Outline ![]()
Files ![]()
loading...
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
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** FileX Component */
/** */
/** Media */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
/* Include necessary system files. */
#include "fx_api.h"
#include "fx_system.h"
#include "fx_media.h"
#include "fx_utility.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fx_media_open PORTABLE C */
/* 6.1.10 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function opens the specified media with the supplied device */
/* driver. The specified media must conform to the FAT compatible */
/* file format, which is verified during the media open process. In */
/* addition, the supplied FileX device driver must also conform to */
/* the FileX device driver specification. */
/* */
/* The FAT boot sector (512 bytes) that is verified by this */
/* function must look like the following: */
/* */
/* Byte Offset Meaning Size */
/* */
/* 0x000 Jump Instructions 3 */
/* 0x003 OEM Name 8 */
/* 0x00B *Bytes per Sector 2 */
/* 0x00D *Sectors per Cluster 1 */
/* 0x00E *Reserved Sectors 2 */
/* 0x010 *Number of FATs 1 */
/* 0x011 *Max Root Dir Entries 2 */
/* 0x013 *Number of Sectors 2 */
/* 0x015 Media Type 1 */
/* 0x016 *Sectors per FAT 2 */
/* 0x018 *Sectors per Track 2 */
/* 0x01A *Number of Heads 2 */
/* 0x01C *Hidden Sectors 4 */
/* 0x020 *Huge Sectors 4 */
/* 0x024 Drive Number 1 */
/* 0x025 Reserved 1 */
/* 0x026 Boot Signature 1 */
/* 0x027 Volume ID 4 */
/* 0x02B Volume Label 11 */
/* 0x036 File System Type 8 */
/* ... ... ... */
/* 0x1FE **Signature (0x55aa) 2 */
/* */
/* * Denotes which elements of the boot record */
/* FileX uses. */
/* */
/* **Denotes the element is checked by the I/O */
/* driver. This eliminates the need for a minimum */
/* 512-byte buffer for FileX. */
/* */
/* Note: All values above are in little endian format, i.e. the LSB is */
/* in the lowest address. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* media_name Pointer to media name string */
/* media_driver Media driver entry function */
/* driver_info_ptr Optional information pointer */
/* supplied to media driver */
/* memory_ptr Pointer to memory used by the */
/* FileX for this media. */
/* memory_size Size of media memory - must */
/* at least 512 bytes and */
/* one sector size. */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* I/O Driver */
/* _fx_utility_exFAT_bitmap_initialize Initialize exFAT bitmap */
/* _fx_utility_16_unsigned_read Read 16-bit unsigned value */
/* _fx_utility_32_unsigned_read Read 32-bit unsigned value */
/* _fx_utility_logical_sector_flush Invalidate log sector cache */
/* _fx_media_boot_info_extract Extract media information */
/* _fx_utility_FAT_entry_read Pickup FAT entry contents */
/* tx_mutex_create Create protection mutex */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 William E. Lamie Modified comment(s), and */
/* added conditional to */
/* disable force memset, */
/* build options and cache, */
/* resulting in version 6.1 */
/* 01-31-2022 William E. Lamie Modified comment(s), fixed */
/* errors without cache, */
/* resulting in version 6.1.10 */
/* */
/**************************************************************************/
UINT _fx_media_open(FX_MEDIA *media_ptr, CHAR *media_name,
VOID (*media_driver)(FX_MEDIA *), VOID *driver_info_ptr,
VOID *memory_ptr, ULONG memory_size)
{
FX_MEDIA_PTR tail_ptr;
ULONG cluster_number;
ULONG FAT_entry, FAT_sector, FAT_read_sectors;
ULONG i, j;
#ifndef FX_DISABLE_CACHE
FX_CACHED_SECTOR *cache_entry_ptr;
#endif /* FX_DISABLE_CACHE */
UINT status;
UINT additional_info_sector;
UCHAR *original_memory_ptr;
ULONG bytes_in_buffer;
FX_INT_SAVE_AREA
#ifndef FX_DISABLE_BUILD_OPTIONS
/* Reference the version ID and option words to ensure they are linked in. */
if ((_fx_system_build_options_1 | _fx_system_build_options_2 | _fx_system_build_options_3) == 0 ||
_fx_version_id[0] == 0)
{
/* We should never get here! */
