ff.c

/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.07a                    (C)ChaN, 2009
/-----------------------------------------------------------------------------/
/ FatFs module is an open source software to implement FAT file system to
/ small embedded systems. This is a free software and is opened for education,
/ research and commercial developments under license policy of following trems.
/
/  Copyright (C) 2009, 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 use 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) patition.
/ 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 algolithm 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 plysical 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.
/---------------------------------------------------------------------------*/

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


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

   Module Private Definitions

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

#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); }

#ifndef NULL
#define NULL    0
#endif


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

   Private Work Area

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

static
FATFS *FatFs[_DRIVES];  /* Pointer to the file system objects (logical drives) */
static
WORD Fsid;              /* File system mount ID */


#if _USE_LFN == 1   /* LFN with static LFN working buffer */
static
WORD LfnBuf[_MAX_LFN + 1];
#define NAMEBUF(sp,lp)  BYTE sp[12]; WCHAR *lp = LfnBuf
#define INITBUF(dj,sp,lp)   dj.fn = sp; dj.lfn = lp

#elif _USE_LFN > 1  /* LFN with dynamic LFN working buffer */
#define NAMEBUF(sp,lp)  BYTE sp[12]; WCHAR lbuf[_MAX_LFN + 1], *lp = lbuf
#define INITBUF(dj,sp,lp)   dj.fn = sp; dj.lfn = lp

#else               /* No LFN */
#define NAMEBUF(sp,lp)  BYTE sp[12]
#define INITBUF(dj,sp,lp)   dj.fn = sp

#endif




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

   Private Functions

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


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

/* Copy memory to memory */
static
void mem_cpy (void* dst, const void* src, int cnt) {
    char *d = (char*)dst;
    const char *s = (const char *)src;
    while (cnt--) *d++ = *s++;
}

/* Fill memory */
static
void mem_set (void* dst, int val, int cnt) {
    char *d = (char*)dst;
    while (cnt--) *d++ = (char)val;
}

/* Compare memory to memory */
static
int mem_cmp (const void* dst, const void* src, int cnt) {
    const char *d = (const char *)dst, *s = (const char *)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
BOOL 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



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

static
FRESULT move_window (
    FATFS *fs,      /* File system object */
    DWORD sector    /* Sector number to make apperance 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->drive, fs->win, wsect, 1) != RES_OK)
                return FR_DISK_ERR;
            fs->wflag = 0;
            if (wsect < (fs->fatbase + fs->sects_fat)) {    /* In FAT area */
                BYTE nf;
                for (nf = fs->n_fats; nf >= 2; nf--) {  /* Refrect the change to FAT copy */
                    wsect += fs->sects_fat;
                    disk_write(fs->drive, fs->win, wsect, 1);
                }
            }
        }
#endif
        if (sector) {
            if (disk_read(fs->drive, 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->drive, 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->drive, CTRL_SYNC, (void*)NULL) != RES_OK)
            res = FR_DISK_ERR;
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* Get a cluster status                                                  */
/*-----------------------------------------------------------------------*/

static
DWORD get_cluster ( /* 0xFFFFFFFF:Disk error, 1:Interal error, Else:Cluster status */
    FATFS *fs,      /* File system object */
    DWORD clst      /* Cluster# to get the link information */
)
{
    WORD wc, bc;
    DWORD fsect;


    if (clst < 2 || clst >= fs->max_clust)  /* Check cluster address range */
        return 1;

    fsect = fs->fatbase;
    switch (fs->fs_type) {
    case FS_FAT12 :
        bc = (WORD)clst * 3 / 2;
        if (move_window(fs, fsect + (bc / SS(fs)))) break;
        wc = fs->win[bc & (SS(fs) - 1)]; bc++;
        if (move_window(fs, fsect + (bc / SS(fs)))) break;
        wc |= (WORD)fs->win[bc & (SS(fs) - 1)] << 8;
        return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);

    case FS_FAT16 :
        if (move_window(fs, fsect + (clst / (SS(fs) / 2)))) break;
        return LD_WORD(&fs->win[((WORD)clst * 2) & (SS(fs) - 1)]);

    case FS_FAT32 :
        if (move_window(fs, fsect + (clst / (SS(fs) / 4)))) break;
        return LD_DWORD(&fs->win[((WORD)clst * 4) & (SS(fs) - 1)]) & 0x0FFFFFFF;
    }

