ff.c

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/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.08a                 (C)ChaN, 2010
/-----------------------------------------------------------------------------/
/ FatFs module is a generic FAT file system module for small embedded systems.
/ This is a free software that opened for education, research and commercial
/ developments under license policy of following terms.
/
/  Copyright (C) 2010, ChaN, all right reserved.
/
/ * The FatFs module is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-----------------------------------------------------------------------------/
/ Feb 26,'06 R0.00  Prototype.
/
/ Apr 29,'06 R0.01  First stable version.
/
/ Jun 01,'06 R0.02  Added FAT12 support.
/                   Removed unbuffered mode.
/                   Fixed a problem on small (<32M) partition.
/ Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
/
/ Sep 22,'06 R0.03  Added f_rename().
/                   Changed option _FS_MINIMUM to _FS_MINIMIZE.
/ Dec 11,'06 R0.03a Improved cluster scan algorithm to write files fast.
/                   Fixed f_mkdir() creates incorrect directory on FAT32.
/
/ Feb 04,'07 R0.04  Supported multiple drive system.
/                   Changed some interfaces for multiple drive system.
/                   Changed f_mountdrv() to f_mount().
/                   Added f_mkfs().
/ Apr 01,'07 R0.04a Supported multiple partitions on a physical drive.
/                   Added a capability of extending file size to f_lseek().
/                   Added minimization level 3.
/                   Fixed an endian sensitive code in f_mkfs().
/ May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
/                   Added FSInfo support.
/                   Fixed DBCS name can result FR_INVALID_NAME.
/                   Fixed short seek (<= csize) collapses the file object.
/
/ Aug 25,'07 R0.05  Changed arguments of f_read(), f_write() and f_mkfs().
/                   Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
/                   Fixed f_mkdir() on FAT32 creates incorrect directory.
/ Feb 03,'08 R0.05a Added f_truncate() and f_utime().
/                   Fixed off by one error at FAT sub-type determination.
/                   Fixed btr in f_read() can be mistruncated.
/                   Fixed cached sector is not flushed when create and close without write.
/
/ Apr 01,'08 R0.06  Added fputc(), fputs(), fprintf() and fgets().
/                   Improved performance of f_lseek() on moving to the same or following cluster.
/
/ Apr 01,'09 R0.07  Merged Tiny-FatFs as a buffer configuration option. (_FS_TINY)
/                   Added long file name support.
/                   Added multiple code page support.
/                   Added re-entrancy for multitask operation.
/                   Added auto cluster size selection to f_mkfs().
/                   Added rewind option to f_readdir().
/                   Changed result code of critical errors.
/                   Renamed string functions to avoid name collision.
/ Apr 14,'09 R0.07a Separated out OS dependent code on reentrant cfg.
/                   Added multiple sector size support.
/ Jun 21,'09 R0.07c Fixed f_unlink() can return FR_OK on error.
/                   Fixed wrong cache control in f_lseek().
/                   Added relative path feature.
/                   Added f_chdir() and f_chdrive().
/                   Added proper case conversion to extended char.
/ Nov 03,'09 R0.07e Separated out configuration options from ff.h to ffconf.h.
/                   Fixed f_unlink() fails to remove a sub-dir on _FS_RPATH.
/                   Fixed name matching error on the 13 char boundary.
/                   Added a configuration option, _LFN_UNICODE.
/                   Changed f_readdir() to return the SFN with always upper case on non-LFN cfg.
/
/ May 15,'10 R0.08  Added a memory configuration option. (_USE_LFN = 3)
/                   Added file lock feature. (_FS_SHARE)
/                   Added fast seek feature. (_USE_FASTSEEK)
/                   Changed some types on the API, XCHAR->TCHAR.
/                   Changed fname member in the FILINFO structure on Unicode cfg.
/                   String functions support UTF-8 encoding files on Unicode cfg.
/ Aug 16,'10 R0.08a Added f_getcwd(). (_FS_RPATH = 2)
/                   Added sector erase feature. (_USE_ERASE)
/                   Moved file lock semaphore table from fs object to the bss.
/                   Fixed a wrong directory entry is created on non-LFN cfg when the given name contains ';'.
/                   Fixed f_mkfs() creates wrong FAT32 volume.
/---------------------------------------------------------------------------*/
#include "circle.h" 
#include "ff.h"         /* FatFs configurations and declarations */
#include "diskio.h"     /* Declarations of low level disk I/O functions */


/*--------------------------------------------------------------------------

   Module Private Definitions

---------------------------------------------------------------------------*/

#if _FATFS != 8255
#error Wrong include file (ff.h).
#endif


/* Definitions on sector size */
#if _MAX_SS != 512 && _MAX_SS != 1024 && _MAX_SS != 2048 && _MAX_SS != 4096
#error Wrong sector size.
#endif
#if _MAX_SS != 512
#define SS(fs)  ((fs)->ssize)   /* Multiple sector size */
#else
#define SS(fs)  512U            /* Fixed sector size */
#endif


/* Reentrancy related */
#if _FS_REENTRANT
#if _USE_LFN == 1
#error Static LFN work area must not be used in re-entrant configuration.
#endif
#define ENTER_FF(fs)        { if (!lock_fs(fs)) return FR_TIMEOUT; }
#define LEAVE_FF(fs, res)   { unlock_fs(fs, res); return res; }
#else
#define ENTER_FF(fs)
#define LEAVE_FF(fs, res)   return res
#endif

#define ABORT(fs, res)      { fp->flag |= FA__ERROR; LEAVE_FF(fs, res); }


/* File shareing feature */
#if _FS_SHARE
#if _FS_READONLY
#error _FS_SHARE must be 0 on read-only cfg.
#endif
typedef struct
{
    FATFS* fs;              /* File ID 1, volume (NULL:blank entry) */
    DWORD clu;              /* File ID 2, directory */
    WORD idx;               /* File ID 3, directory index */
    WORD ctr;               /* File open counter, 0:none, 0x01..0xFF:read open count, 0x100:write mode */
} FILESEM;
#endif


/* Misc definitions */
#define LD_CLUST(dir)   (((DWORD)LD_WORD(dir+DIR_FstClusHI)<<16) | LD_WORD(dir+DIR_FstClusLO))
#define ST_CLUST(dir,cl) {ST_WORD(dir+DIR_FstClusLO, cl); ST_WORD(dir+DIR_FstClusHI, (DWORD)cl>>16);}


/* Character code support macros */
#define IsUpper(c)  (((c)>='A')&&((c)<='Z'))
#define IsLower(c)  (((c)>='a')&&((c)<='z'))
#define IsDigit(c)  (((c)>='0')&&((c)<='9'))

#if _DF1S       /* Code page is DBCS */

#ifdef _DF2S    /* Two 1st byte areas */
#define IsDBCS1(c)  (((BYTE)(c) >= _DF1S && (BYTE)(c) <= _DF1E) || ((BYTE)(c) >= _DF2S && (BYTE)(c) <= _DF2E))
#else           /* One 1st byte area */
#define IsDBCS1(c)  ((BYTE)(c) >= _DF1S && (BYTE)(c) <= _DF1E)
#endif

#ifdef _DS3S    /* Three 2nd byte areas */
#define IsDBCS2(c)  (((BYTE)(c) >= _DS1S && (BYTE)(c) <= _DS1E) || ((BYTE)(c) >= _DS2S && (BYTE)(c) <= _DS2E) || ((BYTE)(c) >= _DS3S && (BYTE)(c) <= _DS3E))
#else           /* Two 2nd byte areas */
#define IsDBCS2(c)  (((BYTE)(c) >= _DS1S && (BYTE)(c) <= _DS1E) || ((BYTE)(c) >= _DS2S && (BYTE)(c) <= _DS2E))
#endif

#else           /* Code page is SBCS */

#define IsDBCS1(c)  0
#define IsDBCS2(c)  0

#endif /* _DF1S */


/* Name status flags */
#define NS          11      /* Offset of name status byte */
#define NS_LOSS     0x01    /* Out of 8.3 format */
#define NS_LFN      0x02    /* Force to create LFN entry */
#define NS_LAST     0x04    /* Last segment */
#define NS_BODY     0x08    /* Lower case flag (body) */
#define NS_EXT      0x10    /* Lower case flag (ext) */
#define NS_DOT      0x20    /* Dot entry */


/* FAT sub-type boundaries */
/* Note that the FAT spec by Microsoft says 4085 but Windows works with 4087! */
#define MIN_FAT16   4086    /* Minimum number of clusters for FAT16 */
#define MIN_FAT32   65526   /* Minimum number of clusters for FAT32 */


/* FatFs refers the members in the FAT structures as byte array instead of
/ structure member because there are incompatibility of the packing option
/ between compilers. */

#define BS_jmpBoot          0
#define BS_OEMName          3
#define BPB_BytsPerSec      11
#define BPB_SecPerClus      13
#define BPB_RsvdSecCnt      14
#define BPB_NumFATs         16
#define BPB_RootEntCnt      17
#define BPB_TotSec16        19
#define BPB_Media           21
#define BPB_FATSz16         22
#define BPB_SecPerTrk       24
#define BPB_NumHeads        26
#define BPB_HiddSec         28
#define BPB_TotSec32        32
#define BS_DrvNum           36
#define BS_BootSig          38
#define BS_VolID            39
#define BS_VolLab           43
#define BS_FilSysType       54
#define BPB_FATSz32         36
#define BPB_ExtFlags        40
#define BPB_FSVer           42
#define BPB_RootClus        44
#define BPB_FSInfo          48
#define BPB_BkBootSec       50
#define BS_DrvNum32         64
#define BS_BootSig32        66
#define BS_VolID32          67
#define BS_VolLab32         71
#define BS_FilSysType32     82
#define FSI_LeadSig         0
#define FSI_StrucSig        484
#define FSI_Free_Count      488
#define FSI_Nxt_Free        492
#define MBR_Table           446
#define BS_55AA             510

#define DIR_Name            0
#define DIR_Attr            11
#define DIR_NTres           12
#define DIR_CrtTime         14
#define DIR_CrtDate         16
#define DIR_FstClusHI       20
#define DIR_WrtTime         22
#define DIR_WrtDate         24
#define DIR_FstClusLO       26
#define DIR_FileSize        28
#define LDIR_Ord            0
#define LDIR_Attr           11
#define LDIR_Type           12
#define LDIR_Chksum         13
#define LDIR_FstClusLO      26



/*------------------------------------------------------------*/
/* Work area                                                  */

#if _VOLUMES
FATFS* FatFs[_VOLUMES]; /* Pointer to the file system objects (logical drives) */
#else
#error Number of drives must not be 0.
#endif

static
WORD Fsid;              /* File system mount ID */

#if _FS_RPATH
static
BYTE CurrVol;           /* Current drive */
#endif

#if _FS_SHARE
static
FILESEM Files[_FS_SHARE];   /* File lock semaphores */
#endif

#if _USE_LFN == 0           /* No LFN */
#define DEF_NAMEBUF         BYTE sfn[12]
#define INIT_BUF(dobj)      (dobj).fn = sfn
#define FREE_BUF()

#elif _USE_LFN == 1         /* LFN with static LFN working buffer */
WCHAR LfnBuf[_MAX_LFN + 1];
#define DEF_NAMEBUF         BYTE sfn[12]
#define INIT_BUF(dobj)      { (dobj).fn = sfn; (dobj).lfn = LfnBuf; }
#define FREE_BUF()

#elif _USE_LFN == 2         /* LFN with dynamic LFN working buffer on the stack */
#define DEF_NAMEBUF         BYTE sfn[12]; WCHAR lbuf[_MAX_LFN+1]
#define INIT_BUF(dobj)      { (dobj).fn = sfn; (dobj).lfn = lbuf; }
#define FREE_BUF()

#elif _USE_LFN == 3         /* LFN with dynamic LFN working buffer on the heap */
#define DEF_NAMEBUF         BYTE sfn[12]; WCHAR *lfn
#define INIT_BUF(dobj)      { lfn = ff_memalloc((_MAX_LFN + 1) * 2); \
                              if (!lfn) LEAVE_FF((dobj).fs, FR_NOT_ENOUGH_CORE); \
                              (dobj).lfn = lfn; (dobj).fn = sfn; }
#define FREE_BUF()          ff_memfree(lfn)

#else
#error Wrong LFN configuration.
#endif




/*--------------------------------------------------------------------------

   Module Private Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* String functions                                                      */
/*-----------------------------------------------------------------------*/

/* Copy memory to memory */
NODEBUG void mem_cpy( void* dst, const void* src, UINT cnt )
{
    BYTE* d = ( BYTE* )dst;
    const BYTE* s = ( const BYTE* )src;

#if _WORD_ACCESS == 1
    while ( cnt >= sizeof( int ) )
    {
        *( int* )d = *( int* )s;
        d += sizeof( int ); s += sizeof( int );
        cnt -= sizeof( int );
    }
#endif
    while ( cnt-- )
        *d++ = *s++;
}


NODEBUG void str_cpy( char* Dest ,  const char* Src )
{
    while ( *Src )
    {
        *Dest++ = *Src++;
    }
    *Dest = 0;
}



/* Fill memory */
NODEBUG void mem_set( void* dst, int val, UINT cnt )
{
    BYTE* d = ( BYTE* )dst;

    while ( cnt-- )
        *d++ = ( BYTE )val;
}

/* Compare memory to memory */
NODEBUG int mem_cmp( const void* dst, const void* src, UINT cnt )
{
    const BYTE* d = ( const BYTE* )dst, *s = ( const BYTE* )src;
    int r = 0;

    while ( cnt-- && ( r = *d++ - *s++ ) == 0 ) ;
    return r;
}

/* Check if chr is contained in the string */
NODEBUG int chk_chr( const char* str, int chr )
{
    while ( *str && *str != chr ) str++;
    return *str;
}



/*-----------------------------------------------------------------------*/
/* Request/Release grant to access the volume                            */
/*-----------------------------------------------------------------------*/
#if _FS_REENTRANT

NODEBUG static
int lock_fs(
    FATFS* fs       /* File system object */
)
{
    return ff_req_grant( fs->sobj );
}


NODEBUG static
void unlock_fs(
    FATFS* fs,      /* File system object */
    FRESULT res     /* Result code to be returned */
)
{
    if ( res != FR_NOT_ENABLED &&
            res != FR_INVALID_DRIVE &&
            res != FR_INVALID_OBJECT &&
            res != FR_TIMEOUT )
    {
        ff_rel_grant( fs->sobj );
    }
}
#endif



/*-----------------------------------------------------------------------*/
/* File shareing control functions                                       */
/*-----------------------------------------------------------------------*/
#if _FS_SHARE

NODEBUG static
FRESULT chk_lock(  /* Check if the file can be accessed */
    DIR* dj,        /* Directory object pointing the file to be checked */
    int acc         /* Desired access (0:Read, 1:Write, 2:Delete/Rename) */
)
{
    UINT i, be;

    /* Search file semaphore table */
    for ( i = be = 0; i < _FS_SHARE; i++ )
    {
        if ( Files[i].fs )  /* Existing entry */
        {
            if ( Files[i].fs == dj->fs &&       /* Check if the file matched with an open file */
                    Files[i].clu == dj->sclust &&
                    Files[i].idx == dj->index ) break;
        }
        else                /* Blank entry */
        {
            be++;
        }
    }
    if ( i == _FS_SHARE ) /* The file is not opened */
        return ( be || acc == 2 ) ? FR_OK : FR_TOO_MANY_OPEN_FILES; /* Is there a blank entry for new file? */

    /* The file has been opened. Reject any open against writing file and all write mode open */
    return ( acc || Files[i].ctr == 0x100 ) ? FR_LOCKED : FR_OK;
}


NODEBUG static
int enq_lock(  /* Check if an entry is available for a new file */
    FATFS* fs   /* File system object */
)
{
    UINT i;

    for ( i = 0; i < _FS_SHARE && Files[i].fs; i++ ) ;
    return ( i == _FS_SHARE ) ? 0 : 1;
}


NODEBUG static
UINT inc_lock(  /* Increment file open counter and returns its index (0:int error) */
    DIR* dj,    /* Directory object pointing the file to register or increment */
    int acc     /* Desired access mode (0:Read, !0:Write) */
)
{
    UINT i;


    for ( i = 0; i < _FS_SHARE; i++ )   /* Find the file */
    {
        if ( Files[i].fs == dj->fs &&
                Files[i].clu == dj->sclust &&
                Files[i].idx == dj->index ) break;
    }

    if ( i == _FS_SHARE )               /* Not opened. Register it as new. */
    {
        for ( i = 0; i < _FS_SHARE && Files[i].fs; i++ ) ;
        if ( i == _FS_SHARE ) return 0; /* No space to register (int err) */
        Files[i].fs = dj->fs;
        Files[i].clu = dj->sclust;
        Files[i].idx = dj->index;
        Files[i].ctr = 0;
    }

    if ( acc && Files[i].ctr ) return 0; /* Access violation (int err) */

    Files[i].ctr = acc ? 0x100 : Files[i].ctr + 1;  /* Set semaphore value */

    return i + 1;
}


NODEBUG static
FRESULT dec_lock(  /* Decrement file open counter */
    UINT i          /* Semaphore index */
)
{
    WORD n;
    FRESULT res;


    if ( --i < _FS_SHARE )
    {
        n = Files[i].ctr;
        if ( n == 0x100 ) n = 0;
        if ( n ) n--;
        Files[i].ctr = n;
        if ( !n ) Files[i].fs = 0;
        res = FR_OK;
    }
    else
    {
        res = FR_INT_ERR;
    }
    return res;
}


NODEBUG static
void clear_lock(  /* Clear lock entries of the volume */
    FATFS* fs
)
{
    UINT i;

    for ( i = 0; i < _FS_SHARE; i++ )
    {
        if ( Files[i].fs == fs ) Files[i].fs = 0;
    }
}
#endif



