summaryrefslogtreecommitdiffstats
path: root/FatPkg/FatPei/FatLiteAccess.c
blob: 0a688a3185e6971779cd9b5dfd2269ea84978f90 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
/** @file
  FAT file system access routines for FAT recovery PEIM

Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>

This program and the accompanying materials are licensed and made available
under the terms and conditions of the BSD License which accompanies this
distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "FatLitePeim.h"


/**
  Check if there is a valid FAT in the corresponding Block device
  of the volume and if yes, fill in the relevant fields for the
  volume structure. Note there should be a valid Block device number
  already set.

  @param  PrivateData            Global memory map for accessing global 
                                 variables. 
  @param  Volume                 On input, the BlockDeviceNumber field of the 
                                 Volume  should be a valid value. On successful 
                                 output, all  fields except the VolumeNumber 
                                 field is initialized. 

  @retval EFI_SUCCESS            A FAT is found and the volume structure is 
                                 initialized. 
  @retval EFI_NOT_FOUND          There is no FAT on the corresponding device. 
  @retval EFI_DEVICE_ERROR       There is something error while accessing device.

**/
EFI_STATUS
FatGetBpbInfo (
  IN      PEI_FAT_PRIVATE_DATA  *PrivateData,
  IN OUT  PEI_FAT_VOLUME        *Volume
  )
{
  EFI_STATUS              Status;
  PEI_FAT_BOOT_SECTOR     Bpb;
  PEI_FAT_BOOT_SECTOR_EX  BpbEx;
  UINT32                  Sectors;
  UINT32                  SectorsPerFat;
  UINT32                  RootDirSectors;
  UINT64                  FatLba;
  UINT64                  RootLba;
  UINT64                  FirstClusterLba;

  //
  // Read in the BPB
  //
  Status = FatReadDisk (
            PrivateData,
            Volume->BlockDeviceNo,
            0,
            sizeof (PEI_FAT_BOOT_SECTOR_EX),
            &BpbEx
            );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  CopyMem (
    (UINT8 *) (&Bpb),
    (UINT8 *) (&BpbEx),
    sizeof (PEI_FAT_BOOT_SECTOR)
    );

  Volume->FatType = FatUnknown;

  Sectors         = Bpb.Sectors;
  if (Sectors == 0) {
    Sectors = Bpb.LargeSectors;
  }

  SectorsPerFat = Bpb.SectorsPerFat;
  if (SectorsPerFat == 0) {
    SectorsPerFat   = BpbEx.LargeSectorsPerFat;
    Volume->FatType = Fat32;
  }
  //
  // Filter out those not a FAT
  //
  if (Bpb.Ia32Jump[0] != 0xe9 && Bpb.Ia32Jump[0] != 0xeb && Bpb.Ia32Jump[0] != 0x49) {
    return EFI_NOT_FOUND;
  }

  if (Bpb.ReservedSectors == 0 || Bpb.NoFats == 0 || Sectors == 0) {
    return EFI_NOT_FOUND;
  }

  if (Bpb.SectorsPerCluster != 1 &&
      Bpb.SectorsPerCluster != 2 &&
      Bpb.SectorsPerCluster != 4 &&
      Bpb.SectorsPerCluster != 8 &&
      Bpb.SectorsPerCluster != 16 &&
      Bpb.SectorsPerCluster != 32 &&
      Bpb.SectorsPerCluster != 64 &&
      Bpb.SectorsPerCluster != 128
      ) {
    return EFI_NOT_FOUND;
  }

  if (Volume->FatType == Fat32 && (SectorsPerFat == 0 || BpbEx.FsVersion != 0)) {
    return EFI_NOT_FOUND;
  }

  if (Bpb.Media != 0xf0 &&
      Bpb.Media != 0xf8 &&
      Bpb.Media != 0xf9 &&
      Bpb.Media != 0xfb &&
      Bpb.Media != 0xfc &&
      Bpb.Media != 0xfd &&
      Bpb.Media != 0xfe &&
      Bpb.Media != 0xff &&
      //
      // FujitsuFMR
      //
      Bpb.Media != 0x00 &&
      Bpb.Media != 0x01 &&
      Bpb.Media != 0xfa
      ) {
    return EFI_NOT_FOUND;
  }

