I fixed following bugs.
[mirror_edk2.git] / EdkModulePkg / Universal / Disk / Partition / Dxe / Mbr.c
1 /*++
2
3 Copyright (c) 2006, Intel Corporation
4 All rights reserved. This program and the accompanying materials
5 are licensed and made available under the terms and conditions of the BSD License
6 which accompanies this distribution. The full text of the license may be found at
7 http://opensource.org/licenses/bsd-license.php
8
9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11
12 Module Name:
13
14 Mbr.c
15
16 Abstract:
17
18 Decode a hard disk partitioned with the legacy MBR found on most PC's
19
20 MBR - Master Boot Record is in the first sector of a partitioned hard disk.
21 The MBR supports four partitions per disk. The MBR also contains legacy
22 code that is not run on an EFI system. The legacy code reads the
23 first sector of the active partition into memory and
24
25 BPB - Boot(?) Parameter Block is in the first sector of a FAT file system.
26 The BPB contains information about the FAT file system. The BPB is
27 always on the first sector of a media. The first sector also contains
28 the legacy boot strap code.
29
30 --*/
31
32 #include "Partition.h"
33 #include "Mbr.h"
34
35 BOOLEAN
36 PartitionValidMbr (
37 IN MASTER_BOOT_RECORD *Mbr,
38 IN EFI_LBA LastLba
39 )
40 /*++
41
42 Routine Description:
43 Test to see if the Mbr buffer is a valid MBR
44
45 Arguments:
46 Mbr - Parent Handle
47 LastLba - Last Lba address on the device.
48
49 Returns:
50 TRUE - Mbr is a Valid MBR
51 FALSE - Mbr is not a Valid MBR
52
53 --*/
54 {
55 UINT32 StartingLBA;
56 UINT32 EndingLBA;
57 UINT32 NewEndingLBA;
58 INTN Index1;
59 INTN Index2;
60 BOOLEAN MbrValid;
61
62 if (Mbr->Signature != MBR_SIGNATURE) {
63 return FALSE;
64 }
65 //
66 // The BPB also has this signature, so it can not be used alone.
67 //
68 MbrValid = FALSE;
69 for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {
70 if (Mbr->Partition[Index1].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {
71 continue;
72 }
73
74 MbrValid = TRUE;
75 StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);
76 EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;
77 if (EndingLBA > LastLba) {
78 //
79 // Compatibility Errata:
80 // Some systems try to hide drive space with their INT 13h driver
81 // This does not hide space from the OS driver. This means the MBR
82 // that gets created from DOS is smaller than the MBR created from
83 // a real OS (NT & Win98). This leads to BlockIo->LastBlock being
84 // wrong on some systems FDISKed by the OS.
85 //
86 // return FALSE since no block devices on a system are implemented
87 // with INT 13h
88 //
89 return FALSE;
90 }
91
92 for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {
93 if (Mbr->Partition[Index2].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {
94 continue;
95 }
96
97 NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;
98 if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {
99 //
100 // This region overlaps with the Index1'th region
101 //
102 return FALSE;
103 }
104 }
105 }
106 //
107 // Non of the regions overlapped so MBR is O.K.
108 //
109 return MbrValid;
110 }
111
112 BOOLEAN
113 PartitionInstallMbrChildHandles (
114 IN EFI_DRIVER_BINDING_PROTOCOL *This,
115 IN EFI_HANDLE Handle,
116 IN EFI_DISK_IO_PROTOCOL *DiskIo,
117 IN EFI_BLOCK_IO_PROTOCOL *BlockIo,
118 IN EFI_DEVICE_PATH_PROTOCOL *DevicePath
119 )
120 /*++
121
122 Routine Description:
123 Install child handles if the Handle supports MBR format.
124
125 Arguments:
126 This - Calling context.
127 Handle - Parent Handle
128 DiskIo - Parent DiskIo interface
129 BlockIo - Parent BlockIo interface
130 DevicePath - Parent Device Path
131
132 Returns:
133 EFI_SUCCESS - If a child handle was added
134 other - A child handle was not added
135
136 --*/
137 {
138 EFI_STATUS Status;
139 MASTER_BOOT_RECORD *Mbr;
140 UINT32 ExtMbrStartingLba;
141 UINTN Index;
142 HARDDRIVE_DEVICE_PATH HdDev;
143 HARDDRIVE_DEVICE_PATH ParentHdDev;
144 BOOLEAN Found;
145 UINT32 PartitionNumber;
146 EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;
147 EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;
148
149 Mbr = NULL;
150 Found = FALSE;
151
152 Mbr = AllocatePool (BlockIo->Media->BlockSize);
153 if (Mbr == NULL) {
154 goto Done;
155 }
156
157 Status = BlockIo->ReadBlocks (
158 BlockIo,
159 BlockIo->Media->MediaId,
160 0,
161 BlockIo->Media->BlockSize,
162 Mbr
163 );
164 if (EFI_ERROR (Status) || !PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {
165 goto Done;
166 }
167 //
168 // We have a valid mbr - add each partition
169 //
170 //
171 // Get starting and ending LBA of the parent block device.