/*-----------------------------------------------------------------------*/
/* Change window offset                                                  */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT move_window(
    FATFS* fs,      /* File system object */
    DWORD sector    /* Sector number to make appearance in the fs->win[] */
)                   /* Move to zero only writes back dirty window */
{
    DWORD wsect;


    wsect = fs->winsect;
    if ( wsect != sector )  /* Changed current window */
    {
#if !_FS_READONLY
        if ( fs->wflag )    /* Write back dirty window if needed */
        {
            if ( disk_write( fs->drv, fs->win, wsect, 1 ) != RES_OK )
                return FR_DISK_ERR;
            fs->wflag = 0;
            if ( wsect < ( fs->fatbase + fs->fsize ) )  /* In FAT area */
            {
                BYTE nf;
                for ( nf = fs->n_fats; nf > 1; nf-- )   /* Reflect the change to all FAT copies */
                {
                    wsect += fs->fsize;
                    disk_write( fs->drv, fs->win, wsect, 1 );
                }
            }
        }
#endif
        if ( sector )
        {
            if ( disk_read( fs->drv, fs->win, sector, 1 ) != RES_OK )
                return FR_DISK_ERR;
            fs->winsect = sector;
        }
    }

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Clean-up cached data                                                  */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
NODEBUG static
FRESULT sync(  /* FR_OK: successful, FR_DISK_ERR: failed */
    FATFS* fs   /* File system object */
)
{
    FRESULT res;


    res = move_window( fs, 0 );
    if ( res == FR_OK )
    {
        /* Update FSInfo sector if needed */
        if ( fs->fs_type == FS_FAT32 && fs->fsi_flag )
        {
            fs->winsect = 0;
            mem_set( fs->win, 0, 512 );
            ST_WORD( fs->win + BS_55AA, 0xAA55 );
            ST_DWORD( fs->win + FSI_LeadSig, 0x41615252 );
            ST_DWORD( fs->win + FSI_StrucSig, 0x61417272 );
            ST_DWORD( fs->win + FSI_Free_Count, fs->free_clust );
            ST_DWORD( fs->win + FSI_Nxt_Free, fs->last_clust );
            disk_write( fs->drv, fs->win, fs->fsi_sector, 1 );
            fs->fsi_flag = 0;
        }
        /* Make sure that no pending write process in the physical drive */
        if ( disk_ioctl( fs->drv, CTRL_SYNC, ( void* )0 ) != RES_OK )
            res = FR_DISK_ERR;
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* Get sector# from cluster#                                             */
/*-----------------------------------------------------------------------*/


NODEBUG2 DWORD clust2sect(  /* !=0: Sector number, 0: Failed - invalid cluster# */
    FATFS* fs,      /* File system object */
    DWORD clst      /* Cluster# to be converted */
)
{
    clst -= 2;
    if ( clst >= ( fs->n_fatent - 2 ) ) return 0;   /* Invalid cluster# */
    return clst * fs->csize + fs->database;
}




/*-----------------------------------------------------------------------*/
/* FAT access - Read value of a FAT entry                                */
/*-----------------------------------------------------------------------*/


NODEBUG2 DWORD get_fat(  /* 0xFFFFFFFF:Disk error, 1:Internal error, Else:Cluster status */
    FATFS* fs,  /* File system object */
    DWORD clst  /* Cluster# to get the link information */
)
{
    UINT wc, bc;
    BYTE* p;


    if ( clst < 2 || clst >= fs->n_fatent ) /* Chack range */
        return 1;

    switch ( fs->fs_type )
    {
    case FS_FAT12 :
        bc = ( UINT )clst; bc += bc / 2;
        if ( move_window( fs, fs->fatbase + ( bc / SS( fs ) ) ) ) break;
        wc = fs->win[bc % SS( fs )]; bc++;
        if ( move_window( fs, fs->fatbase + ( bc / SS( fs ) ) ) ) break;
        wc |= fs->win[bc % SS( fs )] << 8;
        return ( clst & 1 ) ? ( wc >> 4 ) : ( wc & 0xFFF );

    case FS_FAT16 :
        if ( move_window( fs, fs->fatbase + ( clst / ( SS( fs ) / 2 ) ) ) ) break;
        p = &fs->win[clst * 2 % SS( fs )];
        return LD_WORD( p );

    case FS_FAT32 :
        if ( move_window( fs, fs->fatbase + ( clst / ( SS( fs ) / 4 ) ) ) ) break;
        p = &fs->win[clst * 4 % SS( fs )];
        return LD_DWORD( p ) & 0x0FFFFFFF;
    }

    return 0xFFFFFFFF;  /* An error occurred at the disk I/O layer */
}




/*-----------------------------------------------------------------------*/
/* FAT access - Change value of a FAT entry                              */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY

NODEBUG2 FRESULT put_fat(
    FATFS* fs,  /* File system object */
    DWORD clst, /* Cluster# to be changed in range of 2 to fs->n_fatent - 1 */
    DWORD val   /* New value to mark the cluster */
)
{
    UINT bc;
    BYTE* p;
    FRESULT res;


    if ( clst < 2 || clst >= fs->n_fatent ) /* Check range */
    {
        res = FR_INT_ERR;

    }
    else
    {
        switch ( fs->fs_type )
        {
        case FS_FAT12 :
            bc = clst; bc += bc / 2;
            res = move_window( fs, fs->fatbase + ( bc / SS( fs ) ) );
            if ( res != FR_OK ) break;
            p = &fs->win[bc % SS( fs )];
            *p = ( clst & 1 ) ? ( ( *p & 0x0F ) | ( ( BYTE )val << 4 ) ) : ( BYTE )val;
            bc++;
            fs->wflag = 1;
            res = move_window( fs, fs->fatbase + ( bc / SS( fs ) ) );
            if ( res != FR_OK ) break;
            p = &fs->win[bc % SS( fs )];
            *p = ( clst & 1 ) ? ( BYTE )( val >> 4 ) : ( ( *p & 0xF0 ) | ( ( BYTE )( val >> 8 ) & 0x0F ) );
            break;

        case FS_FAT16 :
            res = move_window( fs, fs->fatbase + ( clst / ( SS( fs ) / 2 ) ) );
            if ( res != FR_OK ) break;
            p = &fs->win[clst * 2 % SS( fs )];
            ST_WORD( p, ( WORD )val );
            break;

        case FS_FAT32 :
            res = move_window( fs, fs->fatbase + ( clst / ( SS( fs ) / 4 ) ) );
            if ( res != FR_OK ) break;
            p = &fs->win[clst * 4 % SS( fs )];
            val |= LD_DWORD( p ) & 0xF0000000;
            ST_DWORD( p, val );
            break;

        default :
            res = FR_INT_ERR;
        }
        fs->wflag = 1;
    }

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* FAT handling - Remove a cluster chain                                 */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
NODEBUG static
FRESULT remove_chain(
    FATFS* fs,          /* File system object */
    DWORD clst          /* Cluster# to remove a chain from */
)
{
    FRESULT res;
    DWORD nxt;
#if _USE_ERASE
    DWORD scl = clst, ecl = clst, resion[2];
#endif

    if ( clst < 2 || clst >= fs->n_fatent ) /* Check range */
    {
        res = FR_INT_ERR;

    }
    else
    {
        res = FR_OK;
        while ( clst < fs->n_fatent )           /* Not a last link? */
        {
            nxt = get_fat( fs, clst );          /* Get cluster status */
            if ( nxt == 0 ) break;              /* Empty cluster? */
            if ( nxt == 1 ) { res = FR_INT_ERR; break; } /* Internal error? */
            if ( nxt == 0xFFFFFFFF ) { res = FR_DISK_ERR; break; }  /* Disk error? */
            res = put_fat( fs, clst, 0 );       /* Mark the cluster "empty" */
            if ( res != FR_OK ) break;
            if ( fs->free_clust != 0xFFFFFFFF ) /* Update FSInfo */
            {
                fs->free_clust++;
                fs->fsi_flag = 1;
            }
#if _USE_ERASE
            if ( ecl + 1 == nxt )   /* Next cluster is contiguous */
            {
                ecl = nxt;
            }
            else                    /* End of contiguous clusters */
            {
                resion[0] = clust2sect( fs, scl );                  /* Start sector */
                resion[1] = clust2sect( fs, ecl ) + fs->csize - 1;  /* End sector */
                disk_ioctl( fs->drv, CTRL_ERASE_SECTOR, resion );   /* Erase the block */
                scl = ecl = nxt;
            }
#endif
            clst = nxt; /* Next cluster */
        }
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* FAT handling - Stretch or Create a cluster chain                      */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
NODEBUG static
DWORD create_chain(  /* 0:No free cluster, 1:Internal error, 0xFFFFFFFF:Disk error, >=2:New cluster# */
    FATFS* fs,          /* File system object */
    DWORD clst          /* Cluster# to stretch. 0 means create a new chain. */
)
{
    DWORD cs, ncl, scl;
    FRESULT res;


    if ( clst == 0 )        /* Create a new chain */
    {
        scl = fs->last_clust;           /* Get suggested start point */
        if ( !scl || scl >= fs->n_fatent ) scl = 1;
    }
    else                    /* Stretch the current chain */
    {
        cs = get_fat( fs, clst );       /* Check the cluster status */
        if ( cs < 2 ) return 1;         /* It is an invalid cluster */
        if ( cs < fs->n_fatent ) return cs; /* It is already followed by next cluster */
        scl = clst;
    }

    ncl = scl;              /* Start cluster */
    for ( ;; )
    {
        ncl++;                          /* Next cluster */
        if ( ncl >= fs->n_fatent )      /* Wrap around */
        {
            ncl = 2;
            if ( ncl > scl ) return 0;  /* No free cluster */
        }
        cs = get_fat( fs, ncl );        /* Get the cluster status */
        if ( cs == 0 ) break;           /* Found a free cluster */
        if ( cs == 0xFFFFFFFF || cs == 1 ) /* An error occurred */
            return cs;
        if ( ncl == scl ) return 0;     /* No free cluster */
    }

    res = put_fat( fs, ncl, 0x0FFFFFFF ); /* Mark the new cluster "last link" */
    if ( res == FR_OK && clst != 0 )
    {
        res = put_fat( fs, clst, ncl ); /* Link it to the previous one if needed */
    }
    if ( res == FR_OK )
    {
        fs->last_clust = ncl;           /* Update FSINFO */
        if ( fs->free_clust != 0xFFFFFFFF )
        {
            fs->free_clust--;
            fs->fsi_flag = 1;
        }
    }
    else
    {
        ncl = ( res == FR_DISK_ERR ) ? 0xFFFFFFFF : 1;
    }

    return ncl;     /* Return new cluster number or error code */
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Directory handling - Set directory index                              */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT dir_sdi(
    DIR* dj,        /* Pointer to directory object */
    WORD idx        /* Directory index number */
)
{
    DWORD clst;
    WORD ic;


    dj->index = idx;
    clst = dj->sclust;
    if ( clst == 1 || clst >= dj->fs->n_fatent ) /* Check start cluster range */
        return FR_INT_ERR;
    if ( !clst && dj->fs->fs_type == FS_FAT32 ) /* Replace cluster# 0 with root cluster# if in FAT32 */
        clst = dj->fs->dirbase;

    if ( clst == 0 )    /* Static table (root-dir in FAT12/16) */
    {
        dj->clust = clst;
        if ( idx >= dj->fs->n_rootdir )     /* Index is out of range */
            return FR_INT_ERR;
        dj->sect = dj->fs->dirbase + idx / ( SS( dj->fs ) / 32 ); /* Sector# */
    }
    else                /* Dynamic table (sub-dirs or root-dir in FAT32) */
    {
        ic = SS( dj->fs ) / 32 * dj->fs->csize; /* Entries per cluster */
        while ( idx >= ic ) /* Follow cluster chain */
        {
            clst = get_fat( dj->fs, clst );             /* Get next cluster */
            if ( clst == 0xFFFFFFFF ) return FR_DISK_ERR; /* Disk error */
            if ( clst < 2 || clst >= dj->fs->n_fatent ) /* Reached to end of table or int error */
                return FR_INT_ERR;
            idx -= ic;
        }
        dj->clust = clst;
        dj->sect = clust2sect( dj->fs, clst ) + idx / ( SS( dj->fs ) / 32 ); /* Sector# */
    }

    dj->dir = dj->fs->win + ( idx % ( SS( dj->fs ) / 32 ) ) * 32; /* Ptr to the entry in the sector */

    return FR_OK;   /* Seek succeeded */
}




/*-----------------------------------------------------------------------*/
/* Directory handling - Move directory index next                        */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT dir_next(  /* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not stretch */
    DIR* dj,        /* Pointer to directory object */
    int stretch     /* 0: Do not stretch table, 1: Stretch table if needed */
)
{
    DWORD clst;
    WORD i;


    i = dj->index + 1;
    if ( !i || !dj->sect )  /* Report EOT when index has reached 65535 */
        return FR_NO_FILE;

    if ( !( i % ( SS( dj->fs ) / 32 ) ) ) /* Sector changed? */
    {
        dj->sect++;                 /* Next sector */

        if ( dj->clust == 0 )   /* Static table */
        {
            if ( i >= dj->fs->n_rootdir ) /* Report EOT when end of table */
                return FR_NO_FILE;
        }
        else                    /* Dynamic table */
        {
            if ( ( ( i / ( SS( dj->fs ) / 32 ) ) & ( dj->fs->csize - 1 ) ) == 0 ) /* Cluster changed? */
            {
                clst = get_fat( dj->fs, dj->clust );            /* Get next cluster */
                if ( clst <= 1 ) return FR_INT_ERR;
                if ( clst == 0xFFFFFFFF ) return FR_DISK_ERR;
                if ( clst >= dj->fs->n_fatent )                 /* When it reached end of dynamic table */
                {
#if !_FS_READONLY
                    BYTE c;
                    if ( !stretch ) return FR_NO_FILE;          /* When do not stretch, report EOT */
                    clst = create_chain( dj->fs, dj->clust );   /* Stretch cluster chain */
                    if ( clst == 0 ) return FR_DENIED;          /* No free cluster */
                    if ( clst == 1 ) return FR_INT_ERR;
                    if ( clst == 0xFFFFFFFF ) return FR_DISK_ERR;
                    /* Clean-up stretched table */
                    if ( move_window( dj->fs, 0 ) ) return FR_DISK_ERR; /* Flush active window */
                    mem_set( dj->fs->win, 0, SS( dj->fs ) );        /* Clear window buffer */
                    dj->fs->winsect = clust2sect( dj->fs, clst ); /* Cluster start sector */
                    for ( c = 0; c < dj->fs->csize; c++ )       /* Fill the new cluster with 0 */
                    {
                        dj->fs->wflag = 1;
                        if ( move_window( dj->fs, 0 ) ) return FR_DISK_ERR;
                        dj->fs->winsect++;
                    }
                    dj->fs->winsect -= c;                       /* Rewind window address */
#else
                    return FR_NO_FILE;          /* Report EOT */
#endif
                }
                dj->clust = clst;               /* Initialize data for new cluster */
                dj->sect = clust2sect( dj->fs, clst );
            }
        }
    }

    dj->index = i;
    dj->dir = dj->fs->win + ( i % ( SS( dj->fs ) / 32 ) ) * 32;

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* LFN handling - Test/Pick/Fit an LFN segment from/to directory entry   */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
static
const BYTE LfnOfs[] = {1, 3, 5, 7, 9, 14, 16, 18, 20, 22, 24, 28, 30}; /* Offset of LFN chars in the directory entry */


NODEBUG static
int cmp_lfn(    /* 1:Matched, 0:Not matched */
    WCHAR* lfnbuf,      /* Pointer to the LFN to be compared */
    BYTE* dir           /* Pointer to the directory entry containing a part of LFN */
)
{
    UINT i, s;
    WCHAR wc, uc;


    i = ( ( dir[LDIR_Ord] & 0xBF ) - 1 ) * 13; /* Get offset in the LFN buffer */
    s = 0; wc = 1;
    do
    {
        uc = LD_WORD( dir + LfnOfs[s] ); /* Pick an LFN character from the entry */
        if ( wc )   /* Last char has not been processed */
        {
            wc = ff_wtoupper( uc );     /* Convert it to upper case */
            if ( i >= _MAX_LFN || wc != ff_wtoupper( lfnbuf[i++] ) ) /* Compare it */
                return 0;               /* Not matched */
        }
        else
        {
            if ( uc != 0xFFFF ) return 0; /* Check filler */
        }
    }
    while ( ++s < 13 );             /* Repeat until all chars in the entry are checked */

    if ( ( dir[LDIR_Ord] & 0x40 ) && wc && lfnbuf[i] ) /* Last segment matched but different length */
        return 0;

    return 1;                       /* The part of LFN matched */
}



NODEBUG static
int pick_lfn(    /* 1:Succeeded, 0:Buffer overflow */
    WCHAR* lfnbuf,      /* Pointer to the Unicode-LFN buffer */
    BYTE* dir           /* Pointer to the directory entry */
)
{
    UINT i, s;
    WCHAR wc, uc;


    i = ( ( dir[LDIR_Ord] & 0x3F ) - 1 ) * 13; /* Offset in the LFN buffer */

    s = 0; wc = 1;
    do
    {
        uc = LD_WORD( dir + LfnOfs[s] );    /* Pick an LFN character from the entry */
        if ( wc )   /* Last char has not been processed */
        {
            if ( i >= _MAX_LFN ) return 0;  /* Buffer overflow? */
            lfnbuf[i++] = wc = uc;          /* Store it */
        }
        else
        {
            if ( uc != 0xFFFF ) return 0;   /* Check filler */
        }
    }
    while ( ++s < 13 );                     /* Read all character in the entry */

    if ( dir[LDIR_Ord] & 0x40 )             /* Put terminator if it is the last LFN part */
    {
        if ( i >= _MAX_LFN ) return 0;      /* Buffer overflow? */
        lfnbuf[i] = 0;
    }

    return 1;
}


#if !_FS_READONLY
NODEBUG static
void fit_lfn(
    const WCHAR* lfnbuf,    /* Pointer to the LFN buffer */
    BYTE* dir,              /* Pointer to the directory entry */
    BYTE ord,               /* LFN order (1-20) */
    BYTE sum                /* SFN sum */
)
{
    UINT i, s;
    WCHAR wc;


    dir[LDIR_Chksum] = sum;         /* Set check sum */
    dir[LDIR_Attr] = AM_LFN;        /* Set attribute. LFN entry */
    dir[LDIR_Type] = 0;
    ST_WORD( dir + LDIR_FstClusLO, 0 );

    i = ( ord - 1 ) * 13;           /* Get offset in the LFN buffer */
    s = wc = 0;
    do
    {
        if ( wc != 0xFFFF ) wc = lfnbuf[i++]; /* Get an effective char */
        ST_WORD( dir + LfnOfs[s], wc ); /* Put it */
        if ( !wc ) wc = 0xFFFF;     /* Padding chars following last char */
    }
    while ( ++s < 13 );
    if ( wc == 0xFFFF || !lfnbuf[i] ) ord |= 0x40;  /* Bottom LFN part is the start of LFN sequence */
    dir[LDIR_Ord] = ord;            /* Set the LFN order */
}

