FatPkg/EnhancedFatDxe/FatFileSystem.h

   1 /*++
   2
   3 Copyright (c) 2005, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials are licensed and made available
   5 under the terms and conditions of the BSD License which accompanies this
   6 distribution. The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12
  13 Module Name:
  14
  15   FatFileSystem.h
  16
  17 Abstract:
  18
  19   Definitions for on-disk FAT structures
  20
  21 Revision History
  22
  23 --*/
  24
  25 #ifndef _FATFILESYSTEM_H_
  26 #define _FATFILESYSTEM_H_
  27
  28 #pragma pack(1)
  29 //
  30 // FAT info signature
  31 //
  32 #define FAT_INFO_SIGNATURE        0x41615252
  33 #define FAT_INFO_BEGIN_SIGNATURE  0x61417272
  34 #define FAT_INFO_END_SIGNATURE    0xAA550000
  35 //
  36 // FAT entry values
  37 //
  38 #define FAT_CLUSTER_SPECIAL_EXT       (-1 & (~0xF))
  39 #define FAT_CLUSTER_SPECIAL           ((FAT_CLUSTER_SPECIAL_EXT) | 0x07)
  40 #define FAT_CLUSTER_FREE              0
  41 #define FAT_CLUSTER_RESERVED          (FAT_CLUSTER_SPECIAL)
  42 #define FAT_CLUSTER_BAD               (FAT_CLUSTER_SPECIAL)
  43 #define FAT_CLUSTER_LAST              (-1)
  44 #define FAT_END_OF_FAT_CHAIN(Cluster) ((Cluster) > (FAT_CLUSTER_SPECIAL))
  45 #define FAT_MIN_CLUSTER               2
  46 #define FAT_MAX_FAT12_CLUSTER         0xFF5
  47 #define FAT_MAX_FAT16_CLUSTER         0xFFF5
  48 #define FAT_CLUSTER_SPECIAL_FAT12     0xFF7
  49 #define FAT_CLUSTER_SPECIAL_FAT16     0xFFF7
  50 #define FAT_CLUSTER_SPECIAL_FAT32     0x0FFFFFF7
  51 #define FAT_CLUSTER_MASK_FAT12        0xFFF
  52 #define FAT_CLUSTER_UNMASK_FAT12      0xF000
  53 #define FAT_CLUSTER_MASK_FAT32        0x0FFFFFFF
  54 #define FAT_CLUSTER_UNMASK_FAT32      0xF0000000
  55 #define FAT_POS_FAT12(a)              ((a) * 3 / 2)
  56 #define FAT_POS_FAT16(a)              ((a) * 2)
  57 #define FAT_POS_FAT32(a)              ((a) * 4)
  58 #define FAT_ODD_CLUSTER_FAT12(a)      (((a) & 1) != 0)
  59
  60
  61 //
  62 // FAT attribute define
  63 //
  64 #define FAT_ATTRIBUTE_READ_ONLY 0x01
  65 #define FAT_ATTRIBUTE_HIDDEN    0x02
  66 #define FAT_ATTRIBUTE_SYSTEM    0x04
  67 #define FAT_ATTRIBUTE_VOLUME_ID 0x08
  68 #define FAT_ATTRIBUTE_DIRECTORY 0x10
  69 #define FAT_ATTRIBUTE_ARCHIVE   0x20
  70 #define FAT_ATTRIBUTE_DEVICE    0x40
  71 #define FAT_ATTRIBUTE_LFN       0x0F
  72 //
  73 // Some Long File Name definitions
  74 //
  75 #define FAT_LFN_LAST            0x40  // Ordinal field
  76 #define MAX_LFN_ENTRIES         20
  77 #define LFN_CHAR1_LEN           5
  78 #define LFN_CHAR2_LEN           6
  79 #define LFN_CHAR3_LEN           2
  80 #define LFN_CHAR_TOTAL          (LFN_CHAR1_LEN + LFN_CHAR2_LEN + LFN_CHAR3_LEN)
  81 #define LFN_ENTRY_NUMBER(a)     (((a) + LFN_CHAR_TOTAL - 1) / LFN_CHAR_TOTAL)
  82 //
  83 // Some 8.3 File Name definitions
  84 //
  85 #define FAT_MAIN_NAME_LEN       8
  86 #define FAT_EXTEND_NAME_LEN     3
  87 #define FAT_NAME_LEN            (FAT_MAIN_NAME_LEN + FAT_EXTEND_NAME_LEN)
  88 //
  89 // Some directory entry information
  90 //
  91 #define FAT_ENTRY_INFO_OFFSET   13
  92 #define DELETE_ENTRY_MARK       0xE5
  93 #define EMPTY_ENTRY_MARK        0x00
  94
  95 //
  96 // Volume dirty Mask
  97 //
  98 #define FAT16_DIRTY_MASK        0x7fff
  99 #define FAT32_DIRTY_MASK        0xf7ffffff
 100 //
 101 // internal flag
 102 //
 103 #define FAT_CASE_MIXED          0x01
 104 #define FAT_CASE_NAME_LOWER     0x08
 105 #define FAT_CASE_EXT_LOWER      0x10
