source/partition.h

   1 /*
   2  partition.h
   3  Functions for mounting and dismounting partitions
   4  on various block devices.
   5
   6  Copyright (c) 2006 Michael "Chishm" Chisholm
   7
   8  Redistribution and use in source and binary forms, with or without modification,
   9  are permitted provided that the following conditions are met:
  10
  11   1. Redistributions of source code must retain the above copyright notice,
  12      this list of conditions and the following disclaimer.
  13   2. Redistributions in binary form must reproduce the above copyright notice,
  14      this list of conditions and the following disclaimer in the documentation and/or
  15      other materials provided with the distribution.
  16   3. The name of the author may not be used to endorse or promote products derived
  17      from this software without specific prior written permission.
  18
  19  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  20  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  21  AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
  22  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  27  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28 */
  29
  30 #ifndef _PARTITION_H
  31 #define _PARTITION_H
  32
  33 #include "common.h"
  34 #include "cache.h"
  35 #include "lock.h"
  36
  37 // Device name
  38 extern const char* DEVICE_NAME;
  39
  40 // Filesystem type
  41 typedef enum {FS_UNKNOWN, FS_FAT12, FS_FAT16, FS_FAT32} FS_TYPE;
  42
  43 typedef struct {
  44         sec_t    fatStart;
  45         uint32_t sectorsPerFat;
  46         uint32_t lastCluster;
  47         uint32_t firstFree;
  48 } FAT;
  49
  50 typedef struct {
  51         const DISC_INTERFACE* disc;
  52         CACHE*                cache;
  53         // Info about the partition
  54         FS_TYPE               filesysType;
  55         uint64_t              totalSize;
  56         sec_t                 rootDirStart;
  57         uint32_t              rootDirCluster;
  58         uint32_t              numberOfSectors;
  59         sec_t                 dataStart;
  60         uint32_t              bytesPerSector;
  61         uint32_t              sectorsPerCluster;
  62         uint32_t              bytesPerCluster;
  63         FAT                   fat;
  64         // Values that may change after construction
  65         uint32_t              cwdCluster;                       // Current working directory cluster
  66         int                   openFileCount;
  67         struct _FILE_STRUCT*  firstOpenFile;            // The start of a linked list of files
  68         mutex_t               lock;                                     // A lock for partition operations
  69         bool                  readOnly;                         // If this is set, then do not try writing to the disc
  70 } PARTITION;
  71
  72 /*
  73 Mount the supplied device and return a pointer to the struct necessary to use it
  74 */
  75 PARTITION* _FAT_partition_constructor (const DISC_INTERFACE* disc, uint32_t cacheSize, sec_t startSector);
  76
  77 /*
  78 Dismount the device and free all structures used.
  79 Will also attempt to synchronise all open files to disc.
  80 */
  81 void _FAT_partition_destructor (PARTITION* partition);
  82
  83 /*
  84 Return the partition specified in a path, as taken from the devoptab.
  85 */
  86 PARTITION* _FAT_partition_getPartitionFromPath (const char* path);
  87
  88 #endif // _PARTITION_H