#endif
#endif



/*-----------------------------------------------------------------------*/
/* Create numbered name                                                  */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
NODEBUG2 void gen_numname(
    BYTE* dst,          /* Pointer to generated SFN */
    const BYTE* src,    /* Pointer to source SFN to be modified */
    const WCHAR* lfn,   /* Pointer to LFN */
    WORD seq            /* Sequence number */
)
{
    BYTE ns[8], c;
    UINT i, j;


    mem_cpy( dst, src, 11 );

    if ( seq > 5 )  /* On many collisions, generate a hash number instead of sequential number */
    {
        do seq = ( seq >> 1 ) + ( seq << 15 ) + ( WORD ) * lfn++; while ( *lfn );
    }

    /* itoa */
    i = 7;
    do
    {
        c = ( seq % 16 ) + '0';
        if ( c > '9' ) c += 7;
        ns[i--] = c;
        seq /= 16;
    }
    while ( seq );
    ns[i] = '~';

    /* Append the number */
    for ( j = 0; j < i && dst[j] != ' '; j++ )
    {
        if ( IsDBCS1( dst[j] ) )
        {
            if ( j == i - 1 ) break;
            j++;
        }
    }
    do
    {
        dst[j++] = ( i < 8 ) ? ns[i++] : ' ';
    }
    while ( j < 8 );
}
#endif




/*-----------------------------------------------------------------------*/
/* Calculate sum of an SFN                                               */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
NODEBUG static
BYTE sum_sfn(
    const BYTE* dir     /* Ptr to directory entry */
)
{
    BYTE sum = 0;
    UINT n = 11;

    do sum = ( sum >> 1 ) + ( sum << 7 ) + *dir++; while ( --n );
    return sum;
}
#endif




/*-----------------------------------------------------------------------*/
/* Directory handling - Find an object in the directory                  */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT dir_find(
    DIR* dj         /* Pointer to the directory object linked to the file name */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN
    BYTE a, ord, sum;
#endif

    res = dir_sdi( dj, 0 );         /* Rewind directory object */
    if ( res != FR_OK ) return res;

#if _USE_LFN
    ord = sum = 0xFF;
#endif
    do
    {
        res = move_window( dj->fs, dj->sect );
        if ( res != FR_OK ) break;
        dir = dj->dir;                  /* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if ( c == 0 ) { res = FR_NO_FILE; break; }  /* Reached to end of table */
#if _USE_LFN    /* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if ( c == 0xE5 || ( ( a & AM_VOL ) && a != AM_LFN ) ) /* An entry without valid data */
        {
            ord = 0xFF;
        }
        else
        {
            if ( a == AM_LFN )          /* An LFN entry is found */
            {
                if ( dj->lfn )
                {
                    if ( c & 0x40 )     /* Is it start of LFN sequence? */
                    {
                        sum = dir[LDIR_Chksum];
                        c &= 0xBF; ord = c; /* LFN start order */
                        dj->lfn_idx = dj->index;
                    }
                    /* Check validity of the LFN entry and compare it with given name */
                    ord = ( c == ord && sum == dir[LDIR_Chksum] && cmp_lfn( dj->lfn, dir ) ) ? ord - 1 : 0xFF;
                }
            }
            else                        /* An SFN entry is found */
            {
                if ( !ord && sum == sum_sfn( dir ) ) break; /* LFN matched? */
                ord = 0xFF; dj->lfn_idx = 0xFFFF;   /* Reset LFN sequence */
                if ( !( dj->fn[NS] & NS_LOSS ) && !mem_cmp( dir, dj->fn, 11 ) ) break; /* SFN matched? */
            }
        }
#else       /* Non LFN configuration */
        if ( !( dir[DIR_Attr] & AM_VOL ) && !mem_cmp( dir, dj->fn, 11 ) ) /* Is it a valid entry? */
            break;
#endif
        res = dir_next( dj, 0 );    /* Next entry */
    }
    while ( res == FR_OK );

    return res;
}




/*-----------------------------------------------------------------------*/
/* Read an object from the directory                                     */
/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
NODEBUG static
FRESULT dir_read(
    DIR* dj         /* Pointer to the directory object that pointing the entry to be read */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN
    BYTE a, ord = 0xFF, sum = 0xFF;
#endif

    res = FR_NO_FILE;
    while ( dj->sect )
    {
        res = move_window( dj->fs, dj->sect );
        if ( res != FR_OK ) break;
        dir = dj->dir;                  /* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if ( c == 0 ) { res = FR_NO_FILE; break; }  /* Reached to end of table */
#if _USE_LFN    /* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if ( c == 0xE5 || ( !_FS_RPATH && c == '.' ) || ( ( a & AM_VOL ) && a != AM_LFN ) ) /* An entry without valid data */
        {
            ord = 0xFF;
        }
        else
        {
            if ( a == AM_LFN )          /* An LFN entry is found */
            {
                if ( c & 0x40 )         /* Is it start of LFN sequence? */
                {
                    sum = dir[LDIR_Chksum];
                    c &= 0xBF; ord = c;
                    dj->lfn_idx = dj->index;
                }
                /* Check LFN validity and capture it */
                ord = ( c == ord && sum == dir[LDIR_Chksum] && pick_lfn( dj->lfn, dir ) ) ? ord - 1 : 0xFF;
            }
            else                        /* An SFN entry is found */
            {
                if ( ord || sum != sum_sfn( dir ) ) /* Is there a valid LFN? */
                    dj->lfn_idx = 0xFFFF;       /* It has no LFN. */
                break;
            }
        }
#else       /* Non LFN configuration */
        if ( c != 0xE5 && ( _FS_RPATH || c != '.' ) && !( dir[DIR_Attr] & AM_VOL ) ) /* Is it a valid entry? */
            break;
#endif
        res = dir_next( dj, 0 );            /* Next entry */
        if ( res != FR_OK ) break;
    }

    if ( res != FR_OK ) dj->sect = 0;

    return res;
}
#endif



/*-----------------------------------------------------------------------*/
/* Register an object to the directory                                   */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
NODEBUG static
FRESULT dir_register(  /* FR_OK:Successful, FR_DENIED:No free entry or too many SFN collision, FR_DISK_ERR:Disk error */
    DIR* dj             /* Target directory with object name to be created */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN    /* LFN configuration */
    WORD n, ne, is;
    BYTE sn[12], *fn, sum;
    WCHAR* lfn;


    fn = dj->fn; lfn = dj->lfn;
    mem_cpy( sn, fn, 12 );

    if ( _FS_RPATH && ( sn[NS] & NS_DOT ) ) /* Cannot create dot entry */
        return FR_INVALID_NAME;

    if ( sn[NS] & NS_LOSS )         /* When LFN is out of 8.3 format, generate a numbered name */
    {
        fn[NS] = 0; dj->lfn = 0;            /* Find only SFN */
        for ( n = 1; n < 100; n++ )
        {
            gen_numname( fn, sn, lfn, n );  /* Generate a numbered name */
            res = dir_find( dj );           /* Check if the name collides with existing SFN */
            if ( res != FR_OK ) break;
        }
        if ( n == 100 ) return FR_DENIED;   /* Abort if too many collisions */
        if ( res != FR_NO_FILE ) return res; /* Abort if the result is other than 'not collided' */
        fn[NS] = sn[NS]; dj->lfn = lfn;
    }

    if ( sn[NS] & NS_LFN )          /* When LFN is to be created, reserve an SFN + LFN entries. */
    {
        for ( ne = 0; lfn[ne]; ne++ ) ;
        ne = ( ne + 25 ) / 13;
    }
    else                            /* Otherwise reserve only an SFN entry. */
    {
        ne = 1;
    }

    /* Reserve contiguous entries */
    res = dir_sdi( dj, 0 );
    if ( res != FR_OK ) return res;
    n = is = 0;
    do
    {
        res = move_window( dj->fs, dj->sect );
        if ( res != FR_OK ) break;
        c = *dj->dir;               /* Check the entry status */
        if ( c == 0xE5 || c == 0 )  /* Is it a blank entry? */
        {
            if ( n == 0 ) is = dj->index; /* First index of the contiguous entry */
            if ( ++n == ne ) break; /* A contiguous entry that required count is found */
        }
        else
        {
            n = 0;                  /* Not a blank entry. Restart to search */
        }
        res = dir_next( dj, 1 );    /* Next entry with table stretch */
    }
    while ( res == FR_OK );

    if ( res == FR_OK && ne > 1 )   /* Initialize LFN entry if needed */
    {
        res = dir_sdi( dj, is );
        if ( res == FR_OK )
        {
            sum = sum_sfn( dj->fn ); /* Sum of the SFN tied to the LFN */
            ne--;
            do                      /* Store LFN entries in bottom first */
            {
                res = move_window( dj->fs, dj->sect );
                if ( res != FR_OK ) break;
                fit_lfn( dj->lfn, dj->dir, ( BYTE )ne, sum );
                dj->fs->wflag = 1;
                res = dir_next( dj, 0 ); /* Next entry */
            }
            while ( res == FR_OK && --ne );
        }
    }

#else   /* Non LFN configuration */
    res = dir_sdi( dj, 0 );
    if ( res == FR_OK )
    {
        do      /* Find a blank entry for the SFN */
        {
            res = move_window( dj->fs, dj->sect );
            if ( res != FR_OK ) break;
            c = *dj->dir;
            if ( c == 0xE5 || c == 0 ) break; /* Is it a blank entry? */
            res = dir_next( dj, 1 );        /* Next entry with table stretch */
        }
        while ( res == FR_OK );
    }
#endif

    if ( res == FR_OK )     /* Initialize the SFN entry */
    {
        res = move_window( dj->fs, dj->sect );
        if ( res == FR_OK )
        {
            dir = dj->dir;
            mem_set( dir, 0, 32 );      /* Clean the entry */
            mem_cpy( dir, dj->fn, 11 ); /* Put SFN */
#if _USE_LFN
            dir[DIR_NTres] = *( dj->fn + NS ) & ( NS_BODY | NS_EXT ); /* Put NT flag */
#endif
            dj->fs->wflag = 1;
        }
    }

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Remove an object from the directory                                   */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY && !_FS_MINIMIZE
NODEBUG static
FRESULT dir_remove(  /* FR_OK: Successful, FR_DISK_ERR: A disk error */
    DIR* dj             /* Directory object pointing the entry to be removed */
)
{
    FRESULT res;
#if _USE_LFN    /* LFN configuration */
    WORD i;

    i = dj->index;  /* SFN index */
    res = dir_sdi( dj, ( WORD )( ( dj->lfn_idx == 0xFFFF ) ? i : dj->lfn_idx ) ); /* Goto the SFN or top of the LFN entries */
    if ( res == FR_OK )
    {
        do
        {
            res = move_window( dj->fs, dj->sect );
            if ( res != FR_OK ) break;
            *dj->dir = 0xE5;            /* Mark the entry "deleted" */
            dj->fs->wflag = 1;
            if ( dj->index >= i ) break; /* When reached SFN, all entries of the object has been deleted. */
            res = dir_next( dj, 0 );    /* Next entry */
        }
        while ( res == FR_OK );
        if ( res == FR_NO_FILE ) res = FR_INT_ERR;
    }

#else           /* Non LFN configuration */
    res = dir_sdi( dj, dj->index );
    if ( res == FR_OK )
    {
        res = move_window( dj->fs, dj->sect );
        if ( res == FR_OK )
        {
            *dj->dir = 0xE5;            /* Mark the entry "deleted" */
            dj->fs->wflag = 1;
        }
    }
#endif

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Pick a segment and create the object name in directory form           */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT create_name(
    DIR* dj,            /* Pointer to the directory object */
    const TCHAR** path  /* Pointer to pointer to the segment in the path string */
)
{
#ifdef _EXCVT
    static const BYTE excvt[] = _EXCVT; /* Upper conversion table for extended chars */
#endif

#if _USE_LFN    /* LFN configuration */
    BYTE b, cf;
    WCHAR w, *lfn;
    UINT i, ni, si, di;
    const TCHAR* p;

    /* Create LFN in Unicode */
    si = di = 0;
    p = *path;
    lfn = dj->lfn;
    for ( ;; )
    {
        w = p[si++];                    /* Get a character */
        if ( w < ' ' || w == '/' || w == '\\' ) break;  /* Break on end of segment */
        if ( di >= _MAX_LFN )           /* Reject too long name */
            return FR_INVALID_NAME;
#if !_LFN_UNICODE
        w &= 0xFF;
        if ( IsDBCS1( w ) )             /* Check if it is a DBC 1st byte (always false on SBCS cfg) */
        {
            b = ( BYTE )p[si++];        /* Get 2nd byte */
            if ( !IsDBCS2( b ) )
                return FR_INVALID_NAME; /* Reject invalid sequence */
            w = ( w << 8 ) + b;         /* Create a DBC */
        }
        w = ff_convert( w, 1 );         /* Convert ANSI/OEM to Unicode */
        if ( !w ) return FR_INVALID_NAME; /* Reject invalid code */
#endif
        if ( w < 0x80 && chk_chr( "\"*:<>\?|\x7F", w ) ) /* Reject illegal chars for LFN */
            return FR_INVALID_NAME;
        lfn[di++] = w;                  /* Store the Unicode char */
    }
    *path = &p[si];                     /* Return pointer to the next segment */
    cf = ( w < ' ' ) ? NS_LAST : 0;     /* Set last segment flag if end of path */
#if _FS_RPATH
    if ( ( di == 1 && lfn[di - 1] == '.' ) || /* Is this a dot entry? */
            ( di == 2 && lfn[di - 1] == '.' && lfn[di - 2] == '.' ) )
    {
        lfn[di] = 0;
        for ( i = 0; i < 11; i++ )
            dj->fn[i] = ( i < di ) ? '.' : ' ';
        dj->fn[i] = cf | NS_DOT;        /* This is a dot entry */
        return FR_OK;
    }
#endif
    while ( di )                        /* Strip trailing spaces and dots */
    {
        w = lfn[di - 1];
        if ( w != ' ' && w != '.' ) break;
        di--;
    }
    if ( !di ) return FR_INVALID_NAME;  /* Reject nul string */

    lfn[di] = 0;                        /* LFN is created */

    /* Create SFN in directory form */
    mem_set( dj->fn, ' ', 11 );
    for ( si = 0; lfn[si] == ' ' || lfn[si] == '.'; si++ ) ; /* Strip leading spaces and dots */
    if ( si ) cf |= NS_LOSS | NS_LFN;
    while ( di && lfn[di - 1] != '.' ) di--; /* Find extension (di<=si: no extension) */

    b = i = 0; ni = 8;
    for ( ;; )
    {
        w = lfn[si++];                  /* Get an LFN char */
        if ( !w ) break;                /* Break on end of the LFN */
        if ( w == ' ' || ( w == '.' && si != di ) ) /* Remove spaces and dots */
        {
            cf |= NS_LOSS | NS_LFN; continue;
        }

        if ( i >= ni || si == di )      /* Extension or end of SFN */
        {
            if ( ni == 11 )             /* Long extension */
            {
                cf |= NS_LOSS | NS_LFN; break;
            }
            if ( si != di ) cf |= NS_LOSS | NS_LFN; /* Out of 8.3 format */
            if ( si > di ) break;       /* No extension */
            si = di; i = 8; ni = 11;    /* Enter extension section */
            b <<= 2; continue;
        }

        if ( w >= 0x80 )                /* Non ASCII char */
        {
#ifdef _EXCVT
            w = ff_convert( w, 0 );     /* Unicode -> OEM code */
            if ( w ) w = excvt[w - 0x80]; /* Convert extended char to upper (SBCS) */
#else
            w = ff_convert( ff_wtoupper( w ), 0 ); /* Upper converted Unicode -> OEM code */
#endif
            cf |= NS_LFN;               /* Force create LFN entry */
        }

        if ( _DF1S && w >= 0x100 )      /* Double byte char (always false on SBCS cfg) */
        {
            if ( i >= ni - 1 )
            {
                cf |= NS_LOSS | NS_LFN; i = ni; continue;
            }
            dj->fn[i++] = ( BYTE )( w >> 8 );
        }
        else                            /* Single byte char */
        {
            if ( !w || chk_chr( "+,;=[]", w ) ) /* Replace illegal chars for SFN */
            {
                w = '_'; cf |= NS_LOSS | NS_LFN;/* Lossy conversion */
            }
            else
            {
                if ( IsUpper( w ) )     /* ASCII large capital */
                {
                    b |= 2;
                }
                else
                {
                    if ( IsLower( w ) ) /* ASCII small capital */
                    {
                        b |= 1; w -= 0x20;
                    }
                }
            }
        }
        dj->fn[i++] = ( BYTE )w;
    }

    if ( dj->fn[0] == 0xE5 ) dj->fn[0] = 0x05;  /* If the first char collides with deleted mark, replace it with 0x05 */

    if ( ni == 8 ) b <<= 2;
    if ( ( b & 0x0C ) == 0x0C || ( b & 0x03 ) == 0x03 ) /* Create LFN entry when there are composite capitals */
        cf |= NS_LFN;
    if ( !( cf & NS_LFN ) )                     /* When LFN is in 8.3 format without extended char, NT flags are created */
    {
        if ( ( b & 0x03 ) == 0x01 ) cf |= NS_EXT; /* NT flag (Extension has only small capital) */
        if ( ( b & 0x0C ) == 0x04 ) cf |= NS_BODY; /* NT flag (Filename has only small capital) */
    }

    dj->fn[NS] = cf;    /* SFN is created */

    return FR_OK;


