FatPkg/EnhancedFatDxe/FatFileSystem.h

   1 /** @file
   2   Definitions for on-disk FAT structures.
   3
   4 Copyright (c) 2005 - 2017, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7
   8 **/
   9
  10 #ifndef _FATFILESYSTEM_H_
  11 #define _FATFILESYSTEM_H_
  12
  13 #pragma pack(1)
  14 //
  15 // FAT info signature
  16 //
  17 #define FAT_INFO_SIGNATURE        0x41615252
  18 #define FAT_INFO_BEGIN_SIGNATURE  0x61417272
  19 #define FAT_INFO_END_SIGNATURE    0xAA550000
  20 //
  21 // FAT entry values
  22 //
  23 #define FAT_CLUSTER_SPECIAL_EXT       (MAX_UINTN & (~0xF))
  24 #define FAT_CLUSTER_SPECIAL           ((FAT_CLUSTER_SPECIAL_EXT) | 0x07)
  25 #define FAT_CLUSTER_FREE              0
  26 #define FAT_CLUSTER_RESERVED          (FAT_CLUSTER_SPECIAL)
  27 #define FAT_CLUSTER_BAD               (FAT_CLUSTER_SPECIAL)
  28 #define FAT_CLUSTER_LAST              (-1)
  29 #define FAT_END_OF_FAT_CHAIN(Cluster) ((Cluster) > (FAT_CLUSTER_SPECIAL))
  30 #define FAT_MIN_CLUSTER               2
  31 #define FAT_MAX_FAT12_CLUSTER         0xFF5
  32 #define FAT_MAX_FAT16_CLUSTER         0xFFF5
  33 #define FAT_CLUSTER_SPECIAL_FAT12     0xFF7
  34 #define FAT_CLUSTER_SPECIAL_FAT16     0xFFF7
  35 #define FAT_CLUSTER_SPECIAL_FAT32     0x0FFFFFF7
  36 #define FAT_CLUSTER_MASK_FAT12        0xFFF
  37 #define FAT_CLUSTER_UNMASK_FAT12      0xF000
  38 #define FAT_CLUSTER_MASK_FAT32        0x0FFFFFFF
  39 #define FAT_CLUSTER_UNMASK_FAT32      0xF0000000
  40 #define FAT_POS_FAT12(a)              ((a) * 3 / 2)
  41 #define FAT_POS_FAT16(a)              ((a) * 2)
  42 #define FAT_POS_FAT32(a)              ((a) * 4)
  43 #define FAT_ODD_CLUSTER_FAT12(a)      (((a) & 1) != 0)
  44
  45
  46 //
  47 // FAT attribute define
  48 //
  49 #define FAT_ATTRIBUTE_READ_ONLY 0x01
  50 #define FAT_ATTRIBUTE_HIDDEN    0x02
  51 #define FAT_ATTRIBUTE_SYSTEM    0x04
  52 #define FAT_ATTRIBUTE_VOLUME_ID 0x08
  53 #define FAT_ATTRIBUTE_DIRECTORY 0x10
  54 #define FAT_ATTRIBUTE_ARCHIVE   0x20
  55 #define FAT_ATTRIBUTE_DEVICE    0x40
  56 #define FAT_ATTRIBUTE_LFN       0x0F
  57 //
  58 // Some Long File Name definitions
  59 //
  60 #define FAT_LFN_LAST            0x40  // Ordinal field
  61 #define MAX_LFN_ENTRIES         20
  62 #define LFN_CHAR1_LEN           5
  63 #define LFN_CHAR2_LEN           6
  64 #define LFN_CHAR3_LEN           2
  65 #define LFN_CHAR_TOTAL          (LFN_CHAR1_LEN + LFN_CHAR2_LEN + LFN_CHAR3_LEN)
  66 #define LFN_ENTRY_NUMBER(a)     (((a) + LFN_CHAR_TOTAL - 1) / LFN_CHAR_TOTAL)
  67 //
  68 // Some 8.3 File Name definitions
  69 //
  70 #define FAT_MAIN_NAME_LEN       8
  71 #define FAT_EXTEND_NAME_LEN     3
  72 #define FAT_NAME_LEN            (FAT_MAIN_NAME_LEN + FAT_EXTEND_NAME_LEN)
  73 //
  74 // Some directory entry information
  75 //
  76 #define FAT_ENTRY_INFO_OFFSET   13
  77 #define DELETE_ENTRY_MARK       0xE5
  78 #define EMPTY_ENTRY_MARK        0x00
  79
  80 //
  81 // Volume dirty Mask
  82 //
  83 #define FAT16_DIRTY_MASK        0x7fff
  84 #define FAT32_DIRTY_MASK        0xf7ffffff
  85 //
  86 // internal flag
  87 //
  88 #define FAT_CASE_MIXED          0x01
  89 #define FAT_CASE_NAME_LOWER     0x08
  90 #define FAT_CASE_EXT_LOWER      0x10
  91
  92 typedef struct {
  93   UINT8   Ia32Jump[3];
  94   CHAR8   OemId[8];
  95   UINT16  SectorSize;
  96   UINT8   SectorsPerCluster;