return(FX_NOT_IMPLEMENTED);
}
#endif /* FX_DISABLE_BUILD_OPTIONS */
#ifdef FX_DISABLE_FORCE_MEMORY_OPERATION
_fx_utility_memory_set((UCHAR *)media_ptr, 0, sizeof(FX_MEDIA));
#endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */
#ifdef FX_DISABLE_CACHE
media_ptr -> fx_media_memory_buffer_sector = (ULONG64)-1;
#endif /* FX_DISABLE_CACHE */
/* Save the basic information in the media control block. */
media_ptr -> fx_media_name = media_name;
media_ptr -> fx_media_driver_entry = media_driver;
media_ptr -> fx_media_memory_buffer = (UCHAR *)memory_ptr;
media_ptr -> fx_media_memory_size = memory_size;
#ifndef FX_DISABLE_FORCE_MEMORY_OPERATION
media_ptr -> fx_media_disable_burst_cache = FX_FALSE;
media_ptr -> fx_media_FAT_type = 0;
#endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */
/* Save the original memory pointer. */
original_memory_ptr = (UCHAR *)memory_ptr;
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Clear the optional media statistics. */
media_ptr -> fx_media_directory_attributes_reads = 0;
media_ptr -> fx_media_directory_attributes_sets = 0;
media_ptr -> fx_media_directory_creates = 0;
media_ptr -> fx_media_directory_default_gets = 0;
media_ptr -> fx_media_directory_default_sets = 0;
media_ptr -> fx_media_directory_deletes = 0;
media_ptr -> fx_media_directory_first_entry_finds = 0;
media_ptr -> fx_media_directory_first_full_entry_finds = 0;
media_ptr -> fx_media_directory_information_gets = 0;
media_ptr -> fx_media_directory_local_path_clears = 0;
media_ptr -> fx_media_directory_local_path_gets = 0;
media_ptr -> fx_media_directory_local_path_restores = 0;
media_ptr -> fx_media_directory_local_path_sets = 0;
media_ptr -> fx_media_directory_name_tests = 0;
media_ptr -> fx_media_directory_next_entry_finds = 0;
media_ptr -> fx_media_directory_next_full_entry_finds = 0;
media_ptr -> fx_media_directory_renames = 0;
media_ptr -> fx_media_file_allocates = 0;
media_ptr -> fx_media_file_attributes_reads = 0;
media_ptr -> fx_media_file_attributes_sets = 0;
media_ptr -> fx_media_file_best_effort_allocates = 0;
media_ptr -> fx_media_file_closes = 0;
media_ptr -> fx_media_file_creates = 0;
media_ptr -> fx_media_file_deletes = 0;
media_ptr -> fx_media_file_opens = 0;
media_ptr -> fx_media_file_reads = 0;
media_ptr -> fx_media_file_relative_seeks = 0;
media_ptr -> fx_media_file_renames = 0;
media_ptr -> fx_media_file_seeks = 0;
media_ptr -> fx_media_file_truncates = 0;
media_ptr -> fx_media_file_truncate_releases = 0;
media_ptr -> fx_media_file_writes = 0;
media_ptr -> fx_media_aborts = 0;
media_ptr -> fx_media_flushes = 0;
media_ptr -> fx_media_reads = 0;
media_ptr -> fx_media_writes = 0;
media_ptr -> fx_media_directory_entry_reads = 0;
media_ptr -> fx_media_directory_entry_writes = 0;
media_ptr -> fx_media_directory_searches = 0;
#ifndef FX_MEDIA_DISABLE_SEARCH_CACHE
media_ptr -> fx_media_directory_search_cache_hits = 0;
#endif
media_ptr -> fx_media_directory_free_searches = 0;
media_ptr -> fx_media_fat_entry_reads = 0;
media_ptr -> fx_media_fat_entry_writes = 0;
media_ptr -> fx_media_fat_entry_cache_read_hits = 0;
media_ptr -> fx_media_fat_entry_cache_read_misses = 0;
media_ptr -> fx_media_fat_entry_cache_write_hits = 0;
media_ptr -> fx_media_fat_entry_cache_write_misses = 0;
media_ptr -> fx_media_fat_cache_flushes = 0;
media_ptr -> fx_media_fat_sector_reads = 0;
media_ptr -> fx_media_fat_sector_writes = 0;
media_ptr -> fx_media_logical_sector_reads = 0;
media_ptr -> fx_media_logical_sector_writes = 0;
media_ptr -> fx_media_logical_sector_cache_read_hits = 0;
media_ptr -> fx_media_logical_sector_cache_read_misses = 0;
media_ptr -> fx_media_driver_read_requests = 0;
media_ptr -> fx_media_driver_write_requests = 0;
media_ptr -> fx_media_driver_boot_read_requests = 0;
media_ptr -> fx_media_driver_boot_write_requests = 0;
media_ptr -> fx_media_driver_release_sectors_requests = 0;
media_ptr -> fx_media_driver_flush_requests = 0;
#endif
#ifdef FX_ENABLE_FAULT_TOLERANT
