FatPkg/EnhancedFatDxe/FatFileSystem.h

   1 /** @file
   2   Definitions for on-disk FAT structures.
   3
   4 Copyright (c) 2005, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials are licensed and made available
   6 under the terms and conditions of the BSD License which accompanies this
   7 distribution. The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13
  14 **/
  15
  16 #ifndef _FATFILESYSTEM_H_
  17 #define _FATFILESYSTEM_H_
  18
  19 #pragma pack(1)
  20 //
  21 // FAT info signature
  22 //
  23 #define FAT_INFO_SIGNATURE        0x41615252
  24 #define FAT_INFO_BEGIN_SIGNATURE  0x61417272
  25 #define FAT_INFO_END_SIGNATURE    0xAA550000
  26 //
  27 // FAT entry values
  28 //
  29 #define FAT_CLUSTER_SPECIAL_EXT       (-1 & (~0xF))
  30 #define FAT_CLUSTER_SPECIAL           ((FAT_CLUSTER_SPECIAL_EXT) | 0x07)
  31 #define FAT_CLUSTER_FREE              0
  32 #define FAT_CLUSTER_RESERVED          (FAT_CLUSTER_SPECIAL)
  33 #define FAT_CLUSTER_BAD               (FAT_CLUSTER_SPECIAL)
  34 #define FAT_CLUSTER_LAST              (-1)
  35 #define FAT_END_OF_FAT_CHAIN(Cluster) ((Cluster) > (FAT_CLUSTER_SPECIAL))
  36 #define FAT_MIN_CLUSTER               2
  37 #define FAT_MAX_FAT12_CLUSTER         0xFF5
  38 #define FAT_MAX_FAT16_CLUSTER         0xFFF5
  39 #define FAT_CLUSTER_SPECIAL_FAT12     0xFF7
  40 #define FAT_CLUSTER_SPECIAL_FAT16     0xFFF7
  41 #define FAT_CLUSTER_SPECIAL_FAT32     0x0FFFFFF7
  42 #define FAT_CLUSTER_MASK_FAT12        0xFFF
  43 #define FAT_CLUSTER_UNMASK_FAT12      0xF000
  44 #define FAT_CLUSTER_MASK_FAT32        0x0FFFFFFF
  45 #define FAT_CLUSTER_UNMASK_FAT32      0xF0000000
  46 #define FAT_POS_FAT12(a)              ((a) * 3 / 2)
  47 #define FAT_POS_FAT16(a)              ((a) * 2)
  48 #define FAT_POS_FAT32(a)              ((a) * 4)
  49 #define FAT_ODD_CLUSTER_FAT12(a)      (((a) & 1) != 0)
  50
  51
  52 //
  53 // FAT attribute define
  54 //
  55 #define FAT_ATTRIBUTE_READ_ONLY 0x01
  56 #define FAT_ATTRIBUTE_HIDDEN    0x02
  57 #define FAT_ATTRIBUTE_SYSTEM    0x04
  58 #define FAT_ATTRIBUTE_VOLUME_ID 0x08
  59 #define FAT_ATTRIBUTE_DIRECTORY 0x10
  60 #define FAT_ATTRIBUTE_ARCHIVE   0x20
  61 #define FAT_ATTRIBUTE_DEVICE    0x40
  62 #define FAT_ATTRIBUTE_LFN       0x0F
  63 //
  64 // Some Long File Name definitions
  65 //
  66 #define FAT_LFN_LAST            0x40  // Ordinal field
  67 #define MAX_LFN_ENTRIES         20
  68 #define LFN_CHAR1_LEN           5
  69 #define LFN_CHAR2_LEN           6
  70 #define LFN_CHAR3_LEN           2
  71 #define LFN_CHAR_TOTAL          (LFN_CHAR1_LEN + LFN_CHAR2_LEN + LFN_CHAR3_LEN)
  72 #define LFN_ENTRY_NUMBER(a)     (((a) + LFN_CHAR_TOTAL - 1) / LFN_CHAR_TOTAL)
  73 //
  74 // Some 8.3 File Name definitions
  75 //
  76 #define FAT_MAIN_NAME_LEN       8
  77 #define FAT_EXTEND_NAME_LEN     3
  78 #define FAT_NAME_LEN            (FAT_MAIN_NAME_LEN + FAT_EXTEND_NAME_LEN)
  79 //
  80 // Some directory entry information
  81 //
  82 #define FAT_ENTRY_INFO_OFFSET   13
  83 #define DELETE_ENTRY_MARK       0xE5
  84 #define EMPTY_ENTRY_MARK        0x00
  85
  86 //
  87 // Volume dirty Mask
  88 //
  89 #define FAT16_DIRTY_MASK        0x7fff
  90 #define FAT32_DIRTY_MASK        0xf7ffffff
  91 //
  92 // internal flag
  93 //
  94 #define FAT_CASE_MIXED          0x01
  95 #define FAT_CASE_NAME_LOWER     0x08
  96 #define FAT_CASE_EXT_LOWER      0x10
  97
  98 typedef struct {
  99   UINT8   Ia32Jump[3];