  if (Volume->FatType != Fat32 && Bpb.RootEntries == 0) {
    return EFI_NOT_FOUND;
  }
  //
  // If this is fat32, refuse to mount mirror-disabled volumes
  //
  if (Volume->FatType == Fat32 && ((BpbEx.ExtendedFlags & 0x80) != 0)) {
    return EFI_NOT_FOUND;
  }
  //
  // Fill in the volume structure fields
  // (Sectors & SectorsPerFat is computed earlier already)
  //
  Volume->ClusterSize = Bpb.SectorSize * Bpb.SectorsPerCluster;
  Volume->RootEntries = Bpb.RootEntries;
  Volume->SectorSize  = Bpb.SectorSize;

  RootDirSectors = ((Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) + (Volume->SectorSize - 1)) / Volume->SectorSize;

  FatLba                  = Bpb.ReservedSectors;
  RootLba                 = Bpb.NoFats * SectorsPerFat + FatLba;
  FirstClusterLba         = RootLba + RootDirSectors;

  Volume->VolumeSize      = MultU64x32 (Sectors, Volume->SectorSize);
  Volume->FatPos          = MultU64x32 (FatLba, Volume->SectorSize);
  Volume->RootDirPos      = MultU64x32 (RootLba, Volume->SectorSize);
  Volume->FirstClusterPos = MultU64x32 (FirstClusterLba, Volume->SectorSize);
  Volume->MaxCluster      = (UINT32) (Sectors - FirstClusterLba) / Bpb.SectorsPerCluster;
  Volume->RootDirCluster  = BpbEx.RootDirFirstCluster;

  //
  // If this is not a fat32, determine if it's a fat16 or fat12
  //
  if (Volume->FatType != Fat32) {

    if (Volume->MaxCluster >= 65525) {
      return EFI_NOT_FOUND;
    }

    Volume->FatType = Volume->MaxCluster < 4085 ? Fat12 : Fat16;
  }

  return EFI_SUCCESS;
}


/**
  Gets the next cluster in the cluster chain

  @param  PrivateData            Global memory map for accessing global variables 
  @param  Volume                 The volume 
  @param  Cluster                The cluster 
  @param  NextCluster            The cluster number of the next cluster 

  @retval EFI_SUCCESS            The address is got 
  @retval EFI_INVALID_PARAMETER  ClusterNo exceeds the MaxCluster of the volume. 
  @retval EFI_DEVICE_ERROR       Read disk error

**/
EFI_STATUS
FatGetNextCluster (
  IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  IN  PEI_FAT_VOLUME        *Volume,
  IN  UINT32                Cluster,
  OUT UINT32                *NextCluster
  )
{
  EFI_STATUS  Status;
  UINT64      FatEntryPos;
  UINT32      Dummy;

  *NextCluster = 0;

  if (Volume->FatType == Fat32) {
    FatEntryPos = Volume->FatPos + MultU64x32 (4, Cluster);

    Status      = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 4, NextCluster);
    *NextCluster &= 0x0fffffff;

    //
    // Pad high bits for our FAT_CLUSTER_... macro definitions to work
    //
    if ((*NextCluster) >= 0x0ffffff7) {
      *NextCluster |= (-1 &~0xf);
    }

  } else if (Volume->FatType == Fat16) {
    FatEntryPos = Volume->FatPos + MultU64x32 (2, Cluster);

    Status      = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);

    //
    // Pad high bits for our FAT_CLUSTER_... macro definitions to work
    //
    if ((*NextCluster) >= 0xfff7) {
      *NextCluster |= (-1 &~0xf);
    }

  } else {
    FatEntryPos = Volume->FatPos + DivU64x32Remainder (MultU64x32 (3, Cluster), 2, &Dummy);

    Status      = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);

    if ((Cluster & 0x01) != 0) {
      *NextCluster = (*NextCluster) >> 4;
    } else {
      *NextCluster = (*NextCluster) & 0x0fff;
    }
    //
    // Pad high bits for our FAT_CLUSTER_... macro definitions to work
    //
    if ((*NextCluster) >= 0x0ff7) {
      *NextCluster |= (-1 &~0xf);
    }
  }

  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;

}


/**
  Set a file's CurrentPos and CurrentCluster, then compute StraightReadAmount.

