[258] | 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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[354] | 12 | #include "utils.h" |
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[258] | 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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[291] | 70 | #define FS_FREE_CLUSTER 488 , 4 |
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| 71 | #define FS_FREE_CLUSTER_HINT 492 , 4 |
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[258] | 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 | /******* Directory Entry Structure (32 bytes) ******************************************/ |
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| 77 | // offset | length |
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| 78 | #define DIR_NAME 0 , 11 // dir_entry name |
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| 79 | #define DIR_ATTR 11 , 1 // attributes |
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| 80 | #define DIR_NTRES 12 , 1 // reserved for the OS |
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| 81 | #define DIR_CRT_TIMES_TENTH 13 , 1 |
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| 82 | #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits |
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| 83 | #define DIR_WRT_TIME 22 , 2 // time of last write |
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| 84 | #define DIR_WRT_DATE 24 , 2 // date of last write |
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| 85 | #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit |
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| 86 | #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) |
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| 87 | /***************************************************************************************/ |
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| 88 | |
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| 89 | /******* LFN Directory Entry Structure (32 bytes) *************************************/ |
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| 90 | // offset | length |
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| 91 | #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) |
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| 92 | #define LDIR_NAME_1 1 , 10 // name broken into 3 parts |
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| 93 | #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) |
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| 94 | #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) |
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| 95 | #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir |
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| 96 | #define LDIR_NAME_2 14 , 12 |
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| 97 | #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) |
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| 98 | #define LDIR_NAME_3 28 , 4 |
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| 99 | /***************************************************************************************/ |
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| 100 | |
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[291] | 101 | /*********************** DIR_ATTR values (attributes) ********************************/ |
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[258] | 102 | #define ATTR_READ_ONLY 0x01 |
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| 103 | #define ATTR_HIDDEN 0x02 |
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| 104 | #define ATTR_SYSTEM 0x04 |
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| 105 | #define ATTR_VOLUME_ID 0x08 |
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| 106 | #define ATTR_DIRECTORY 0x10 |
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| 107 | #define ATTR_ARCHIVE 0x20 |
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| 108 | #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID |
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| 109 | /***************************************************************************************/ |
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| 110 | |
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| 111 | /********************* DIR_ORD special values ******************************************/ |
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| 112 | #define FREE_ENTRY 0xE5 // this entry is free in the directory |
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| 113 | #define NO_MORE_ENTRY 0x00 // no more entry in the directory |
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| 114 | /***************************************************************************************/ |
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| 115 | |
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| 116 | /******************** CLuster Index Special Values *************************************/ |
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| 117 | #define FREE_CLUSTER 0x00000000 |
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| 118 | #define RESERVED_CLUSTER 0x00000001 |
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| 119 | #define BAD_CLUSTER 0x0FFFFFF7 |
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| 120 | #define END_OF_CHAIN_CLUSTER 0x0ffffff8 |
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| 121 | /***************************************************************************************/ |
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| 122 | |
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| 123 | #define FAT_INITIALISED 0xBABEF00D |
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| 124 | |
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| 125 | /************ This struct defines a file descriptor ************************************/ |
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| 126 | typedef struct file_descriptor_s |
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| 127 | { |
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| 128 | unsigned int used; // descriptor contains an open file |
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[300] | 129 | unsigned int first_cluster; // first cluster index on disk |
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[258] | 130 | unsigned int file_size; // number of bytes |
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[291] | 131 | unsigned int lba_dir_entry; // lba of dir_entry for an open file |
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[258] | 132 | char name[244]; // pathname |
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| 133 | } file_desc_t; |
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| 134 | /***************************************************************************************/ |
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| 135 | |
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[300] | 136 | /************ This struct describes a FAT32 disk **********************************/ |
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[258] | 137 | typedef struct fat32_fs_s |
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| 138 | { |
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| 139 | char fat_cache[512]; // FAT cache: 1 sector = 128 cluster indexes |
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[354] | 140 | giet_lock_t fat_lock; // lock protecting exclusive access |
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[258] | 141 | file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array |
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| 142 | unsigned int initialised; // contains 0xBABEF00D when FAT initialised |
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| 143 | unsigned int sector_size; // number of bytes (power of 2) |
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| 144 | unsigned int sectors_per_cluster; // power of 2 (must be greater than 4) |
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| 145 | unsigned int cluster_size; // sector_size * sector_per_cluster (bytes) |
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| 146 | unsigned int fat_sectors; // number of sectors occupied by one FAT copy |
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[300] | 147 | unsigned int fat_lba; // lba of first FAT sector |
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[258] | 148 | unsigned int data_lba; // lba of first data sector |
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| 149 | unsigned int cache_lba; // lba of sector loaded in fat_cache |
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[291] | 150 | unsigned int last_cluster_allocated; // Last known cluster allocated |
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| 151 | unsigned int number_free_cluster; // number of free clusters |
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| 152 | unsigned int fs_info_lba; // lba of fs_info |
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[258] | 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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[260] | 181 | extern int _fat_fstat( unsigned int fd_id ); // file descriptor index |
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| 182 | |
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[258] | 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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