aplfw/driver/volume/fat/fatvol_constructor.c

   1 /**
   2  *  Hyper Operating System  Application Framework
   3  *
   4  * @file  fatvol.h
   5  * @brief %jp{FATボリューム用デバイスドライバ}
   6  *
   7  * Copyright (C) 2006-2007 by Project HOS
   8  * http://sourceforge.jp/projects/hos/
   9  */
  10
  11
  12 #include <string.h>
  13 #include "fatvol_local.h"
  14
  15
  16
  17 /* コンストラクタ */
  18 FATVOL_ERR FatVol_Constructor(C_FATVOL *self, const T_VOLUMEOBJ_METHODS *pMethods, const char *pszPath)
  19 {
  20         unsigned char ubBuf[512];
  21         int           i;
  22
  23         /* ブロックデバイスのオープン */
  24         self->hBlockFile = File_Open(pszPath, FILE_OPEN_READ | FILE_OPEN_WRITE);
  25         if ( self->hBlockFile == HANDLE_NULL )
  26         {
  27                 return FATVOL_ERR_NG;
  28         }
  29
  30         self->Offset = 0;
  31
  32         /* パーティーションテーブルチェック */
  33         File_Seek(self->hBlockFile, 0, FILE_SEEK_SET);
  34         File_Read(self->hBlockFile, ubBuf, 512);
  35         if ( ubBuf[0x1fe] == 0x55 && ubBuf[0x1ff] == 0xaa )     /* シグネチャコードチェック */
  36         {
  37                 /* パーティーションテーブル０のみ確認 */
  38                 if ( ubBuf[0x1be + 0x04] == 0x01                        /* FAT12 */
  39                                 || ubBuf[0x1be + 0x04] == 0x04          /* FAT16(32MB未満) */
  40                                 || ubBuf[0x1be + 0x04] == 0x06          /* FAT16(32MB以上) */
  41                                 || ubBuf[0x1be + 0x04] == 0x0b          /* FAT32 */
  42                                 || ubBuf[0x1be + 0x04] == 0x0c          /* FAT32X (LBA) */
  43                                 || ubBuf[0x1be + 0x04] == 0x0e )        /* FAT16X (LBA) */
  44                 {
  45                         self->Offset = ubBuf[0x1be + 0x08]
  46                                                         + (ubBuf[0x1be + 0x09] << 8)
  47                                                         + (ubBuf[0x1be + 0x0a] << 16)
  48                                                         + (ubBuf[0x1be + 0x0b] << 24);
  49                         self->Offset *= 512;
  50                 }
  51         }
  52
  53
  54         /* サイズ取得 */
  55         self->DriveSize  = File_Seek(self->hBlockFile, 0, FILE_SEEK_END);
  56         self->iFatType   = FATVOL_TYPE_UNKNOWN;
  57
  58
  59         /* BIOS Parameter Block */
  60         File_Seek(self->hBlockFile, self->Offset, FILE_SEEK_SET);
  61         File_Read(self->hBlockFile, ubBuf, 512);
  62
  63         /* FAT12/16/32判定 */
  64         if ( ubBuf[0x36] == 'F' && ubBuf[0x37] == 'A' && ubBuf[0x38] == 'T' && ubBuf[0x39] == '1' )
  65         {
  66                 if ( ubBuf[0x3a] == '2' )
  67                 {
  68                         self->iFatType = FATVOL_TYPE_FAT12;
  69                 }
  70                 else if ( ubBuf[0x3a] == '6' )
  71                 {
  72                         self->iFatType = FATVOL_TYPE_FAT16;
  73                 }
  74         }
  75         else if ( ubBuf[0x52] == 'F' && ubBuf[0x53] == 'A' && ubBuf[0x54] == 'T' && ubBuf[0x55] == '3' && ubBuf[0x56] == '2')
  76         {
  77                 self->iFatType = FATVOL_TYPE_FAT32;
  78         }
  79
  80
  81         /* フォーマット別情報解析 */
  82         switch ( self->iFatType )
  83         {
  84         case FATVOL_TYPE_FAT12:
  85         case FATVOL_TYPE_FAT16:
  86                 self->BytesPerSector    = ubBuf[0x0b] + (ubBuf[0x0c] << 8);                                     /**< セクタサイズ */
  87                 self->SectorsPerCluster = ubBuf[0x0d];                                                                          /**< 1クラスタのセクタ数 */
  88                 self->FatStartSector    = ubBuf[0x0e] + (ubBuf[0x0f] << 8);                                     /**< FATの開始セクタ番号 */
  89                 self->RootDirEntryNum   = ubBuf[0x11] + (ubBuf[0x12] << 8);                                     /**< ルートディレクトリ最大エントリ数 */
  90                 self->SectorNum         = ubBuf[0x13] + (ubBuf[0x14] << 8);                                     /**< 総セクタ数 */
  91                 self->SectorPerFat      = ubBuf[0x16] + (ubBuf[0x17] << 8);                                     /**< FATあたりのセクタ数 */
  92                 self->FatNum            = ubBuf[0x10];                                                                          /**< FAT個数 */
  93                 self->RootDirSector     = self->FatStartSector + (self->SectorPerFat * self->FatNum);
  94                                                                                                                                                                         /**< ルートディレクトリ開始位置 */
  95
  96                 self->BytesPerCluster   = self->BytesPerSector * self->SectorsPerCluster;       /**< 1クラスタサイズ */
  97                 self->Cluster0Sector    = self->RootDirSector
  98                                                                                 + (((self->RootDirEntryNum * 32) + self->BytesPerSector - 1) / self->BytesPerSector)
