[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 - Boot(?) 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
STATIC\r
BOOLEAN\r
PartitionValidMbr (\r
  IN  MASTER_BOOT_RECORD      *Mbr,\r
  IN  EFI_LBA                 LastLba\r
  )\r
/*++\r
\r
Routine Description:\r
  Test to see if the Mbr buffer is a valid MBR\r
\r
Arguments:       \r
  Mbr     - Parent Handle \r
  LastLba - Last Lba address on the device.\r
\r
Returns:\r
  TRUE  - Mbr is a Valid MBR\r
  FALSE - Mbr is not a Valid MBR\r
\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
  // Non of the regions overlapped so MBR is O.K.\r
  //\r
  return MbrValid;\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
\r
Routine Description:\r
  Install child handles if the Handle supports MBR format.\r
\r
Arguments:       \r
  This       - Calling context.\r
  Handle     - Parent Handle \r
  DiskIo     - Parent DiskIo interface\r
  BlockIo    - Parent BlockIo interface\r
  DevicePath - Parent Device Path\r
\r
Returns:\r
  EFI_SUCCESS       - If a child handle was added\r
  EFI_MEDIA_CHANGED - Media changed Detected\r
	!EFI_SUCCESS      - Not found MBR partition.\r
\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
  Mbr             = NULL;\r
  Found           = EFI_NOT_FOUND;\r
\r
  Mbr             = AllocatePool (BlockIo->Media->BlockSize);\r
  if (Mbr == NULL) {\r
    goto Done;\r
  }\r
\r
  Status = BlockIo->ReadBlocks (\r
                      BlockIo,\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 (!EfiIsDevicePathEnd (DevicePathNode)) {\r
    LastDevicePathNode  = DevicePathNode;\r
    DevicePathNode      = EfiNextDevicePathNode (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 (UINT32));\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 = BlockIo->ReadBlocks (\r
                          BlockIo,\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
	9	BPB - Boot(?) Parameter Block is in the first sector of a FAT file system. \r
	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
	27	STATIC\r
	28	BOOLEAN\r
	29	PartitionValidMbr (\r
	30	IN MASTER_BOOT_RECORD *Mbr,\r
	31	IN EFI_LBA LastLba\r
	32	)\r
	33	/*++\r
	34	\r
	35	Routine Description:\r
	36	Test to see if the Mbr buffer is a valid MBR\r
	37	\r
	38	Arguments: \r
	39	Mbr - Parent Handle \r
	40	LastLba - Last Lba address on the device.\r
	41	\r
	42	Returns:\r
	43	TRUE - Mbr is a Valid MBR\r
	44	FALSE - Mbr is not a Valid MBR\r
	45	\r
	46	--*/\r
	47	{\r
	48	UINT32 StartingLBA;\r
	49	UINT32 EndingLBA;\r
	50	UINT32 NewEndingLBA;\r
	51	INTN Index1;\r
	52	INTN Index2;\r
	53	BOOLEAN MbrValid;\r
	54	\r
	55	if (Mbr->Signature != MBR_SIGNATURE) {\r
	56	return FALSE;\r
	57	}\r
	58	//\r
	59	// The BPB also has this signature, so it can not be used alone.\r
	60	//\r
	61	MbrValid = FALSE;\r
	62	for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
	63	if (Mbr->Partition[Index1].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
	64	continue;\r
	65	}\r
	66	\r
	67	MbrValid = TRUE;\r
	68	StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
	69	EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
	70	if (EndingLBA > LastLba) {\r
	71	//\r
	72	// Compatibility Errata:\r
	73	// Some systems try to hide drive space with their INT 13h driver\r
	74	// This does not hide space from the OS driver. This means the MBR\r
	75	// that gets created from DOS is smaller than the MBR created from\r
	76	// a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
	77	// wrong on some systems FDISKed by the OS.\r
	78	//\r
	79	// return FALSE since no block devices on a system are implemented\r
	80	// with INT 13h\r
	81	//\r
	82	return FALSE;\r
	83	}\r
	84	\r
	85	for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
	86	if (Mbr->Partition[Index2].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
	87	continue;\r
88	}\r
89	\r
90	NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
91	if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
92	//\r
93	// This region overlaps with the Index1'th region\r
94	//\r
95	return FALSE;\r
96	}\r
97	}\r
98	}\r
99	//\r
100	// Non of the regions overlapped so MBR is O.K.\r
101	//\r
102	return MbrValid;\r
103	}\r
104	\r
105	EFI_STATUS\r
106	PartitionInstallMbrChildHandles (\r
107	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
