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FATFileSystem/Core/ff.c

Committer:
cicklaus
Date:
2012-02-13
Revision:
0:afb2650fb49a

File content as of revision 0:afb2650fb49a:

/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.08                  (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.
/                   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)
/                   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.
/---------------------------------------------------------------------------*/

//Modified by Thomas Hamilton, Copyright 2010

#include "ff.h"            /* FatFs configurations and declarations */
#include "diskio.h"        /* Declarations of low level disk I/O functions */


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

   Module Private Definitions

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

#if _FATFS != 8085
#error Wrong include file (ff.h).
#endif


/* 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 */


/* Definitions corresponds to multiple sector size */
#if _MAX_SS == 512        /* Single sector size */
#define    SS(fs)    512U
#elif _MAX_SS == 1024 || _MAX_SS == 2048 || _MAX_SS == 4096    /* Multiple sector size */
#define    SS(fs)    ((fs)->ssize)
#else
#error Wrong 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); }


/* 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 */



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

#if !_DRIVES
#error Number of drives must not be 0.
#endif
static
WORD Fsid;                /* File system mount ID */
static
FATFS *FatFs[_DRIVES];    /* Pointer to the file system objects (logical drives) */

#if _FS_RPATH
static
BYTE Drive;                /* Current drive */
#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 */
static 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 */
static
void mem_cpy (void* dst, const void* src, int 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++;
}

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

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

/* Compare memory to memory */
static
int mem_cmp (const void* dst, const void* src, int 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 */
static
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

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


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

static
FRESULT chk_lock (    /* Check if the file can be accessed */
    FAT_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 (dj->fs->flsem[i].ctr) {    /* Existing entry */
            if (dj->fs->flsem[i].clu == dj->sclust &&     /* The file is found (identified with its location) */
                dj->fs->flsem[i].idx == dj->index) break;
        } else {                    /* Blank entry */
            be++;
        }
    }
    if (i == _FS_SHARE)    /* The file has not been 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 || dj->fs->flsem[i].ctr == 0x100) ? FR_LOCKED : FR_OK;
}


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 && fs->flsem[i].ctr; i++) ;
    return (i == _FS_SHARE) ? 0 : 1;
}


static
UINT inc_lock (    /* Increment file open counter and returns its index (0:int error) */
    FAT_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 (dj->fs->flsem[i].ctr &&
            dj->fs->flsem[i].clu == dj->sclust &&
            dj->fs->flsem[i].idx == dj->index) break;
    }

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

    if (acc && dj->fs->flsem[i].ctr) return 0;    /* Access violation (int err) */

    dj->fs->flsem[i].ctr = acc ? 0x100 : dj->fs->flsem[i].ctr + 1;    /* Set semaphore value */

    return i + 1;
}


static
FRESULT dec_lock (    /* Decrement file open counter */
    FATFS* fs,        /* File system object */
    UINT i            /* Semaphore index */
)
{
    WORD n;
    FRESULT res;


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

#endif



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

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
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




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


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

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
static
FRESULT remove_chain (
    FATFS *fs,            /* File system object */
    DWORD clst            /* Cluster# to remove a chain from */
)
{
    FRESULT res;
    DWORD nxt;


    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;
            }
            clst = nxt;    /* Next cluster */
        }
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* FAT handling - Stretch or Create a cluster chain                      */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
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;


    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 */
    }

    if (put_fat(fs, ncl, 0x0FFFFFFF))    /* Mark the new cluster "last link" */
        return 0xFFFFFFFF;
    if (clst != 0) {                    /* Link it to the previous one if needed */
        if (put_fat(fs, clst, ncl))
            return 0xFFFFFFFF;
    }

    fs->last_clust = ncl;                /* Update FSINFO */
    if (fs->free_clust != 0xFFFFFFFF) {
        fs->free_clust--;
        fs->fsi_flag = 1;
    }

