[mirror_edk2.git] / EdkModulePkg / Universal / Disk / Partition / Dxe / Mbr.c

/*++\r
\r
Copyright (c) 2006, Intel Corporation                                                         \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
Module Name:\r
\r
  Mbr.c\r
  \r
Abstract:\r
\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
--*/\r
\r
#include "Partition.h"\r
#include "Mbr.h"\r
\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
BOOLEAN\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
  other       - A child handle was not added\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
  BOOLEAN                   Found;\r
  UINT32                    PartitionNumber;\r
  EFI_DEVICE_PATH_PROTOCOL  *DevicePathNode;\r
  EFI_DEVICE_PATH_PROTOCOL  *LastDevicePathNode;\r
\r
  Mbr             = NULL;\r
  Found           = FALSE;\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) || !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
      gBS->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 == 0xEE) {\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 = TRUE;\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
        goto Done;\r
      }\r
\r
      if (Mbr->Partition[0].OSIndicator == 0) {\r
        break;\r
      }\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 >=\r
            ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) {\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 = TRUE;\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
  gBS->FreePool (Mbr);\r
\r
  return Found;\r
}\r
Commit	Line	Data
878ddf1f	1	/*++\r
	2	\r
	3	Copyright (c) 2006, Intel Corporation \r
	4	All rights reserved. This program and the accompanying materials \r
	5	are licensed and made available under the terms and conditions of the BSD License \r
	6	which accompanies this distribution. The full text of the license may be found at \r
	7	http://opensource.org/licenses/bsd-license.php \r
	8	\r
	9	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
	10	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
	11	\r
	12	Module Name:\r
	13	\r
	14	Mbr.c\r
	15	\r
	16	Abstract:\r
	17	\r
	18	Decode a hard disk partitioned with the legacy MBR found on most PC's\r
	19	\r
	20	MBR - Master Boot Record is in the first sector of a partitioned hard disk.\r
	21	The MBR supports four partitions per disk. The MBR also contains legacy\r
	22	code that is not run on an EFI system. The legacy code reads the \r
	23	first sector of the active partition into memory and \r
	24	\r
	25	BPB - Boot(?) Parameter Block is in the first sector of a FAT file system. \r
	26	The BPB contains information about the FAT file system. The BPB is \r
	27	always on the first sector of a media. The first sector also contains\r
	28	the legacy boot strap code.\r
	29	\r
	30	--*/\r
	31	\r
	32	#include "Partition.h"\r
	33	#include "Mbr.h"\r
	34	\r
	35	BOOLEAN\r
	36	PartitionValidMbr (\r
	37	IN MASTER_BOOT_RECORD *Mbr,\r
	38	IN EFI_LBA LastLba\r
	39	)\r
	40	/*++\r
	41	\r
	42	Routine Description:\r
	43	Test to see if the Mbr buffer is a valid MBR\r
	44	\r
	45	Arguments: \r
	46	Mbr - Parent Handle \r
	47	LastLba - Last Lba address on the device.\r
	48	\r
	49	Returns:\r
	50	TRUE - Mbr is a Valid MBR\r
	51	FALSE - Mbr is not a Valid MBR\r
	52	\r
	53	--*/\r
	54	{\r
	55	UINT32 StartingLBA;\r
	56	UINT32 EndingLBA;\r
	57	UINT32 NewEndingLBA;\r
	58	INTN Index1;\r
	59	INTN Index2;\r
	60	BOOLEAN MbrValid;\r
	61	\r
	62	if (Mbr->Signature != MBR_SIGNATURE) {\r
	63	return FALSE;\r
	64	}\r
65	//\r
66	// The BPB also has this signature, so it can not be used alone.\r
67	//\r
68	MbrValid = FALSE;\r
69	for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
70	if (Mbr->Partition[Index1].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
71	continue;\r
72	}\r
73	\r
74	MbrValid = TRUE;\r
75	StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
76	EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
77	if (EndingLBA > LastLba) {\r
78	//\r
79	// Compatibility Errata:\r
80	// Some systems try to hide drive space with their INT 13h driver\r
81	// This does not hide space from the OS driver. This means the MBR\r
82	// that gets created from DOS is smaller than the MBR created from\r
83	// a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
84	// wrong on some systems FDISKed by the OS.\r
85	//\r
86	// return FALSE since no block devices on a system are implemented\r
87	// with INT 13h\r
88	//\r
89	return FALSE;\r
90	}\r
91	\r
92	for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
93	if (Mbr->Partition[Index2].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
94	continue;\r
95	}\r
96	\r
97	NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
98	if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
99	//\r
100	// This region overlaps with the Index1'th region\r
101	//\r
102	return FALSE;\r
103	}\r
104	}\r
105	}\r
106	//\r
107	// Non of the regions overlapped so MBR is O.K.\r
108	//\r
109	return MbrValid;\r
110	}\r
111	\r
112	BOOLEAN\r
113	PartitionInstallMbrChildHandles (\r
114	IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
115	IN EFI_HANDLE Handle,\r
116	IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
117	IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
118	IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
119	)\r
120	/*++\r
121	\r
122	Routine Description:\r
123	Install child handles if the Handle supports MBR format.\r
124	\r
125	Arguments: \r
126	This - Calling context.\r