108	IN EFI_HANDLE Handle,\r
109	IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
110	IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
111	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
112	)\r
113	/*++\r
114	\r
115	Routine Description:\r
116	Install child handles if the Handle supports MBR format.\r
117	\r
118	Arguments: \r
119	This - Calling context.\r
120	Handle - Parent Handle \r
121	DiskIo - Parent DiskIo interface\r
122	BlockIo - Parent BlockIo interface\r
123	DevicePath - Parent Device Path\r
124	\r
125	Returns:\r
126	EFI_SUCCESS - If a child handle was added\r
127	EFI_MEDIA_CHANGED - Media changed Detected\r
128	!EFI_SUCCESS - Not found MBR partition.\r
129	\r
130	--*/\r
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
142	\r
143	Mbr = NULL;\r
144	Found = EFI_NOT_FOUND;\r
145	\r
146	Mbr = AllocatePool (BlockIo->Media->BlockSize);\r
147	if (Mbr == NULL) {\r
148	goto Done;\r
149	}\r
150	\r
151	Status = BlockIo->ReadBlocks (\r
152	BlockIo,\r
153	BlockIo->Media->MediaId,\r
154	0,\r
155	BlockIo->Media->BlockSize,\r
156	Mbr\r
157	);\r
158	if (EFI_ERROR (Status)) {\r
159	Found = Status;\r
160	goto Done;\r
161	}\r
162	if (!PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {\r
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
174	while (!EfiIsDevicePathEnd (DevicePathNode)) {\r
175	LastDevicePathNode = DevicePathNode;\r
176	DevicePathNode = EfiNextDevicePathNode (DevicePathNode);\r
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
223	CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (UINT32));\r
224	\r
225	Status = PartitionInstallChildHandle (\r
226	This,\r
227	Handle,\r
228	DiskIo,\r
229	BlockIo,\r
230	DevicePath,\r
231	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
232	HdDev.PartitionStart,\r
233	HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
234	MBR_SIZE,\r
235	(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
236	);\r
237	\r
238	if (!EFI_ERROR (Status)) {\r
239	Found = EFI_SUCCESS;\r
240	}\r
241	}\r
242	} else {\r
243	//\r
244	// It's an extended partition. Follow the extended partition\r
245	// chain to get all the logical drives\r
246	//\r
247	ExtMbrStartingLba = 0;\r
248	\r
249	do {\r
250	\r
251	Status = BlockIo->ReadBlocks (\r
252	BlockIo,\r
253	BlockIo->Media->MediaId,\r
254	ExtMbrStartingLba,\r
255	BlockIo->Media->BlockSize,\r
256	Mbr\r
257	);\r
258	if (EFI_ERROR (Status)) {\r
259	Found = Status;\r
260	goto Done;\r
261	}\r
262	\r
c63cd426	263	if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {\r
adbcbf8f	264	break;\r
	265	}\r
	266	\r
	267	if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) \|\|\r
	268	(Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
	269	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
	270	continue;\r
	271	}\r
	272	HdDev.PartitionNumber = PartitionNumber ++;\r
	273	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
	274	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
	275	if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) \|\|\r
	276	(HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
	277	break;\r
	278	}\r
	279	\r
	280	//\r
	281	// The signature in EBR(Extended Boot Record) should always be 0.\r
	282	//\r
	283	((UINT32 ) &HdDev.Signature[0]) = 0;\r
	284	\r
	285	Status = PartitionInstallChildHandle (\r
	286	This,\r
	287	Handle,\r
	288	DiskIo,\r
	289	BlockIo,\r
	290	DevicePath,\r
	291	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
	292	HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
	293	HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
	294	MBR_SIZE,\r
	295	(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
	296	);\r
	297	if (!EFI_ERROR (Status)) {\r
	298	Found = EFI_SUCCESS;\r
	299	}\r
	300	\r
	301	if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
	302	(Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
	303	) {\r
	304	break;\r
	305	}\r
	306	\r
	307	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
	308	//\r
	309	// Don't allow partition to be self referencing\r
	310	//\r
	311	if (ExtMbrStartingLba == 0) {\r
	312	break;\r
	313	}\r
	314	} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
	315	}\r
	316	\r
	317	Done:\r
	318	FreePool (Mbr);\r
	319	\r
	320	return Found;\r
	321	}\r