  97   UINT16  ReservedSectors;
  98   UINT8   NumFats;
  99   UINT16  RootEntries;          // < FAT32, root dir is fixed size
 100   UINT16  Sectors;
 101   UINT8   Media;
 102   UINT16  SectorsPerFat;        // < FAT32
 103   UINT16  SectorsPerTrack;      // (ignored)
 104   UINT16  Heads;                // (ignored)
 105   UINT32  HiddenSectors;        // (ignored)
 106   UINT32  LargeSectors;         // Used if Sectors==0
 107 } FAT_BOOT_SECTOR_BASIC;
 108
 109 typedef struct {
 110   UINT8 PhysicalDriveNumber;    // (ignored)
 111   UINT8 CurrentHead;            // holds boot_sector_dirty bit
 112   UINT8 Signature;              // (ignored)
 113   CHAR8 Id[4];
 114   CHAR8 FatLabel[11];
 115   CHAR8 SystemId[8];
 116 } FAT_BOOT_SECTOR_EXT;
 117
 118 typedef struct {
 119   UINT32  LargeSectorsPerFat;   // FAT32
 120   UINT16  ExtendedFlags;        // FAT32 (ignored)
 121   UINT16  FsVersion;            // FAT32 (ignored)
 122   UINT32  RootDirFirstCluster;  // FAT32
 123   UINT16  FsInfoSector;         // FAT32
 124   UINT16  BackupBootSector;     // FAT32
 125   UINT8   Reserved[12];         // FAT32 (ignored)
 126   UINT8   PhysicalDriveNumber;  // (ignored)
 127   UINT8   CurrentHead;          // holds boot_sector_dirty bit
 128   UINT8   Signature;            // (ignored)
 129   CHAR8   Id[4];
 130   CHAR8   FatLabel[11];
 131   CHAR8   SystemId[8];
 132 } FAT32_BOOT_SECTOR_EXT;
 133
 134 typedef union {
 135     FAT_BOOT_SECTOR_EXT   FatBse;
 136     FAT32_BOOT_SECTOR_EXT Fat32Bse;
 137   } FAT_BSE;
 138
 139 typedef struct {
 140   FAT_BOOT_SECTOR_BASIC   FatBsb;
 141   FAT_BSE  FatBse;
 142 } FAT_BOOT_SECTOR;
 143
 144 //
 145 // FAT Info Structure
 146 //
 147 typedef struct {
 148   UINT32  ClusterCount;
 149   UINT32  NextCluster;
 150 } FAT_FREE_INFO;
 151
 152 typedef struct {
 153   UINT32        Signature;
 154   UINT8         ExtraBootCode[480];
 155   UINT32        InfoBeginSignature;
 156   FAT_FREE_INFO FreeInfo;
 157   UINT8         Reserved[12];
 158   UINT32        InfoEndSignature;
 159 } FAT_INFO_SECTOR;
 160
 161 //
 162 // Directory Entry
 163 //
 164 #define FAT_MAX_YEAR_FROM_1980  0x7f
 165 typedef struct {
 166   UINT16  Day : 5;
 167   UINT16  Month : 4;
 168   UINT16  Year : 7;                 // From 1980
 169 } FAT_DATE;
 170
 171 typedef struct {
 172   UINT16  DoubleSecond : 5;
 173   UINT16  Minute : 6;
 174   UINT16  Hour : 5;
 175 } FAT_TIME;
 176
 177 typedef struct {
 178   FAT_TIME  Time;
 179   FAT_DATE  Date;
 180 } FAT_DATE_TIME;
 181
 182 typedef struct {
 183   CHAR8         FileName[11];       // 8.3 filename
 184   UINT8         Attributes;
 185   UINT8         CaseFlag;
 186   UINT8         CreateMillisecond;  // (creation milliseconds - ignored)
 187   FAT_DATE_TIME FileCreateTime;
 188   FAT_DATE      FileLastAccess;
 189   UINT16        FileClusterHigh;    // >= FAT32
 190   FAT_DATE_TIME FileModificationTime;
 191   UINT16        FileCluster;
 192   UINT32        FileSize;
 193 } FAT_DIRECTORY_ENTRY;
 194
 195 typedef struct {
 196   UINT8   Ordinal;
 197   CHAR8   Name1[10];                // (Really 5 chars, but not WCHAR aligned)
 198   UINT8   Attributes;
 199   UINT8   Type;
 200   UINT8   Checksum;
 201   CHAR16  Name2[6];
 202   UINT16  MustBeZero;
 203   CHAR16  Name3[2];
 204 } FAT_DIRECTORY_LFN;
 205
 206 #pragma pack()
 207
 208 #endif