1 | //////////////////////////////////////////////////////////////////////////////// |
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2 | // File : fat32.h |
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3 | // Date : 01/09/2013 |
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4 | // Author : Alain Greiner / Marco Jankovic |
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5 | // Copyright (c) UPMC-LIP6 |
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6 | //////////////////////////////////////////////////////////////////////////////// |
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7 | |
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8 | #ifndef _FAT32_H |
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9 | #define _FAT32_H |
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10 | |
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11 | #include "giet_config.h" |
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12 | #include "kernel_locks.h" |
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13 | |
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14 | /*************** Partition Boot Sector Format **********************************/ |
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15 | // offset | length |
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16 | #define BS_JMPBOOT 0 , 3 |
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17 | #define BS_OEMNAME 3 , 8 |
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18 | #define BPB_BYTSPERSEC 11 , 2 |
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19 | #define BPB_SECPERCLUS 13 , 1 |
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20 | #define BPB_RSVDSECCNT 14 , 2 |
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21 | #define BPB_NUMFATS 16 , 1 |
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22 | #define BPB_ROOTENTCNT 17 , 2 |
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23 | #define BPB_TOTSEC16 19 , 2 |
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24 | #define BPB_MEDIA 21 , 1 |
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25 | #define BPB_FATSZ16 22 , 2 |
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26 | #define BPB_SECPERTRK 24 , 2 |
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27 | #define BPB_NUMHEADS 26 , 2 |
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28 | #define BPB_HIDDSEC 28 , 4 |
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29 | #define BPB_TOTSEC32 32 , 4 |
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30 | #define BPB_PARTITION_TABLE 446 , 64 |
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31 | |
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32 | // FAT 32 |
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33 | #define BPB_FAT32_FATSZ32 36 , 4 |
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34 | #define BPB_FAT32_EXTFLAGS 40 , 2 |
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35 | #define BPB_FAT32_FSVER 42 , 2 |
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36 | #define BPB_FAT32_ROOTCLUS 44 , 4 |
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37 | #define BPB_FAT32_FSINFO 48 , 2 |
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38 | #define BPB_FAT32_BKBOOTSEC 50 , 2 |
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39 | #define BS_FAT32_DRVNUM 64 , 1 |
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40 | #define BS_FAT32_BOOTSIG 66 , 1 |
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41 | #define BS_FAT32_VOLID 67 , 4 |
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42 | #define BS_FAT32_VOLLAB 71 , 11 |
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43 | #define BS_FAT32_FILSYSTYPE 82 , 8 |
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44 | |
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45 | // Partitions |
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46 | #define FIRST_PARTITION_ACTIVE 446 , 8 |
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47 | #define FIRST_PARTITION_BEGIN_LBA 454 , 4 |
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48 | #define FIRST_PARTITION_SIZE 458 , 4 |
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49 | #define SECOND_PARTITION_ACTIVE 462 , 8 |
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50 | #define SECOND_PARTITION_BEGIN_LBA 470 , 4 |
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51 | #define SECOND_PARTITION_SIZE 474 , 4 |
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52 | #define THIRD_PARTITION_ACTIVE 478 , 8 |
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53 | #define THIRD_PARTITION_BEGIN_LBA 486 , 4 |
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54 | #define THIRD_PARTITION_SIZE 490 , 4 |
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55 | #define FOURTH_PARTITION_ACTIVE 494 , 8 |
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56 | #define FOURTH_PARTITION_BEGIN_LBA 502 , 4 |
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57 | #define FOURTH_PARTITION_SIZE 506 , 4 |
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58 | /*******************************************************************************/ |
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59 | |
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60 | #define MBR_SIGNATURE_POSITION 510 , 2 |
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61 | #define MBR_SIGNATURE_VALUE 0xAA55 |
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62 | |
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63 | /************** FAT_FS_INFO SECTOR ********************************************/ |
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64 | #define FS_SIGNATURE_VALUE_1 0x52526141 |
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65 | #define FS_SIGNATURE_VALUE_2 0x72724161 |
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66 | #define FS_SIGNATURE_VALUE_3 0x000055AA |
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67 | #define FS_SIGNATURE_POSITION_1 0 , 4 |
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68 | #define FS_SIGNATURE_POSITION_2 484 , 4 |
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69 | #define FS_SIGNATURE_POSITION_3 508 , 4 |
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70 | #define FS_FREE_CLUSTERS 488 , 4 |
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71 | #define FS_FREE_CLUSTER_HINT 492 , 4 |
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72 | /*******************************************************************************/ |
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73 | |
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74 | #define DIR_ENTRY_SIZE 32 |
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75 | |
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76 | #define NAME_MAX_SIZE 31 |
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77 | |
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78 | /******* Directory Entry Structure (32 bytes) **********************************/ |
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79 | // offset | length |
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80 | #define DIR_NAME 0 , 11 // dir_entry name |
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81 | #define DIR_ATTR 11 , 1 // attributes |
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82 | #define DIR_NTRES 12 , 1 // reserved for the OS |
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83 | #define DIR_CRT_TIMES_TENTH 13 , 1 |
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84 | #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits |
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85 | #define DIR_WRT_TIME 22 , 2 // time of last write |
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86 | #define DIR_WRT_DATE 24 , 2 // date of last write |
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87 | #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit |
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88 | #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) |
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89 | /*******************************************************************************/ |
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90 | |
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91 | /******* LFN Directory Entry Structure (32 bytes) *****************************/ |
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92 | // offset | length |
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93 | #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) |
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94 | #define LDIR_NAME_1 1 , 10 // name broken into 3 parts |
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95 | #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) |
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96 | #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) |
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97 | #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir |
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98 | #define LDIR_NAME_2 14 , 12 |
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99 | #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) |
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100 | #define LDIR_NAME_3 28 , 4 |