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




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


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;
}




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

static
FRESULT dir_sdi (
    FAT_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 */
        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 */
        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                        */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_next (    /* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not stretch */
    FAT_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 */


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 */
)
{
    int 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 */
}



static
int pick_lfn (            /* 1:Succeeded, 0:Buffer overflow */
    WCHAR *lfnbuf,        /* Pointer to the Unicode-LFN buffer */
    BYTE *dir            /* Pointer to the directory entry */
)
{
    int 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
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 */
)
{
    int 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
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;
    int 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
static
BYTE sum_sfn (
    const BYTE *dir        /* Ptr to directory entry */
)
{
    BYTE sum = 0;
    int n = 11;

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




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

static
FRESULT dir_find (
    FAT_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
static
FRESULT dir_read (
    FAT_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
static
FRESULT dir_register (    /* FR_OK:Successful, FR_DENIED:No free entry or too many SFN collision, FR_DISK_ERR:Disk error */
    FAT_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)) return FR_INVALID_NAME;    /* Cannot create dot entry */

    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
static
FRESULT dir_remove (    /* FR_OK: Successful, FR_DISK_ERR: A disk error */
    FAT_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           */
/*-----------------------------------------------------------------------*/

static
FRESULT create_name (
    FAT_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;
    int 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)) {                /* If it is a DBC 1st byte */
            b = p[si++];                /* Get 2nd byte */
            if (!IsDBCS2(b))            /* Reject invalid code for DBC */
                return FR_INVALID_NAME;
            w = (w << 8) + b;
        }
        w = ff_convert(w, 1);            /* Convert 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 */
            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;
    int 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 */
#ifdef _EXCVT
            c = excvt[c - 0x80];        /* Convert extend char (SBCS) */
#else
            b |= 3;                        /* Eliminate NT flag if extended char is exist */
#if !_DF1S    /* ASCII only cfg */
            return FR_INVALID_NAME;
#endif
#endif
        }
        if (IsDBCS1(c)) {                /* DBC 1st byte? */
            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
static
void get_fileinfo (        /* No return code */
    FAT_DIR *dj,            /* Pointer to the directory object */
    FILINFO *fno         /* Pointer to the file information to be filled */
)
{
    int 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;

#if _USE_LFN
    if (fno->lfname) {
        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 */
                    tp[i++] = (TCHAR)(w >> 8);
#endif
                if (i >= fno->lfsize - 1) { i = 0; break; }    /* Buffer overrun, no LFN */
                tp[i++] = (TCHAR)w;
            }
        }
        tp[i] = 0;    /* Terminator */
    }
#endif
}
#endif /* _FS_MINIMIZE <= 1 */




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

static
FRESULT follow_path (    /* FR_OK(0): successful, !=0: error code */
    FAT_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 = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
        }
    }

    return res;
}




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

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;
}




/*-----------------------------------------------------------------------*/
/* Make sure that the file system is valid                               */
/*-----------------------------------------------------------------------*/

static
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 = Drive;                /* Use current drive */
#else
        vol = 0;                    /* Use drive 0 */
#endif
    }

    /* Check if the logical drive is valid or not */
    if (vol >= _DRIVES)             /* 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 the volume (initialize the file system 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 drive is ready */
        return FR_NOT_READY;
#if _MAX_SS != 512                        /* Get disk sector size if needed */
    if (disk_ioctl(fs->drv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK || SS(fs) > _MAX_SS)
        return FR_NO_FILESYSTEM;
#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 1,2,4...128) */

    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 */
    for (vol = 0; vol < _FS_SHARE; vol++)
        fs->flsem[vol].ctr = 0;
#endif

    return FR_OK;
}




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

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

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

    if (rfs) {
#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                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_open (
    FAT_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;
    FAT_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;
            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 = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);    /* Get start cluster */
            ST_WORD(dir+DIR_FstClusHI, 0);        /* cluster = 0 */
            ST_WORD(dir+DIR_FstClusLO, 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_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW))
            mode |= FA__WRITTEN;                /* Set file changed flag */
        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 =                        /* File start cluster */
            ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
        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                                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_read (
    FAT_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 = (BYTE*)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                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_write (
    FAT_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 = (const BYTE*)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 changed flag */