#else   /* Non-LFN configuration */
    BYTE b, c, d, *sfn;
    UINT ni, si, i;
    const char* p;

    /* Create file name in directory form */
    sfn = dj->fn;
    mem_set( sfn, ' ', 11 );
    si = i = b = 0; ni = 8;
    p = *path;
#if _FS_RPATH
    if ( p[si] == '.' ) /* Is this a dot entry? */
    {
        for ( ;; )
        {
            c = ( BYTE )p[si++];
            if ( c != '.' || si >= 3 ) break;
            sfn[i++] = c;
        }
        if ( c != '/' && c != '\\' && c > ' ' ) return FR_INVALID_NAME;
        *path = &p[si];                                 /* Return pointer to the next segment */
        sfn[NS] = ( c <= ' ' ) ? NS_LAST | NS_DOT : NS_DOT; /* Set last segment flag if end of path */
        return FR_OK;
    }
#endif
    for ( ;; )
    {
        c = ( BYTE )p[si++];
        if ( c <= ' ' || c == '/' || c == '\\' ) break; /* Break on end of segment */
        if ( c == '.' || i >= ni )
        {
            if ( ni != 8 || c != '.' ) return FR_INVALID_NAME;
            i = 8; ni = 11;
            b <<= 2; continue;
        }
        if ( c >= 0x80 )                /* Extended char? */
        {
            b |= 3;                     /* Eliminate NT flag */
#ifdef _EXCVT
            c = excvt[c - 0x80];        /* Upper conversion (SBCS) */
#else
#if !_DF1S  /* ASCII only cfg */
            return FR_INVALID_NAME;
#endif
#endif
        }
        if ( IsDBCS1( c ) )             /* Check if it is a DBC 1st byte (always false on SBCS cfg) */
        {
            d = ( BYTE )p[si++];        /* Get 2nd byte */
            if ( !IsDBCS2( d ) || i >= ni - 1 ) /* Reject invalid DBC */
                return FR_INVALID_NAME;
            sfn[i++] = c;
            sfn[i++] = d;
        }
        else                            /* Single byte code */
        {
            if ( chk_chr( "\"*+,:;<=>\?[]|\x7F", c ) ) /* Reject illegal chrs for SFN */
                return FR_INVALID_NAME;
            if ( IsUpper( c ) )         /* ASCII large capital? */
            {
                b |= 2;
            }
            else
            {
                if ( IsLower( c ) )     /* ASCII small capital? */
                {
                    b |= 1; c -= 0x20;
                }
            }
            sfn[i++] = c;
        }
    }
    *path = &p[si];                     /* Return pointer to the next segment */
    c = ( c <= ' ' ) ? NS_LAST : 0;     /* Set last segment flag if end of path */

    if ( !i ) return FR_INVALID_NAME;   /* Reject nul string */
    if ( sfn[0] == 0xE5 ) sfn[0] = 0x05; /* When first char collides with 0xE5, replace it with 0x05 */

    if ( ni == 8 ) b <<= 2;
    if ( ( b & 0x03 ) == 0x01 ) c |= NS_EXT; /* NT flag (Name extension has only small capital) */
    if ( ( b & 0x0C ) == 0x04 ) c |= NS_BODY; /* NT flag (Name body has only small capital) */

    sfn[NS] = c;        /* Store NT flag, File name is created */

    return FR_OK;
#endif
}




/*-----------------------------------------------------------------------*/
/* Get file information from directory entry                             */
/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
NODEBUG static
void get_fileinfo(   /* No return code */
    DIR* dj,            /* Pointer to the directory object */
    FILINFO* fno        /* Pointer to the file information to be filled */
)
{
    UINT i;
    BYTE nt, *dir;
    TCHAR* p, c;


    p = fno->fname;
    if ( dj->sect )
    {
        dir = dj->dir;
        nt = dir[DIR_NTres];        /* NT flag */
        for ( i = 0; i < 8; i++ )   /* Copy name body */
        {
            c = dir[i];
            if ( c == ' ' ) break;
            if ( c == 0x05 ) c = ( TCHAR )0xE5;
            if ( _USE_LFN && ( nt & NS_BODY ) && IsUpper( c ) ) c += 0x20;
#if _LFN_UNICODE
            if ( IsDBCS1( c ) && i < 7 && IsDBCS2( dir[i + 1] ) )
                c = ( c << 8 ) | dir[++i];
            c = ff_convert( c, 1 );
            if ( !c ) c = '?';
#endif
            *p++ = c;
        }
        if ( dir[8] != ' ' )        /* Copy name extension */
        {
            *p++ = '.';
            for ( i = 8; i < 11; i++ )
            {
                c = dir[i];
                if ( c == ' ' ) break;
                if ( _USE_LFN && ( nt & NS_EXT ) && IsUpper( c ) ) c += 0x20;
#if _LFN_UNICODE
                if ( IsDBCS1( c ) && i < 10 && IsDBCS2( dir[i + 1] ) )
                    c = ( c << 8 ) | dir[++i];
                c = ff_convert( c, 1 );
                if ( !c ) c = '?';
#endif
                *p++ = c;
            }
        }
        fno->fattrib = dir[DIR_Attr];               /* Attribute */
        fno->fsize = LD_DWORD( dir + DIR_FileSize ); /* Size */
        fno->fdate = LD_WORD( dir + DIR_WrtDate );  /* Date */
        fno->ftime = LD_WORD( dir + DIR_WrtTime );  /* Time */
    }
    *p = 0;     /* Terminate SFN str by a \0 */

#if _USE_LFN
    if ( fno->lfname && fno->lfsize )
    {
        TCHAR* tp = fno->lfname;
        WCHAR w, *lfn;

        i = 0;
        if ( dj->sect && dj->lfn_idx != 0xFFFF ) /* Get LFN if available */
        {
            lfn = dj->lfn;
            while ( ( w = *lfn++ ) != 0 )       /* Get an LFN char */
            {
#if !_LFN_UNICODE
                w = ff_convert( w, 0 );         /* Unicode -> OEM conversion */
                if ( !w ) { i = 0; break; }     /* Could not convert, no LFN */
                if ( _DF1S && w >= 0x100 )      /* Put 1st byte if it is a DBC (always false on SBCS cfg) */
                    tp[i++] = ( TCHAR )( w >> 8 );
#endif
                if ( i >= fno->lfsize - 1 ) { i = 0; break; } /* Buffer overflow, no LFN */
                tp[i++] = ( TCHAR )w;
            }
        }
        tp[i] = 0;  /* Terminate the LFN str by a \0 */
    }
#endif
}
#endif /* _FS_MINIMIZE <= 1 */




/*-----------------------------------------------------------------------*/
/* Follow a file path                                                    */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT follow_path(  /* FR_OK(0): successful, !=0: error code */
    DIR* dj,            /* Directory object to return last directory and found object */
    const TCHAR* path   /* Full-path string to find a file or directory */
)
{
    FRESULT res;
    BYTE* dir, ns;


#if _FS_RPATH
    if ( *path == '/' || *path == '\\' ) /* There is a heading separator */
    {
        path++; dj->sclust = 0;     /* Strip it and start from the root dir */
    }
    else                                /* No heading separator */
    {
        dj->sclust = dj->fs->cdir;  /* Start from the current dir */
    }
#else
    if ( *path == '/' || *path == '\\' ) /* Strip heading separator if exist */
        path++;
    dj->sclust = 0;                     /* Start from the root dir */
#endif

    if ( ( UINT )*path < ' ' )          /* Nul path means the start directory itself */
    {
        res = dir_sdi( dj, 0 );
        dj->dir = 0;

    }
    else                                /* Follow path */
    {
        for ( ;; )
        {
            res = create_name( dj, &path ); /* Get a segment */
            if ( res != FR_OK ) break;
            res = dir_find( dj );           /* Find it */
            ns = *( dj->fn + NS );
            if ( res != FR_OK )             /* Failed to find the object */
            {
                if ( res != FR_NO_FILE ) break; /* Abort if any hard error occured */
                /* Object not found */
                if ( _FS_RPATH && ( ns & NS_DOT ) ) /* If dot entry is not exit */
                {
                    dj->sclust = 0; dj->dir = 0;    /* It is the root dir */
                    res = FR_OK;
                    if ( !( ns & NS_LAST ) ) continue;
                }
                else                                /* Could not find the object */
                {
                    if ( !( ns & NS_LAST ) ) res = FR_NO_PATH;
                }
                break;
            }
            if ( ns & NS_LAST ) break;          /* Last segment match. Function completed. */
            dir = dj->dir;                      /* There is next segment. Follow the sub directory */
            if ( !( dir[DIR_Attr] & AM_DIR ) )  /* Cannot follow because it is a file */
            {
                res = FR_NO_PATH; break;
            }
            dj->sclust = LD_CLUST( dir );
        }
    }

    return res;
}




/*-----------------------------------------------------------------------*/
/* Load boot record and check if it is an FAT boot record                */
/*-----------------------------------------------------------------------*/

NODEBUG static
BYTE check_fs(  /* 0:The FAT BR, 1:Valid BR but not an FAT, 2:Not a BR, 3:Disk error */
    FATFS* fs,  /* File system object */
    DWORD sect  /* Sector# (lba) to check if it is an FAT boot record or not */
)
{
    if ( disk_read( fs->drv, fs->win, sect, 1 ) != RES_OK ) /* Load boot record */
        return 3;
    if ( LD_WORD( &fs->win[BS_55AA] ) != 0xAA55 )   /* Check record signature (always placed at offset 510 even if the sector size is >512) */
        return 2;

    if ( ( LD_DWORD( &fs->win[BS_FilSysType] ) & 0xFFFFFF ) == 0x544146 ) /* Check "FAT" string */
        return 0;
    if ( ( LD_DWORD( &fs->win[BS_FilSysType32] ) & 0xFFFFFF ) == 0x544146 )
        return 0;

    return 1;
}




/*-----------------------------------------------------------------------*/
/* Check if the file system object is valid or not                       */
/*-----------------------------------------------------------------------*/
NODEBUG2 FRESULT chk_mounted(  /* FR_OK(0): successful, !=0: any error occurred */
    const TCHAR** path, /* Pointer to pointer to the path name (drive number) */
    FATFS** rfs,        /* Pointer to pointer to the found file system object */
    BYTE chk_wp         /* !=0: Check media write protection for write access */
)
{
    BYTE fmt, b, *tbl;
    UINT vol;
    DSTATUS stat;
    DWORD bsect, fasize, tsect, sysect, nclst, szbfat;
    WORD nrsv;
    const TCHAR* p = *path;
    FATFS* fs;

    /* Get logical drive number from the path name */
    vol = p[0] - '0';                   /* Is there a drive number? */
    if ( vol <= 9 && p[1] == ':' )      /* Found a drive number, get and strip it */
    {
        p += 2; *path = p;              /* Return pointer to the path name */
    }
    else                                /* No drive number is given */
    {
#if _FS_RPATH
        vol = CurrVol;                  /* Use current drive */
#else
        vol = 0;                        /* Use drive 0 */
#endif
    }

    /* Check if the logical drive is valid or not */
    if ( vol >= _VOLUMES )              /* Is the drive number valid? */
        return FR_INVALID_DRIVE;
    *rfs = fs = FatFs[vol];             /* Return pointer to the corresponding file system object */
    if ( !fs ) return FR_NOT_ENABLED;   /* Is the file system object available? */

    ENTER_FF( fs );                     /* Lock file system */

    if ( fs->fs_type )                  /* If the logical drive has been mounted */
    {
        stat = disk_status( fs->drv );
        if ( !( stat & STA_NOINIT ) )   /* and the physical drive is kept initialized (has not been changed), */
        {
#if !_FS_READONLY
            if ( chk_wp && ( stat & STA_PROTECT ) ) /* Check write protection if needed */
                return FR_WRITE_PROTECTED;
#endif
            return FR_OK;               /* The file system object is valid */
        }
    }

    /* The logical drive must be mounted. */
    /* Following code attempts to mount a volume. (analyze BPB and initialize the fs object) */

    fs->fs_type = 0;                    /* Clear the file system object */
    fs->drv = ( BYTE )LD2PD( vol );     /* Bind the logical drive and a physical drive */
    stat = disk_initialize( fs->drv );  /* Initialize low level disk I/O layer */
    if ( stat & STA_NOINIT )            /* Check if the initialization succeeded */
        return FR_NOT_READY;            /* Failed to initialize due to no media or hard error */
#if _MAX_SS != 512                      /* Get disk sector size (variable sector size cfg only) */
    if ( disk_ioctl( fs->drv, GET_SECTOR_SIZE, &fs->ssize ) != RES_OK )
        return FR_DISK_ERR;
#endif
#if !_FS_READONLY
    if ( chk_wp && ( stat & STA_PROTECT ) ) /* Check disk write protection if needed */
        return FR_WRITE_PROTECTED;
#endif
    /* Search FAT partition on the drive. Supports only generic partitionings, FDISK and SFD. */
    fmt = check_fs( fs, bsect = 0 );    /* Check sector 0 if it is a VBR */
    if ( fmt == 1 )                     /* Not an FAT-VBR, the disk may be partitioned */
    {
        /* Check the partition listed in top of the partition table */
        tbl = &fs->win[MBR_Table + LD2PT( vol ) * 16];  /* Partition table */
        if ( tbl[4] )                                   /* Is the partition existing? */
        {
            bsect = LD_DWORD( &tbl[8] );                /* Partition offset in LBA */
            fmt = check_fs( fs, bsect );                /* Check the partition */
        }
    }
    if ( fmt == 3 ) return FR_DISK_ERR;
    if ( fmt ) return FR_NO_FILESYSTEM;                 /* No FAT volume is found */

    /* Following code initializes the file system object */

    if ( LD_WORD( fs->win + BPB_BytsPerSec ) != SS( fs ) ) /* (BPB_BytsPerSec must be equal to the physical sector size) */
        return FR_NO_FILESYSTEM;

    fasize = LD_WORD( fs->win + BPB_FATSz16 );          /* Number of sectors per FAT */
    if ( !fasize ) fasize = LD_DWORD( fs->win + BPB_FATSz32 );
    fs->fsize = fasize;

    fs->n_fats = b = fs->win[BPB_NumFATs];              /* Number of FAT copies */
    if ( b != 1 && b != 2 ) return FR_NO_FILESYSTEM;    /* (Must be 1 or 2) */
    fasize *= b;                                        /* Number of sectors for FAT area */

    fs->csize = b = fs->win[BPB_SecPerClus];            /* Number of sectors per cluster */
    if ( !b || ( b & ( b - 1 ) ) ) return FR_NO_FILESYSTEM; /* (Must be power of 2) */

    fs->n_rootdir = LD_WORD( fs->win + BPB_RootEntCnt ); /* Number of root directory entries */
    if ( fs->n_rootdir % ( SS( fs ) / 32 ) ) return FR_NO_FILESYSTEM; /* (BPB_RootEntCnt must be sector aligned) */

    tsect = LD_WORD( fs->win + BPB_TotSec16 );          /* Number of sectors on the volume */
    if ( !tsect ) tsect = LD_DWORD( fs->win + BPB_TotSec32 );

    nrsv = LD_WORD( fs->win + BPB_RsvdSecCnt );         /* Number of reserved sectors */
    if ( !nrsv ) return FR_NO_FILESYSTEM;               /* (BPB_RsvdSecCnt must not be 0) */

    /* Determine the FAT sub type */
    sysect = nrsv + fasize + fs->n_rootdir / ( SS( fs ) / 32 ); /* RSV+FAT+DIR */
    if ( tsect < sysect ) return FR_NO_FILESYSTEM;      /* (Invalid volume size) */
    nclst = ( tsect - sysect ) / fs->csize;             /* Number of clusters */
    if ( !nclst ) return FR_NO_FILESYSTEM;              /* (Invalid volume size) */
    fmt = FS_FAT12;
    if ( nclst >= MIN_FAT16 ) fmt = FS_FAT16;
    if ( nclst >= MIN_FAT32 ) fmt = FS_FAT32;