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101 | /*******************************************************************************/ |
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102 | |
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103 | /*********************** DIR_ATTR values (attributes) ************************/ |
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104 | #define ATTR_READ_ONLY 0x01 |
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105 | #define ATTR_HIDDEN 0x02 |
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106 | #define ATTR_SYSTEM 0x04 |
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107 | #define ATTR_VOLUME_ID 0x08 |
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108 | #define ATTR_DIRECTORY 0x10 |
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109 | #define ATTR_ARCHIVE 0x20 |
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110 | #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID |
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111 | /*******************************************************************************/ |
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112 | |
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113 | /********************* DIR_ORD special values **********************************/ |
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114 | #define FREE_ENTRY 0xE5 // this entry is free in the directory |
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115 | #define NO_MORE_ENTRY 0x00 // no more entry in the directory |
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116 | /*******************************************************************************/ |
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117 | |
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118 | /******************** CLuster Index Special Values *****************************/ |
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119 | #define FREE_CLUSTER 0x00000000 |
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120 | #define RESERVED_CLUSTER 0x00000001 |
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121 | #define BAD_CLUSTER 0x0FFFFFF7 |
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122 | #define END_OF_CHAIN_CLUSTER_MIN 0x0ffffff8 |
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123 | #define END_OF_CHAIN_CLUSTER_MAX 0x0fffffff |
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124 | /*******************************************************************************/ |
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125 | |
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126 | #define FAT_INITIALISED 0xBABEF00D |
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127 | |
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128 | #ifndef _FAT32_SHARED |
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129 | #define _FAT32_SHARED |
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130 | typedef struct fat_file_info_s |
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131 | { |
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132 | unsigned int size; |
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133 | unsigned int offset; |
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134 | unsigned int is_dir; |
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135 | } fat_file_info_t; |
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136 | |
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137 | typedef struct fat_dirent_s |
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138 | { |
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139 | unsigned int cluster; |
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140 | unsigned int size; |
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141 | unsigned int is_dir; |
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142 | char name[36]; |
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143 | } fat_dirent_t; |
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144 | |
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145 | #define SEEK_SET 0 |
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146 | #define SEEK_CUR 1 |
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147 | |
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148 | #define O_RDONLY 0x01 |
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149 | #define O_TRUNC 0x10 |
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150 | #define O_CREATE 0x20 |
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151 | #endif // _FAT32_SHARED |
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152 | |
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153 | /******************************************************************************** |
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154 | This struct defines a non terminal node in a 64-tree implementing a File-Cache |
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155 | associated to an open file, or the Fat-Cache, associated to the FAT itself. |
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156 | Each node has 64 children, and we use the void* type, because the children |
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157 | can be non-terminal (fat_cache_node_t) or terminal (fat_cache_cluster_t). |
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158 | ********************************************************************************/ |
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159 | |
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160 | typedef struct fat_cache_node_s |
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161 | { |
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162 | void* children[64]; // pointers on the 64 children |
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163 | } fat_cache_node_t; |
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164 | |
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165 | |
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166 | /******************************************************************************** |
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167 | This struct defines a cluster descriptor, that is a leaf cell in a 64-tree. |
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168 | Each cluster descriptor contains a pointer on a 4K bytes buffer, and the |
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169 | lba on block device. |
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170 | ********************************************************************************/ |
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171 | |
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172 | typedef struct fat_cache_desc_s |
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173 | { |
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174 | unsigned int lba; // cluster lba on block device |
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175 | unsigned int dirty; // modified if non zero |
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176 | unsigned char* buffer; // pointer on the 4 Kbytes buffer |
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177 | } fat_cache_desc_t; |
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178 | |
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179 | |
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180 | /******************************************************************************** |
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181 | This struct defines a file/directory inode / size = 64 bytes |
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182 | ********************************************************************************/ |
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183 | |
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184 | typedef struct fat_inode_s |
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185 | { |
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186 | struct fat_inode_s* parent; // parent directory inode |
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187 | struct fat_inode_s* next; // next inode in same directory |
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188 | struct fat_inode_s* child; // first children inode (dir only) |
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189 | fat_cache_node_t* cache; // pointer on the file_cache root |
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190 | unsigned int cluster; // first cluster index in FAT |
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191 | unsigned int size; // number of bytes (file only) |
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192 | unsigned int count; // number open if file / 0 if dir |
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193 | unsigned short dentry; // directory entry index in parent |
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194 | unsigned char levels; // number of levels in file_cache |
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195 | unsigned char is_dir; // directory if non zero |
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196 | char name[32]; // file directory name |
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197 | } fat_inode_t; |
