freeldr/freeldr/fs.h

   1 /*
   2  *  FreeLoader
   3  *  Copyright (C) 1999, 2000  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
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #ifndef __FS_FAT_H
  21 #define __FS_FAT_H
  22
  23 // Bootsector BPB defines
  24 #define BPB_JMPBOOT                                     0
  25 #define BPB_OEMNAME                                     3
  26 #define BPB_BYTESPERSECTOR                      11
  27 #define BPB_SECTORSPERCLUSTER           13
  28 #define BPB_RESERVEDSECTORS                     14
  29 #define BPB_NUMBEROFFATS                        16
  30 #define BPB_ROOTDIRENTRIES                      17
  31 #define BPB_TOTALSECTORS16                      19
  32 #define BPB_MEDIADESCRIPTOR                     21
  33 #define BPB_SECTORSPERFAT16                     22
  34 #define BPB_SECTORSPERTRACK                     24
  35 #define BPB_NUMBEROFHEADS                       26
  36 #define BPB_HIDDENSECTORS                       28
  37 #define BPB_TOTALSECTORS32                      32
  38
  39 // Fat12/16 extended BPB defines
  40 #define BPB_DRIVENUMBER16                       36
  41 #define BPB_RESERVED16_1                        37
  42 #define BPB_BOOTSIGNATURE16                     38
  43 #define BPB_VOLUMESERIAL16                      39
  44 #define BPB_VOLUMELABEL16                       43
  45 #define BPB_FILESYSTEMTYPE16            54
  46
  47 // Fat32 extended BPB defines
  48 #define BPB_SECTORSPERFAT32                     36
  49 #define BPB_EXTENDEDFLAGS32                     40
  50 #define BPB_FILESYSTEMVERSION32         42
  51 #define BPB_ROOTDIRSTARTCLUSTER32       44
  52 #define BPB_FILESYSTEMINFOSECTOR32      48
  53 #define BPB_BACKUPBOOTSECTOR32          50
  54 #define BPB_RESERVED32_1                        52
  55 #define BPB_DRIVENUMBER32                       64
  56 #define BPB_RESERVED32_2                        65
  57 #define BPB_BOOTSIGNATURE32                     66
  58 #define BPB_VOLUMESERIAL32                      67
  59 #define BPB_VOLUMELABEL32                       71
  60 #define BPB_FILESYSTEMTYPE32            82
  61
  62 /*
  63  * Structure of MSDOS directory entry
  64  */
  65 typedef struct //_DIRENTRY
  66 {
  67         BYTE    cFileName[11];  /* Filename + extension */
  68         BYTE    cAttr;                  /* File attributes */
  69         BYTE    cReserved[10];  /* Reserved area */
  70         WORD    wTime;                  /* Time last modified */
  71         WORD    wData;                  /* Date last modified */
  72         WORD    wCluster;               /* First cluster number */
  73         DWORD   dwSize;                 /* File size */
  74 } DIRENTRY, * PDIRENTRY;
  75
  76 /*
  77  * Structure of internal file control block
  78  */
  79 typedef struct //_FCB
  80 {
  81         BYTE            cAttr;                  /* Open attributes */
  82         BYTE            cSector;                /* Sector within cluster */
  83         PDIRENTRY       pDirptr;                /* Pointer to directory entry */
  84         WORD            wDirSector;             /* Directory sector */
  85         WORD            wFirstCluster;  /* First cluster in file */
  86         WORD            wLastCluster;   /* Last cluster read/written */
  87         WORD            wNextCluster;   /* Next cluster to read/write */
  88         WORD            wOffset;                /* Read/Write offset within sector */
  89         DWORD           dwSize;                 /* File size */
  90         BYTE            cBuffer[512];   /* Data transfer buffer */
  91 } FCB, * PFCB;
  92
  93 typedef struct //_FAT_STRUCT
  94 {
  95         DWORD   dwStartCluster;         // File's starting cluster
  96         DWORD   dwCurrentCluster;       // Current read cluster number
  97         DWORD   dwSize;                         // File size
  98         DWORD   dwCurrentReadOffset;// Amount of data already read
  99 } FAT_STRUCT, * PFAT_STRUCT;
 100
 101 typedef struct //_FILE
 102 {
 103         //DIRENTRY              de;
 104         //FCB                           fcb;
 105         FAT_STRUCT              fat;
 106         unsigned long   filesize;
 107 } FILE;
 108
 109 extern  int             nSectorBuffered;        // Tells us which sector was read into SectorBuffer[]