media_ptr -> fx_media_fault_tolerant_enabled = FX_FALSE;
media_ptr -> fx_media_fault_tolerant_state = 0;
#endif /* FX_ENABLE_FAULT_TOLERANT */
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_MEDIA_OPEN, media_ptr, media_driver, memory_ptr, memory_size, FX_TRACE_MEDIA_EVENTS, 0, 0)
/* Initialize the supplied media I/O driver. First, build the
initialize driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_INIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_info = driver_info_ptr;
media_ptr -> fx_media_driver_write_protect = FX_FALSE;
media_ptr -> fx_media_driver_free_sector_update = FX_FALSE;
media_ptr -> fx_media_driver_data_sector_read = FX_FALSE;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_INIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the initialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Determine if the I/O driver initialized successfully. */
if (media_ptr -> fx_media_driver_status != FX_SUCCESS)
{
/* Return the driver error status. */
return(FX_IO_ERROR);
}
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver boot read requests. */
media_ptr -> fx_media_driver_boot_read_requests++;
#endif
/* Read the boot sector from the device. Build the read boot sector
command. */
media_ptr -> fx_media_driver_request = FX_DRIVER_BOOT_READ;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = memory_ptr;
media_ptr -> fx_media_driver_sectors = 1;
media_ptr -> fx_media_driver_sector_type = FX_BOOT_SECTOR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_BOOT_READ, media_ptr, memory_ptr, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to read the boot sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Determine if the boot sector was read correctly. */
if (media_ptr -> fx_media_driver_status != FX_SUCCESS)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Return the boot sector error status. */
return(FX_BOOT_ERROR);
}
/* Extract and validate the media parameters from the boot sector. */
if (_fx_media_boot_info_extract(media_ptr) != FX_SUCCESS)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Return the invalid media error status. */
return(FX_MEDIA_INVALID);
}
/* Pickup the additional info sector number. This will only be used in FAT32 situations. */
additional_info_sector = _fx_utility_16_unsigned_read(&media_ptr -> fx_media_driver_buffer[48]);
#ifndef FX_DISABLE_CACHE
/* Determine how many logical sectors can be cached with user's supplied
buffer area - there must be at least enough for one sector! */
media_ptr -> fx_media_sector_cache_size = memory_size / media_ptr -> fx_media_bytes_per_sector;
/* Is there at least one? */
if (media_ptr -> fx_media_sector_cache_size == 0)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Error in the buffer size supplied by user. */
return(FX_BUFFER_ERROR);
}
/* If trace is enabled, register this object. */
FX_TRACE_OBJECT_REGISTER(FX_TRACE_OBJECT_TYPE_MEDIA, media_ptr, media_name, FX_MAX_FAT_CACHE, media_ptr -> fx_media_sector_cache_size)
/* Adjust the internal cache to fit the fixed number of sector cache control blocks
built into the media control block. */
if (media_ptr -> fx_media_sector_cache_size > FX_MAX_SECTOR_CACHE)
{
/* Adjust the number of cache sectors downward. If this is insufficient,
the FX_MAX_SECTOR_CACHE constant in FX_API.H must be changed and the FileX
library must be rebuilt. */
media_ptr -> fx_media_sector_cache_size = FX_MAX_SECTOR_CACHE;
}
/* Otherwise, everything is okay. Initialize the data structures for managing the
logical sector cache. */
i = (UINT)media_ptr -> fx_media_sector_cache_size;
cache_entry_ptr = media_ptr -> fx_media_sector_cache;
while (i--)
{
/* Initialize each of the cache entries. */
cache_entry_ptr -> fx_cached_sector_memory_buffer = (UCHAR *)memory_ptr;
cache_entry_ptr -> fx_cached_sector = (~(ULONG64)0);
cache_entry_ptr -> fx_cached_sector_buffer_dirty = FX_FALSE;
cache_entry_ptr -> fx_cached_sector_valid = FX_FALSE;
cache_entry_ptr -> fx_cached_sector_next_used = cache_entry_ptr + 1;