172 //
173 LastDevicePathNode = NULL;
174 ZeroMem (&ParentHdDev, sizeof (ParentHdDev));
175 DevicePathNode = DevicePath;
176 while (!EfiIsDevicePathEnd (DevicePathNode)) {
177 LastDevicePathNode = DevicePathNode;
178 DevicePathNode = EfiNextDevicePathNode (DevicePathNode);
179 }
180
181 if (LastDevicePathNode != NULL) {
182 if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&
183 DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP
184 ) {
185 gBS->CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));
186 } else {
187 LastDevicePathNode = NULL;
188 }
189 }
190
191 PartitionNumber = 1;
192
193 ZeroMem (&HdDev, sizeof (HdDev));
194 HdDev.Header.Type = MEDIA_DEVICE_PATH;
195 HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;
196 SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));
197 HdDev.MBRType = MBR_TYPE_PCAT;
198 HdDev.SignatureType = SIGNATURE_TYPE_MBR;
199
200 if (LastDevicePathNode == NULL) {
201 //
202 // This is a MBR, add each partition
203 //
204 for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {
205 if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {
206 //
207 // Don't use null MBR entries
208 //
209 continue;
210 }
211
212 if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {
213 //
214 // This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.
215 // We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating
216 // this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format
217 // that corrupted the GPT partition.
218 //
219 continue;
220 }
221
222 HdDev.PartitionNumber = PartitionNumber ++;
223 HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);
224 HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);
225 CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (UINT32));
226
227 Status = PartitionInstallChildHandle (
228 This,
229 Handle,
230 DiskIo,
231 BlockIo,
232 DevicePath,
233 (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,
234 HdDev.PartitionStart,
235 HdDev.PartitionStart + HdDev.PartitionSize - 1,
236 MBR_SIZE,
237 (BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)
238 );
239
240 if (!EFI_ERROR (Status)) {
241 Found = TRUE;
242 }
243 }
244 } else {
245 //
246 // It's an extended partition. Follow the extended partition
247 // chain to get all the logical drives
248 //
249 ExtMbrStartingLba = 0;
250
251 do {
252
253 Status = BlockIo->ReadBlocks (
254 BlockIo,
255 BlockIo->Media->MediaId,
256 ExtMbrStartingLba,
257 BlockIo->Media->BlockSize,
258 Mbr
259 );
260 if (EFI_ERROR (Status)) {
261 goto Done;
262 }
263
264 if (Mbr->Partition[0].OSIndicator == 0) {
265 break;
266 }
267
268 if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) ||
269 (Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {
270 ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);
271 continue;
272 }
273 HdDev.PartitionNumber = PartitionNumber ++;
274 HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;
275 HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);
276 if (HdDev.PartitionStart + HdDev.PartitionSize - 1 >=
277 ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) {
278 break;
279 }
280
281 //
282 // The signature in EBR(Extended Boot Record) should always be 0.
283 //
284 *((UINT32 *) &HdDev.Signature[0]) = 0;
285
286 Status = PartitionInstallChildHandle (
287 This,
288 Handle,
289 DiskIo,
290 BlockIo,
291 DevicePath,
292 (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,
293 HdDev.PartitionStart - ParentHdDev.PartitionStart,
294 HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,
295 MBR_SIZE,
296 (BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)
297 );
298 if (!EFI_ERROR (Status)) {
299 Found = TRUE;
300 }
301
302 if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&
303 (Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)
304 ) {
305 break;
306 }
307
308 ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);
309 //
310 // Don't allow partition to be self referencing
311 //
312 if (ExtMbrStartingLba == 0) {
313 break;
314 }
315 } while (ExtMbrStartingLba < ParentHdDev.PartitionSize);
316 }
317
318 Done:
319 gBS->FreePool (Mbr);
320
321 return Found;
322 }