aplfw/volume/fat/fatvol_setnextcluster.c

   1
   2
   3 #include "fatvol_local.h"
   4
   5
   6 void FatVol_SetNextCluster(C_FATVOL *self, FATVOL_UINT uiCluster, FATVOL_UINT uiNextCluster)
   7 {
   8         switch ( self->iFatType )
   9         {
  10         case FATVOL_TYPE_FAT12:
  11                 /* FAT更新 */
  12                 if ( uiCluster % 2 == 0 )
  13                 {
  14                         self->pubFatBuf[(uiCluster / 2) * 3 + 0] = uiNextCluster & 0xff;
  15                         self->pubFatBuf[(uiCluster / 2) * 3 + 1] = ((uiNextCluster >> 8) & 0x0f) | (self->pubFatBuf[(uiCluster / 2) * 3 + 1] & 0xf0);
  16                 }
  17                 else
  18                 {
  19                         self->pubFatBuf[(uiCluster / 2) * 3 + 1] = ((uiNextCluster << 4) & 0xf0) | (self->pubFatBuf[(uiCluster / 2) * 3 + 1] & 0x0f);
  20                         self->pubFatBuf[(uiCluster / 2) * 3 + 2] = ((uiNextCluster >> 4) & 0xff);
  21                 }
  22
  23                 /* 更新フラグ設定 */
  24                 self->pubFatDirty[((uiCluster / 2) * 3 + 0) / self->uiBytesPerSector] = 1;
  25                 self->pubFatDirty[((uiCluster / 2) * 3 + 2) / self->uiBytesPerSector] = 1;
  26                 break;
  27
  28         case FATVOL_TYPE_FAT16:
  29                 /* FAT更新 */
  30                 self->pubFatBuf[uiCluster * 2 + 0] = uiNextCluster % 256;
  31                 self->pubFatBuf[uiCluster * 2 + 1] = uiNextCluster / 256;
  32
  33                 /* 更新フラグ設定 */
  34                 self->pubFatDirty[(uiCluster * 2) / self->uiBytesPerSector] = 1;
  35                 break;
  36
  37         case FATVOL_TYPE_FAT32:
  38                 /* FAT更新 */
  39                 self->pubFatBuf[uiCluster * 2 + 0] = uiNextCluster % 256;
  40                 self->pubFatBuf[uiCluster * 2 + 1] = (uiNextCluster / 256) % 256;
  41                 self->pubFatBuf[uiCluster * 2 + 2] = (uiNextCluster / 256 / 256) % 256;
  42                 self->pubFatBuf[uiCluster * 2 + 3] = (uiNextCluster / 256 / 256 / 256) % 256;
  43
  44                 /* 更新フラグ設定 */
  45                 self->pubFatDirty[(uiCluster * 4) / self->uiBytesPerSector] = 1;
  46         }
  47 }
  48
  49
  50 /* end of file */