 106
 107 typedef struct {
 108   UINT8   Ia32Jump[3];
 109   CHAR8   OemId[8];
 110   UINT16  SectorSize;
 111   UINT8   SectorsPerCluster;
 112   UINT16  ReservedSectors;
 113   UINT8   NumFats;
 114   UINT16  RootEntries;          // < FAT32, root dir is fixed size
 115   UINT16  Sectors;
 116   UINT8   Media;
 117   UINT16  SectorsPerFat;        // < FAT32
 118   UINT16  SectorsPerTrack;      // (ignored)
 119   UINT16  Heads;                // (ignored)
 120   UINT32  HiddenSectors;        // (ignored)
 121   UINT32  LargeSectors;         // Used if Sectors==0
 122 } FAT_BOOT_SECTOR_BASIC;
 123
 124 typedef struct {
 125   UINT8 PhysicalDriveNumber;    // (ignored)
 126   UINT8 CurrentHead;            // holds boot_sector_dirty bit
 127   UINT8 Signature;              // (ignored)
 128   CHAR8 Id[4];
 129   CHAR8 FatLabel[11];
 130   CHAR8 SystemId[8];
 131 } FAT_BOOT_SECTOR_EXT;
 132
 133 typedef struct {
 134   UINT32  LargeSectorsPerFat;   // FAT32
 135   UINT16  ExtendedFlags;        // FAT32 (ignored)
 136   UINT16  FsVersion;            // FAT32 (ignored)
 137   UINT32  RootDirFirstCluster;  // FAT32
 138   UINT16  FsInfoSector;         // FAT32
 139   UINT16  BackupBootSector;     // FAT32
 140   UINT8   Reserved[12];         // FAT32 (ignored)
 141   UINT8   PhysicalDriveNumber;  // (ignored)
 142   UINT8   CurrentHead;          // holds boot_sector_dirty bit
 143   UINT8   Signature;            // (ignored)
 144   CHAR8   Id[4];
 145   CHAR8   FatLabel[11];
 146   CHAR8   SystemId[8];
 147 } FAT32_BOOT_SECTOR_EXT;
 148
 149 typedef union {
 150     FAT_BOOT_SECTOR_EXT   FatBse;
 151     FAT32_BOOT_SECTOR_EXT Fat32Bse;
 152   } FAT_BSE;
 153
 154 typedef struct {
 155   FAT_BOOT_SECTOR_BASIC   FatBsb;
 156   FAT_BSE  FatBse;
 157 } FAT_BOOT_SECTOR;
 158
 159 //
 160 // FAT Info Structure
 161 //
 162 typedef struct {
 163   UINT32  ClusterCount;
 164   UINT32  NextCluster;
 165 } FAT_FREE_INFO;
 166
 167 typedef struct {
 168   UINT32        Signature;
 169   UINT8         ExtraBootCode[480];
 170   UINT32        InfoBeginSignature;
 171   FAT_FREE_INFO FreeInfo;
 172   UINT8         Reserved[12];
 173   UINT32        InfoEndSignature;
 174 } FAT_INFO_SECTOR;
 175
 176 //
 177 // Directory Entry
 178 //
 179 #define FAT_MAX_YEAR_FROM_1980  0x7f
 180 typedef struct {
 181   UINT16  Day : 5;
 182   UINT16  Month : 4;
 183   UINT16  Year : 7;                 // From 1980
 184 } FAT_DATE;
 185
 186 typedef struct {
 187   UINT16  DoubleSecond : 5;
 188   UINT16  Minute : 6;
 189   UINT16  Hour : 5;
 190 } FAT_TIME;
 191
 192 typedef struct {
 193   FAT_TIME  Time;
 194   FAT_DATE  Date;
 195 } FAT_DATE_TIME;
 196
 197 typedef struct {
 198   CHAR8         FileName[11];       // 8.3 filename
 199   UINT8         Attributes;
 200   UINT8         CaseFlag;
 201   UINT8         CreateMillisecond;  // (creation milliseconds - ignored)
 202   FAT_DATE_TIME FileCreateTime;
 203   FAT_DATE      FileLastAccess;
 204   UINT16        FileClusterHigh;    // >= FAT32
 205   FAT_DATE_TIME FileModificationTime;
 206   UINT16        FileCluster;
 207   UINT32        FileSize;
 208 } FAT_DIRECTORY_ENTRY;
 209
 210 typedef struct {
 211   UINT8   Ordinal;
 212   CHAR8   Name1[10];                // (Really 5 chars, but not WCHAR aligned)
 213   UINT8   Attributes;
 214   UINT8   Type;
 215   UINT8   Checksum;
 216   CHAR16  Name2[6];
 217   UINT16  MustBeZero;
 218   CHAR16  Name3[2];
 219 } FAT_DIRECTORY_LFN;
 220
 221 #pragma pack()
 222
 223 #endif