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




/*-----------------------------------------------------------------------*/
/* Change a cluster status                                               */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT put_cluster (
    FATFS *fs,      /* File system object */
    DWORD clst,     /* Cluster# to be changed (must be 2 to fs->max_clust-1) */
    DWORD val       /* New value to mark the cluster */
)
{
    WORD bc;
    BYTE *p;
    DWORD fsect;
    FRESULT res;


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

    } else {
        fsect = fs->fatbase;
        switch (fs->fs_type) {
        case FS_FAT12 :
            bc = (WORD)clst * 3 / 2;
            res = move_window(fs, fsect + (bc / SS(fs)));
            if (res != FR_OK) break;
            p = &fs->win[bc & (SS(fs) - 1)];
            *p = (clst & 1) ? ((*p & 0x0F) | ((BYTE)val << 4)) : (BYTE)val;
            bc++;
            fs->wflag = 1;
            res = move_window(fs, fsect + (bc / SS(fs)));
            if (res != FR_OK) break;
            p = &fs->win[bc & (SS(fs) - 1)];
            *p = (clst & 1) ? (BYTE)(val >> 4) : ((*p & 0xF0) | ((BYTE)(val >> 8) & 0x0F));
            break;

        case FS_FAT16 :
            res = move_window(fs, fsect + (clst / (SS(fs) / 2)));
            if (res != FR_OK) break;
            ST_WORD(&fs->win[((WORD)clst * 2) & (SS(fs) - 1)], (WORD)val);
            break;

        case FS_FAT32 :
            res = move_window(fs, fsect + (clst / (SS(fs) / 4)));
            if (res != FR_OK) break;
            ST_DWORD(&fs->win[((WORD)clst * 4) & (SS(fs) - 1)], val);
            break;

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

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




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


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

    } else {
        res = FR_OK;
        while (clst < fs->max_clust) {          /* Not a last link? */
            nxt = get_cluster(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_cluster(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




/*-----------------------------------------------------------------------*/
/* 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, mcl;


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

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

    if (put_cluster(fs, ncl, 0x0FFFFFFF))   /* Mark the new cluster "in use" */
        return 0xFFFFFFFF;
    if (clst != 0) {                        /* Link it to previous one if needed */
        if (put_cluster(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#                                             */
/*-----------------------------------------------------------------------*/

static
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->max_clust - 2)) return 0;      /* Invalid cluster# */
    return clst * fs->csize + fs->database;
}




/*-----------------------------------------------------------------------*/
/* Seek directory index                                                  */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_seek (
    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->max_clust) /* Check start cluster range */
        return FR_INT_ERR;

    if (clst == 0) {    /* Static table */
        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);
    }
    else {              /* Dynamic table */
        ic = SS(dj->fs) / 32 * dj->fs->csize;   /* Indexes per cluster */
        while (idx >= ic) { /* Follow cluster chain */
            clst = get_cluster(dj->fs, clst);           /* Get next cluster */
            if (clst == 0xFFFFFFFF) return FR_DISK_ERR; /* Disk error */
            if (clst < 2 || clst >= dj->fs->max_clust)  /* 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);
    }
    dj->dir = dj->fs->win + (idx % (SS(dj->fs) / 32)) * 32;

    return FR_OK;   /* Seek succeeded */
}




/*-----------------------------------------------------------------------*/
/* Move directory index next                                             */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_next (  /* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not streach */
    DIR *dj,        /* Pointer to directory object */
    BOOL streach    /* FALSE: Do not streach table, TRUE: Streach 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->sclust == 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_cluster(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->max_clust) {                /* When it reached end of dinamic table */
#if !_FS_READONLY
                    BYTE c;
                    if (!streach) return FR_NO_FILE;            /* When do not streach, report EOT */
                    clst = create_chain(dj->fs, dj->clust);     /* Streach 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 streached 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;
}