    LEAVE_FF(fp->fs, FR_OK);
}




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

FRESULT f_sync (
    FAT_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_WORD(dir+DIR_FstClusLO, fp->org_clust);    /* Update start cluster */
                ST_WORD(dir+DIR_FstClusHI, fp->org_clust >> 16);
                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                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_close (
    FAT_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->fs, fp->lockid);    
            unlock_fs(fp->fs, FR_OK);
        }
#else
        res = dec_lock(fp->fs, fp->lockid);
#endif
    }
#endif
    if (res == FR_OK) fp->fs = 0;    /* Discard file object */
    return res;
#endif
}




/*-----------------------------------------------------------------------*/
/* Change Current Drive/Directory                                        */
/*-----------------------------------------------------------------------*/

#if _FS_RPATH

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

    Drive = drv;

    return FR_OK;
}




FRESULT f_chdir (
    const TCHAR *path    /* Pointer to the directory path */
)
{
    FRESULT res;
    FAT_DIR dj;
    BYTE *dir;
    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 */
            dir = dj.dir;                    /* Pointer to the entry */
            if (!dir) {
                dj.fs->cdir = dj.sclust;    /* Start directory itself */
            } else {
                if (dir[DIR_Attr] & AM_DIR)    /* Reached to the directory */
                    dj.fs->cdir = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
                else
                    res = FR_NO_PATH;        /* Reached but a file */
            }
        }
        if (res == FR_NO_FILE) res = FR_NO_PATH;
    }

    LEAVE_FF(dj.fs, res);
}

#endif



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

FRESULT f_lseek (
    FAT_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 changed 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                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_opendir (
    FAT_DIR *dj,            /* Pointer to directory object to create */
    const TCHAR *path    /* Pointer to the directory path */
)
{
    FRESULT res;
    BYTE *dir;
    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 */
            dir = dj->dir;
            if (dir) {                            /* It is not the current dir */
                if (dir[DIR_Attr] & AM_DIR) {    /* The object is a directory */
                    dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
                } 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                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_readdir (
    FAT_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);
        } else {
            INIT_BUF(*dj);
            res = dir_read(dj);
            if (res == FR_NO_FILE) {
                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                                                       */
/*-----------------------------------------------------------------------*/

FRESULT f_stat (
    const TCHAR *path,    /* Pointer to the file path */
    FILINFO *fno        /* Pointer to file information to return */
)
{
    FRESULT res;
    FAT_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                                           */
/*-----------------------------------------------------------------------*/

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

FRESULT f_truncate (
    FAT_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                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_unlink (
    const TCHAR *path        /* Pointer to the file or directory path */
)
{
    FRESULT res;
    FAT_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 = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
            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(FAT_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                                                    */
/*-----------------------------------------------------------------------*/

FRESULT f_mkdir (
    const TCHAR *path        /* Pointer to the directory path */
)
{
    FRESULT res;
    FAT_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_WORD(dir+DIR_FstClusLO, dcl);
                ST_WORD(dir+DIR_FstClusHI, dcl >> 16);
                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_WORD(dir+32+DIR_FstClusLO, pcl);
                ST_WORD(dir+32+DIR_FstClusHI, pcl >> 16);
                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_WORD(dir+DIR_FstClusLO, dcl);        /* Table start cluster */
                ST_WORD(dir+DIR_FstClusHI, dcl >> 16);
                dj.fs->wflag = 1;
                res = sync(dj.fs);
            }
        }
        FREE_BUF();
    }