  @param  PrivateData            the global memory map 
  @param  File                   the file 
  @param  Pos                    the Position which is offset from the file's 
                                 CurrentPos 

  @retval EFI_SUCCESS            Success. 
  @retval EFI_INVALID_PARAMETER  Pos is beyond file's size. 
  @retval EFI_DEVICE_ERROR       Something error while accessing media.

**/
EFI_STATUS
FatSetFilePos (
  IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  IN  PEI_FAT_FILE          *File,
  IN  UINT32                Pos
  )
{
  EFI_STATUS  Status;
  UINT32      AlignedPos;
  UINT32      Offset;
  UINT32      Cluster;
  UINT32      PrevCluster;

  if (File->IsFixedRootDir) {

    if (Pos >= MultU64x32 (File->Volume->RootEntries, 32) - File->CurrentPos) {
      return EFI_INVALID_PARAMETER;
    }

    File->CurrentPos += Pos;
    File->StraightReadAmount = (UINT32) (MultU64x32 (File->Volume->RootEntries, 32) - File->CurrentPos);

  } else {

    DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
    AlignedPos = (UINT32) File->CurrentPos - (UINT32) Offset;

    while
    (
      !FAT_CLUSTER_FUNCTIONAL (File->CurrentCluster) &&
      AlignedPos + File->Volume->ClusterSize <= File->CurrentPos + Pos
    ) {
      AlignedPos += File->Volume->ClusterSize;
      Status = FatGetNextCluster (
                PrivateData,
                File->Volume,
                File->CurrentCluster,
                &File->CurrentCluster
                );
      if (EFI_ERROR (Status)) {
        return EFI_DEVICE_ERROR;
      }
    }

    if (FAT_CLUSTER_FUNCTIONAL (File->CurrentCluster)) {
      return EFI_INVALID_PARAMETER;
    }

    File->CurrentPos += Pos;

    File->StraightReadAmount  = 0;
    Cluster                   = File->CurrentCluster;
    while (!FAT_CLUSTER_FUNCTIONAL (Cluster)) {
      File->StraightReadAmount += File->Volume->ClusterSize;
      PrevCluster = Cluster;
      Status      = FatGetNextCluster (PrivateData, File->Volume, Cluster, &Cluster);
      if (EFI_ERROR (Status)) {
        return EFI_DEVICE_ERROR;
      }

      if (Cluster != PrevCluster + 1) {
        break;
      }
    }

    DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
    File->StraightReadAmount -= (UINT32) Offset;

  }

  return EFI_SUCCESS;
}


/**
  Reads file data. Updates the file's CurrentPos.

  @param  PrivateData            Global memory map for accessing global variables 
  @param  File                   The file. 
  @param  Size                   The amount of data to read. 
  @param  Buffer                 The buffer storing the data. 

  @retval EFI_SUCCESS            The data is read. 
  @retval EFI_INVALID_PARAMETER  File is invalid. 
  @retval EFI_DEVICE_ERROR       Something error while accessing media.

**/
EFI_STATUS
FatReadFile (
  IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  IN  PEI_FAT_FILE          *File,
  IN  UINTN                 Size,
  OUT VOID                  *Buffer
  )
{
  EFI_STATUS  Status;
  CHAR8       *BufferPtr;
  UINT32      Offset;
  UINT64      PhysicalAddr;
  UINTN       Amount;

  BufferPtr = Buffer;

  if (File->IsFixedRootDir) {
    //
    // This is the fixed root dir in FAT12 and FAT16
    //
    if (File->CurrentPos + Size > File->Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) {
      return EFI_INVALID_PARAMETER;
    }

    Status = FatReadDisk (
              PrivateData,
              File->Volume->BlockDeviceNo,
              File->Volume->RootDirPos + File->CurrentPos,
              Size,
              Buffer
              );
    File->CurrentPos += (UINT32) Size;
    return Status;

  } else {

    if ((File->Attributes & FAT_ATTR_DIRECTORY) == 0) {
      Size = Size < (File->FileSize - File->CurrentPos) ? Size : (UINTN) (File->FileSize - File->CurrentPos);
    }
    //
    // This is a normal cluster based file
    //
    while (Size != 0) {
      DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
      PhysicalAddr  = File->Volume->FirstClusterPos + MultU64x32 (File->Volume->ClusterSize, File->CurrentCluster - 2);