 110 extern  BYTE    SectorBuffer[512];      // 512 byte buffer space for read operations, ReadOneSector reads to here
 111
 112 extern  int             nFATType;
 113
 114 extern  DWORD   nBytesPerSector;                // Bytes per sector
 115 extern  DWORD   nSectorsPerCluster;             // Number of sectors in a cluster
 116 extern  DWORD   nReservedSectors;               // Reserved sectors, usually 1 (the bootsector)
 117 extern  DWORD   nNumberOfFATs;                  // Number of FAT tables
 118 extern  DWORD   nRootDirEntries;                // Number of root directory entries (fat12/16)
 119 extern  DWORD   nTotalSectors16;                // Number of total sectors on the drive, 16-bit
 120 extern  DWORD   nSectorsPerFAT16;               // Sectors per FAT table (fat12/16)
 121 extern  DWORD   nSectorsPerTrack;               // Number of sectors in a track
 122 extern  DWORD   nNumberOfHeads;                 // Number of heads on the disk
 123 extern  DWORD   nHiddenSectors;                 // Hidden sectors (sectors before the partition start like the partition table)
 124 extern  DWORD   nTotalSectors32;                // Number of total sectors on the drive, 32-bit
 125
 126 extern  DWORD   nSectorsPerFAT32;               // Sectors per FAT table (fat32)
 127 extern  DWORD   nExtendedFlags;                 // Extended flags (fat32)
 128 extern  DWORD   nFileSystemVersion;             // File system version (fat32)
 129 extern  DWORD   nRootDirStartCluster;   // Starting cluster of the root directory (fat32)
 130
 131 extern  DWORD   nRootDirSectorStart;    // Starting sector of the root directory (fat12/16)
 132 extern  DWORD   nDataSectorStart;               // Starting sector of the data area
 133 extern  DWORD   nSectorsPerFAT;                 // Sectors per FAT table
 134 extern  DWORD   nRootDirSectors;                // Number of sectors of the root directory (fat32)
 135 extern  DWORD   nTotalSectors;                  // Total sectors on the drive
 136 extern  DWORD   nNumberOfClusters;              // Number of clusters on the drive
 137
 138 extern  int     FSType;                                         // Type of filesystem on boot device, set by OpenDiskDrive()
 139
 140 extern  char *pFileSysData;                             // Load address for filesystem data
 141 extern  char *pFat32FATCacheIndex;              // Load address for filesystem data
 142
 143 BOOL    OpenDiskDrive(int nDrive, int nPartition);      // Opens the disk drive device for reading
 144 BOOL    ReadMultipleSectors(int nSect, int nNumberOfSectors, void *pBuffer);// Reads a sector from the open device
 145 BOOL    ReadOneSector(int nSect);                               // Reads one sector from the open device
 146 BOOL    OpenFile(char *filename, FILE *pFile);  // Opens a file
 147 int             ReadFile(FILE *pFile, int count, void *buffer); // Reads count bytes from pFile into buffer
 148 DWORD   GetFileSize(FILE *pFile);
 149 DWORD   Rewind(FILE *pFile);    // Rewinds a file and returns it's size
 150 int             feof(FILE *pFile);
 151 int             fseek(FILE *pFILE, DWORD offset);
 152
 153 BOOL    FATLookupFile(char *file, PFAT_STRUCT pFatStruct);
 154 int             FATGetNumPathParts(char *name);
 155 BOOL    FATGetFirstNameFromPath(char *buffer, char *name);
 156 void    FATParseFileName(char *buffer, char *name);
 157 DWORD   FATGetFATEntry(DWORD nCluster);
 158 BOOL    FATOpenFile(char *szFileName, PFAT_STRUCT pFatStruct);
 159 int             FATReadCluster(DWORD nCluster, char *cBuffer);
 160 int             FATRead(PFAT_STRUCT pFatStruct, int nNumBytes, char *cBuffer);
 161 int             FATfseek(PFAT_STRUCT pFatStruct, DWORD offset);
 162
 163
 164 #define EOF     -1
 165
 166 #define ATTR_NORMAL             0x00
 167 #define ATTR_READONLY   0x01
 168 #define ATTR_HIDDEN             0x02
 169 #define ATTR_SYSTEM             0x04
 170 #define ATTR_VOLUMENAME 0x08
 171 #define ATTR_DIRECTORY  0x10
 172 #define ATTR_ARCHIVE    0x20
 173
 174 #define FS_FAT                  1
 175 #define FS_NTFS                 2
 176 #define FS_EXT2                 3
 177
 178 #define FAT12                   1
 179 #define FAT16                   2
 180 #define FAT32                   3
 181
 182 #endif // #defined __FS_FAT_H