/* Move to the next cache sector entry. */
cache_entry_ptr++;
/* Update the memory pointer to the next buffer slot. */
memory_ptr = (VOID *)(((UCHAR *)memory_ptr) + media_ptr -> fx_media_bytes_per_sector);
}
/* Backup to the last cache entry to set its next pointer to NULL. */
cache_entry_ptr--;
cache_entry_ptr -> fx_cached_sector_next_used = FX_NULL;
/* Remember the last memory address used by the caching logic. */
media_ptr -> fx_media_sector_cache_end = ((UCHAR *)memory_ptr) - 1;
/* Setup the head pointer of the list. */
media_ptr -> fx_media_sector_cache_list_ptr = media_ptr -> fx_media_sector_cache;
/* Setup the bit map that keeps track of the valid hashed cache logical sectors. */
media_ptr -> fx_media_sector_cache_hashed_sector_valid = 0;
/* Clear the counter of the number of outstanding dirty sectors. */
media_ptr -> fx_media_sector_cache_dirty_count = 0;
/* Determine if the logical sector cache should be managed by the hash function
instead of the linear search. The cache must be a power of 2 that is between the
minimum and maximum cache size. */
if ((media_ptr -> fx_media_sector_cache_size >= FX_SECTOR_CACHE_HASH_ENABLE) &&
((media_ptr -> fx_media_sector_cache_size ^ (media_ptr -> fx_media_sector_cache_size - 1)) ==
(media_ptr -> fx_media_sector_cache_size | (media_ptr -> fx_media_sector_cache_size - 1))))
{
/* Set the logical sector cache hash flag. When this flag is set, the logical
sector cache is accessed with a hash function instead of a linear search. */
media_ptr -> fx_media_sector_cache_hashed = FX_TRUE;
media_ptr -> fx_media_sector_cache_hash_mask =
((media_ptr -> fx_media_sector_cache_size / FX_SECTOR_CACHE_DEPTH) - 1);
}
else
{
/* Clear the logical sector cache flag. */
media_ptr -> fx_media_sector_cache_hashed = FX_FALSE;
}
#else
media_ptr -> fx_media_memory_buffer = memory_ptr;
#endif /* FX_DISABLE_CACHE */
#ifndef FX_DISABLE_FORCE_MEMORY_OPERATION
/* Initialize the FAT cache entry array. */
for (i = 0; i < FX_MAX_FAT_CACHE; i++)
{
/* Clear entry in the FAT cache. */
media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_cluster = 0;
media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_value = 0;
media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_dirty = 0;
}
/* Initialize the secondary FAT update map. */
for (i = 0; i < FX_FAT_MAP_SIZE; i++)
{
/* Clear bit map entry for secondary FAT update. */
media_ptr -> fx_media_fat_secondary_update_map[i] = 0;
}
#endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */
#ifdef FX_ENABLE_EXFAT
if (media_ptr -> fx_media_FAT_type != FX_exFAT)
{
#endif /* FX_ENABLE_EXFAT */
/* Root_sector_start has been computed */
media_ptr -> fx_media_root_sector_start = media_ptr -> fx_media_reserved_sectors +
(media_ptr -> fx_media_number_of_FATs *
media_ptr -> fx_media_sectors_per_FAT);
/* Calculate the number of directory sectors. */
media_ptr -> fx_media_root_sectors =
((media_ptr -> fx_media_root_directory_entries * FX_DIR_ENTRY_SIZE) +
media_ptr -> fx_media_bytes_per_sector - 1) /
media_ptr -> fx_media_bytes_per_sector;
/* Calculate the starting data sector. */
media_ptr -> fx_media_data_sector_start = media_ptr -> fx_media_root_sector_start +
media_ptr -> fx_media_root_sectors;
/* Calculate the total number of clusters. */
media_ptr -> fx_media_total_clusters = (ULONG)((media_ptr -> fx_media_total_sectors - media_ptr -> fx_media_data_sector_start) /
media_ptr -> fx_media_sectors_per_cluster);
/* Determine if a 12-bit FAT is in use. */
if (media_ptr -> fx_media_total_clusters < FX_12_BIT_FAT_SIZE)
{
/* Yes, 12-bit FAT is present. Set flag accordingly. */
media_ptr -> fx_media_12_bit_FAT = FX_TRUE;
media_ptr -> fx_media_32_bit_FAT = FX_FALSE;
#ifdef FX_ENABLE_EXFAT
media_ptr -> fx_media_FAT_type = FX_FAT12;
#endif /* FX_ENABLE_EXFAT */
/* No additional information sector in FAT12. */
media_ptr -> fx_media_FAT32_additional_info_sector = 0;
/* Set FAT last and FAT reserved. */
media_ptr -> fx_media_fat_reserved = FX_RESERVED_1;
