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 #include "vmc.h" | 
 
 
 
 
 
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 // Fat table functions | 
 
 
 
 
 
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 unsigned int getFatEntry ( int fd, unsigned int cluster, unsigned int* indir_fat_clusters, GetFat_Mode Mode )  | 
 
 
 
 
 
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 { | 
 
 
 
 
 
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         int unit = ( fd == g_Vmc_Image[ 0 ].fd ) ? 0 : 1; | 
 
 
 
 
 
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         // The fat index, aka which cluster we want to know about | 
 
 
 
 
 
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         unsigned int fat_index = cluster; | 
 
 
 
 
 
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         // The offset in the fat cluster where we can find information about the sector | 
 
 
 
 
 
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         unsigned int fat_offset = fat_index % ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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         // Which fat cluster that the information would be in | 
 
 
 
 
 
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         unsigned int indirect_index = fat_index / ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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         // The offset in the indirect fat cluster that points to the fat table we are interested in | 
 
 
 
 
 
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         unsigned int indirect_offset = indirect_index % ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // This gives the location of the fat_offset inside of the indirect fat cluster list.  Each indirect fat cluster can point to | 
 
 
 
 
 
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         // 256 regular fat clusters, and each fat cluster holds information on 256 sectors. | 
 
 
 
 
 
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         unsigned int dbl_indirect_index = fat_index / (  ( g_Vmc_Image[ unit ].cluster_size / 4 ) * ( g_Vmc_Image[ unit ].cluster_size / 4 )  ); | 
 
 
 
 
 
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         // Cache indirect file table? ( Generally we will be accessing the first part of it for most virtual memory cards )  | 
 
 
 
 
 
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         // Get the data for the indirect fat cluster ( as indicated by dbl_indirect_index )  | 
 
 
 
 
 
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         unsigned int indirect_cluster_num        = indir_fat_clusters[ dbl_indirect_index ]; | 
 
 
 
 
 
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         if ( g_Vmc_Image[ unit ].last_idc != indirect_cluster_num )  | 
 
 
 
 
 
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                 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].indirect_cluster, indirect_cluster_num ); | 
 
 
 
 
 
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         g_Vmc_Image[ unit ].last_idc = indirect_cluster_num; | 
 
 
 
 
 
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         // Get the data from the fat cluster ( pointed to by the indirect fat cluster )  | 
 
 
 
 
 
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         unsigned int fat_cluster_num = g_Vmc_Image[ unit ].indirect_cluster[ indirect_offset ]; | 
 
 
 
 
 
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         if ( g_Vmc_Image[ unit ].last_cluster != fat_cluster_num )  | 
 
 
 
 
 
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                 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num ); | 
 
 
 
 
 
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         g_Vmc_Image[ unit ].last_cluster = fat_cluster_num; | 
 
 
 
 
 
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         // Check if the entry in the fat table corresponds to a free cluster or a eof cluster | 
 
 
 
 
 
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         if ( g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] == FREE_CLUSTER || g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] == EOF_CLUSTER )  | 
 
 
 
 
 
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                 return g_Vmc_Image[ unit ].fat_cluster[ fat_offset ]; | 
 
 
 
 
 
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         if ( Mode == FAT_MASK ) | 
 
 
 
 
 
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         { | 
 
 
 
 
 
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                 if ( g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] & MASK_CLUSTER ) | 
 
 
 
 
 
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                 { | 
 
 
 
 
 
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                         return MASK_CLUSTER; | 
 
 
 
 
 
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                 } | 
 
 
 
 
 
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                 else | 
 
 
 
 
 
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                 { | 
 
 
 
 
 
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                         return 0; | 
 
 
 
 
 
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                 } | 
 
 
 
 
 
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                  | 
 
 
 
 
 
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         } | 
 
 
 
 
 
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         // Return the fat entry, but remove the most significant bit. | 
 
 
 
 
 
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         return g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] & FREE_CLUSTER; | 
 
 
 
 
 
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 } | 
 
 
 
 
 
