1 | //////////////////////////////////////////////////////////////////////////// |
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2 | // File : fat32.h |
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3 | // Date : 01/09/2013 |
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4 | // Author : Marco Jankovic / Alain Greiner |
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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 | |
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13 | /*************** Partition Boot Sector Format ******************************************/ |
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14 | // offset | length |
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15 | #define BS_JMPBOOT 0 , 3 |
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16 | #define BS_OEMNAME 3 , 8 |
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17 | #define BPB_BYTSPERSEC 11 , 2 |
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18 | #define BPB_SECPERCLUS 13 , 1 |
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19 | #define BPB_RSVDSECCNT 14 , 2 |
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20 | #define BPB_NUMFATS 16 , 1 |
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21 | #define BPB_ROOTENTCNT 17 , 2 |
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22 | #define BPB_TOTSEC16 19 , 2 |
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23 | #define BPB_MEDIA 21 , 1 |
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24 | #define BPB_FATSZ16 22 , 2 |
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25 | #define BPB_SECPERTRK 24 , 2 |
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26 | #define BPB_NUMHEADS 26 , 2 |
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27 | #define BPB_HIDDSEC 28 , 4 |
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28 | #define BPB_TOTSEC32 32 , 4 |
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29 | #define BPB_PARTITION_TABLE 446 , 64 |
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30 | |
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31 | // FAT 32 |
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32 | #define BPB_FAT32_FATSZ32 36 , 4 |
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33 | #define BPB_FAT32_EXTFLAGS 40 , 2 |
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34 | #define BPB_FAT32_FSVER 42 , 2 |
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35 | #define BPB_FAT32_ROOTCLUS 44 , 4 |
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36 | #define BPB_FAT32_FSINFO 48 , 2 |
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37 | #define BPB_FAT32_BKBOOTSEC 50 , 2 |
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38 | #define BS_FAT32_DRVNUM 64 , 1 |
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39 | #define BS_FAT32_BOOTSIG 66 , 1 |
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40 | #define BS_FAT32_VOLID 67 , 4 |
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41 | #define BS_FAT32_VOLLAB 71 , 11 |
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42 | #define BS_FAT32_FILSYSTYPE 82 , 8 |
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43 | |
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44 | // Partitions |
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45 | #define FIRST_PARTITION_ACTIVE 446 , 8 |
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46 | #define FIRST_PARTITION_BEGIN_LBA 454 , 4 |
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47 | #define FIRST_PARTITION_SIZE 458 , 4 |
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48 | #define SECOND_PARTITION_ACTIVE 462 , 8 |
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49 | #define SECOND_PARTITION_BEGIN_LBA 470 , 4 |
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50 | #define SECOND_PARTITION_SIZE 474 , 4 |
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51 | #define THIRD_PARTITION_ACTIVE 478 , 8 |
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52 | #define THIRD_PARTITION_BEGIN_LBA 486 , 4 |
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53 | #define THIRD_PARTITION_SIZE 490 , 4 |
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54 | #define FOURTH_PARTITION_ACTIVE 494 , 8 |
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55 | #define FOURTH_PARTITION_BEGIN_LBA 502 , 4 |
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56 | #define FOURTH_PARTITION_SIZE 506 , 4 |
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57 | /***************************************************************************************/ |
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58 | |
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59 | #define MBR_SIGNATURE_POSITION 510 , 2 |
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60 | #define MBR_SIGNATURE_VALUE 0xAA55 |
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61 | |
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62 | /************** FAT_FS_INFO SECTOR ****************************************************/ |
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63 | #define FS_SIGNATURE_VALUE_1 0x52526141 |
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64 | #define FS_SIGNATURE_VALUE_2 0x72724161 |
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65 | #define FS_SIGNATURE_VALUE_3 0x000055AA |
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66 | #define FS_SIGNATURE_POSITION_1 0 , 4 |
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67 | #define FS_SIGNATURE_POSITION_2 484 , 4 |
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68 | #define FS_SIGNATURE_POSITION_3 508 , 4 |
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69 | #define FS_FREE_CLUSTER 488 , 4 |
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70 | #define FS_FREE_CLUSTER_HINT 492 , 4 |
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71 | /***************************************************************************************/ |
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72 | |
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73 | #define DIR_ENTRY_SIZE 32 |
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74 | |
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75 | /******* Directory Entry Structure (32 bytes) ******************************************/ |
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76 | // offset | length |
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77 | #define DIR_NAME 0 , 11 // dir_entry name |
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78 | #define DIR_ATTR 11 , 1 // attributes |
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79 | #define DIR_NTRES 12 , 1 // reserved for the OS |
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80 | #define DIR_CRT_TIMES_TENTH 13 , 1 |
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81 | #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits |
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82 | #define DIR_WRT_TIME 22 , 2 // time of last write |
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83 | #define DIR_WRT_DATE 24 , 2 // date of last write |
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84 | #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit |
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85 | #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) |
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86 | /***************************************************************************************/ |
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87 | |
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88 | /******* LFN Directory Entry Structure (32 bytes) *************************************/ |
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89 | // offset | length |
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90 | #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) |
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91 | #define LDIR_NAME_1 1 , 10 // name broken into 3 parts |
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92 | #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) |
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93 | #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) |
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94 | #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir |
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95 | #define LDIR_NAME_2 14 , 12 |
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96 | #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) |
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97 | #define LDIR_NAME_3 28 , 4 |
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98 | /***************************************************************************************/ |
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99 | |
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100 | /*********************** DIR_ATTR values (attributes) ********************************/ |
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101 | #define ATTR_READ_ONLY 0x01 |
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102 | #define ATTR_HIDDEN 0x02 |
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103 | #define ATTR_SYSTEM 0x04 |
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104 | #define ATTR_VOLUME_ID 0x08 |
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105 | #define ATTR_DIRECTORY 0x10 |
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106 | #define ATTR_ARCHIVE 0x20 |
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107 | #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID |
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108 | /***************************************************************************************/ |
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109 | |
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110 | /********************* DIR_ORD special values ******************************************/ |
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111 | #define FREE_ENTRY 0xE5 // this entry is free in the directory |
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112 | #define NO_MORE_ENTRY 0x00 // no more entry in the directory |
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113 | /***************************************************************************************/ |
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114 | |