media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2;
}
else if (media_ptr -> fx_media_total_clusters < FX_16_BIT_FAT_SIZE)
{
/* A 16-bit FAT is present. Set flag accordingly. */
media_ptr -> fx_media_12_bit_FAT = FX_FALSE;
media_ptr -> fx_media_32_bit_FAT = FX_FALSE;
#ifdef FX_ENABLE_EXFAT
media_ptr -> fx_media_FAT_type = FX_FAT16;
#endif /* FX_ENABLE_EXFAT */
/* No additional information sector in FAT16. */
media_ptr -> fx_media_FAT32_additional_info_sector = 0;
/* Set FAT last and FAT reserved. */
media_ptr -> fx_media_fat_reserved = FX_RESERVED_1;
media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2;
}
else
{
/* Yes, a 32-bit FAT is present. */
media_ptr -> fx_media_12_bit_FAT = FX_FALSE;
media_ptr -> fx_media_32_bit_FAT = FX_TRUE;
#ifdef FX_ENABLE_EXFAT
media_ptr -> fx_media_FAT_type = FX_FAT32;
#endif /* FX_ENABLE_EXFAT */
/* Save the additional information sector FAT32. This was read from the boot
sector earlier in this routine. */
media_ptr -> fx_media_FAT32_additional_info_sector = additional_info_sector;
/* Set FAT last and FAT reserved. */
media_ptr -> fx_media_fat_reserved = FX_RESERVED_1_32;
media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2_32;
}
#ifdef FX_ENABLE_EXFAT
}
else
{
/* Set FAT last and FAT reserved. */
media_ptr -> fx_media_fat_reserved = FX_RESERVED_1_exFAT;
media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_exFAT;
}
#endif /* FX_ENABLE_EXFAT */
/* Determine if a 32-bit FAT is present. If so, calculate the size of the root directory (since
it is variable in FAT32. */
#ifdef FX_ENABLE_EXFAT
if (media_ptr -> fx_media_32_bit_FAT == FX_TRUE ||
(media_ptr -> fx_media_FAT_type == FX_exFAT))
#else
if (media_ptr -> fx_media_32_bit_FAT == FX_TRUE)
#endif /* FX_ENABLE_EXFAT */
{
#ifdef FX_ENABLE_EXFAT
if (media_ptr -> fx_media_32_bit_FAT == FX_TRUE)
{
#endif /* FX_ENABLE_EXFAT */
/* Root First cluster starts from at least cluster 2, or higher. */
if (media_ptr -> fx_media_root_cluster_32 < FX_FAT_ENTRY_START)
{
return(FX_MEDIA_INVALID);
}
/* Calculate logical number of root dir sector. */
media_ptr -> fx_media_root_sector_start = media_ptr -> fx_media_data_sector_start +
(media_ptr -> fx_media_root_cluster_32 - FX_FAT_ENTRY_START) *
media_ptr -> fx_media_sectors_per_cluster;
#ifdef FX_ENABLE_EXFAT
}
#endif /* FX_ENABLE_EXFAT */
/* Calculate maximum possible value for fx_media_root_directory_entries */
i = 0;
for (cluster_number = media_ptr -> fx_media_root_cluster_32;;)
{
status = _fx_utility_FAT_entry_read(media_ptr, cluster_number, &FAT_entry);
i++;
/* Determine if the read was successful. */
if (status != FX_SUCCESS)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
return(FX_FAT_READ_ERROR);
}
if ((cluster_number == FAT_entry) || (i > media_ptr -> fx_media_total_clusters))
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
return(FX_FAT_READ_ERROR);
}
if (FAT_entry >= FX_RESERVED_1_32)
{
break;
}
cluster_number = FAT_entry;
}
/* Calculate the number of directory entries. */
media_ptr -> fx_media_root_directory_entries = (i * media_ptr -> fx_media_sectors_per_cluster *
media_ptr -> fx_media_bytes_per_sector) / FX_DIR_ENTRY_SIZE;
}
#ifndef FX_DISABLE_FORCE_MEMORY_OPERATION
/* Calculate the number of available clusters. */
media_ptr -> fx_media_available_clusters = 0;
/* Set the cluster search start to an invalid value. */
media_ptr -> fx_media_cluster_search_start = 0;
#endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */
/* Determine if there is 32-bit FAT additional information sector. */
if (media_ptr -> fx_media_FAT32_additional_info_sector)
{
UCHAR *buffer_ptr;
ULONG signature;
/* Yes, read the FAT32 additional information sector to get the available cluster count and
the hint for the first available cluster. */
#ifndef FX_DISABLE_CACHE
/* Setup a pointer to the first cached entry's buffer. */
buffer_ptr = (media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector_memory_buffer;
/* Invalidate this cache entry. */