    /* Boundaries and Limits */
    fs->n_fatent = nclst + 2;                           /* Number of FAT entries */
    fs->database = bsect + sysect;                      /* Data start sector */
    fs->fatbase = bsect + nrsv;                         /* FAT start sector */
    if ( fmt == FS_FAT32 )
    {
        if ( fs->n_rootdir ) return FR_NO_FILESYSTEM;   /* (BPB_RootEntCnt must be 0) */
        fs->dirbase = LD_DWORD( fs->win + BPB_RootClus ); /* Root directory start cluster */
        szbfat = fs->n_fatent * 4;                      /* (Required FAT size) */
    }
    else
    {
        if ( !fs->n_rootdir ) return FR_NO_FILESYSTEM;  /* (BPB_RootEntCnt must not be 0) */
        fs->dirbase = fs->fatbase + fasize;             /* Root directory start sector */
        szbfat = ( fmt == FS_FAT16 ) ?                  /* (Required FAT size) */
                 fs->n_fatent * 2 : fs->n_fatent * 3 / 2 + ( fs->n_fatent & 1 );
    }
    if ( fs->fsize < ( szbfat + ( SS( fs ) - 1 ) ) / SS( fs ) ) /* (FAT size must not be less than FAT sectors */
        return FR_NO_FILESYSTEM;

#if !_FS_READONLY
    /* Initialize cluster allocation information */
    fs->free_clust = 0xFFFFFFFF;
    fs->last_clust = 0;

    /* Get fsinfo if available */
    if ( fmt == FS_FAT32 )
    {
        fs->fsi_flag = 0;
        fs->fsi_sector = bsect + LD_WORD( fs->win + BPB_FSInfo );
        if ( disk_read( fs->drv, fs->win, fs->fsi_sector, 1 ) == RES_OK &&
                LD_WORD( fs->win + BS_55AA ) == 0xAA55 &&
                LD_DWORD( fs->win + FSI_LeadSig ) == 0x41615252 &&
                LD_DWORD( fs->win + FSI_StrucSig ) == 0x61417272 )
        {
            fs->last_clust = LD_DWORD( fs->win + FSI_Nxt_Free );
            fs->free_clust = LD_DWORD( fs->win + FSI_Free_Count );
        }
    }
#endif
    fs->fs_type = fmt;      /* FAT sub-type */
    fs->id = ++Fsid;        /* File system mount ID */
    fs->winsect = 0;        /* Invalidate sector cache */
    fs->wflag = 0;
#if _FS_RPATH
    fs->cdir = 0;           /* Current directory (root dir) */
#endif
#if _FS_SHARE               /* Clear file lock semaphores */
    clear_lock( fs );
#endif

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Check if the file/dir object is valid or not                          */
/*-----------------------------------------------------------------------*/

NODEBUG static
FRESULT validate(  /* FR_OK(0): The object is valid, !=0: Invalid */
    FATFS* fs,      /* Pointer to the file system object */
    WORD id         /* Member id of the target object to be checked */
)
{
    if ( !fs || !fs->fs_type || fs->id != id )
        return FR_INVALID_OBJECT;

    ENTER_FF( fs );     /* Lock file system */

    if ( disk_status( fs->drv ) & STA_NOINIT )
        return FR_NOT_READY;

    return FR_OK;
}




/*--------------------------------------------------------------------------

   Public Functions

--------------------------------------------------------------------------*/



/*-----------------------------------------------------------------------*/
/* Mount/Unmount a Logical Drive                                         */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_mount(
    BYTE vol,       /* Logical drive number to be mounted/unmounted */
    FATFS* fs       /* Pointer to new file system object (NULL for unmount)*/
)
{
    FATFS* rfs;


    if ( vol >= _VOLUMES )          /* Check if the drive number is valid */
        return FR_INVALID_DRIVE;
    rfs = FatFs[vol];               /* Get current fs object */

    if ( rfs )
    {
#if _FS_SHARE
        clear_lock( rfs );
#endif
#if _FS_REENTRANT                   /* Discard sync object of the current volume */
        if ( !ff_del_syncobj( rfs->sobj ) ) return FR_INT_ERR;
#endif
        rfs->fs_type = 0;           /* Clear old fs object */
    }

    if ( fs )
    {
        fs->fs_type = 0;            /* Clear new fs object */
#if _FS_REENTRANT                   /* Create sync object for the new volume */
        if ( !ff_cre_syncobj( vol, &fs->sobj ) ) return FR_INT_ERR;
#endif
    }
    FatFs[vol] = fs;
    /* Register new fs object */

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Open or Create a File                                                 */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_open(
    FIL* fp,            /* Pointer to the blank file object */
    const TCHAR* path,  /* Pointer to the file name */
    BYTE mode           /* Access mode and file open mode flags */
)
{
    FRESULT res;
    DIR dj;
    BYTE* dir;
    DEF_NAMEBUF;


    fp->fs = 0;         /* Clear file object */

#if !_FS_READONLY
    mode &= FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW;
    res = chk_mounted( &path, &dj.fs, ( BYTE )( mode & ~FA_READ ) );
#else
    mode &= FA_READ;
    res = chk_mounted( &path, &dj.fs, 0 );
#endif
    INIT_BUF( dj );
    if ( res == FR_OK )
        res = follow_path( &dj, path ); /* Follow the file path */
    dir = dj.dir;

#if !_FS_READONLY   /* R/W configuration */
    if ( res == FR_OK )
    {
        if ( !dir ) /* Current dir itself */
            res = FR_INVALID_NAME;
#if _FS_SHARE
        else
            res = chk_lock( &dj, ( mode & ~FA_READ ) ? 1 : 0 );
#endif
    }
    /* Create or Open a file */
    if ( mode & ( FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW ) )
    {
        DWORD dw, cl;

        if ( res != FR_OK )                 /* No file, create new */
        {
            if ( res == FR_NO_FILE )        /* There is no file to open, create a new entry */
#if _FS_SHARE
                res = enq_lock( dj.fs ) ? dir_register( &dj ) : FR_TOO_MANY_OPEN_FILES;
#else
                res = dir_register( &dj );
#endif
            mode |= FA_CREATE_ALWAYS;       /* File is created */
            dir = dj.dir;                   /* New entry */
        }
        else                                /* Any object is already existing */
        {
            if ( mode & FA_CREATE_NEW )     /* Cannot create new */
            {
                res = FR_EXIST;
            }
            else
            {
                if ( dir[DIR_Attr] & ( AM_RDO | AM_DIR ) ) /* Cannot overwrite it (R/O or DIR) */
                    res = FR_DENIED;
            }
        }
        if ( res == FR_OK && ( mode & FA_CREATE_ALWAYS ) )  /* Truncate it if overwrite mode */
        {
            dw = get_fattime();                 /* Created time */
            ST_DWORD( dir + DIR_CrtTime, dw );
            dir[DIR_Attr] = 0;                  /* Reset attribute */
            ST_DWORD( dir + DIR_FileSize, 0 );  /* size = 0 */
            cl = LD_CLUST( dir );               /* Get start cluster */
            ST_CLUST( dir, 0 );                 /* cluster = 0 */
            dj.fs->wflag = 1;
            if ( cl )                           /* Remove the cluster chain if exist */
            {
                dw = dj.fs->winsect;
                res = remove_chain( dj.fs, cl );
                if ( res == FR_OK )
                {
                    dj.fs->last_clust = cl - 1; /* Reuse the cluster hole */
                    res = move_window( dj.fs, dw );
                }
            }
        }
    }
    else    /* Open an existing file */
    {
        if ( res == FR_OK )                     /* Follow succeeded */
        {
            if ( dir[DIR_Attr] & AM_DIR )       /* It is a directory */
            {
                res = FR_NO_FILE;
            }
            else
            {
                if ( ( mode & FA_WRITE ) && ( dir[DIR_Attr] & AM_RDO ) ) /* R/O violation */
                    res = FR_DENIED;
            }
        }
    }
    if ( res == FR_OK )
    {
        if ( mode & FA_CREATE_ALWAYS )          /* Set file change flag if created or overwritten */
            mode |= FA__WRITTEN;
        fp->dir_sect = dj.fs->winsect;          /* Pointer to the directory entry */
        fp->dir_ptr = dir;
#if _FS_SHARE
        fp->lockid = inc_lock( &dj, ( mode & ~FA_READ ) ? 1 : 0 );
        if ( !fp->lockid ) res = FR_INT_ERR;
#endif
    }

#else               /* R/O configuration */
    if ( res == FR_OK )                 /* Follow succeeded */
    {
        if ( !dir )                     /* Current dir itself */
        {
            res = FR_INVALID_NAME;
        }
        else
        {
            if ( dir[DIR_Attr] & AM_DIR ) /* It is a directory */
                res = FR_NO_FILE;
        }
    }
#endif
    FREE_BUF();

    if ( res == FR_OK )
    {
        fp->flag = mode;                    /* File access mode */
        fp->org_clust = LD_CLUST( dir );    /* File start cluster */
        fp->fsize = LD_DWORD( dir + DIR_FileSize ); /* File size */
        fp->fptr = 0;                       /* File pointer */
        fp->dsect = 0;
#if _USE_FASTSEEK
        fp->cltbl = 0;                      /* No cluster link map table */
#endif
        fp->fs = dj.fs; fp->id = dj.fs->id; /* Validate file object */
    }

    LEAVE_FF( dj.fs, res );
}




/*-----------------------------------------------------------------------*/
/* Read File                                                             */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_read(
    FIL* fp,        /* Pointer to the file object */
    void* buff,     /* Pointer to data buffer */
    UINT btr,       /* Number of bytes to read */
    UINT* br        /* Pointer to number of bytes read */
)
{
    FRESULT res;
    DWORD clst, sect, remain;
    UINT rcnt, cc;
    BYTE csect, *rbuff = buff;


    *br = 0;    /* Initialize byte counter */

    res = validate( fp->fs, fp->id );               /* Check validity of the object */
    if ( res != FR_OK ) LEAVE_FF( fp->fs, res );
    if ( fp->flag & FA__ERROR )                     /* Check abort flag */
        LEAVE_FF( fp->fs, FR_INT_ERR );
    if ( !( fp->flag & FA_READ ) )                  /* Check access mode */
        LEAVE_FF( fp->fs, FR_DENIED );
    remain = fp->fsize - fp->fptr;
    if ( btr > remain ) btr = ( UINT )remain;       /* Truncate btr by remaining bytes */

    for ( ;  btr;                                   /* Repeat until all data transferred */
            rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt )
    {
        if ( ( fp->fptr % SS( fp->fs ) ) == 0 )     /* On the sector boundary? */
        {
            csect = ( BYTE )( fp->fptr / SS( fp->fs ) & ( fp->fs->csize - 1 ) ); /* Sector offset in the cluster */
            if ( !csect )                           /* On the cluster boundary? */
            {
                clst = ( fp->fptr == 0 ) ?          /* On the top of the file? */
                       fp->org_clust : get_fat( fp->fs, fp->curr_clust );
                if ( clst <= 1 ) ABORT( fp->fs, FR_INT_ERR );
                if ( clst == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                fp->curr_clust = clst;              /* Update current cluster */
            }
            sect = clust2sect( fp->fs, fp->curr_clust ); /* Get current sector */
            if ( !sect ) ABORT( fp->fs, FR_INT_ERR );
            sect += csect;
            cc = btr / SS( fp->fs );                /* When remaining bytes >= sector size, */
            if ( cc )                               /* Read maximum contiguous sectors directly */
            {
                if ( csect + cc > fp->fs->csize )   /* Clip at cluster boundary */
                    cc = fp->fs->csize - csect;
                if ( disk_read( fp->fs->drv, rbuff, sect, ( BYTE )cc ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
#if !_FS_READONLY && _FS_MINIMIZE <= 2              /* Replace one of the read sectors with cached data if it contains a dirty sector */
#if _FS_TINY
                if ( fp->fs->wflag && fp->fs->winsect - sect < cc )
                    mem_cpy( rbuff + ( ( fp->fs->winsect - sect ) * SS( fp->fs ) ), fp->fs->win, SS( fp->fs ) );
#else
                if ( ( fp->flag & FA__DIRTY ) && fp->dsect - sect < cc )
                    mem_cpy( rbuff + ( ( fp->dsect - sect ) * SS( fp->fs ) ), fp->buf, SS( fp->fs ) );
#endif
#endif
                rcnt = SS( fp->fs ) * cc;           /* Number of bytes transferred */
                continue;
            }
#if !_FS_TINY
#if !_FS_READONLY
            if ( fp->flag & FA__DIRTY )             /* Write sector I/O buffer if needed */
            {
                if ( disk_write( fp->fs->drv, fp->buf, fp->dsect, 1 ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
                fp->flag &= ~FA__DIRTY;
            }
#endif
            if ( fp->dsect != sect )                /* Fill sector buffer with file data */
            {
                if ( disk_read( fp->fs->drv, fp->buf, sect, 1 ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
            }
#endif
            fp->dsect = sect;
        }
        rcnt = SS( fp->fs ) - ( fp->fptr % SS( fp->fs ) ); /* Get partial sector data from sector buffer */
        if ( rcnt > btr ) rcnt = btr;
#if _FS_TINY
        if ( move_window( fp->fs, fp->dsect ) )     /* Move sector window */
            ABORT( fp->fs, FR_DISK_ERR );
        mem_cpy( rbuff, &fp->fs->win[fp->fptr % SS( fp->fs )], rcnt ); /* Pick partial sector */
#else
        mem_cpy( rbuff, &fp->buf[fp->fptr % SS( fp->fs )], rcnt ); /* Pick partial sector */
#endif
    }

    LEAVE_FF( fp->fs, FR_OK );
}




#if !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Write File                                                            */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_write(
    FIL* fp,            /* Pointer to the file object */
    const void* buff,   /* Pointer to the data to be written */
    UINT btw,           /* Number of bytes to write */
    UINT* bw            /* Pointer to number of bytes written */
)
{
    FRESULT res;
    DWORD clst, sect;
    UINT wcnt, cc;
    const BYTE* wbuff = buff;
    BYTE csect;


    *bw = 0;    /* Initialize byte counter */

    res = validate( fp->fs, fp->id );               /* Check validity of the object */
    if ( res != FR_OK ) LEAVE_FF( fp->fs, res );
    if ( fp->flag & FA__ERROR )                     /* Check abort flag */
        LEAVE_FF( fp->fs, FR_INT_ERR );
    if ( !( fp->flag & FA_WRITE ) )                 /* Check access mode */
        LEAVE_FF( fp->fs, FR_DENIED );
    if ( fp->fsize + btw < fp->fsize ) btw = 0;     /* File size cannot reach 4GB */

    for ( ;  btw;                                   /* Repeat until all data transferred */
            wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt )
    {
        if ( ( fp->fptr % SS( fp->fs ) ) == 0 )     /* On the sector boundary? */
        {
            csect = ( BYTE )( fp->fptr / SS( fp->fs ) & ( fp->fs->csize - 1 ) ); /* Sector offset in the cluster */
            if ( !csect )                           /* On the cluster boundary? */
            {
                if ( fp->fptr == 0 )                /* On the top of the file? */
                {
                    clst = fp->org_clust;           /* Follow from the origin */
                    if ( clst == 0 )                /* When there is no cluster chain, */
                        fp->org_clust = clst = create_chain( fp->fs, 0 ); /* Create a new cluster chain */
                }
                else                                /* Middle or end of the file */
                {
                    clst = create_chain( fp->fs, fp->curr_clust );          /* Follow or stretch cluster chain */
                }
                if ( clst == 0 ) break;             /* Could not allocate a new cluster (disk full) */
                if ( clst == 1 ) ABORT( fp->fs, FR_INT_ERR );
                if ( clst == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                fp->curr_clust = clst;              /* Update current cluster */
            }
#if _FS_TINY
            if ( fp->fs->winsect == fp->dsect && move_window( fp->fs, 0 ) ) /* Write back data buffer prior to following direct transfer */
                ABORT( fp->fs, FR_DISK_ERR );
#else
            if ( fp->flag & FA__DIRTY )     /* Write back data buffer prior to following direct transfer */
            {
                if ( disk_write( fp->fs->drv, fp->buf, fp->dsect, 1 ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
                fp->flag &= ~FA__DIRTY;
            }
#endif
            sect = clust2sect( fp->fs, fp->curr_clust ); /* Get current sector */
            if ( !sect ) ABORT( fp->fs, FR_INT_ERR );
            sect += csect;
            cc = btw / SS( fp->fs );                /* When remaining bytes >= sector size, */
            if ( cc )                               /* Write maximum contiguous sectors directly */
            {
                if ( csect + cc > fp->fs->csize )   /* Clip at cluster boundary */
                    cc = fp->fs->csize - csect;
                if ( disk_write( fp->fs->drv, wbuff, sect, ( BYTE )cc ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
#if _FS_TINY
                if ( fp->fs->winsect - sect < cc )  /* Refill sector cache if it gets dirty by the direct write */
                {
                    mem_cpy( fp->fs->win, wbuff + ( ( fp->fs->winsect - sect ) * SS( fp->fs ) ), SS( fp->fs ) );
                    fp->fs->wflag = 0;
                }
#else
                if ( fp->dsect - sect < cc )        /* Refill sector cache if it gets dirty by the direct write */
                {
                    mem_cpy( fp->buf, wbuff + ( ( fp->dsect - sect ) * SS( fp->fs ) ), SS( fp->fs ) );
                    fp->flag &= ~FA__DIRTY;
                }
#endif
                wcnt = SS( fp->fs ) * cc;           /* Number of bytes transferred */
                continue;
            }
#if _FS_TINY
            if ( fp->fptr >= fp->fsize )            /* Avoid silly buffer filling at growing edge */
            {
                if ( move_window( fp->fs, 0 ) ) ABORT( fp->fs, FR_DISK_ERR );
                fp->fs->winsect = sect;
            }
#else
            if ( fp->dsect != sect )                /* Fill sector buffer with file data */
            {
                if ( fp->fptr < fp->fsize &&
                        disk_read( fp->fs->drv, fp->buf, sect, 1 ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
            }
#endif
            fp->dsect = sect;
        }
        wcnt = SS( fp->fs ) - ( fp->fptr % SS( fp->fs ) ); /* Put partial sector into file I/O buffer */
        if ( wcnt > btw ) wcnt = btw;
#if _FS_TINY
        if ( move_window( fp->fs, fp->dsect ) )     /* Move sector window */
            ABORT( fp->fs, FR_DISK_ERR );
        mem_cpy( &fp->fs->win[fp->fptr % SS( fp->fs )], wbuff, wcnt ); /* Fit partial sector */
        fp->fs->wflag = 1;
#else
        mem_cpy( &fp->buf[fp->fptr % SS( fp->fs )], wbuff, wcnt ); /* Fit partial sector */
        fp->flag |= FA__DIRTY;
#endif
    }

    if ( fp->fptr > fp->fsize ) fp->fsize = fp->fptr; /* Update file size if needed */
    fp->flag |= FA__WRITTEN;                        /* Set file change flag */