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 unsigned int setFatEntry ( int fd, unsigned int cluster, unsigned int value, unsigned int* indir_fat_clusters, SetFat_Mode Mode )  | 
 
 
 
 
 
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 { | 
 
 
 
 
 
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         int unit = ( fd == g_Vmc_Image[ 0 ].fd ) ? 0 : 1; | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // The fat index, aka which cluster we want to know about | 
 
 
 
 
 
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         unsigned int fat_index = cluster; | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // The offset in the fat cluster where we can find information about the sector | 
 
 
 
 
 
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         unsigned int fat_offset = fat_index % ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // Which fat cluster that the information would be in | 
 
 
 
 
 
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         unsigned int indirect_index = fat_index / ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // The offset in the indirect fat cluster that points to the fat table we are interested in | 
 
 
 
 
 
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         unsigned int indirect_offset = indirect_index % ( g_Vmc_Image[ unit ].cluster_size / 4 ); | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // This gives the location of the fat_offset inside of the indirect fat cluster list.  Each indirect fat cluster can point to | 
 
 
 
 
 
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         // 256 regular fat clusters, and each fat cluster holds information on 256 sectors. | 
 
 
 
 
 
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         unsigned int dbl_indirect_index = fat_index / (  ( g_Vmc_Image[ unit ].cluster_size / 4 ) * ( g_Vmc_Image[ unit ].cluster_size / 4 )  ); | 
 
 
 
 
 
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  | 
 
 
 
 
 
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         // Cache indirect file table? ( Generally we will be accessing the first part of it for most virtual memory cards | 
 
 
 
 
 
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         // Get the data for the indirect fat cluster ( as indicated by dbl_indirect_index )  | 
 
 
 
 
 
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         unsigned int indirect_cluster_num        = indir_fat_clusters[ dbl_indirect_index ]; | 
 
 
 
 
 
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         if ( g_Vmc_Image[ unit ].last_idc != indirect_cluster_num )  | 
 
 
 
 
 
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                 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].indirect_cluster, indirect_cluster_num ); | 
 
 
 
 
 
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         g_Vmc_Image[ unit ].last_idc = indirect_cluster_num; | 
 
 
 
 
 
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         // Get the data from the fat cluster ( pointed to by the indirect fat cluster )  | 
 
 
 
 
 
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         unsigned int fat_cluster_num = g_Vmc_Image[ unit ].indirect_cluster[ indirect_offset ]; | 
 
 
 
 
 
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         if ( g_Vmc_Image[ unit ].last_cluster != fat_cluster_num )  | 
 
 
 
 
 
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                 readCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num ); | 
 
 
 
 
 
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         g_Vmc_Image[ unit ].last_cluster = fat_cluster_num; | 
 
 
 
 
 
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         if ( value == FREE_CLUSTER || value == EOF_CLUSTER || Mode == FAT_RESET ) | 
 
 
 
 
 
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         { | 
 
 
 
 
 
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                 g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] = value; | 
 
 
 
 
 
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         } | 
 
 
 
 
 
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         else | 
 
 
 
 
 
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         { | 
 
 
 
 
 
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                 g_Vmc_Image[ unit ].fat_cluster[ fat_offset ] = value | MASK_CLUSTER; | 
 
 
 
 
 
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         } | 
 
 
 
 
 
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         writeCluster ( fd, ( unsigned char* ) g_Vmc_Image[ unit ].fat_cluster, fat_cluster_num ); | 
 
 
 
 
 
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         // Update last free cluster | 
 
 
 
 
 
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         if ( ( value == FREE_CLUSTER && Mode == FAT_SET ) || ( Mode == FAT_RESET ) ) | 
 
 
 
 
 
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         { | 
 
 
 
 
 
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                 if ( cluster < g_Vmc_Image[ unit ].last_free_cluster ) | 
 
 
 
 
 
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                 { | 
 
 
 
 
 
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                         g_Vmc_Image[ unit ].last_free_cluster = cluster; | 
 
 
 
 
 
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                 } | 
 
 
 
 
 
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         } | 
 
 
 
 
 
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         return 0; | 
 
 
 
 
 
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 } |