(media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector = (~((ULONG64) 0));
(media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector_valid = FX_FALSE;
#else
buffer_ptr = media_ptr -> fx_media_memory_buffer;
#endif /* FX_DISABLE_CACHE */
/* Read the FAT32 additional information sector from the device. */
media_ptr -> fx_media_driver_request = FX_DRIVER_READ;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = buffer_ptr;
media_ptr -> fx_media_driver_logical_sector = media_ptr -> fx_media_FAT32_additional_info_sector;
media_ptr -> fx_media_driver_sectors = 1;
media_ptr -> fx_media_driver_sector_type = FX_DIRECTORY_SECTOR;
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver read sector(s) requests. */
media_ptr -> fx_media_driver_read_requests++;
#endif
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, media_ptr -> fx_media_FAT32_additional_info_sector, 1, buffer_ptr, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to read the FAT32 additional information sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Determine if the FAT32 sector was read correctly. */
if (media_ptr -> fx_media_driver_status == FX_SUCCESS)
{
/* Yes, setup a pointer into the FAT32 additional information sector. */
buffer_ptr = media_ptr -> fx_media_driver_buffer;
/* Pickup the first signature long word. */
signature = _fx_utility_32_unsigned_read(&buffer_ptr[0]);
/* Determine if the signature is correct. */
if (signature == 0x41615252)
{
/* Yes, the first signature is correct, now pickup the next signature. */
signature = _fx_utility_32_unsigned_read(&buffer_ptr[484]);
/* Determine if this signature is correct. */
if (signature == 0x61417272)
{
/* Yes, we have a good FAT32 additional information sector. */
/* Pickup the current available cluster count on the media. */
media_ptr -> fx_media_available_clusters = _fx_utility_32_unsigned_read(&buffer_ptr[488]);
/* Initialize the last reported available cluster count to the same value. */
media_ptr -> fx_media_FAT32_additional_info_last_available = media_ptr -> fx_media_available_clusters;
/* Pickup the hint for the starting free cluster search. */
media_ptr -> fx_media_cluster_search_start = _fx_utility_32_unsigned_read(&buffer_ptr[492]);
/* Perform a quick sanity check on the available cluster count and the starting free
cluster search. */
if ((media_ptr -> fx_media_available_clusters > media_ptr -> fx_media_total_clusters) ||
(media_ptr -> fx_media_cluster_search_start > media_ptr -> fx_media_total_clusters + FX_FAT_ENTRY_START) ||
(media_ptr -> fx_media_cluster_search_start < FX_FAT_ENTRY_START))
{
/* Something is wrong, clear the available cluster count and search so the regular processing
is used. */
media_ptr -> fx_media_available_clusters = 0;
media_ptr -> fx_media_cluster_search_start = 0;
/* We don't invalidate the additional info sector here because only the data is bad. */
}
}
else
{
/* Signature is bad, invalidate the additional info sector. */
media_ptr -> fx_media_FAT32_additional_info_sector = 0;
}
}
else
{
/* Signature is bad, invalidate the additional info sector. */
media_ptr -> fx_media_FAT32_additional_info_sector = 0;
}
}
else
{
/* IO error trying to read additional information sector, invalidate the additional info sector. */
media_ptr -> fx_media_FAT32_additional_info_sector = 0;
}
}
/* Search the media to find the first available cluster as well as the total
available clusters. */
/* Determine what type of FAT is present. */
if (media_ptr -> fx_media_12_bit_FAT)
{
/* A 12-bit FAT is present. Utilize the FAT entry read utility to pickup
each FAT entry's contents. */
/* Loop to read each cluster entry in the first FAT. */
for (cluster_number = FX_FAT_ENTRY_START;
cluster_number < (media_ptr -> fx_media_total_clusters) + FX_FAT_ENTRY_START;
cluster_number++)
{
/* Read a FAT entry. */
status = _fx_utility_FAT_entry_read(media_ptr, cluster_number, &FAT_entry);
/* Determine if the read was successful. */
if (status != FX_SUCCESS)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