/*-----------------------------------------------------------------------*/
/* 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
BOOL test_lfn (         /* TRUE:Matched, FALSE: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 wc1, wc2;


    i = ((dir[LDIR_Ord] & 0xBF) - 1) * 13;  /* Offset in the LFN buffer */
    s = 0;
    do {
        if (i >= _MAX_LFN) return FALSE;    /* Out of buffer range? */
        wc1 = LD_WORD(dir+LfnOfs[s]);       /* Get both characters to compare */
        wc2 = lfnbuf[i++];
        if (IsLower(wc1)) wc1 -= 0x20;      /* Compare it (ignore case) */
        if (IsLower(wc2)) wc2 -= 0x20;
        if (wc1 != wc2) return FALSE;
    } while (++s < 13 && wc1);              /* Repeat until last char or a NUL char is processed */

    return TRUE;                            /* The LFN entry matched */
}



static
BOOL pick_lfn (         /* TRUE:Succeeded, FALSE:Buffer overflow */
    WCHAR *lfnbuf,      /* Pointer to the Unicode-LFN buffer */
    BYTE *dir           /* Pointer to the directory entry */
)
{
    int i, s;
    WCHAR wchr;


    i = ((dir[LDIR_Ord] & 0xBF) - 1) * 13;  /* Offset in the LFN buffer */
    s = 0;
    do {
        wchr = LD_WORD(dir+LfnOfs[s]);      /* Get an LFN char */
        if (!wchr) break;                   /* End of LFN? */
        if (i >= _MAX_LFN) return FALSE;    /* Buffer overflow */
        lfnbuf[i++] = wchr;                 /* Store it */
    } while (++s < 13);                     /* Repeat until last char is copied */
    if (dir[LDIR_Ord] & 0x40) lfnbuf[i] = 0;    /* Put terminator if last LFN entry */

    return TRUE;
}


#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 wchr;


    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;             /* Offset in the LFN buffer */
    s = wchr = 0;
    do {
        if (wchr != 0xFFFF) wchr = lfnbuf[i++]; /* Get an effective char */
        ST_WORD(dir+LfnOfs[s], wchr);   /* Put it */
        if (!wchr) wchr = 0xFFFF;   /* Padding chars following last char */
    } while (++s < 13);
    if (wchr == 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 genartated SFN */
    const BYTE *src,    /* Pointer to source SFN to be modified */
    const WCHAR *lfn,   /* Pointer to LFN */
    WORD num            /* Sequense number */
)
{
    char ns[8];
    int i, j;


    mem_cpy(dst, src, 11);

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

    /* itoa */
    i = 7;
    do {
        ns[i--] = (num % 10) + '0';
        num /= 10;
    } while (num);
    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




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

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


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

    ord = sum = 0xFF; lfen = *(dj->fn+11) & 1;
    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 */
        a = dir[DIR_Attr] & AM_MASK;
#if _USE_LFN    /* LFN configuration */
        if (c == 0xE5 || 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 (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 LFN validity. Compare LFN if it is out of 8.3 format */
                    ord = (c == ord && sum == dir[LDIR_Chksum] && (!lfen || test_lfn(dj->lfn, dir))) ? ord - 1 : 0xFF;
                }
            } else {                    /* An SFN entry is found */
                if (ord || sum != sum_sfn(dir)) {   /* Did not LFN match? */
                    dj->lfn_idx = 0xFFFF;
                    ord = 0xFF;
                }
                if (lfen) {             /* Match LFN if it is out of 8.3 format */
                    if (ord == 0) break;
                } else {                /* Match SFN if LFN is in 8.3 format */
                    if (!mem_cmp(dir, dj->fn, 11)) break;
                }
            }
        }
#else   /* Non LFN configuration */
        if (c != 0xE5 && c != '.' && !(a & AM_VOL) && !mem_cmp(dir, dj->fn, 11)) /* Is it a valid entry? */
            break;
#endif
        res = dir_next(dj, FALSE);              /* Next entry */
    } while (res == FR_OK);