    LEAVE_FF( fp->fs, FR_OK );
}




/*-----------------------------------------------------------------------*/
/* Synchronize the File Object                                           */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_sync(
    FIL* fp     /* Pointer to the file object */
)
{
    FRESULT res;
    DWORD tim;
    BYTE* dir;


    res = validate( fp->fs, fp->id );   /* Check validity of the object */
    if ( res == FR_OK )
    {
        if ( fp->flag & FA__WRITTEN )   /* Has the file been written? */
        {
#if !_FS_TINY   /* Write-back dirty buffer */
            if ( fp->flag & FA__DIRTY )
            {
                if ( disk_write( fp->fs->drv, fp->buf, fp->dsect, 1 ) != RES_OK )
                    LEAVE_FF( fp->fs, FR_DISK_ERR );
                fp->flag &= ~FA__DIRTY;
            }
#endif
            /* Update the directory entry */
            res = move_window( fp->fs, fp->dir_sect );
            if ( res == FR_OK )
            {
                dir = fp->dir_ptr;
                dir[DIR_Attr] |= AM_ARC;                    /* Set archive bit */
                ST_DWORD( dir + DIR_FileSize, fp->fsize );  /* Update file size */
                ST_CLUST( dir, fp->org_clust );             /* Update start cluster */
                tim = get_fattime();                        /* Update updated time */
                ST_DWORD( dir + DIR_WrtTime, tim );
                fp->flag &= ~FA__WRITTEN;
                fp->fs->wflag = 1;
                res = sync( fp->fs );
            }
        }
    }

    LEAVE_FF( fp->fs, res );
}

#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Close File                                                            */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_close(
    FIL* fp     /* Pointer to the file object to be closed */
)
{
    FRESULT res;

#if _FS_READONLY
    FATFS* fs = fp->fs;
    res = validate( fs, fp->id );
    if ( res == FR_OK ) fp->fs = 0; /* Discard file object */
    LEAVE_FF( fs, res );

#else
    res = f_sync( fp );     /* Flush cached data */
#if _FS_SHARE
    if ( res == FR_OK )     /* Decrement open counter */
    {
#if _FS_REENTRANT
        res = validate( fp->fs, fp->id );
        if ( res == FR_OK )
        {
            res = dec_lock( fp->lockid );
            unlock_fs( fp->fs, FR_OK );
        }
#else
        res = dec_lock( fp->lockid );
#endif
    }
#endif
    if ( res == FR_OK ) fp->fs = 0; /* Discard file object */
    return res;
#endif
}




/*-----------------------------------------------------------------------*/
/* Current Drive/Directory Handlings                                     */
/*-----------------------------------------------------------------------*/

#if _FS_RPATH >= 1

NODEBUG FRESULT f_chdrive(
    BYTE drv        /* Drive number */
)
{
    if ( drv >= _VOLUMES ) return FR_INVALID_DRIVE;

    CurrVol = drv;

    return FR_OK;
}



NODEBUG FRESULT f_chdir(
    const TCHAR* path   /* Pointer to the directory path */
)
{
    FRESULT res;
    DIR dj;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 0 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path );     /* Follow the path */
        FREE_BUF();
        if ( res == FR_OK )                 /* Follow completed */
        {
            if ( !dj.dir )
            {
                dj.fs->cdir = dj.sclust;    /* Start directory itself */
            }
            else
            {
                if ( dj.dir[DIR_Attr] & AM_DIR ) /* Reached to the directory */
                    dj.fs->cdir = LD_CLUST( dj.dir );
                else
                    res = FR_NO_PATH;       /* Reached but a file */
            }
        }
        if ( res == FR_NO_FILE ) res = FR_NO_PATH;
    }

    LEAVE_FF( dj.fs, res );
}


#if _FS_RPATH >= 2
NODEBUG FRESULT f_getcwd(
    TCHAR* path,    /* Pointer to the directory path */
    UINT sz_path    /* Size of path */
)
{
    FRESULT res;
    DIR dj;
    UINT i, n;
    DWORD ccl;
    TCHAR* tp;
    FILINFO fno;
    DEF_NAMEBUF;


    *path = 0;
    res = chk_mounted( ( const TCHAR** )&path, &dj.fs, 0 ); /* Get current volume */
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        i = sz_path;        /* Bottom of buffer (dir stack base) */
        dj.sclust = dj.fs->cdir;            /* Start to follow upper dir from current dir */
        while ( ( ccl = dj.sclust ) != 0 )  /* Repeat while current dir is a sub-dir */
        {
            res = dir_sdi( &dj, 1 );        /* Get parent dir */
            if ( res != FR_OK ) break;
            res = dir_read( &dj );
            if ( res != FR_OK ) break;
            dj.sclust = LD_CLUST( dj.dir ); /* Goto parent dir */
            res = dir_sdi( &dj, 0 );
            if ( res != FR_OK ) break;
            do                              /* Find the entry links to the child dir */
            {
                res = dir_read( &dj );
                if ( res != FR_OK ) break;
                if ( ccl == LD_CLUST( dj.dir ) ) break; /* Found the entry */
                res = dir_next( &dj, 0 );
            }
            while ( res == FR_OK );
            if ( res == FR_NO_FILE ) res = FR_INT_ERR; /* It cannot be 'not found'. */
            if ( res != FR_OK ) break;
#if _USE_LFN
            fno.lfname = path;
            fno.lfsize = i;
#endif
            get_fileinfo( &dj, &fno );      /* Get the dir name and push it to the buffer */
            tp = fno.fname;
            if ( _USE_LFN && *path ) tp = path;
            for ( n = 0; tp[n]; n++ ) ;
            if ( i < n + 3 )
            {
                res = FR_NOT_ENOUGH_CORE; break;
            }
            while ( n ) path[--i] = tp[--n];
            path[--i] = '/';
        }
        tp = path;
        if ( res == FR_OK )
        {
            *tp++ = '0' + CurrVol;          /* Put drive number */
            *tp++ = ':';
            if ( i == sz_path )             /* Root-dir */
            {
                *tp++ = '/';
            }
            else                            /* Sub-dir */
            {
                do      /* Add stacked path str */
                    *tp++ = path[i++];
                while ( i < sz_path );
            }
        }
        *tp = 0;
        FREE_BUF();
    }

    LEAVE_FF( dj.fs, res );
}
#endif /* _FS_RPATH >= 2 */
#endif /* _FS_RPATH >= 1 */



#if _FS_MINIMIZE <= 2
/*-----------------------------------------------------------------------*/
/* Seek File R/W Pointer                                                 */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_lseek(
    FIL* fp,        /* Pointer to the file object */
    DWORD ofs       /* File pointer from top of file */
)
{
    FRESULT res;


    res = validate( fp->fs, fp->id );   /* Check validity of the object */
    if ( res != FR_OK ) LEAVE_FF( fp->fs, res );
    if ( fp->flag & FA__ERROR )         /* Check abort flag */
        LEAVE_FF( fp->fs, FR_INT_ERR );

#if _USE_FASTSEEK
    if ( fp->cltbl )    /* Fast seek */
    {
        DWORD cl, pcl, ncl, tcl, dsc, tlen, *tbl = fp->cltbl;
        BYTE csc;

        tlen = *tbl++;
        if ( ofs == CREATE_LINKMAP )    /* Create link map table */
        {
            cl = fp->org_clust;
            if ( cl )
            {
                do
                {
                    if ( tlen < 4 ) /* Not enough table items */
                    {
                        res = FR_NOT_ENOUGH_CORE; break;
                    }
                    tcl = cl; ncl = 0;
                    do          /* Get a fragment and store the top and length */
                    {
                        pcl = cl; ncl++;
                        cl = get_fat( fp->fs, cl );
                        if ( cl <= 1 ) ABORT( fp->fs, FR_INT_ERR );
                        if ( cl == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                    }
                    while ( cl == pcl + 1 );
                    *tbl++ = ncl; *tbl++ = tcl;
                    tlen -= 2;
                }
                while ( cl < fp->fs->n_fatent );
            }
            *tbl = 0;   /* Terminate table */

        }
        else                            /* Fast seek */
        {
            if ( ofs > fp->fsize )      /* Clip offset at the file size */
                ofs = fp->fsize;
            fp->fptr = ofs;             /* Set file pointer */
            if ( ofs )
            {
                dsc = ( ofs - 1 ) / SS( fp->fs );
                cl = dsc / fp->fs->csize;
                for ( ;; )
                {
                    ncl = *tbl++;
                    if ( !ncl ) ABORT( fp->fs, FR_INT_ERR );
                    if ( cl < ncl ) break;
                    cl -= ncl; tbl++;
                }
                fp->curr_clust = cl + *tbl;
                csc = ( BYTE )( dsc & ( fp->fs->csize - 1 ) );
                dsc = clust2sect( fp->fs, fp->curr_clust );
                if ( !dsc ) ABORT( fp->fs, FR_INT_ERR );
                dsc += csc;
                if ( fp->fptr % SS( fp->fs ) && dsc != fp->dsect )
                {
#if !_FS_TINY
#if !_FS_READONLY
                    if ( fp->flag & FA__DIRTY )     /* Flush dirty buffer if needed */
                    {
                        if ( disk_write( fp->fs->drv, fp->buf, fp->dsect, 1 ) != RES_OK )
                            ABORT( fp->fs, FR_DISK_ERR );
                        fp->flag &= ~FA__DIRTY;
                    }
#endif
                    if ( disk_read( fp->fs->drv, fp->buf, dsc, 1 ) != RES_OK )
                        ABORT( fp->fs, FR_DISK_ERR );
#endif
                    fp->dsect = dsc;
                }
            }
        }
    }
    else
#endif

        /* Normal Seek */
    {
        DWORD clst, bcs, nsect, ifptr;

        if ( ofs > fp->fsize                /* In read-only mode, clip offset with the file size */
#if !_FS_READONLY
                && !( fp->flag & FA_WRITE )
#endif
           ) ofs = fp->fsize;

        ifptr = fp->fptr;
        fp->fptr = nsect = 0;
        if ( ofs )
        {
            bcs = ( DWORD )fp->fs->csize * SS( fp->fs ); /* Cluster size (byte) */
            if ( ifptr > 0 &&
                    ( ofs - 1 ) / bcs >= ( ifptr - 1 ) / bcs ) /* When seek to same or following cluster, */
            {
                fp->fptr = ( ifptr - 1 ) & ~( bcs - 1 ); /* start from the current cluster */
                ofs -= fp->fptr;
                clst = fp->curr_clust;
            }
            else                                        /* When seek to back cluster, */
            {
                clst = fp->org_clust;                   /* start from the first cluster */
#if !_FS_READONLY
                if ( clst == 0 )                        /* If no cluster chain, create a new chain */
                {
                    clst = create_chain( fp->fs, 0 );
                    if ( clst == 1 ) ABORT( fp->fs, FR_INT_ERR );
                    if ( clst == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                    fp->org_clust = clst;
                }
#endif
                fp->curr_clust = clst;
            }
            if ( clst != 0 )
            {
                while ( ofs > bcs )                     /* Cluster following loop */
                {
#if !_FS_READONLY
                    if ( fp->flag & FA_WRITE )          /* Check if in write mode or not */
                    {
                        clst = create_chain( fp->fs, clst ); /* Force stretch if in write mode */
                        if ( clst == 0 )                /* When disk gets full, clip file size */
                        {
                            ofs = bcs; break;
                        }
                    }
                    else
#endif
                        clst = get_fat( fp->fs, clst ); /* Follow cluster chain if not in write mode */
                    if ( clst == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                    if ( clst <= 1 || clst >= fp->fs->n_fatent ) ABORT( fp->fs, FR_INT_ERR );
                    fp->curr_clust = clst;
                    fp->fptr += bcs;
                    ofs -= bcs;
                }
                fp->fptr += ofs;
                if ( ofs % SS( fp->fs ) )
                {
                    nsect = clust2sect( fp->fs, clst ); /* Current sector */
                    if ( !nsect ) ABORT( fp->fs, FR_INT_ERR );
                    nsect += ofs / SS( fp->fs );
                }
            }
        }
        if ( fp->fptr % SS( fp->fs ) && nsect != fp->dsect )
        {
#if !_FS_TINY
#if !_FS_READONLY
            if ( fp->flag & FA__DIRTY )         /* Flush dirty buffer if needed */
            {
                if ( disk_write( fp->fs->drv, fp->buf, fp->dsect, 1 ) != RES_OK )
                    ABORT( fp->fs, FR_DISK_ERR );
                fp->flag &= ~FA__DIRTY;
            }
#endif
            if ( disk_read( fp->fs->drv, fp->buf, nsect, 1 ) != RES_OK )
                ABORT( fp->fs, FR_DISK_ERR );
#endif
            fp->dsect = nsect;
        }
#if !_FS_READONLY
        if ( fp->fptr > fp->fsize )         /* Set change flag if the file size is extended */
        {
            fp->fsize = fp->fptr;
            fp->flag |= FA__WRITTEN;
        }
#endif
    }

    LEAVE_FF( fp->fs, res );
}



#if _FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Create a Directroy Object                                             */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_opendir(
    DIR* dj,            /* Pointer to directory object to create */
    const TCHAR* path   /* Pointer to the directory path */
)
{
    FRESULT res;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj->fs, 0 );
    if ( res == FR_OK )
    {
        INIT_BUF( *dj );
        res = follow_path( dj, path );          /* Follow the path to the directory */
        FREE_BUF();
        if ( res == FR_OK )                     /* Follow completed */
        {
            if ( dj->dir )                      /* It is not the root dir */
            {
                if ( dj->dir[DIR_Attr] & AM_DIR )   /* The object is a directory */
                {
                    dj->sclust = LD_CLUST( dj->dir );
                }
                else                            /* The object is not a directory */
                {
                    res = FR_NO_PATH;
                }
            }
            if ( res == FR_OK )
            {
                dj->id = dj->fs->id;
                res = dir_sdi( dj, 0 );         /* Rewind dir */
            }
        }
        if ( res == FR_NO_FILE ) res = FR_NO_PATH;
    }

    LEAVE_FF( dj->fs, res );
}




/*-----------------------------------------------------------------------*/
/* Read Directory Entry in Sequense                                      */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_readdir(
    DIR* dj,            /* Pointer to the open directory object */
    FILINFO* fno        /* Pointer to file information to return */
)
{
    FRESULT res;
    DEF_NAMEBUF;


    res = validate( dj->fs, dj->id );       /* Check validity of the object */
    if ( res == FR_OK )
    {
        if ( !fno )
        {
            res = dir_sdi( dj, 0 );         /* Rewind the directory object */
        }
        else
        {
            INIT_BUF( *dj );
            res = dir_read( dj );           /* Read an directory item */
            if ( res == FR_NO_FILE )        /* Reached end of dir */
            {
                dj->sect = 0;
                res = FR_OK;
            }
            if ( res == FR_OK )             /* A valid entry is found */
            {
                get_fileinfo( dj, fno );    /* Get the object information */
                res = dir_next( dj, 0 );    /* Increment index for next */
                if ( res == FR_NO_FILE )
                {
                    dj->sect = 0;
                    res = FR_OK;
                }
            }
            FREE_BUF();
        }
    }

    LEAVE_FF( dj->fs, res );
}



#if _FS_MINIMIZE == 0
/*-----------------------------------------------------------------------*/
/* Get File Status                                                       */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_stat(
    const TCHAR* path,  /* Pointer to the file path */
    FILINFO* fno        /* Pointer to file information to return */
)
{
    FRESULT res;
    DIR dj;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 0 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path ); /* Follow the file path */
        if ( res == FR_OK )             /* Follow completed */
        {
            if ( dj.dir )   /* Found an object */
                get_fileinfo( &dj, fno );
            else            /* It is root dir */
                res = FR_INVALID_NAME;
        }
        FREE_BUF();
    }

    LEAVE_FF( dj.fs, res );
}



#if !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Get Number of Free Clusters                                           */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_getfree(
    const TCHAR* path,  /* Pointer to the logical drive number (root dir) */
    DWORD* nclst,       /* Pointer to the variable to return number of free clusters */
    FATFS** fatfs       /* Pointer to pointer to corresponding file system object to return */
)
{
    FRESULT res;
    DWORD n, clst, sect, stat;
    UINT i;
    BYTE fat, *p;


