[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 - 2008, Intel Corporation. <BR>\r
All rights reserved. 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  This              Calling context.\r
  @param  Handle            Parent Handle.\r
  @param  DiskIo            Parent DiskIo interface.\r
  @param  BlockIo           Parent BlockIo interface.\r
  @param  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_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
\r
  Found           = EFI_NOT_FOUND;\r
\r
  Mbr             = AllocatePool (BlockIo->Media->BlockSize);\r
  if (Mbr == NULL) {\r
    goto Done;\r
  }\r
\r
  Status = DiskIo->ReadDisk (\r
                     DiskIo,\r
                     BlockIo->Media->MediaId,\r
                     0,\r
                     BlockIo->Media->BlockSize,\r
                     Mbr\r
                     );\r
  if (EFI_ERROR (Status)) {\r
    Found = Status;\r
    goto Done;\r
  }\r
  if (!PartitionValidMbr (Mbr, BlockIo->Media->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
                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
                         BlockIo->Media->MediaId,\r
                         ExtMbrStartingLba,\r
                         BlockIo->Media->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
                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
f42be642	14	Copyright (c) 2006 - 2008, Intel Corporation. <BR>\r
	15	All rights reserved. This program and the accompanying materials\r
	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
	104	@param This Calling context.\r
	105	@param Handle Parent Handle.\r
	106	@param DiskIo Parent DiskIo interface.\r
	107	@param BlockIo Parent BlockIo interface.\r
	108	@param DevicePath Parent Device Path.\r
	109	\r
	110	@retval EFI_SUCCESS A child handle was added.\r
	111	@retval EFI_MEDIA_CHANGED Media change was detected.\r
	112	@retval Others MBR partition was not found.\r
	113	\r
	114	**/\r
adbcbf8f	115	EFI_STATUS\r
	116	PartitionInstallMbrChildHandles (\r
	117	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
	118	IN EFI_HANDLE Handle,\r
	119	IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
	120	IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
	121	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
	122	)\r
adbcbf8f	123	{\r
	124	EFI_STATUS Status;\r
	125	MASTER_BOOT_RECORD *Mbr;\r
	126	UINT32 ExtMbrStartingLba;\r
	127	UINTN Index;\r
	128	HARDDRIVE_DEVICE_PATH HdDev;\r
	129	HARDDRIVE_DEVICE_PATH ParentHdDev;\r
	130	EFI_STATUS Found;\r
	131	UINT32 PartitionNumber;\r
	132	EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
	133	EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
	134	\r
adbcbf8f	135	Found = EFI_NOT_FOUND;\r
	136	\r
	137	Mbr = AllocatePool (BlockIo->Media->BlockSize);\r
	138	if (Mbr == NULL) {\r
	139	goto Done;\r
	140	}\r
	141	\r
96f99e1d	142	Status = DiskIo->ReadDisk (\r
	143	DiskIo,\r
	144	BlockIo->Media->MediaId,\r
	145	0,\r
	146	BlockIo->Media->BlockSize,\r
	147	Mbr\r
	148	);\r
adbcbf8f	149	if (EFI_ERROR (Status)) {\r
	150	Found = Status;\r
	151	goto Done;\r
	152	}\r
	153	if (!PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {\r
	154	goto Done;\r
	155	}\r
	156	//\r
	157	// We have a valid mbr - add each partition\r
	158	//\r
	159	//\r
	160	// Get starting and ending LBA of the parent block device.\r
	161	//\r
	162	LastDevicePathNode = NULL;\r
	163	ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
	164	DevicePathNode = DevicePath;\r
1232b214	165	while (!IsDevicePathEnd (DevicePathNode)) {\r
adbcbf8f	166	LastDevicePathNode = DevicePathNode;\r
1232b214	167	DevicePathNode = NextDevicePathNode (DevicePathNode);\r
adbcbf8f	168	}\r
	169	\r
	170	if (LastDevicePathNode != NULL) {\r
	171	if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
	172	DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
	173	) {\r
	174	CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
	175	} else {\r
	176	LastDevicePathNode = NULL;\r
	177	}\r
	178	}\r
	179	\r
	180	PartitionNumber = 1;\r
