boot/freeldr/freeldr/include/fs/fat.h

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1998-2003  Brian Palmer  <brianp@sginet.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #pragma once
  21
  22 #include <pshpack1.h>
  23 typedef struct _FAT_BOOTSECTOR
  24 {
  25     UCHAR        JumpBoot[3];                // Jump instruction to boot code
  26     CHAR        OemName[8];                    // "MSWIN4.1" for MS formatted volumes
  27     USHORT        BytesPerSector;                // Bytes per sector
  28     UCHAR        SectorsPerCluster;            // Number of sectors in a cluster
  29     USHORT        ReservedSectors;            // Reserved sectors, usually 1 (the bootsector)
  30     UCHAR        NumberOfFats;                // Number of FAT tables
  31     USHORT        RootDirEntries;                // Number of root directory entries (fat12/16)
  32     USHORT        TotalSectors;                // Number of total sectors on the drive, 16-bit
  33     UCHAR        MediaDescriptor;            // Media descriptor byte
  34     USHORT        SectorsPerFat;                // Sectors per FAT table (fat12/16)
  35     USHORT        SectorsPerTrack;            // Number of sectors in a track
  36     USHORT        NumberOfHeads;                // Number of heads on the disk
  37     ULONG        HiddenSectors;                // Hidden sectors (sectors before the partition start like the partition table)
  38     ULONG        TotalSectorsBig;            // This field is the new 32-bit total count of sectors on the volume
  39     UCHAR        DriveNumber;                // Int 0x13 drive number (e.g. 0x80)
  40     UCHAR        Reserved1;                    // Reserved (used by Windows NT). Code that formats FAT volumes should always set this byte to 0.
  41     UCHAR        BootSignature;                // Extended boot signature (0x29). This is a signature byte that indicates that the following three fields in the boot sector are present.
  42     ULONG        VolumeSerialNumber;            // Volume serial number
  43     CHAR        VolumeLabel[11];            // Volume label. This field matches the 11-byte volume label recorded in the root directory
  44     CHAR        FileSystemType[8];            // One of the strings "FAT12   ", "FAT16   ", or "FAT     "
  45
  46     UCHAR        BootCodeAndData[448];        // The remainder of the boot sector
  47
  48     USHORT        BootSectorMagic;            // 0xAA55
  49
  50 } FAT_BOOTSECTOR, *PFAT_BOOTSECTOR;
  51
  52 typedef struct _FAT32_BOOTSECTOR
  53 {
  54     UCHAR        JumpBoot[3];                // Jump instruction to boot code
  55     CHAR        OemName[8];                    // "MSWIN4.1" for MS formatted volumes
  56     USHORT        BytesPerSector;                // Bytes per sector
  57     UCHAR        SectorsPerCluster;            // Number of sectors in a cluster
  58     USHORT        ReservedSectors;            // Reserved sectors, usually 1 (the bootsector)
  59     UCHAR        NumberOfFats;                // Number of FAT tables
  60     USHORT        RootDirEntries;                // Number of root directory entries (fat12/16)
  61     USHORT        TotalSectors;                // Number of total sectors on the drive, 16-bit
  62     UCHAR        MediaDescriptor;            // Media descriptor byte
  63     USHORT        SectorsPerFat;                // Sectors per FAT table (fat12/16)
  64     USHORT        SectorsPerTrack;            // Number of sectors in a track
  65     USHORT        NumberOfHeads;                // Number of heads on the disk
  66     ULONG        HiddenSectors;                // Hidden sectors (sectors before the partition start like the partition table)
  67     ULONG        TotalSectorsBig;            // This field is the new 32-bit total count of sectors on the volume
  68     ULONG        SectorsPerFatBig;            // This field is the FAT32 32-bit count of sectors occupied by ONE FAT. BPB_FATSz16 must be 0
  69     USHORT        ExtendedFlags;                // Extended flags (fat32)
  70     USHORT        FileSystemVersion;            // File system version (fat32)
  71     ULONG        RootDirStartCluster;        // Starting cluster of the root directory (fat32)
  72     USHORT        FsInfo;                        // Sector number of FSINFO structure in the reserved area of the FAT32 volume. Usually 1.
  73     USHORT        BackupBootSector;            // If non-zero, indicates the sector number in the reserved area of the volume of a copy of the boot record. Usually 6.
  74     UCHAR        Reserved[12];                // Reserved for future expansion
  75     UCHAR        DriveNumber;                // Int 0x13 drive number (e.g. 0x80)
  76     UCHAR        Reserved1;                    // Reserved (used by Windows NT). Code that formats FAT volumes should always set this byte to 0.
  77     UCHAR        BootSignature;                // Extended boot signature (0x29). This is a signature byte that indicates that the following three fields in the boot sector are present.
