## FATFS

The `FATFS` structure holds dynamic work area of individual logical drives. It is given by application program and registerd/unregisterd to the FatFs module with f_mount function. Following members are in standard configuration. There is no member that can be changed from the application program.

#### FatFs

    typedef struct _FATFS {
        WORD    id;             /* File system mount ID */
        WORD    n_rootdir;      /* Number of root directory entries */
        DWORD   winsect;        /* Current sector appearing in the win[] */
        DWORD   sects_fat;      /* Sectors per fat */
        DWORD   max_clust;      /* Maximum cluster# + 1 */
        DWORD   fatbase;        /* FAT start sector */
        DWORD   dirbase;        /* Root directory start sector (cluster# for FAT32) */
        DWORD   database;       /* Data start sector */
        DWORD   last_clust;     /* Last allocated cluster */
        DWORD   free_clust;     /* Number of free clusters */
        BYTE    fs_type;        /* FAT type (0:Not mounted) */
        BYTE    sects_clust;    /* Sectors per cluster */
        BYTE    n_fats;         /* Number of FAT copies */
        BYTE    drive;          /* Physical drive number */
        BYTE    winflag;        /* win[] dirty flag (1:must be written back) */
        BYTE    pad1;
        BYTE    win[512];       /* Disk access window for Directory/FAT */
    } FATFS;

#### Tiny-FatFs

    typedef struct _FATFS {
        WORD    id;             /* File system mount ID */
        WORD    n_rootdir;      /* Number of root directory entries */
        DWORD   winsect;        /* Current sector appearing in the win[] */
        DWORD   fatbase;        /* FAT start sector */
        DWORD   dirbase;        /* Root directory start sector */
        DWORD   database;       /* Data start sector */
        CLUST   sects_fat;      /* Sectors per fat */
        CLUST   max_clust;      /* Maximum cluster# + 1 */
        CLUST   last_clust;     /* Last allocated cluster */
        CLUST   free_clust;     /* Number of free clusters */
        BYTE    fs_type;        /* FAT type (0:Not mounted) */
        BYTE    sects_clust;    /* Sectors per cluster */
        BYTE    n_fats;         /* Number of FAT copies */
        BYTE    winflag;        /* win[] dirty flag (1:must be written back) */
        BYTE    win[512];       /* Disk access window for Directory/FAT/File */
    } FATFS;

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