    return res;
}




/*-----------------------------------------------------------------------*/
/* Read an object from the directory                                     */
/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 2
static
FRESULT dir_read (
    DIR *dj         /* Pointer to the directory object to store read object name */
)
{
    FRESULT res;
    BYTE a, c, ord, sum, *dir;


    ord = sum = 0xFF;
    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 */
        a = dir[DIR_Attr] & AM_MASK;
#if _USE_LFN    /* LFN configuration */
        if (c == 0xE5 || 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 entry? */
                    dj->lfn_idx = 0xFFFF;       /* No LFN. */
                break;
            }
        }
#else   /* Non LFN configuration */
        if (c != 0xE5 && c != '.' && !(a & AM_VOL)) /* Is it a valid entry? */
            break;
#endif
        res = dir_next(dj, FALSE);              /* 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 */
    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 (sn[11] & 1) {       /* When LFN is out of 8.3 format, generate a numbered name */
        fn[11] = 0; dj->lfn = NULL;         /* 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[11] = sn[11]; dj->lfn = lfn;
    }
    if (sn[11] & 2) {       /* When eliminate LFN, reserve only an SFN entry. */
        ne = 1;
    } else {                /* Otherwise reserve an SFN + LFN entries. */
        for (ne = 0; lfn[ne]; ne++) ;
        ne = (ne + 25) / 13;
    }

    /* Reserve contiguous entries */
    res = dir_seek(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 contigulus entry */
            if (++n == ne) break;   /* A contiguous entry that requiered count is found */
        } else {
            n = 0;                  /* Not a blank entry. Restart to search */
        }
        res = dir_next(dj, TRUE);   /* Next entry with table streach */
    } while (res == FR_OK);

    if (res == FR_OK && ne > 1) {   /* Initialize LFN entry if needed */
        res = dir_seek(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, FALSE);  /* Next entry */
            } while (res == FR_OK && --ne);
        }
    }

#else   /* Non LFN configuration */
    res = dir_seek(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, TRUE);       /* Next entry with table streach */
        } 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 */
            dir[DIR_NTres] = *(dj->fn+11) & 0x18;   /* Put NT flag */
            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 */
    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_seek(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 SFN is deleted, all entries of the object is deleted. */
            res = dir_next(dj, FALSE);      /* Next entry */
        } while (res == FR_OK);
        if (res == FR_NO_FILE) res = FR_INT_ERR;
    }

#else           /* Non LFN configuration */
    res = dir_seek(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 (
    DIR *dj,            /* Pointer to the directory object */
    const char **path   /* Pointer to pointer to the segment in the path string */
)
{
#if _USE_LFN
    BYTE c, b, cf, *sfn;
    WCHAR w, *lfn;
    int i, ni, si, di;
    const char *p;

    /* Create LFN in Unicode */
    si = di = 0;
    p = *path;
    lfn = dj->lfn;
    for (;;) {
        w = (BYTE)p[si++];              /* Get a character */
        if (w < ' ' || w == '/' || w == '\\') break;    /* Break on end of segment */
        if (IsDBCS1(w)) {               /* If it is DBC 1st byte */
            c = p[si++];                /* Get 2nd byte */
            if (!IsDBCS2(c))            /* Reject invalid DBC */
                return FR_INVALID_NAME;
            w = (w << 8) + c;
        } else {
            if (chk_chr("\"*:<>\?|\x7F", w))    /* Reject unallowable chars for LFN */
                return FR_INVALID_NAME;
        }
        w = ff_convert(w, 1);           /* Convert OEM to Unicode, store it */
        if (!w || di >= _MAX_LFN)       /* Reject invalid code or too long name */
            return FR_INVALID_NAME;
        lfn[di++] = w;
    }
    *path = &p[si];                     /* Rerurn pointer to the next segment */
    cf = (w < ' ') ? 4 : 0;             /* Set last segment flag if end of path */