  78     ULONG        VolumeSerialNumber;            // Volume serial number
  79     CHAR        VolumeLabel[11];            // Volume label. This field matches the 11-byte volume label recorded in the root directory
  80     CHAR        FileSystemType[8];            // Always set to the string "FAT32   "
  81
  82     UCHAR        BootCodeAndData[420];        // The remainder of the boot sector
  83
  84     USHORT        BootSectorMagic;            // 0xAA55
  85
  86 } FAT32_BOOTSECTOR, *PFAT32_BOOTSECTOR;
  87
  88 typedef struct _FATX_BOOTSECTOR
  89 {
  90     CHAR        FileSystemType[4];            /* String "FATX" */
  91     ULONG        VolumeSerialNumber;            /* Volume serial number */
  92     ULONG        SectorsPerCluster;            /* Number of sectors in a cluster */
  93     USHORT        NumberOfFats;                /* Number of FAT tables */
  94     ULONG        Unknown;                /* Always 0? */
  95     UCHAR        Unused[494];                /* Actually size should be 4078 (boot block is 4096 bytes) */
  96
  97 } FATX_BOOTSECTOR, *PFATX_BOOTSECTOR;
  98
  99 /*
 100  * Structure of MSDOS directory entry
 101  */
 102 typedef struct //_DIRENTRY
 103 {
 104     CHAR    FileName[11];    /* Filename + extension */
 105     UCHAR    Attr;        /* File attributes */
 106     UCHAR    ReservedNT;    /* Reserved for use by Windows NT */
 107     UCHAR    TimeInTenths;    /* Millisecond stamp at file creation */
 108     USHORT    CreateTime;    /* Time file was created */
 109     USHORT    CreateDate;    /* Date file was created */
 110     USHORT    LastAccessDate;    /* Date file was last accessed */
 111     USHORT    ClusterHigh;    /* High word of this entry's start cluster */
 112     USHORT    Time;        /* Time last modified */
 113     USHORT    Date;        /* Date last modified */
 114     USHORT    ClusterLow;    /* First cluster number low word */
 115     ULONG    Size;        /* File size */
 116 } DIRENTRY, * PDIRENTRY;
 117
 118 typedef struct
 119 {
 120     UCHAR    SequenceNumber;        /* Sequence number for slot */
 121     WCHAR    Name0_4[5];        /* First 5 characters in name */
 122     UCHAR    EntryAttributes;    /* Attribute byte */
 123     UCHAR    Reserved;        /* Always 0 */
 124     UCHAR    AliasChecksum;        /* Checksum for 8.3 alias */
 125     WCHAR    Name5_10[6];        /* 6 more characters in name */
 126     USHORT    StartCluster;        /* Starting cluster number */
 127     WCHAR    Name11_12[2];        /* Last 2 characters in name */
 128 } LFN_DIRENTRY, * PLFN_DIRENTRY;
 129
 130 typedef struct
 131 {
 132     UCHAR    FileNameSize;    /* Size of filename (max 42) */
 133     UCHAR    Attr;        /* File attributes */
 134     CHAR    FileName[42];    /* Filename in ASCII, padded with 0xff (not zero-terminated) */
 135     ULONG    StartCluster;    /* Starting cluster number */
 136     ULONG    Size;        /* File size */
 137     USHORT    Time;        /* Time last modified */
 138     USHORT    Date;        /* Date last modified */
 139     USHORT    CreateTime;    /* Time file was created */
 140     USHORT    CreateDate;    /* Date file was created */
 141     USHORT    LastAccessTime;    /* Time file was last accessed */
 142     USHORT    LastAccessDate;    /* Date file was last accessed */
 143 } FATX_DIRENTRY, * PFATX_DIRENTRY;
 144 #include <poppack.h>
 145
 146 typedef struct _FAT_VOLUME_INFO *PFAT_VOLUME_INFO;
 147
 148 typedef struct
 149 {
 150     UCHAR    Attributes;        /* File attributes */
 151     ULONG    FileSize;        /* File size */
 152     ULONG    FilePointer;        /* File pointer */
 153     ULONG*    FileFatChain;        /* File fat chain array */
 154     ULONG    DriveNumber;
 155     PFAT_VOLUME_INFO    Volume;
 156 } FAT_FILE_INFO, * PFAT_FILE_INFO;
 157
 158 #define    ATTR_NORMAL        0x00
 159 #define    ATTR_READONLY    0x01
 160 #define    ATTR_HIDDEN        0x02
 161 #define    ATTR_SYSTEM        0x04
 162 #define    ATTR_VOLUMENAME    0x08
 163 #define    ATTR_DIRECTORY    0x10
 164 #define    ATTR_ARCHIVE    0x20
 165 #define ATTR_LONG_NAME    (ATTR_READONLY | ATTR_HIDDEN | ATTR_SYSTEM | ATTR_VOLUMENAME)
 166
 167 #define    FAT12            1
 168 #define    FAT16            2
 169 #define    FAT32            3
 170 #define FATX16            4
 171 #define FATX32            5
 172
 173 #define ISFATX(FT) ((FT) == FATX16 || (FT) == FATX32)
 174
 175 const DEVVTBL* FatMount(ULONG DeviceId);