    LEAVE_FF(dj.fs, res);
}




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

FRESULT f_chmod (
    const TCHAR *path,    /* Pointer to the file path */
    BYTE value,            /* Attribute bits */
    BYTE mask            /* Attribute mask to change */
)
{
    FRESULT res;
    FAT_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                                                      */
/*-----------------------------------------------------------------------*/

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;
    FAT_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                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_rename (
    const TCHAR *path_old,    /* Pointer to the old name */
    const TCHAR *path_new    /* Pointer to the new name */
)
{
    FRESULT res;
    FAT_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(FAT_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, (DWORD)LD_WORD(dir+DIR_FstClusHI) | LD_WORD(dir+DIR_FstClusLO));
                            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_WORD(dir+DIR_FstClusLO, dw);
                                    ST_WORD(dir+DIR_FstClusHI, dw >> 16);
                                    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

FRESULT f_forward (
    FAT_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 */


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;
    UINT as, i;
    DWORD b_vol, b_fat, b_dir, b_data;        /* Area offset (LBA) */
    DWORD n_vol, n_rsv, n_fat, n_dir;        /* Area size */
    FATFS *fs;
    DSTATUS stat;


    /* Check mounted drive and clear work area */
    if (drv >= _DRIVES) 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 || SS(fs) > _MAX_SS)
        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 == 1) ? 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];
    }
    if (_MAX_SS != 512 && au < SS(fs)) au = SS(fs);
    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) return FR_DISK_ERR;
    if (!n || n > 32768) return FR_MKFS_ABORTED;
    n = (b_data + n - 1) & ~(n - 1);    /* Next nearest boundary from current data start */
    n = (n - b_data) / N_FATS;
    if (fmt == FS_FAT32) {        /* FAT32: Move FAT start */
        n_rsv += n;
        b_fat += n;
    } else {                    /* FAT12/16: Expand FAT size */
        n_fat += n;
    }
    /* b_dir and b_data are no longer used below */

    /* 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 == 1) {
        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 VBR */
    tbl = fs->win;                                /* Clear buffer */
    mem_set(tbl, 0, SS(fs));
    ST_DWORD(tbl+BS_jmpBoot, 0x90FEEB);            /* Boot code (jmp $, nop) */
    as = SS(fs);                                /* Sector size */
    ST_WORD(tbl+BPB_BytsPerSec, as);
    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 */
    as = (fmt == FS_FAT32) ? 0 : N_ROOTDIR;        /* Number of rootdir entries */
    ST_WORD(tbl+BPB_RootEntCnt, as);
    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)    /* Original (VBR) */
        return FR_DISK_ERR;
    if (fmt == FS_FAT32)                        /* Backup (VBR+6) */
        disk_write(drv, tbl, b_vol + 6, 1);

    /* Initialize FAT area */
    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 |= 0x0FFFFF00;
            ST_DWORD(tbl+0, n);                /* Reserve cluster #0-1 (FAT32) */
            ST_DWORD(tbl+4, 0x0FFFFFFF);
            ST_DWORD(tbl+8, 0x0FFFFFFF);    /* Reserve cluster #2 for root dir */
        }
        if (disk_write(drv, tbl, b_fat++, 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, b_fat++, 1) != RES_OK)
                return FR_DISK_ERR;
        }
    }

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

    /* Create FSInfo record 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);    /* Original (VBR+1) */
        disk_write(drv, tbl, b_vol + 7, 1);    /* 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                                            */
/*-----------------------------------------------------------------------*/
TCHAR* f_gets (
    TCHAR* buff,    /* Pointer to the string buffer to read */
    int len,        /* Size of string buffer (characters) */
    FAT_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                                           */
/*-----------------------------------------------------------------------*/
int f_putc (
    TCHAR c,    /* A character to be output */
    FAT_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                                              */
/*-----------------------------------------------------------------------*/
int f_puts (
    const TCHAR* str,    /* Pointer to the string to be output */
    FAT_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                                    */
/*-----------------------------------------------------------------------*/
int f_printf (
    FAT_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 */