127	Handle - Parent Handle \r
128	DiskIo - Parent DiskIo interface\r
129	BlockIo - Parent BlockIo interface\r
130	DevicePath - Parent Device Path\r
131	\r
132	Returns:\r
133	EFI_SUCCESS - If a child handle was added\r
134	other - A child handle was not added\r
135	\r
136	--*/\r
137	{\r
138	EFI_STATUS Status;\r
139	MASTER_BOOT_RECORD *Mbr;\r
140	UINT32 ExtMbrStartingLba;\r
141	UINTN Index;\r
142	HARDDRIVE_DEVICE_PATH HdDev;\r
143	HARDDRIVE_DEVICE_PATH ParentHdDev;\r
144	BOOLEAN Found;\r
145	UINT32 PartitionNumber;\r
146	EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
147	EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
148	\r
149	Mbr = NULL;\r
150	Found = FALSE;\r
151	\r
152	Mbr = AllocatePool (BlockIo->Media->BlockSize);\r
153	if (Mbr == NULL) {\r
154	goto Done;\r
155	}\r
156	\r
157	Status = BlockIo->ReadBlocks (\r
158	BlockIo,\r
159	BlockIo->Media->MediaId,\r
160	0,\r
161	BlockIo->Media->BlockSize,\r
162	Mbr\r
163	);\r
164	if (EFI_ERROR (Status) \|\| !PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {\r
165	goto Done;\r
166	}\r
167	//\r
168	// We have a valid mbr - add each partition\r
169	//\r
170	//\r
171	// Get starting and ending LBA of the parent block device.\r
172	//\r
173	LastDevicePathNode = NULL;\r
174	ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
175	DevicePathNode = DevicePath;\r
176	while (!EfiIsDevicePathEnd (DevicePathNode)) {\r
177	LastDevicePathNode = DevicePathNode;\r
178	DevicePathNode = EfiNextDevicePathNode (DevicePathNode);\r
179	}\r
180	\r
181	if (LastDevicePathNode != NULL) {\r
182	if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
183	DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
184	) {\r
185	gBS->CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
186	} else {\r
187	LastDevicePathNode = NULL;\r
188	}\r
189	}\r
190	\r
191	PartitionNumber = 1;\r
192	\r
193	ZeroMem (&HdDev, sizeof (HdDev));\r
194	HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
195	HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
196	SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
197	HdDev.MBRType = MBR_TYPE_PCAT;\r
198	HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
199	\r
200	if (LastDevicePathNode == NULL) {\r
201	//\r
202	// This is a MBR, add each partition\r
203	//\r
204	for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
205	if (Mbr->Partition[Index].OSIndicator == 0x00 \|\| UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
206	//\r
207	// Don't use null MBR entries\r
208	//\r
209	continue;\r
210	}\r
211	\r
212	if (Mbr->Partition[Index].OSIndicator == 0xEE) {\r
213	//\r
214	// This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
215	// We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
216	// this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
217	// that corrupted the GPT partition. \r
218	//\r
219	continue;\r
220	}\r
221	\r
222	HdDev.PartitionNumber = PartitionNumber ++;\r
223	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
224	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
225	CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (UINT32));\r
226	\r
227	Status = PartitionInstallChildHandle (\r
228	This,\r
229	Handle,\r
230	DiskIo,\r
231	BlockIo,\r
232	DevicePath,\r
233	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
234	HdDev.PartitionStart,\r
235	HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
236	MBR_SIZE,\r
237	(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
238	);\r
239	\r
240	if (!EFI_ERROR (Status)) {\r
241	Found = TRUE;\r
242	}\r
243	}\r
244	} else {\r
245	//\r
246	// It's an extended partition. Follow the extended partition\r
247	// chain to get all the logical drives\r
248	//\r
249	ExtMbrStartingLba = 0;\r
250	\r
251	do {\r
252	\r
253	Status = BlockIo->ReadBlocks (\r
254	BlockIo,\r
255	BlockIo->Media->MediaId,\r
256	ExtMbrStartingLba,\r
257	BlockIo->Media->BlockSize,\r
258	Mbr\r
259	);\r
260	if (EFI_ERROR (Status)) {\r
261	goto Done;\r
262	}\r
263	\r
264	if (Mbr->Partition[0].OSIndicator == 0) {\r
265	break;\r
266	}\r
267	\r
268	HdDev.PartitionNumber = PartitionNumber ++;\r
269	HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
270	HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
271	if (HdDev.PartitionStart + HdDev.PartitionSize - 1 >=\r
272	ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) {\r
273	break;\r
274	}\r
275	\r
276	//\r
277	// The signature in EBR(Extended Boot Record) should always be 0.\r
278	//\r
279	((UINT32 ) &HdDev.Signature[0]) = 0;\r
280	\r
281	Status = PartitionInstallChildHandle (\r
282	This,\r
283	Handle,\r
284	DiskIo,\r
285	BlockIo,\r
286	DevicePath,\r
287	(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
288	HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
289	HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
290	MBR_SIZE,\r
291	(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
292	);\r
293	if (!EFI_ERROR (Status)) {\r
294	Found = TRUE;\r
295	}\r
296	\r
297	if (Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION &&\r
298	Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION\r
299	) {\r
300	break;\r
301	}\r
302	\r
303	ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
304	//\r
305	// Don't allow partition to be self referencing\r
306	//\r
307	if (ExtMbrStartingLba == 0) {\r
308	break;\r
309	}\r
310	} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
311	}\r
312	\r
313	Done:\r
314	gBS->FreePool (Mbr);\r
315	\r
316	return Found;\r
317	}\r