    /* Get drive number */
    res = chk_mounted( &path, fatfs, 0 );
    if ( res == FR_OK )
    {
        /* If free_clust is valid, return it without full cluster scan */
        if ( ( *fatfs )->free_clust <= ( *fatfs )->n_fatent - 2 )
        {
            *nclst = ( *fatfs )->free_clust;
        }
        else
        {
            /* Get number of free clusters */
            fat = ( *fatfs )->fs_type;
            n = 0;
            if ( fat == FS_FAT12 )
            {
                clst = 2;
                do
                {
                    stat = get_fat( *fatfs, clst );
                    if ( stat == 0xFFFFFFFF ) { res = FR_DISK_ERR; break; }
                    if ( stat == 1 ) { res = FR_INT_ERR; break; }
                    if ( stat == 0 ) n++;
                }
                while ( ++clst < ( *fatfs )->n_fatent );
            }
            else
            {
                clst = ( *fatfs )->n_fatent;
                sect = ( *fatfs )->fatbase;
                i = 0; p = 0;
                do
                {
                    if ( !i )
                    {
                        res = move_window( *fatfs, sect++ );
                        if ( res != FR_OK ) break;
                        p = ( *fatfs )->win;
                        i = SS( *fatfs );
                    }
                    if ( fat == FS_FAT16 )
                    {
                        if ( LD_WORD( p ) == 0 ) n++;
                        p += 2; i -= 2;
                    }
                    else
                    {
                        if ( ( LD_DWORD( p ) & 0x0FFFFFFF ) == 0 ) n++;
                        p += 4; i -= 4;
                    }
                }
                while ( --clst );
            }
            ( *fatfs )->free_clust = n;
            if ( fat == FS_FAT32 )( *fatfs )->fsi_flag = 1;
            *nclst = n;
        }
    }
    LEAVE_FF( *fatfs, res );
}




/*-----------------------------------------------------------------------*/
/* Truncate File                                                         */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_truncate(
    FIL* fp     /* Pointer to the file object */
)
{
    FRESULT res;
    DWORD ncl;


    res = validate( fp->fs, fp->id );   /* Check validity of the object */
    if ( res == FR_OK )
    {
        if ( fp->flag & FA__ERROR )         /* Check abort flag */
        {
            res = FR_INT_ERR;
        }
        else
        {
            if ( !( fp->flag & FA_WRITE ) ) /* Check access mode */
                res = FR_DENIED;
        }
    }
    if ( res == FR_OK )
    {
        if ( fp->fsize > fp->fptr )
        {
            fp->fsize = fp->fptr;   /* Set file size to current R/W point */
            fp->flag |= FA__WRITTEN;
            if ( fp->fptr == 0 )    /* When set file size to zero, remove entire cluster chain */
            {
                res = remove_chain( fp->fs, fp->org_clust );
                fp->org_clust = 0;
            }
            else                    /* When truncate a part of the file, remove remaining clusters */
            {
                ncl = get_fat( fp->fs, fp->curr_clust );
                res = FR_OK;
                if ( ncl == 0xFFFFFFFF ) res = FR_DISK_ERR;
                if ( ncl == 1 ) res = FR_INT_ERR;
                if ( res == FR_OK && ncl < fp->fs->n_fatent )
                {
                    res = put_fat( fp->fs, fp->curr_clust, 0x0FFFFFFF );
                    if ( res == FR_OK ) res = remove_chain( fp->fs, ncl );
                }
            }
        }
        if ( res != FR_OK ) fp->flag |= FA__ERROR;
    }

    LEAVE_FF( fp->fs, res );
}




/*-----------------------------------------------------------------------*/
/* Delete a File or Directory                                            */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_unlink(
    const TCHAR* path       /* Pointer to the file or directory path */
)
{
    FRESULT res;
    DIR dj, sdj;
    BYTE* dir;
    DWORD dclst;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 1 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path );     /* Follow the file path */
        if ( _FS_RPATH && res == FR_OK && ( dj.fn[NS] & NS_DOT ) )
            res = FR_INVALID_NAME;          /* Cannot remove dot entry */
#if _FS_SHARE
        if ( res == FR_OK ) res = chk_lock( &dj, 2 ); /* Cannot remove open file */
#endif
        if ( res == FR_OK )                 /* The object is accessible */
        {
            dir = dj.dir;
            if ( !dir )
            {
                res = FR_INVALID_NAME;      /* Cannot remove the start directory */
            }
            else
            {
                if ( dir[DIR_Attr] & AM_RDO )
                    res = FR_DENIED;        /* Cannot remove R/O object */
            }
            dclst = LD_CLUST( dir );
            if ( res == FR_OK && ( dir[DIR_Attr] & AM_DIR ) ) /* Is it a sub-dir? */
            {
                if ( dclst < 2 )
                {
                    res = FR_INT_ERR;
                }
                else
                {
                    mem_cpy( &sdj, &dj, sizeof( DIR ) ); /* Check if the sub-dir is empty or not */
                    sdj.sclust = dclst;
                    res = dir_sdi( &sdj, 2 );   /* Exclude dot entries */
                    if ( res == FR_OK )
                    {
                        res = dir_read( &sdj );
                        if ( res == FR_OK           /* Not empty dir */
#if _FS_RPATH
                                || dclst == sdj.fs->cdir    /* Current dir */
#endif
                           ) res = FR_DENIED;
                        if ( res == FR_NO_FILE ) res = FR_OK; /* Empty */
                    }
                }
            }
            if ( res == FR_OK )
            {
                res = dir_remove( &dj );    /* Remove the directory entry */
                if ( res == FR_OK )
                {
                    if ( dclst )            /* Remove the cluster chain if exist */
                        res = remove_chain( dj.fs, dclst );
                    if ( res == FR_OK ) res = sync( dj.fs );
                }
            }
        }
        FREE_BUF();
    }
    LEAVE_FF( dj.fs, res );
}




/*-----------------------------------------------------------------------*/
/* Create a Directory                                                    */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_mkdir(
    const TCHAR* path       /* Pointer to the directory path */
)
{
    FRESULT res;
    DIR dj;
    BYTE* dir, n;
    DWORD dsc, dcl, pcl, tim = get_fattime();
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 1 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path );         /* Follow the file path */
        if ( res == FR_OK ) res = FR_EXIST;     /* Any object with same name is already existing */
        if ( _FS_RPATH && res == FR_NO_FILE && ( dj.fn[NS] & NS_DOT ) )
            res = FR_INVALID_NAME;
        if ( res == FR_NO_FILE )                /* Can create a new directory */
        {
            dcl = create_chain( dj.fs, 0 );     /* Allocate a cluster for the new directory table */
            res = FR_OK;
            if ( dcl == 0 ) res = FR_DENIED;    /* No space to allocate a new cluster */
            if ( dcl == 1 ) res = FR_INT_ERR;
            if ( dcl == 0xFFFFFFFF ) res = FR_DISK_ERR;
            if ( res == FR_OK )                 /* Flush FAT */
                res = move_window( dj.fs, 0 );
            if ( res == FR_OK )                 /* Initialize the new directory table */
            {
                dsc = clust2sect( dj.fs, dcl );
                dir = dj.fs->win;
                mem_set( dir, 0, SS( dj.fs ) );
                mem_set( dir + DIR_Name, ' ', 8 + 3 ); /* Create "." entry */
                dir[DIR_Name] = '.';
                dir[DIR_Attr] = AM_DIR;
                ST_DWORD( dir + DIR_WrtTime, tim );
                ST_CLUST( dir, dcl );
                mem_cpy( dir + 32, dir, 32 );       /* Create ".." entry */
                dir[33] = '.'; pcl = dj.sclust;
                if ( dj.fs->fs_type == FS_FAT32 && pcl == dj.fs->dirbase )
                    pcl = 0;
                ST_CLUST( dir + 32, pcl );
                for ( n = dj.fs->csize; n; n-- )    /* Write dot entries and clear following sectors */
                {
                    dj.fs->winsect = dsc++;
                    dj.fs->wflag = 1;
                    res = move_window( dj.fs, 0 );
                    if ( res != FR_OK ) break;
                    mem_set( dir, 0, SS( dj.fs ) );
                }
            }
            if ( res == FR_OK ) res = dir_register( &dj ); /* Register the object to the directoy */
            if ( res != FR_OK )
            {
                remove_chain( dj.fs, dcl );         /* Could not register, remove cluster chain */
            }
            else
            {
                dir = dj.dir;
                dir[DIR_Attr] = AM_DIR;             /* Attribute */
                ST_DWORD( dir + DIR_WrtTime, tim ); /* Created time */
                ST_CLUST( dir, dcl );               /* Table start cluster */
                dj.fs->wflag = 1;
                res = sync( dj.fs );
            }
        }
        FREE_BUF();
    }

    LEAVE_FF( dj.fs, res );
}




/*-----------------------------------------------------------------------*/
/* Change Attribute                                                      */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_chmod(
    const TCHAR* path,  /* Pointer to the file path */
    BYTE value,         /* Attribute bits */
    BYTE mask           /* Attribute mask to change */
)
{
    FRESULT res;
    DIR dj;
    BYTE* dir;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 1 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path );     /* Follow the file path */
        FREE_BUF();
        if ( _FS_RPATH && res == FR_OK && ( dj.fn[NS] & NS_DOT ) )
            res = FR_INVALID_NAME;
        if ( res == FR_OK )
        {
            dir = dj.dir;
            if ( !dir )                     /* Is it a root directory? */
            {
                res = FR_INVALID_NAME;
            }
            else                            /* File or sub directory */
            {
                mask &= AM_RDO | AM_HID | AM_SYS | AM_ARC; /* Valid attribute mask */
                dir[DIR_Attr] = ( value & mask ) | ( dir[DIR_Attr] & ( BYTE )~mask ); /* Apply attribute change */
                dj.fs->wflag = 1;
                res = sync( dj.fs );
            }
        }
    }

    LEAVE_FF( dj.fs, res );
}




/*-----------------------------------------------------------------------*/
/* Change Timestamp                                                      */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_utime(
    const TCHAR* path,  /* Pointer to the file/directory name */
    const FILINFO* fno  /* Pointer to the time stamp to be set */
)
{
    FRESULT res;
    DIR dj;
    BYTE* dir;
    DEF_NAMEBUF;


    res = chk_mounted( &path, &dj.fs, 1 );
    if ( res == FR_OK )
    {
        INIT_BUF( dj );
        res = follow_path( &dj, path ); /* Follow the file path */
        FREE_BUF();
        if ( _FS_RPATH && res == FR_OK && ( dj.fn[NS] & NS_DOT ) )
            res = FR_INVALID_NAME;
        if ( res == FR_OK )
        {
            dir = dj.dir;
            if ( !dir )                 /* Root directory */
            {
                res = FR_INVALID_NAME;
            }
            else                        /* File or sub-directory */
            {
                ST_WORD( dir + DIR_WrtTime, fno->ftime );
                ST_WORD( dir + DIR_WrtDate, fno->fdate );
                dj.fs->wflag = 1;
                res = sync( dj.fs );
            }
        }
    }

    LEAVE_FF( dj.fs, res );
}




/*-----------------------------------------------------------------------*/
/* Rename File/Directory                                                 */
/*-----------------------------------------------------------------------*/

NODEBUG FRESULT f_rename(
    const TCHAR* path_old,  /* Pointer to the old name */
    const TCHAR* path_new   /* Pointer to the new name */
)
{
    FRESULT res;
    DIR djo, djn;
    BYTE buf[21], *dir;
    DWORD dw;
    DEF_NAMEBUF;


    res = chk_mounted( &path_old, &djo.fs, 1 );
    if ( res == FR_OK )
    {
        djn.fs = djo.fs;
        INIT_BUF( djo );
        res = follow_path( &djo, path_old );    /* Check old object */
        if ( _FS_RPATH && res == FR_OK && ( djo.fn[NS] & NS_DOT ) )
            res = FR_INVALID_NAME;
#if _FS_SHARE
        if ( res == FR_OK ) res = chk_lock( &djo, 2 );
#endif
        if ( res == FR_OK )                     /* Old object is found */
        {
            if ( !djo.dir )                     /* Is root dir? */
            {
                res = FR_NO_FILE;
            }
            else
            {
                mem_cpy( buf, djo.dir + DIR_Attr, 21 ); /* Save the object information except for name */
                mem_cpy( &djn, &djo, sizeof( DIR ) );   /* Check new object */
                res = follow_path( &djn, path_new );
                if ( res == FR_OK ) res = FR_EXIST;     /* The new object name is already existing */
                if ( res == FR_NO_FILE )                /* Is it a valid path and no name collision? */
                {
                    /* Start critical section that any interruption or error can cause cross-link */
                    res = dir_register( &djn );         /* Register the new entry */
                    if ( res == FR_OK )
                    {
                        dir = djn.dir;                  /* Copy object information except for name */
                        mem_cpy( dir + 13, buf + 2, 19 );
                        dir[DIR_Attr] = buf[0] | AM_ARC;
                        djo.fs->wflag = 1;
                        if ( djo.sclust != djn.sclust && ( dir[DIR_Attr] & AM_DIR ) )   /* Update .. entry in the directory if needed */
                        {
                            dw = clust2sect( djn.fs, LD_CLUST( dir ) );
                            if ( !dw )
                            {
                                res = FR_INT_ERR;
                            }
                            else
                            {
                                res = move_window( djn.fs, dw );
                                dir = djn.fs->win + 32; /* .. entry */
                                if ( res == FR_OK && dir[1] == '.' )
                                {
                                    dw = ( djn.fs->fs_type == FS_FAT32 && djn.sclust == djn.fs->dirbase ) ? 0 : djn.sclust;
                                    ST_CLUST( dir, dw );
                                    djn.fs->wflag = 1;
                                }
                            }
                        }
                        if ( res == FR_OK )
                        {
                            res = dir_remove( &djo );   /* Remove old entry */
                            if ( res == FR_OK )
                                res = sync( djo.fs );
                        }
                    }
                    /* End critical section */
                }
            }
        }
        FREE_BUF();
    }
    LEAVE_FF( djo.fs, res );
}

#endif /* !_FS_READONLY */
#endif /* _FS_MINIMIZE == 0 */
#endif /* _FS_MINIMIZE <= 1 */
#endif /* _FS_MINIMIZE <= 2 */



/*-----------------------------------------------------------------------*/
/* Forward data to the stream directly (available on only tiny cfg)      */
/*-----------------------------------------------------------------------*/
#if _USE_FORWARD && _FS_TINY

NODEBUG FRESULT f_forward(
    FIL* fp,                        /* Pointer to the file object */
    UINT( *func )( const BYTE*, UINT ), /* Pointer to the streaming function */
    UINT btr,                       /* Number of bytes to forward */
    UINT* bf                        /* Pointer to number of bytes forwarded */
)
{
    FRESULT res;
    DWORD remain, clst, sect;
    UINT rcnt;
    BYTE csect;


    *bf = 0;    /* Initialize byte counter */

    res = validate( fp->fs, fp->id );               /* Check validity of the object */
    if ( res != FR_OK ) LEAVE_FF( fp->fs, res );
    if ( fp->flag & FA__ERROR )                     /* Check error flag */
        LEAVE_FF( fp->fs, FR_INT_ERR );
    if ( !( fp->flag & FA_READ ) )                  /* Check access mode */
        LEAVE_FF( fp->fs, FR_DENIED );

    remain = fp->fsize - fp->fptr;
    if ( btr > remain ) btr = ( UINT )remain;       /* Truncate btr by remaining bytes */

    for ( ;  btr && ( *func )( 0, 0 );              /* Repeat until all data transferred or stream becomes busy */
            fp->fptr += rcnt, *bf += rcnt, btr -= rcnt )
    {
        csect = ( BYTE )( fp->fptr / SS( fp->fs ) & ( fp->fs->csize - 1 ) ); /* Sector offset in the cluster */
        if ( ( fp->fptr % SS( fp->fs ) ) == 0 )     /* On the sector boundary? */
        {
            if ( !csect )                           /* On the cluster boundary? */
            {
                clst = ( fp->fptr == 0 ) ?          /* On the top of the file? */
                       fp->org_clust : get_fat( fp->fs, fp->curr_clust );
                if ( clst <= 1 ) ABORT( fp->fs, FR_INT_ERR );
                if ( clst == 0xFFFFFFFF ) ABORT( fp->fs, FR_DISK_ERR );
                fp->curr_clust = clst;              /* Update current cluster */
            }
        }
        sect = clust2sect( fp->fs, fp->curr_clust ); /* Get current data sector */
        if ( !sect ) ABORT( fp->fs, FR_INT_ERR );
        sect += csect;
        if ( move_window( fp->fs, sect ) )          /* Move sector window */
            ABORT( fp->fs, FR_DISK_ERR );
        fp->dsect = sect;
        rcnt = SS( fp->fs ) - ( WORD )( fp->fptr % SS( fp->fs ) ); /* Forward data from sector window */
        if ( rcnt > btr ) rcnt = btr;
        rcnt = ( *func )( &fp->fs->win[( WORD )fp->fptr % SS( fp->fs )], rcnt );
        if ( !rcnt ) ABORT( fp->fs, FR_INT_ERR );
    }

    LEAVE_FF( fp->fs, FR_OK );
}
#endif /* _USE_FORWARD */



#if _USE_MKFS && !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Create File System on the Drive                                       */
/*-----------------------------------------------------------------------*/
#define N_ROOTDIR   512     /* Multiple of 32 */
#define N_FATS      1       /* 1 or 2 */


NODEBUG FRESULT f_mkfs(
    BYTE drv,       /* Logical drive number */
    BYTE sfd,       /* Partitioning rule 0:FDISK, 1:SFD */
    UINT au         /* Allocation unit size [bytes] */
)
{
    static const WORD vst[] = { 1024,   512,  256,  128,   64,    32,   16,    8,    4,    2,   0};
    static const WORD cst[] = {32768, 16384, 8192, 4096, 2048, 16384, 8192, 4096, 2048, 1024, 512};
    BYTE fmt, md, *tbl;
    DWORD n_clst, vs, n, wsect;
    UINT i;
    DWORD b_vol, b_fat, b_dir, b_data;  /* Offset (LBA) */
    DWORD n_vol, n_rsv, n_fat, n_dir;   /* Size */
    FATFS* fs;
    DSTATUS stat;


    /* Check mounted drive and clear work area */
    if ( drv >= _VOLUMES ) return FR_INVALID_DRIVE;
    fs = FatFs[drv];
    if ( !fs ) return FR_NOT_ENABLED;
    fs->fs_type = 0;
    drv = LD2PD( drv );