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115 | /******************** CLuster Index Special Values *************************************/ |
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116 | #define FREE_CLUSTER 0x00000000 |
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117 | #define RESERVED_CLUSTER 0x00000001 |
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118 | #define BAD_CLUSTER 0x0FFFFFF7 |
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119 | #define END_OF_CHAIN_CLUSTER 0x0ffffff8 |
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120 | /***************************************************************************************/ |
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121 | |
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122 | #define FAT_INITIALISED 0xBABEF00D |
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123 | |
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124 | /************ This struct defines a file descriptor ************************************/ |
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125 | typedef struct file_descriptor_s |
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126 | { |
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127 | unsigned int used; // descriptor contains an open file |
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128 | unsigned int first_cluster; // first cluster index in partition |
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129 | unsigned int file_size; // number of bytes |
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130 | unsigned int lba_dir_entry; // lba of dir_entry for an open file |
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131 | char name[244]; // pathname |
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132 | } file_desc_t; |
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133 | /***************************************************************************************/ |
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134 | |
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135 | /************ This struct describes a FAT32 partition **********************************/ |
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136 | typedef struct fat32_fs_s |
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137 | { |
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138 | char fat_cache[512]; // FAT cache: 1 sector = 128 cluster indexes |
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139 | file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array |
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140 | unsigned int initialised; // contains 0xBABEF00D when FAT initialised |
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141 | unsigned int sector_size; // number of bytes (power of 2) |
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142 | unsigned int sectors_per_cluster; // power of 2 (must be greater than 4) |
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143 | unsigned int cluster_size; // sector_size * sector_per_cluster (bytes) |
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144 | unsigned int fat_sectors; // number of sectors occupied by one FAT copy |
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145 | unsigned int partition_sectors; // total number of sectors (RESVD+FAT+DATA) |
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146 | unsigned int partition_lba; // lba of first partiton sector |
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147 | unsigned int data_lba; // lba of first data sector |
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148 | unsigned int cache_lba; // lba of sector loaded in fat_cache |
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149 | unsigned int last_cluster_allocated; // Last known cluster allocated |
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150 | unsigned int number_free_cluster; // number of free clusters |
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151 | unsigned int fs_info_lba; // lba of fs_info |
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152 | unsigned int lock; // lock protecting exclusive access |
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153 | } fat32_fs_t; |
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154 | /***************************************************************************************/ |
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155 | |
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156 | /*********************** Export Functions *********************************************/ |
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157 | |
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158 | extern void _fat_print(); |
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159 | |
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160 | // functions used for low level access to fat |
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161 | // (move sectors between block device and system buffers) |
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162 | |
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163 | extern int _fat_init( unsigned int mode ); // mode for IOC driver |
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164 | |
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165 | extern int _fat_open( unsigned int mode, // mode for IOC driver |
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166 | char* pathname, // file pathname from root |
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167 | unsigned int create ); // create new file if non zero |
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168 | |
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169 | extern int _fat_read( unsigned int mode, // mode for IOC driver |
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170 | unsigned int fd_id, // file descriptor index |
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171 | void* buffer, // destination buffer |
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172 | unsigned int count, // number of sectors to read |
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173 | unsigned int offset ); // offset sector in file |
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174 | |
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175 | extern int _fat_write( unsigned int mode, // mode for IOC driver |
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176 | unsigned int fd_id, // file descriptor index |
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177 | void* buffer, // source buffer |
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178 | unsigned int count, // number of sectors to write |
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179 | unsigned int offset ); // offset sector in file |
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180 | |
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181 | extern int _fat_fstat( unsigned int fd_id ); // file descriptor index |
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182 | |
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183 | extern int _fat_close( unsigned int fd_id ); // file descriptor index |
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184 | |
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185 | |
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186 | // functions used by user system calls |
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187 | // (should move bytes between system buffers and user buffers) |
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188 | |
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189 | extern int _fat_user_open( char* pathname, // file pathname from root |
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190 | unsigned int flags ); // unused |
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191 | |
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192 | extern int _fat_user_read( unsigned int fd_id, // file descriptor index |
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193 | void* buffer, // destination buffer |
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194 | unsigned int count, // number of sectors to read |
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195 | unsigned int offset ); // number of sectors to skip in file |
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196 | |
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197 | extern int _fat_user_write( unsigned int fd_id, // file descriptor index |
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198 | void* buffer, // source buffer |
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199 | unsigned int count, // number of sectors to write |
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200 | unsigned int offset ); // number of sectors to skip in file |
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201 | |
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202 | extern int _fat_user_lseek( unsigned int fd_id, |
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203 | unsigned int offset, |
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204 | unsigned int whence ); |
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205 | |
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206 | /***************************************************************************************/ |
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207 | |
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208 | |
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209 | #endif |
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210 | |
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211 | |
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212 | // Local Variables: |
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213 | // tab-width: 4 |
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214 | // c-basic-offset: 4 |
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215 | // c-file-offsets:((innamespace . 0)(inline-open . 0)) |
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216 | // indent-tabs-mode: nil |
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217 | // End: |
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218 | // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 |
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219 | |
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