\r
adbcbf8f	147	if (Mbr == NULL) {\r
737dfc36	148	return Found;\r
adbcbf8f	149	}\r
adbcbf8f	150	\r
96f99e1d	151	Status = DiskIo->ReadDisk (\r
96f99e1d	152	DiskIo,\r
490b5ea1	153	MediaId,\r
96f99e1d	154	0,\r
490b5ea1	155	BlockSize,\r
96f99e1d	156	Mbr\r
96f99e1d	157	);\r
adbcbf8f	158	if (EFI_ERROR (Status)) {\r
	159	Found = Status;\r
	160	goto Done;\r
	161	}\r
490b5ea1	162	if (!PartitionValidMbr (Mbr, LastBlock)) {\r
adbcbf8f	163	goto Done;\r
	164	}\r
	165	//\r
	166	// We have a valid mbr - add each partition\r
	167	//\r
	168	//\r
	169	// Get starting and ending LBA of the parent block device.\r
	170	//\r
	171	LastDevicePathNode = NULL;\r
	172	ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
	173	DevicePathNode = DevicePath;\r
1232b214	174	while (!IsDevicePathEnd (DevicePathNode)) {\r
adbcbf8f	175	LastDevicePathNode = DevicePathNode;\r
1232b214	176	DevicePathNode = NextDevicePathNode (DevicePathNode);\r
adbcbf8f	177	}\r
	178	\r
	179	if (LastDevicePathNode != NULL) {\r
	180	if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
	181	DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
	182	) {\r
	183	CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
	184	} else {\r
	185	LastDevicePathNode = NULL;\r
	186	}\r
	187	}\r
	188	\r
	189	PartitionNumber = 1;\r
	190	\r
	191	ZeroMem (&HdDev, sizeof (HdDev));\r
	192	HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
	193	HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
	194	SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
	195	HdDev.MBRType = MBR_TYPE_PCAT;\r
	196	HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
	197	\r
	198	if (LastDevicePathNode == NULL) {\r
	199	//\r
	200	// This is a MBR, add each partition\r
	201	//\r
	202	for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
	203	if (Mbr->Partition[Index].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
	204	//\r
	205	// Don't use null MBR entries\r
	206	//\r
	207	continue;\r
	208	}\r
	209	\r
	210	if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
	211	//\r
	212	// This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
	213	// We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
	214	// this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
	215	// that corrupted the GPT partition. \r
	216	//\r
	217	continue;\r
	218	}\r
	219	\r
	220	HdDev.PartitionNumber = PartitionNumber ++;\r
	221	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
	222	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
48557c65	223	CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (Mbr->UniqueMbrSignature));\r
adbcbf8f	224	\r
	225	Status = PartitionInstallChildHandle (\r
	226	This,\r
	227	Handle,\r
	228	DiskIo,\r
	229	BlockIo,\r
490b5ea1	230	BlockIo2,\r
adbcbf8f	231	DevicePath,\r
	232	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	233	HdDev.PartitionStart,\r
	234	HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	235	MBR_SIZE,\r
	236	(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
	237	);\r
	238	\r
	239	if (!EFI_ERROR (Status)) {\r
	240	Found = EFI_SUCCESS;\r
	241	}\r
	242	}\r
	243	} else {\r
	244	//\r
	245	// It's an extended partition. Follow the extended partition\r
	246	// chain to get all the logical drives\r
	247	//\r
	248	ExtMbrStartingLba = 0;\r
	249	\r
	250	do {\r
	251	\r
96f99e1d	252	Status = DiskIo->ReadDisk (\r
96f99e1d	253	DiskIo,\r
490b5ea1	254	MediaId,\r
	255	MultU64x32 (ExtMbrStartingLba, BlockSize),\r
	256	BlockSize,\r
96f99e1d	257	Mbr\r
96f99e1d	258	);\r
adbcbf8f	259	if (EFI_ERROR (Status)) {\r
	260	Found = Status;\r
	261	goto Done;\r
	262	}\r
	263	\r
c63cd426	264	if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {\r
adbcbf8f	265	break;\r
	266	}\r
	267	\r
	268	if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) \|\|\r
	269	(Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
	270	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
	271	continue;\r
	272	}\r
	273	HdDev.PartitionNumber = PartitionNumber ++;\r
	274	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
	275	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
	276	if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) \|\|\r
	277	(HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
	278	break;\r
	279	}\r
	280	\r
	281	//\r
	282	// The signature in EBR(Extended Boot Record) should always be 0.\r
	283	//\r
	284	((UINT32 ) &HdDev.Signature[0]) = 0;\r
	285	\r
	286	Status = PartitionInstallChildHandle (\r
490b5ea1	287	This,\r
	288	Handle,\r
	289	DiskIo,\r
	290	BlockIo,\r
	291	BlockIo2,\r
	292	DevicePath,\r
	293	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	294	HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
	295	HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	296	MBR_SIZE,\r
	297	(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
	298	);\r
adbcbf8f	299	if (!EFI_ERROR (Status)) {\r
	300	Found = EFI_SUCCESS;\r
	301	}\r
	302	\r
	303	if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
	304	(Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
	305	) {\r
	306	break;\r
	307	}\r
	308	\r
	309	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
	310	//\r
	311	// Don't allow partition to be self referencing\r
	312	//\r
	313	if (ExtMbrStartingLba == 0) {\r
	314	break;\r
	315	}\r
	316	} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
	317	}\r
	318	\r
	319	Done:\r
	320	FreePool (Mbr);\r
	321	\r
	322	return Found;\r
	323	}\r