return(FX_FAT_READ_ERROR);
}
/* Now determine if the FAT entry is available. */
if (FAT_entry == FX_FREE_CLUSTER)
{
/* Increment the number of available clusters. */
media_ptr -> fx_media_available_clusters++;
/* Determine if the starting free cluster has been found yet. */
if (media_ptr -> fx_media_cluster_search_start == 0)
{
/* Remember the first free cluster to start further searches from. */
media_ptr -> fx_media_cluster_search_start = cluster_number;
}
}
}
}
#ifdef FX_ENABLE_EXFAT
else if ((media_ptr -> fx_media_available_clusters == 0)
&& (media_ptr -> fx_media_FAT_type != FX_exFAT))
#else
else if (media_ptr -> fx_media_available_clusters == 0)
#endif /* FX_ENABLE_EXFAT */
{
/* A 16 or 32-bit FAT is present. Read directly into the logical sector
cache memory to optimize I/O on larger devices. Since we are looking for
values of zero, endian issues are not important. */
/* Invalidate the current logical sector cache. */
_fx_utility_logical_sector_flush(media_ptr, ((ULONG64) 1), (ULONG64) (media_ptr -> fx_media_total_sectors), FX_TRUE);
/* Reset the memory pointer. */
media_ptr -> fx_media_memory_buffer = original_memory_ptr;
/* Loop through all FAT sectors in the primary FAT. The first two entries are
examined in this loop, but they are always unavailable. */
cluster_number = 0;
#ifndef FX_DISABLE_CACHE
for (i = 0; i < media_ptr -> fx_media_sectors_per_FAT; i = i + media_ptr -> fx_media_sector_cache_size)
{
/* Calculate the starting next FAT sector. */
FAT_sector = media_ptr -> fx_media_reserved_sectors + i;
/* Calculate how many sectors to read. */
FAT_read_sectors = media_ptr -> fx_media_sectors_per_FAT - i;
/* Determine if there is not enough memory to read the remaining FAT sectors. */
if (FAT_read_sectors > media_ptr -> fx_media_sector_cache_size)
{
FAT_read_sectors = media_ptr -> fx_media_sector_cache_size;
}
#else
for (i = 0; i < media_ptr -> fx_media_sectors_per_FAT; i++)
{
/* Calculate the starting next FAT sector. */
FAT_sector = media_ptr -> fx_media_reserved_sectors + i;
/* Calculate how many sectors to read. */
FAT_read_sectors = 1;
#endif /* FX_DISABLE_CACHE */
/* Read the FAT sectors directly from the driver. */
media_ptr -> fx_media_driver_request = FX_DRIVER_READ;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = media_ptr -> fx_media_memory_buffer;
media_ptr -> fx_media_driver_logical_sector = FAT_sector;
media_ptr -> fx_media_driver_sectors = FAT_read_sectors;
media_ptr -> fx_media_driver_sector_type = FX_FAT_SECTOR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, FAT_sector, FAT_read_sectors, media_ptr -> fx_media_memory_buffer, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to read the FAT sectors. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Determine if the read was successful. */
if (media_ptr -> fx_media_driver_status != FX_SUCCESS)
{
/* Build the "uninitialize" I/O driver request. */
media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Call the specified I/O driver with the uninitialize request. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
return(FX_FAT_READ_ERROR);
}
/* Calculate the number of bytes in the buffer. */
bytes_in_buffer = (media_ptr -> fx_media_bytes_per_sector * FAT_read_sectors);
/* Walk through the sector cache memory to search for available clusters and the first
available if not already found. */
for (j = 0; j < bytes_in_buffer;)
{
/* Check for a 32-bit FAT. */
if (media_ptr -> fx_media_32_bit_FAT)
{
/* Pickup 32-bit FAT entry. */
FAT_entry = *((ULONG *)&(media_ptr -> fx_media_memory_buffer[j]));
/* Advance to next FAT entry. */
j = j + 4;
}
else
{
/* Process a 16-bit FAT entry. */
FAT_entry = (((ULONG)(media_ptr -> fx_media_memory_buffer[j])) & 0xFF) |
((((ULONG)(media_ptr -> fx_media_memory_buffer[j + 1])) & 0xFF) << 8);
/* Advance to next FAT entry. */
j = j + 2;
}
/* Determine if the FAT entry is free. */
if (FAT_entry == FX_FREE_CLUSTER)
{
/* Entry is free, increment available clusters. */
media_ptr -> fx_media_available_clusters++;