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198 | |
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199 | /******************************************************************************** |
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200 | This struct defines a file descriptor (handler) / size = 16 bytes |
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201 | ********************************************************************************/ |
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202 | |
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203 | typedef struct fat_file_desc_s |
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204 | { |
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205 | unsigned int seek; // current offset value (bytes) |
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206 | fat_inode_t* inode; // pointer on inode |
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207 | char allocated; // file descriptor allocated |
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208 | char read_only; // write protected |
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209 | char reserved[6]; // reserved |
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210 | } fat_file_desc_t; |
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211 | |
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212 | /******************************************************************************** |
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213 | This struct defines a FAT32 File system descriptor |
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214 | *******************************************************************************/ |
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215 | |
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216 | typedef struct fat_desc_s |
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217 | { |
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218 | unsigned char block_buffer[512]; // one block buffer (for FS_INFO) |
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219 | fat_file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array |
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220 | spin_lock_t fat_lock; // global lock protecting FAT |
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221 | fat_inode_t* inode_tree_root; // Inode-Tree root pointer |
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222 | fat_cache_node_t* fat_cache_root; // Fat_Cache root pointer |
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223 | unsigned int fat_cache_levels; // number of levels in Fat-Cache |
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224 | unsigned int block_buffer_lba; // lba of block in block_buffer |
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225 | unsigned int initialised; // 0xBABEF00D when FAT initialised |
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226 | unsigned int sector_size; // must be 512 |
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227 | unsigned int cluster_size; // must be 4096 |
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228 | unsigned int fat_lba; // lba of first FAT sector |
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229 | unsigned int fat_sectors; // number of sectors in FAT region |
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230 | unsigned int data_lba; // lba of first DATA sector |
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231 | unsigned int data_sectors; // number of sectors inf DATA region |
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232 | unsigned int fs_info_lba; // lba of fs_info |
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233 | unsigned int first_free_cluster; // free cluster with smallest index |
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234 | unsigned int free_clusters_number; // total number of free clusters |
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235 | } fat_desc_t; |
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236 | |
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237 | |
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238 | /*********************** Extern Functions *************************************/ |
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239 | |
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240 | extern int _fat_init(); |
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241 | |
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242 | extern int _fat_open( char* pathname, // path from root |
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243 | unsigned int flags ); // O_CREATE/O_RDONLY |
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244 | |
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245 | extern int _fat_close( unsigned int fd_id ); // file descriptor |
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246 | |
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247 | extern int _fat_file_info( unsigned int fd_id, // file descriptor |
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248 | fat_file_info_t* info ); // file info struct |
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249 | |
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250 | extern int _fat_read( unsigned int fd_id, // file descriptor |
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251 | void* buffer, // destination buffer |
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252 | unsigned int count ); // number of bytes |
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253 | |
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254 | extern int _fat_write( unsigned int fd_id, // file descriptor |
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255 | void* buffer, // source buffer |
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256 | unsigned int count ); // number of bytes |
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257 | |
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258 | extern int _fat_lseek( unsigned int fd_id, // file descriptor |
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259 | unsigned int offset, // new offset value |
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260 | unsigned int whence ); // command type |
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261 | |
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262 | extern int _fat_remove( char* pathname, // path from root |
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263 | unsigned int should_be_dir ); // for checking |
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264 | |
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265 | extern int _fat_rename( char* old_path, // path from root |
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266 | char* new_path ); // path from root |
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267 | |
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268 | extern int _fat_mkdir( char* pathname ); // path from root |
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269 | |
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270 | extern int _fat_opendir( char* pathname ); // path from root |
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271 | |
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272 | extern int _fat_closedir( unsigned int fd_id ); // file descriptor |
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273 | |
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274 | extern int _fat_readdir( unsigned int fd_id, // file descriptor |
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275 | fat_dirent_t* entry ); // directory entry |
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276 | |
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277 | extern int _fat_load_no_cache( char* pathname, // path from root |
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278 | unsigned int buffer_vbase, // buffer base |
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279 | unsigned int buffer_size ); // buffer size |
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280 | |
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281 | /*******************************************************************************/ |
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282 | |
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283 | |
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284 | #endif |
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285 | |
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286 | |
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287 | // Local Variables: |
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288 | // tab-width: 4 |
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289 | // c-basic-offset: 4 |
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290 | // c-file-offsets:((innamespace . 0)(inline-open . 0)) |
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291 | // indent-tabs-mode: nil |
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292 | // End: |
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293 | // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 |
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294 | |
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