  99                                                                                 - (2 * self->SectorsPerCluster);                        /**< クラスタ0の開始セクタ */
 100                 self->ClusterNum        = (self->SectorNum - self->Cluster0Sector) / self->SectorsPerCluster;
 101                                                                                                                                                                         /**< 総クラスタ数 */
 102                 self->RootDirCluster    = 0xf0000000;
 103
 104                 /* FATバッファ準備 */
 105                 self->pubFatBuf   = (unsigned char *)SysMem_Alloc(self->SectorPerFat * self->BytesPerSector);
 106                 self->pubFatDirty = (unsigned char *)SysMem_Alloc(self->SectorPerFat);
 107
 108                 /* FAT読み出し */
 109                 File_Seek(self->hBlockFile, self->FatStartSector * self->BytesPerSector  + self->Offset, FILE_SEEK_SET);
 110                 File_Read(self->hBlockFile, self->pubFatBuf, self->SectorPerFat * self->BytesPerSector);
 111                 memset(self->pubFatDirty, 0, self->SectorPerFat);
 112
 113                 break;
 114
 115         case FATVOL_TYPE_FAT32:
 116                 self->BytesPerSector    = ubBuf[0x0b] + (ubBuf[0x0c] << 8);                                     /**< セクタサイズ */
 117                 self->SectorsPerCluster = ubBuf[0x0d];                                                                          /**< 1クラスタのセクタ数 */
 118                 self->FatStartSector    = ubBuf[0x0e] + (ubBuf[0x0f] << 8);                                     /**< FATの開始セクタ番号 */
 119                 self->RootDirEntryNum   = ubBuf[0x11] + (ubBuf[0x12] << 8);                                     /**< ルートディレクトリ最大エントリ数 */
 120 /*              self->SectorNum         = ubBuf[0x13] + (ubBuf[0x14] << 8);             */                      /**< 総セクタ数 */
 121                 self->SectorNum         = ubBuf[0x20] + (ubBuf[0x21] << 8) + (ubBuf[0x22] << 16) + (ubBuf[0x23] << 24);
 122                 self->SectorPerFat      = ubBuf[0x24] + (ubBuf[0x25] << 8) + (ubBuf[0x26] << 16) + (ubBuf[0x27] << 24); /**< FATあたりのセクタ数 */
 123                 self->FatNum            = ubBuf[0x10];                                                                          /**< FAT個数 */
 124                 self->RootDirSector     = self->FatStartSector + (self->SectorPerFat * self->FatNum);
 125                                                                                                                                                                         /**< ルートディレクトリ開始位置 */
 126
 127                 self->BytesPerCluster   = self->BytesPerSector * self->SectorsPerCluster;       /**< 1クラスタサイズ */
 128                 self->Cluster0Sector    = self->RootDirSector
 129                                                                                 + (((self->RootDirEntryNum * 32) + self->BytesPerSector - 1) / self->BytesPerSector)
 130                                                                                 - (2 * self->SectorsPerCluster);                        /**< クラスタ0の開始セクタ */
 131                 self->ClusterNum        = (self->SectorNum - self->Cluster0Sector) / self->SectorsPerCluster;
 132                                                                                                                                                                         /**< 総クラスタ数 */
 133                 self->RootDirCluster    = ubBuf[0x2c] + (ubBuf[0x2d] << 8) + (ubBuf[0x2e] << 16) + (ubBuf[0x2f] << 24);
 134
 135                 /* FATバッファ準備 */
 136                 self->pubFatBuf   = (unsigned char *)SysMem_Alloc(self->SectorPerFat * self->BytesPerSector);
 137                 self->pubFatDirty = (unsigned char *)SysMem_Alloc(self->SectorPerFat);
 138
 139                 /* FAT読み出し */
 140                 File_Seek(self->hBlockFile, self->FatStartSector * self->BytesPerSector  + self->Offset, FILE_SEEK_SET);
 141                 File_Read(self->hBlockFile, self->pubFatBuf, self->SectorPerFat * self->BytesPerSector);
 142                 memset(self->pubFatDirty, 0, self->SectorPerFat);
 143
 144                 break;
 145
 146         default:
 147                 return FATVOL_ERR_NG;
 148         }
 149
 150         /* クラスタバッファ取得 */
 151         self->iClusterBufNum   = 8;
 152         self->pClusterBuf = (T_FATVOL_CLUSTERBUF *)SysMem_Alloc(sizeof(T_FATVOL_CLUSTERBUF) * self->iClusterBufNum);
 153         for ( i = 0; i < self->iClusterBufNum; i++ )
 154         {
 155                 self->pClusterBuf[i].uiClusterNum = FATVOL_CLUSTER_ENDMARKER;
 156                 self->pClusterBuf[i].iDirty       = 0;
 157                 self->pClusterBuf[i].pubBuf       = SysMem_Alloc(self->BytesPerCluster);
 158         }
 159
 160
 161         /* 親クラスコンストラクタ呼び出し */
 162         VolumeObj_Constructor(&self->VolumeObj, pMethods);
 163
 164         /* ミューテックス生成 */
 165         self->hMtx = SysMtx_Create(SYSMTX_ATTR_NORMAL);
 166
 167         return FATVOL_ERR_OK;
 168 }
 169
 170
 171