/* Determine if the starting free cluster has been found yet. */
if (media_ptr -> fx_media_cluster_search_start == 0)
{
/* Remember the first free cluster to start further searches from. */
media_ptr -> fx_media_cluster_search_start = cluster_number;
}
}
/* Increment the cluster number. */
cluster_number++;
/* Determine if we have reviewed all FAT entries. */
if (cluster_number >= (media_ptr -> fx_media_total_clusters + FX_FAT_ENTRY_START))
{
/* Yes, we have looked at all the FAT entries. */
/* Ensure that the outer loop terminates as well. */
i = media_ptr -> fx_media_sectors_per_FAT;
break;
}
}
}
}
#ifdef FX_ENABLE_EXFAT
else if (media_ptr -> fx_media_FAT_type == FX_exFAT)
{
status = _fx_utility_exFAT_bitmap_initialize(media_ptr);
if ((FX_SUCCESS != status) &&
(FX_NO_MORE_SPACE != status))
{
return(status);
}
}
#endif /* FX_ENABLE_EXFAT */
/* If there were no free clusters, just set the search pointer to the
first cluster number. */
if (media_ptr -> fx_media_cluster_search_start == 0)
{
media_ptr -> fx_media_cluster_search_start = FX_FAT_ENTRY_START;
}
/* Setup the current working directory fields to default to the root
directory. */
media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_name =
media_ptr -> fx_media_default_path.fx_path_name_buffer;
media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_short_name[0] = 0;
media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_name[0] = 0;
media_ptr -> fx_media_default_path.fx_path_string[0] = (CHAR)0;
media_ptr -> fx_media_default_path.fx_path_string[FX_MAXIMUM_PATH - 1] = (CHAR)0;
media_ptr -> fx_media_default_path.fx_path_current_entry = 0;
#ifndef FX_MEDIA_DISABLE_SEARCH_CACHE
/* Invalidate the previously found directory entry. */
media_ptr -> fx_media_last_found_name[0] = 0;
#endif
#ifndef FX_DISABLE_FORCE_MEMORY_OPERATION
/* Initialize the opened file linked list and associated counter. */
media_ptr -> fx_media_opened_file_list = FX_NULL;
media_ptr -> fx_media_opened_file_count = 0;
#endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */
/* Create the media protection structure if FX_SINGLE_THREAD is not
defined. */
#ifndef FX_SINGLE_THREAD
#ifndef FX_DONT_CREATE_MUTEX
/* Create ThreadX mutex for protection. */
tx_mutex_create(&(media_ptr -> fx_media_protect), "FileX Media Mutex", TX_NO_INHERIT);
#endif
#endif
#ifdef FX_DONT_CREATE_MUTEX
/* Load the media ID field in the media control block. This allows the FX_PROTECT
call to succeed. */
media_ptr -> fx_media_id = (ULONG)FX_MEDIA_ID;
/* Protect against other threads accessing the media. */
FX_PROTECT
#endif
/* Lockout interrupts. */
FX_DISABLE_INTS
/* At this point, the media has been opened successfully. Place the
media on the linked list of currently opened media. */
/* Load the media ID field in the media control block. */
media_ptr -> fx_media_id = (ULONG)FX_MEDIA_ID;
/* Place the thread on the list of opened media. First,
check for an empty list. */
if (_fx_system_media_opened_ptr)
{
/* Pickup tail pointer. */
tail_ptr = _fx_system_media_opened_ptr -> fx_media_opened_previous;
/* Place the new media in the list. */
_fx_system_media_opened_ptr -> fx_media_opened_previous = media_ptr;
tail_ptr -> fx_media_opened_next = media_ptr;
/* Setup this media's opened links. */
media_ptr -> fx_media_opened_previous = tail_ptr;
media_ptr -> fx_media_opened_next = _fx_system_media_opened_ptr;
}
else
{
/* The opened media list is empty. Add the media to empty list. */
_fx_system_media_opened_ptr = media_ptr;
media_ptr -> fx_media_opened_next = media_ptr;
media_ptr -> fx_media_opened_previous = media_ptr;
}
/* Increment the opened media counter. */
_fx_system_media_opened_count++;
/* Invoke media open callback. */
if (media_ptr -> fx_media_open_notify)
{
media_ptr -> fx_media_open_notify(media_ptr);
}
/* Restore interrupts. */
FX_RESTORE_INTS
#ifdef FX_DONT_CREATE_MUTEX
/* Release media protection. */
FX_UNPROTECT
#endif
/* Return a successful status. */
return(FX_SUCCESS);
}