 100   CHAR8   OemId[8];
 101   UINT16  SectorSize;
 102   UINT8   SectorsPerCluster;
 103   UINT16  ReservedSectors;
 104   UINT8   NumFats;
 105   UINT16  RootEntries;          // < FAT32, root dir is fixed size
 106   UINT16  Sectors;
 107   UINT8   Media;
 108   UINT16  SectorsPerFat;        // < FAT32
 109   UINT16  SectorsPerTrack;      // (ignored)
 110   UINT16  Heads;                // (ignored)
 111   UINT32  HiddenSectors;        // (ignored)
 112   UINT32  LargeSectors;         // Used if Sectors==0
 113 } FAT_BOOT_SECTOR_BASIC;
 114
 115 typedef struct {
 116   UINT8 PhysicalDriveNumber;    // (ignored)
 117   UINT8 CurrentHead;            // holds boot_sector_dirty bit
 118   UINT8 Signature;              // (ignored)
 119   CHAR8 Id[4];
 120   CHAR8 FatLabel[11];
 121   CHAR8 SystemId[8];
 122 } FAT_BOOT_SECTOR_EXT;
 123
 124 typedef struct {
 125   UINT32  LargeSectorsPerFat;   // FAT32
 126   UINT16  ExtendedFlags;        // FAT32 (ignored)
 127   UINT16  FsVersion;            // FAT32 (ignored)
 128   UINT32  RootDirFirstCluster;  // FAT32
 129   UINT16  FsInfoSector;         // FAT32
 130   UINT16  BackupBootSector;     // FAT32
 131   UINT8   Reserved[12];         // FAT32 (ignored)
 132   UINT8   PhysicalDriveNumber;  // (ignored)
 133   UINT8   CurrentHead;          // holds boot_sector_dirty bit
 134   UINT8   Signature;            // (ignored)
 135   CHAR8   Id[4];
 136   CHAR8   FatLabel[11];
 137   CHAR8   SystemId[8];
 138 } FAT32_BOOT_SECTOR_EXT;
 139
 140 typedef union {
 141     FAT_BOOT_SECTOR_EXT   FatBse;
 142     FAT32_BOOT_SECTOR_EXT Fat32Bse;
 143   } FAT_BSE;
 144
 145 typedef struct {
 146   FAT_BOOT_SECTOR_BASIC   FatBsb;
 147   FAT_BSE  FatBse;
 148 } FAT_BOOT_SECTOR;
 149
 150 //
 151 // FAT Info Structure
 152 //
 153 typedef struct {
 154   UINT32  ClusterCount;
 155   UINT32  NextCluster;
 156 } FAT_FREE_INFO;
 157
 158 typedef struct {
 159   UINT32        Signature;
 160   UINT8         ExtraBootCode[480];
 161   UINT32        InfoBeginSignature;
 162   FAT_FREE_INFO FreeInfo;
 163   UINT8         Reserved[12];
 164   UINT32        InfoEndSignature;
 165 } FAT_INFO_SECTOR;
 166
 167 //
 168 // Directory Entry
 169 //
 170 #define FAT_MAX_YEAR_FROM_1980  0x7f
 171 typedef struct {
 172   UINT16  Day : 5;
 173   UINT16  Month : 4;
 174   UINT16  Year : 7;                 // From 1980
 175 } FAT_DATE;
 176
 177 typedef struct {
 178   UINT16  DoubleSecond : 5;
 179   UINT16  Minute : 6;
 180   UINT16  Hour : 5;
 181 } FAT_TIME;
 182
 183 typedef struct {
 184   FAT_TIME  Time;
 185   FAT_DATE  Date;
 186 } FAT_DATE_TIME;
 187
 188 typedef struct {
 189   CHAR8         FileName[11];       // 8.3 filename
 190   UINT8         Attributes;
 191   UINT8         CaseFlag;
 192   UINT8         CreateMillisecond;  // (creation milliseconds - ignored)
 193   FAT_DATE_TIME FileCreateTime;
 194   FAT_DATE      FileLastAccess;
 195   UINT16        FileClusterHigh;    // >= FAT32
 196   FAT_DATE_TIME FileModificationTime;
 197   UINT16        FileCluster;
 198   UINT32        FileSize;
 199 } FAT_DIRECTORY_ENTRY;
 200
 201 typedef struct {
 202   UINT8   Ordinal;
 203   CHAR8   Name1[10];                // (Really 5 chars, but not WCHAR aligned)
 204   UINT8   Attributes;
 205   UINT8   Type;
 206   UINT8   Checksum;
 207   CHAR16  Name2[6];
 208   UINT16  MustBeZero;
 209   CHAR16  Name3[2];
 210 } FAT_DIRECTORY_LFN;
 211
 212 #pragma pack()
 213
 214 #endif