      Amount        = File->StraightReadAmount;
      Amount        = Size > Amount ? Amount : Size;
      Status = FatReadDisk (
                PrivateData,
                File->Volume->BlockDeviceNo,
                PhysicalAddr + Offset,
                Amount,
                BufferPtr
                );
      if (EFI_ERROR (Status)) {
        return EFI_DEVICE_ERROR;
      }
      //
      // Advance the file's current pos and current cluster
      //
      FatSetFilePos (PrivateData, File, (UINT32) Amount);

      BufferPtr += Amount;
      Size -= Amount;
    }

    return EFI_SUCCESS;
  }
}


/**
  This function reads the next item in the parent directory and
  initializes the output parameter SubFile (CurrentPos is initialized to 0).
  The function updates the CurrentPos of the parent dir to after the item read.
  If no more items were found, the function returns EFI_NOT_FOUND.

  @param  PrivateData            Global memory map for accessing global variables 
  @param  ParentDir              The parent directory. 
  @param  SubFile                The File structure containing the sub file that 
                                 is caught. 

  @retval EFI_SUCCESS            The next sub file is obtained. 
  @retval EFI_INVALID_PARAMETER  The ParentDir is not a directory. 
  @retval EFI_NOT_FOUND          No more sub file exists. 
  @retval EFI_DEVICE_ERROR       Something error while accessing media.

**/
EFI_STATUS
FatReadNextDirectoryEntry (
  IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  IN  PEI_FAT_FILE          *ParentDir,
  OUT PEI_FAT_FILE          *SubFile
  )
{
  EFI_STATUS          Status;
  FAT_DIRECTORY_ENTRY DirEntry;
  CHAR16              *Pos;
  CHAR16              BaseName[9];
  CHAR16              Ext[4];

  ZeroMem ((UINT8 *) SubFile, sizeof (PEI_FAT_FILE));

  //
  // Pick a valid directory entry
  //
  while (1) {
    //
    // Read one entry
    //
    Status = FatReadFile (PrivateData, ParentDir, 32, &DirEntry);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }
    //
    // We only search for *FILE* in root directory
    // Long file name entry is *NOT* supported
    //
    if ((DirEntry.Attributes == FAT_ATTR_DIRECTORY) || (DirEntry.Attributes == FAT_ATTR_LFN)) {
      continue;
    }
    //
    // if this is a terminator dir entry, just return EFI_NOT_FOUND
    //
    if (DirEntry.FileName[0] == EMPTY_ENTRY_MARK) {
      return EFI_NOT_FOUND;
    }
    //
    // If this not an invalid entry neither an empty entry, this is what we want.
    // otherwise we will start a new loop to continue to find something meaningful
    //
    if ((UINT8) DirEntry.FileName[0] != DELETE_ENTRY_MARK) {
      break;
    }
  }
  //
  // fill in the output parameter
  //
  EngFatToStr (8, DirEntry.FileName, BaseName);
  EngFatToStr (3, DirEntry.FileName + 8, Ext);

  Pos = (UINT16 *) SubFile->FileName;
  SetMem ((UINT8 *) Pos, FAT_MAX_FILE_NAME_LENGTH, 0);
  CopyMem ((UINT8 *) Pos, (UINT8 *) BaseName, 2 * (StrLen (BaseName) + 1));

  if (Ext[0] != 0) {
    Pos += StrLen (BaseName);
    *Pos = '.';
    Pos++;
    CopyMem ((UINT8 *) Pos, (UINT8 *) Ext, 2 * (StrLen (Ext) + 1));
  }

  SubFile->Attributes     = DirEntry.Attributes;
  SubFile->CurrentCluster = DirEntry.FileCluster;
  if (ParentDir->Volume->FatType == Fat32) {
    SubFile->CurrentCluster |= DirEntry.FileClusterHigh << 16;
  }

  SubFile->CurrentPos       = 0;
  SubFile->FileSize         = DirEntry.FileSize;
  SubFile->StartingCluster  = SubFile->CurrentCluster;
  SubFile->Volume           = ParentDir->Volume;

  if (SubFile->StartingCluster != 0) {
    Status = FatSetFilePos (PrivateData, SubFile, 0);
  }
  //
  // in Pei phase, time parameters do not need to be filled for minimum use.
  //
  return Status;
}