	181	\r
	182	ZeroMem (&HdDev, sizeof (HdDev));\r
	183	HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
	184	HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
	185	SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
	186	HdDev.MBRType = MBR_TYPE_PCAT;\r
	187	HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
	188	\r
	189	if (LastDevicePathNode == NULL) {\r
	190	//\r
	191	// This is a MBR, add each partition\r
	192	//\r
	193	for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
	194	if (Mbr->Partition[Index].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
	195	//\r
	196	// Don't use null MBR entries\r
	197	//\r
	198	continue;\r
	199	}\r
	200	\r
	201	if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
	202	//\r
	203	// This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
	204	// We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
	205	// this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
	206	// that corrupted the GPT partition. \r
	207	//\r
	208	continue;\r
	209	}\r
	210	\r
	211	HdDev.PartitionNumber = PartitionNumber ++;\r
	212	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
	213	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
48557c65	214	CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (Mbr->UniqueMbrSignature));\r
adbcbf8f	215	\r
	216	Status = PartitionInstallChildHandle (\r
	217	This,\r
	218	Handle,\r
	219	DiskIo,\r
	220	BlockIo,\r
	221	DevicePath,\r
	222	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	223	HdDev.PartitionStart,\r
	224	HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	225	MBR_SIZE,\r
	226	(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
	227	);\r
	228	\r
	229	if (!EFI_ERROR (Status)) {\r
	230	Found = EFI_SUCCESS;\r
	231	}\r
	232	}\r
	233	} else {\r
	234	//\r
	235	// It's an extended partition. Follow the extended partition\r
	236	// chain to get all the logical drives\r
	237	//\r
	238	ExtMbrStartingLba = 0;\r
	239	\r
	240	do {\r
	241	\r
96f99e1d	242	Status = DiskIo->ReadDisk (\r
	243	DiskIo,\r
	244	BlockIo->Media->MediaId,\r
	245	ExtMbrStartingLba,\r
	246	BlockIo->Media->BlockSize,\r
	247	Mbr\r
	248	);\r
adbcbf8f	249	if (EFI_ERROR (Status)) {\r
	250	Found = Status;\r
	251	goto Done;\r
	252	}\r
	253	\r
c63cd426	254	if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {\r
adbcbf8f	255	break;\r
	256	}\r
	257	\r
	258	if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) \|\|\r
	259	(Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
	260	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
	261	continue;\r
	262	}\r
	263	HdDev.PartitionNumber = PartitionNumber ++;\r
	264	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
	265	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
	266	if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) \|\|\r
	267	(HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
	268	break;\r
	269	}\r
	270	\r
	271	//\r
	272	// The signature in EBR(Extended Boot Record) should always be 0.\r
	273	//\r
	274	((UINT32 ) &HdDev.Signature[0]) = 0;\r
	275	\r
	276	Status = PartitionInstallChildHandle (\r
	277	This,\r
	278	Handle,\r
	279	DiskIo,\r
	280	BlockIo,\r
	281	DevicePath,\r
	282	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	283	HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
	284	HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	285	MBR_SIZE,\r
	286	(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
	287	);\r
	288	if (!EFI_ERROR (Status)) {\r
	289	Found = EFI_SUCCESS;\r
	290	}\r
	291	\r
	292	if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
	293	(Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
	294	) {\r
	295	break;\r
	296	}\r
	297	\r
	298	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
	299	//\r
	300	// Don't allow partition to be self referencing\r
	301	//\r
	302	if (ExtMbrStartingLba == 0) {\r
	303	break;\r
	304	}\r
	305	} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
	306	}\r
	307	\r
	308	Done:\r
	309	FreePool (Mbr);\r
	310	\r
	311	return Found;\r
	312	}\r