    /* Get disk statics */
    stat = disk_initialize( drv );
    if ( stat & STA_NOINIT ) return FR_NOT_READY;
    if ( stat & STA_PROTECT ) return FR_WRITE_PROTECTED;
#if _MAX_SS != 512                  /* Get disk sector size */
    if ( disk_ioctl( drv, GET_SECTOR_SIZE, &SS( fs ) ) != RES_OK )
        return FR_DISK_ERR;
#endif
    if ( disk_ioctl( drv, GET_SECTOR_COUNT, &n_vol ) != RES_OK || n_vol < 128 )
        return FR_DISK_ERR;
    b_vol = ( sfd ) ? 0 : 63; /* Volume start sector */
    n_vol -= b_vol;
    if ( au & ( au - 1 ) ) au = 0;  /* Check validity of the allocation unit size */
    if ( !au )                      /* AU auto selection */
    {
        vs = n_vol / ( 2000 / ( SS( fs ) / 512 ) );
        for ( i = 0; vs < vst[i]; i++ ) ;
        au = cst[i];
    }
    au /= SS( fs );     /* Number of sectors per cluster */
    if ( au == 0 ) au = 1;
    if ( au > 128 ) au = 128;

    /* Pre-compute number of clusters and FAT syb-type */
    n_clst = n_vol / au;
    fmt = FS_FAT12;
    if ( n_clst >= MIN_FAT16 ) fmt = FS_FAT16;
    if ( n_clst >= MIN_FAT32 ) fmt = FS_FAT32;

    /* Determine offset and size of FAT structure */
    if ( fmt == FS_FAT32 )
    {
        n_fat = ( ( n_clst * 4 ) + 8 + SS( fs ) - 1 ) / SS( fs );
        n_rsv = 32;
        n_dir = 0;
    }
    else
    {
        n_fat = ( fmt == FS_FAT12 ) ? ( n_clst * 3 + 1 ) / 2 + 3 : ( n_clst * 2 ) + 4;
        n_fat = ( n_fat + SS( fs ) - 1 ) / SS( fs );
        n_rsv = 1;
        n_dir = N_ROOTDIR * 32UL / SS( fs );
    }
    b_fat = b_vol + n_rsv;              /* FAT area start sector */
    b_dir = b_fat + n_fat * N_FATS;     /* Directory area start sector */
    b_data = b_dir + n_dir;             /* Data area start sector */
    if ( n_vol < b_data + au ) return FR_MKFS_ABORTED;  /* Too small volume */

    /* Align data start sector to erase block boundary (for flash memory media) */
    if ( disk_ioctl( drv, GET_BLOCK_SIZE, &n ) != RES_OK || !n || n > 32768 ) n = 1;
    n = ( b_data + n - 1 ) & ~( n - 1 ); /* Next nearest erase block from current data start */
    n = ( n - b_data ) / N_FATS;
    if ( fmt == FS_FAT32 )      /* FAT32: Move FAT offset */
    {
        n_rsv += n;
        b_fat += n;
    }
    else                        /* FAT12/16: Expand FAT size */
    {
        n_fat += n;
    }

    /* Determine number of cluster and final check of validity of the FAT sub-type */
    n_clst = ( n_vol - n_rsv - n_fat * N_FATS - n_dir ) / au;
    if ( ( fmt == FS_FAT16 && n_clst < MIN_FAT16 )
            || ( fmt == FS_FAT32 && n_clst < MIN_FAT32 ) )
        return FR_MKFS_ABORTED;

    /* Create partition table if required */
    if ( sfd )
    {
        md = 0xF0;
    }
    else
    {
        DWORD n_disk = b_vol + n_vol;

        mem_set( fs->win, 0, SS( fs ) );
        tbl = fs->win + MBR_Table;
        ST_DWORD( tbl, 0x00010180 );        /* Partition start in CHS */
        if ( n_disk < 63UL * 255 * 1024 )   /* Partition end in CHS */
        {
            n_disk = n_disk / 63 / 255;
            tbl[7] = ( BYTE )n_disk;
            tbl[6] = ( BYTE )( ( n_disk >> 2 ) | 63 );
        }
        else
        {
            ST_WORD( &tbl[6], 0xFFFF );
        }
        tbl[5] = 254;
        if ( fmt != FS_FAT32 )              /* System ID */
            tbl[4] = ( n_vol < 0x10000 ) ? 0x04 : 0x06;
        else
            tbl[4] = 0x0c;
        ST_DWORD( tbl + 8, 63 );            /* Partition start in LBA */
        ST_DWORD( tbl + 12, n_vol );        /* Partition size in LBA */
        ST_WORD( tbl + 64, 0xAA55 );        /* Signature */
        if ( disk_write( drv, fs->win, 0, 1 ) != RES_OK )
            return FR_DISK_ERR;
        md = 0xF8;
    }

    /* Create volume boot record */
    tbl = fs->win;                          /* Clear sector */
    mem_set( tbl, 0, SS( fs ) );
    mem_cpy( tbl, "\xEB\xFE\x90" "MSDOS5.0", 11 ); /* Boot code, OEM name */
    i = SS( fs );                           /* Sector size */
    ST_WORD( tbl + BPB_BytsPerSec, i );
    tbl[BPB_SecPerClus] = ( BYTE )au;       /* Sectors per cluster */
    ST_WORD( tbl + BPB_RsvdSecCnt, n_rsv ); /* Reserved sectors */
    tbl[BPB_NumFATs] = N_FATS;              /* Number of FATs */
    i = ( fmt == FS_FAT32 ) ? 0 : N_ROOTDIR; /* Number of rootdir entries */
    ST_WORD( tbl + BPB_RootEntCnt, i );
    if ( n_vol < 0x10000 )                  /* Number of total sectors */
    {
        ST_WORD( tbl + BPB_TotSec16, n_vol );
    }
    else
    {
        ST_DWORD( tbl + BPB_TotSec32, n_vol );
    }
    tbl[BPB_Media] = md;                    /* Media descriptor */
    ST_WORD( tbl + BPB_SecPerTrk, 63 );     /* Number of sectors per track */
    ST_WORD( tbl + BPB_NumHeads, 255 );     /* Number of heads */
    ST_DWORD( tbl + BPB_HiddSec, b_vol );   /* Hidden sectors */
    n = get_fattime();                      /* Use current time as VSN */
    if ( fmt == FS_FAT32 )
    {
        ST_DWORD( tbl + BS_VolID32, n );    /* VSN */
        ST_DWORD( tbl + BPB_FATSz32, n_fat ); /* Number of sectors per FAT */
        ST_DWORD( tbl + BPB_RootClus, 2 );  /* Root directory start cluster (2) */
        ST_WORD( tbl + BPB_FSInfo, 1 );     /* FSInfo record offset (VBR+1) */
        ST_WORD( tbl + BPB_BkBootSec, 6 );  /* Backup boot record offset (VBR+6) */
        tbl[BS_DrvNum32] = 0x80;            /* Drive number */
        tbl[BS_BootSig32] = 0x29;           /* Extended boot signature */
        mem_cpy( tbl + BS_VolLab32, "NO NAME    " "FAT32   ", 19 ); /* Volume label, FAT signature */
    }
    else
    {
        ST_DWORD( tbl + BS_VolID, n );      /* VSN */
        ST_WORD( tbl + BPB_FATSz16, n_fat ); /* Number of sectors per FAT */
        tbl[BS_DrvNum] = 0x80;              /* Drive number */
        tbl[BS_BootSig] = 0x29;             /* Extended boot signature */
        mem_cpy( tbl + BS_VolLab, "NO NAME    " "FAT     ", 19 ); /* Volume label, FAT signature */
    }
    ST_WORD( tbl + BS_55AA, 0xAA55 );       /* Signature (Offset is fixed here regardless of sector size) */
    if ( disk_write( drv, tbl, b_vol, 1 ) != RES_OK ) /* Write original (VBR) */
        return FR_DISK_ERR;
    if ( fmt == FS_FAT32 )                  /* Write backup (VBR+6) */
        disk_write( drv, tbl, b_vol + 6, 1 );

    /* Initialize FAT area */
    wsect = b_fat;
    for ( i = 0; i < N_FATS; i++ )
    {
        mem_set( tbl, 0, SS( fs ) );        /* 1st sector of the FAT  */
        n = md;                             /* Media descriptor byte */
        if ( fmt != FS_FAT32 )
        {
            n |= ( fmt == FS_FAT12 ) ? 0x00FFFF00 : 0xFFFFFF00;
            ST_DWORD( tbl + 0, n );         /* Reserve cluster #0-1 (FAT12/16) */
        }
        else
        {
            n |= 0xFFFFFF00;
            ST_DWORD( tbl + 0, n );         /* Reserve cluster #0-1 (FAT32) */
            ST_DWORD( tbl + 4, 0xFFFFFFFF );
            ST_DWORD( tbl + 8, 0x0FFFFFFF ); /* Reserve cluster #2 for root dir */
        }
        if ( disk_write( drv, tbl, wsect++, 1 ) != RES_OK )
            return FR_DISK_ERR;
        mem_set( tbl, 0, SS( fs ) );        /* Fill following FAT entries with zero */
        for ( n = 1; n < n_fat; n++ )       /* This loop may take a time on FAT32 volume due to many single sector write */
        {
            if ( disk_write( drv, tbl, wsect++, 1 ) != RES_OK )
                return FR_DISK_ERR;
        }
    }

    /* Initialize root directory */
    i = ( fmt == FS_FAT32 ) ? au : n_dir;
    do
    {
        if ( disk_write( drv, tbl, wsect++, 1 ) != RES_OK )
            return FR_DISK_ERR;
    }
    while ( --i );

#if _USE_ERASE  /* Erase data area if needed */
    {
        DWORD eb[2];

        eb[0] = wsect; eb[1] = wsect + n_clst * au - 1;
        disk_ioctl( drv, CTRL_ERASE_SECTOR, eb );
    }
#endif

    /* Create FSInfo if needed */
    if ( fmt == FS_FAT32 )
    {
        ST_WORD( tbl + BS_55AA, 0xAA55 );
        ST_DWORD( tbl + FSI_LeadSig, 0x41615252 );
        ST_DWORD( tbl + FSI_StrucSig, 0x61417272 );
        ST_DWORD( tbl + FSI_Free_Count, n_clst - 1 );
        ST_DWORD( tbl + FSI_Nxt_Free, 0xFFFFFFFF );
        disk_write( drv, tbl, b_vol + 1, 1 ); /* Write original (VBR+1) */
        disk_write( drv, tbl, b_vol + 7, 1 ); /* Write backup (VBR+7) */
    }

    return ( disk_ioctl( drv, CTRL_SYNC, ( void* )0 ) == RES_OK ) ? FR_OK : FR_DISK_ERR;
}

#endif /* _USE_MKFS && !_FS_READONLY */




#if _USE_STRFUNC
/*-----------------------------------------------------------------------*/
/* Get a string from the file                                            */
/*-----------------------------------------------------------------------*/
NODEBUG TCHAR* f_gets(
    TCHAR* buff,    /* Pointer to the string buffer to read */
    int len,        /* Size of string buffer (characters) */
    FIL* fil        /* Pointer to the file object */
)
{
    int n = 0;
    TCHAR c, *p = buff;
    BYTE s[2];
    UINT rc;


    while ( n < len - 1 )           /* Read bytes until buffer gets filled */
    {
        f_read( fil, s, 1, &rc );
        if ( rc != 1 ) break;       /* Break on EOF or error */
        c = s[0];
#if _LFN_UNICODE                    /* Read a character in UTF-8 encoding */
        if ( c >= 0x80 )
        {
            if ( c < 0xC0 ) continue; /* Skip stray trailer */
            if ( c < 0xE0 )         /* Two-byte sequense */
            {
                f_read( fil, s, 1, &rc );
                if ( rc != 1 ) break;
                c = ( ( c & 0x1F ) << 6 ) | ( s[0] & 0x3F );
                if ( c < 0x80 ) c = '?';
            }
            else
            {
                if ( c < 0xF0 )     /* Three-byte sequense */
                {
                    f_read( fil, s, 2, &rc );
                    if ( rc != 2 ) break;
                    c = ( c << 12 ) | ( ( s[0] & 0x3F ) << 6 ) | ( s[1] & 0x3F );
                    if ( c < 0x800 ) c = '?';
                }
                else                /* Reject four-byte sequense */
                {
                    c = '?';
                }
            }
        }
#endif
#if _USE_STRFUNC >= 2
        if ( c == '\r' ) continue;  /* Strip '\r' */
#endif
        *p++ = c;
        n++;
        if ( c == '\n' ) break;     /* Break on EOL */
    }
    *p = 0;
    return n ? buff : 0;            /* When no data read (eof or error), return with error. */
}



#if !_FS_READONLY
#include <stdarg.h>
/*-----------------------------------------------------------------------*/
/* Put a character to the file                                           */
/*-----------------------------------------------------------------------*/
NODEBUG int f_putc(
    TCHAR c,    /* A character to be output */
    FIL* fil    /* Pointer to the file object */
)
{
    UINT bw, btw;
    BYTE s[3];


#if _USE_STRFUNC >= 2
    if ( c == '\n' ) f_putc( '\r', fil ); /* LF -> CRLF conversion */
#endif

#if _LFN_UNICODE    /* Write the character in UTF-8 encoding */
    if ( c < 0x80 )         /* 7-bit */
    {
        s[0] = ( BYTE )c;
        btw = 1;
    }
    else
    {
        if ( c < 0x800 )    /* 11-bit */
        {
            s[0] = ( BYTE )( 0xC0 | ( c >> 6 ) );
            s[1] = ( BYTE )( 0x80 | ( c & 0x3F ) );
            btw = 2;
        }
        else                /* 16-bit */
        {
            s[0] = ( BYTE )( 0xE0 | ( c >> 12 ) );
            s[1] = ( BYTE )( 0x80 | ( ( c >> 6 ) & 0x3F ) );
            s[2] = ( BYTE )( 0x80 | ( c & 0x3F ) );
            btw = 3;
        }
    }
#else               /* Write the character without conversion */
    s[0] = ( BYTE )c;
    btw = 1;
#endif
    f_write( fil, s, btw, &bw );    /* Write the char to the file */
    return ( bw == btw ) ? 1 : EOF; /* Return the result */
}




/*-----------------------------------------------------------------------*/
/* Put a string to the file                                              */
/*-----------------------------------------------------------------------*/
NODEBUG int f_puts(
    const TCHAR* str,   /* Pointer to the string to be output */
    FIL* fil            /* Pointer to the file object */
)
{
    int n;


    for ( n = 0; *str; str++, n++ )
    {
        if ( f_putc( *str, fil ) == EOF ) return EOF;
    }
    return n;
}




/*-----------------------------------------------------------------------*/
/* Put a formatted string to the file                                    */
/*-----------------------------------------------------------------------*/
NODEBUG int f_printf(
    FIL* fil,           /* Pointer to the file object */
    const TCHAR* str,   /* Pointer to the format string */
    ...                 /* Optional arguments... */
)
{
    va_list arp;
    BYTE f, r;
    UINT i, w;
    ULONG val;
    TCHAR c, d, s[16];
    int res, cc;


    va_start( arp, str );

    for ( cc = res = 0; cc != EOF; res += cc )
    {
        c = *str++;
        if ( c == 0 ) break;        /* End of string */
        if ( c != '%' )             /* Non escape character */
        {
            cc = f_putc( c, fil );
            if ( cc != EOF ) cc = 1;
            continue;
        }
        w = f = 0;
        c = *str++;
        if ( c == '0' )             /* Flag: '0' padding */
        {
            f = 1; c = *str++;
        }
        while ( IsDigit( c ) )      /* Precision */
        {
            w = w * 10 + c - '0';
            c = *str++;
        }
        if ( c == 'l' || c == 'L' ) /* Prefix: Size is long int */
        {
            f |= 2; c = *str++;
        }
        if ( !c ) break;
        d = c;
        if ( IsLower( d ) ) d -= 0x20;
        switch ( d )                /* Type is... */
        {
        case 'S' :                  /* String */
            cc = f_puts( va_arg( arp, TCHAR* ), fil ); continue;
        case 'C' :                  /* Character */
            cc = f_putc( ( TCHAR )va_arg( arp, int ), fil ); continue;
        case 'B' :                  /* Binary */
            r = 2; break;
        case 'O' :                  /* Octal */
            r = 8; break;
        case 'D' :                  /* Signed decimal */
        case 'U' :                  /* Unsigned decimal */
            r = 10; break;
        case 'X' :                  /* Hexdecimal */
            r = 16; break;
        default:                    /* Unknown */
            cc = f_putc( c, fil ); continue;
        }

        /* Get an argument */
        val = ( f & 2 ) ? va_arg( arp, long ) : ( ( d == 'D' ) ? ( long )va_arg( arp, int ) : va_arg( arp, unsigned int ) );
        if ( d == 'D' && ( val & 0x80000000 ) )
        {
            val = 0 - val;
            f |= 4;
        }
        /* Put it in numeral string */
        i = 0;
        do
        {
            d = ( TCHAR )( val % r ); val /= r;
            if ( d > 9 )
            {
                d += 7;
                if ( c == 'x' ) d += 0x20;
            }
            s[i++] = d + '0';
        }
        while ( val && i < sizeof( s ) / sizeof( s[0] ) );
        if ( f & 4 ) s[i++] = '-';
        cc = 0;
        while ( i < w-- && cc != EOF )
        {
            cc = f_putc( ( TCHAR )( ( f & 1 ) ? '0' : ' ' ), fil );
            res++;
        }
        do
        {
            cc = f_putc( s[--i], fil );
            res++;
        }
        while ( i && cc != EOF );
        if ( cc != EOF ) cc = 0;
    }

    va_end( arp );
    return ( cc == EOF ) ? cc : res;
}

#endif /* !_FS_READONLY */
#endif /* _USE_STRFUNC */