Fix a critical bug: When reading block succeeds but detecting MBR fails, it should...
[mirror_edk2.git] / EdkModulePkg / Universal / Disk / Partition / Dxe / Mbr.c
CommitLineData
878ddf1f 1/*++\r
2\r
2c33bcb4 3Copyright (c) 2006 - 2007, Intel Corporation \r
878ddf1f 4All rights reserved. This program and the accompanying materials \r
5are licensed and made available under the terms and conditions of the BSD License \r
6which accompanies this distribution. The full text of the license may be found at \r
7http://opensource.org/licenses/bsd-license.php \r
8 \r
9THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
10WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
11\r
12Module Name:\r
13\r
14 Mbr.c\r
15 \r
16Abstract:\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
878ddf1f 33\r
1cc8ee78 34STATIC\r
878ddf1f 35BOOLEAN\r
36PartitionValidMbr (\r
37 IN MASTER_BOOT_RECORD *Mbr,\r
38 IN EFI_LBA LastLba\r
39 )\r
40/*++\r
41\r
42Routine Description:\r
43 Test to see if the Mbr buffer is a valid MBR\r
44\r
45Arguments: \r
46 Mbr - Parent Handle \r
47 LastLba - Last Lba address on the device.\r
48\r
49Returns:\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
c7c02fab 112EFI_STATUS\r
878ddf1f 113PartitionInstallMbrChildHandles (\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
122Routine Description:\r
123 Install child handles if the Handle supports MBR format.\r
124\r
125Arguments: \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
132Returns:\r
c7c02fab 133 EFI_SUCCESS - If a child handle was added\r
134 EFI_MEDIA_CHANGED - Media changed Detected\r
135 !EFI_SUCCESS - Not found MBR partition.\r
878ddf1f 136\r
137--*/\r
138{\r
139 EFI_STATUS Status;\r
140 MASTER_BOOT_RECORD *Mbr;\r
141 UINT32 ExtMbrStartingLba;\r
142 UINTN Index;\r
143 HARDDRIVE_DEVICE_PATH HdDev;\r
144 HARDDRIVE_DEVICE_PATH ParentHdDev;\r
c7c02fab 145 EFI_STATUS Found;\r
878ddf1f 146 UINT32 PartitionNumber;\r
147 EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
148 EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
149\r
150 Mbr = NULL;\r
c7c02fab 151 Found = EFI_NOT_FOUND;\r
878ddf1f 152\r
153 Mbr = AllocatePool (BlockIo->Media->BlockSize);\r
154 if (Mbr == NULL) {\r
155 goto Done;\r
156 }\r
157\r
158 Status = BlockIo->ReadBlocks (\r
159 BlockIo,\r
160 BlockIo->Media->MediaId,\r
161 0,\r
162 BlockIo->Media->BlockSize,\r
163 Mbr\r
164 );\r
3c17ed18 165 if (EFI_ERROR (Status)) {\r
c7c02fab 166 Found = Status;\r
878ddf1f 167 goto Done;\r
168 }\r
3c17ed18 169 if (!PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {\r
170 goto Done;\r
171 }\r
878ddf1f 172 //\r
173 // We have a valid mbr - add each partition\r
174 //\r
175 //\r
176 // Get starting and ending LBA of the parent block device.\r
177 //\r
178 LastDevicePathNode = NULL;\r
179 ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
180 DevicePathNode = DevicePath;\r
181 while (!EfiIsDevicePathEnd (DevicePathNode)) {\r
182 LastDevicePathNode = DevicePathNode;\r
183 DevicePathNode = EfiNextDevicePathNode (DevicePathNode);\r
184 }\r
185\r
186 if (LastDevicePathNode != NULL) {\r
187 if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
188 DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
189 ) {\r
6626ad11 190 CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
878ddf1f 191 } else {\r
192 LastDevicePathNode = NULL;\r
193 }\r
194 }\r
195\r
196 PartitionNumber = 1;\r
197\r
198 ZeroMem (&HdDev, sizeof (HdDev));\r
199 HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
200 HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
201 SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
202 HdDev.MBRType = MBR_TYPE_PCAT;\r
203 HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
204\r
205 if (LastDevicePathNode == NULL) {\r
206 //\r
207 // This is a MBR, add each partition\r
208 //\r
209 for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
210 if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
211 //\r
212 // Don't use null MBR entries\r
213 //\r
214 continue;\r
215 }\r
216\r
3114b334 217 if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
878ddf1f 218 //\r
219 // This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
220 // We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
221 // this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
222 // that corrupted the GPT partition. \r
223 //\r
224 continue;\r
225 }\r
226\r
227 HdDev.PartitionNumber = PartitionNumber ++;\r
228 HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
229 HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
230 CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (UINT32));\r
231\r
232 Status = PartitionInstallChildHandle (\r
233 This,\r
234 Handle,\r
235 DiskIo,\r
236 BlockIo,\r
237 DevicePath,\r
238 (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
239 HdDev.PartitionStart,\r
240 HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
241 MBR_SIZE,\r
242 (BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
243 );\r
244\r
245 if (!EFI_ERROR (Status)) {\r
c7c02fab 246 Found = EFI_SUCCESS;\r
878ddf1f 247 }\r
248 }\r
249 } else {\r
250 //\r
251 // It's an extended partition. Follow the extended partition\r
252 // chain to get all the logical drives\r
253 //\r
254 ExtMbrStartingLba = 0;\r
255\r
256 do {\r
257\r
258 Status = BlockIo->ReadBlocks (\r
259 BlockIo,\r
260 BlockIo->Media->MediaId,\r
261 ExtMbrStartingLba,\r
262 BlockIo->Media->BlockSize,\r
263 Mbr\r
264 );\r
265 if (EFI_ERROR (Status)) {\r
c7c02fab 266 Found = Status;\r
878ddf1f 267 goto Done;\r
268 }\r
269\r
270 if (Mbr->Partition[0].OSIndicator == 0) {\r
271 break;\r
272 }\r
273\r
3114b334 274 if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) ||\r
275 (Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
276 ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
277 continue;\r
278 }\r
878ddf1f 279 HdDev.PartitionNumber = PartitionNumber ++;\r
280 HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
281 HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
2c33bcb4 282 if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) ||\r
283 (HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
878ddf1f 284 break;\r
285 }\r
286\r
287 //\r
288 // The signature in EBR(Extended Boot Record) should always be 0.\r
289 //\r
290 *((UINT32 *) &HdDev.Signature[0]) = 0;\r
291\r
292 Status = PartitionInstallChildHandle (\r
293 This,\r
294 Handle,\r
295 DiskIo,\r
296 BlockIo,\r
297 DevicePath,\r
298 (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
299 HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
300 HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
301 MBR_SIZE,\r
302 (BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
303 );\r
304 if (!EFI_ERROR (Status)) {\r
c7c02fab 305 Found = EFI_SUCCESS;\r
878ddf1f 306 }\r
307\r
3114b334 308 if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
309 (Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
878ddf1f 310 ) {\r
311 break;\r
312 }\r
313\r
314 ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
315 //\r
316 // Don't allow partition to be self referencing\r
317 //\r
318 if (ExtMbrStartingLba == 0) {\r
319 break;\r
320 }\r
321 } while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
322 }\r
323\r
324Done:\r
6626ad11 325 FreePool (Mbr);\r
878ddf1f 326\r
327 return Found;\r
328}\r