| 1 | /* ----------------------------------------------------------------------- * |
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| 2 | * |
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| 3 | * Copyright 2001-2008 H. Peter Anvin - All Rights Reserved |
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| 4 | * |
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| 5 | * This program is free software; you can redistribute it and/or modify |
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| 6 | * it under the terms of the GNU General Public License as published by |
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| 7 | * the Free Software Foundation, Inc., 53 Temple Place Ste 330, |
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| 8 | * Boston MA 02111-1307, USA; either version 2 of the License, or |
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| 9 | * (at your option) any later version; incorporated herein by reference. |
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| 10 | * |
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| 11 | * ----------------------------------------------------------------------- */ |
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| 12 | |
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| 13 | /* |
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| 14 | * fat.h |
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| 15 | * |
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| 16 | * Basic data structures for a FAT filesystem |
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| 17 | */ |
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| 18 | |
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| 19 | #ifndef FAT_H |
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| 20 | #define FAT_H |
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| 21 | |
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| 22 | #include "ulint.h" |
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| 23 | |
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| 24 | /* The poor excuse FAT has for a superblock -- in the boot sector */ |
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| 25 | struct fat_bootsect { |
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| 26 | le8_t bsJump[3]; /* Jump to code */ |
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| 27 | char bsOemName[8]; /* Formatting program */ |
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| 28 | le16_t bsBytesPerSec; /* Bytes/sector */ |
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| 29 | le8_t bsSecPerClust; /* Sectors/cluster */ |
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| 30 | le16_t bsResSectors; /* Reserved sectors */ |
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| 31 | le8_t bsFATs; /* Number of FATs */ |
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| 32 | le16_t bsRootDirEnts; /* Number of entries/root directory */ |
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| 33 | le16_t bsSectors; /* Number of sectors [1] */ |
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| 34 | le8_t bsMedia; /* Magic media type byte */ |
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| 35 | le16_t bsFATsecs; /* Sectors/FAT */ |
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| 36 | le16_t bsSecPerTrack; /* Sectors/track */ |
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| 37 | le16_t bsHeads; /* Number of heads */ |
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| 38 | le32_t bsHiddenSecs; /* Number of hidden sectors */ |
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| 39 | le32_t bsHugeSectors; /* Number of sectors [2] */ |
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| 40 | union { |
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| 41 | /* FAT12/16 */ |
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| 42 | struct { |
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| 43 | le8_t bsDriveNumber; /* Drive number */ |
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| 44 | le8_t bsReserved1; /* Reserved */ |
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| 45 | le8_t bsBootSignature; /* 0x29 */ |
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| 46 | le32_t bsVolumeID; /* Volume serial number */ |
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| 47 | char bsVolumeLabel[11]; /* Volume name */ |
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| 48 | char bsFileSysType[8]; /* File system type */ |
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| 49 | |
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| 50 | le8_t bsCode[448]; /* Boot sector code */ |
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| 51 | } fat16; |
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| 52 | |
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| 53 | /* FAT32 */ |
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| 54 | struct { |
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| 55 | le32_t bpb_fatsz32; /* Sectors/FAT */ |
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| 56 | le16_t bpb_extflags; /* Extended flags */ |
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| 57 | le16_t bpb_fsver; /* Filesystem version */ |
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| 58 | le32_t bpb_rootclus; /* Root directory cluster */ |
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| 59 | le16_t bpb_fsinfo; /* FSINFO sector number */ |
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| 60 | le16_t bpb_bkbootsec; /* Backup boot sector (superblock) */ |
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| 61 | char bpb_reserved[12]; |
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| 62 | |
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| 63 | /* Same shit, different offset! */ |
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| 64 | le8_t bsDriveNumber; /* Drive number */ |
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| 65 | le8_t bsReserved1; /* Reserved */ |
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| 66 | le8_t bsBootSignature; /* 0x29 */ |
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| 67 | le32_t bsVolumeID; /* Volume serial number */ |
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| 68 | char bsVolumeLabel[11]; /* Volume name */ |
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| 69 | char bsFileSysType[8]; /* File system type */ |
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| 70 | |
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| 71 | le8_t bsCode[420]; /* Boot sector code */ |
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| 72 | } fat32; |
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| 73 | } u; |
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| 74 | |
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| 75 | le16_t bsSignature; /* 0xAA55 */ |
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| 76 | }; |
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| 77 | |
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| 78 | #define BS_BOOTSIGNATURE 0x29 |
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| 79 | #define BS_SIGNATURE 0xAA55 |
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| 80 | |
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| 81 | /* A FAT filesystem directory entry */ |
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| 82 | |
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| 83 | struct fat_dirent { |
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| 84 | le8_t name[11]; /* Mangled filename */ |
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| 85 | le8_t attribute; /* File type/attribute */ |
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| 86 | le8_t caseflags; /* VFAT: case for basis and extension */ |
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| 87 | le8_t ctime_ms; /* ms of creation time */ |
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| 88 | le32_t ctime; /* Creation time */ |
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| 89 | le16_t atime; /* Date portion (high 16 bits) of atime */ |
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| 90 | le16_t clusthi; /* FAT32: high 16 bits of cluster */ |
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| 91 | le32_t mtime; /* Modification time */ |
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| 92 | le16_t clustlo; /* First cluster pointer */ |
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| 93 | le32_t size; /* File size (bytes) */ |
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| 94 | }; |
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| 95 | |
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| 96 | /* A VFAT filesystem continuation entry */ |
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| 97 | struct fat_vfat_slot { |
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| 98 | le8_t id; /* Sequence number for slot */ |
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| 99 | le16_t name0[5]; /* 5 characters */ |
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| 100 | le8_t attribute; /* Attribute byte */ |
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| 101 | le8_t reserved; /* Reserved, MBZ */ |
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| 102 | le8_t alias_csum; /* Short name checksum */ |
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| 103 | le16_t name5[6]; /* 6 characters */ |
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| 104 | le16_t firstclust; /* MBZ */ |
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| 105 | le16_t name11[2]; /* 2 characters */ |
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| 106 | }; |
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| 107 | |
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| 108 | #endif /* FAT_H */ |
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