    while (di) {                        /* Strip trailing spaces and dots */
        w = lfn[di - 1];
        if (w != ' ' && w != '.') break;
        di--;
    }
    if (!di) return FR_INVALID_NAME;    /* Reject null string */

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

    /* Create SFN in directory form */
    sfn = dj->fn;
    mem_set(sfn, ' ', 11);
    for (si = 0; lfn[si] == ' ' || lfn[si] == '.'; si++) ;  /* Strip leading spaces and dots */
    if (si) cf |= 1;
    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 == 0) break;              /* Break when enf of the LFN */
        if (w == ' ' || (w == '.' && si != di)) {   /* Remove spaces and dots */
            cf |= 1; continue;
        }
        if (i >= ni || si == di) {      /* Here is extension or end of SFN */
            if (ni == 11) {             /* Extension is longer than 3 bytes */
                cf |= 1; break;
            }
            if (si != di) cf |= 1;      /* File name is longer than 8 bytes */
            if (si > di) break;         /* No extension */
            si = di; i = 8; ni = 11;    /* Enter extension section */
            b <<= 2; continue;
        }
        w = ff_convert(w, 0);           /* Unicode -> OEM code */
        if (w >= 0x80) cf |= 0x20;      /* If there is any extended char, force create an LFN */
        if (w >= 0x100) {               /* Double byte char */
            if (i >= ni - 1) {
                cf |= 1; i = ni; continue;
            }
            sfn[i++] = (BYTE)(w >> 8);
        } else {                        /* Single byte char */
            if (chk_chr("+,;[=]", w)) { /* Replace unallowable chars for SFN */
                w = '_'; cf |= 1;
            } else {
                if (IsUpper(w)) {       /* Large capital */
                    b |= 2;
                } else {
                    if (IsLower(w)) {   /* Small capital */
                        b |= 1; w -= 0x20;
                    }
                }
            }
        }
        sfn[i++] = (BYTE)w;
    }
    if (sfn[0] == 0xE5) sfn[0] = 0x05;  /* When first char collides with 0xE5, replace it with 0x05 */

    if (ni == 8) b <<= 2;
    if ((cf & 0x21) == 0) { /* When LFN is in 8.3 format without extended char, NT flags are created */
        if ((b & 0x03) == 0x01) cf |= 0x10; /* NT flag (Extension has only small capital) */
        if ((b & 0x0C) == 0x04) cf |= 0x08; /* NT flag (Filename has only small capital) */
        if ((b & 0x0C) != 0x0C && (b & 0x03) != 0x03) cf |= 2;  /* Eliminate LFN when non composite capitals */
    }

    sfn[11] = cf;       /* SFN is created */

#else
    BYTE c, d, b, *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;
    for (;;) {
        c = 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) b |= 3;          /* If there is any extended char, eliminate NT flag */
        if (IsDBCS1(c)) {               /* If it is DBC 1st byte */
            d = 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 {
            if (chk_chr(" +,;[=]\"*:<>\?|\x7F", c)) /* Reject unallowable chrs for SFN */
                return FR_INVALID_NAME;
            if (IsUpper(c)) {
                b |= 2;
            } else {
                if (IsLower(c)) {
                    b |= 1; c -= 0x20;
                }
            }
            sfn[i++] = c;
        }
    }
    *path = &p[si];                     /* Rerurn pointer to the next segment */
    c = (c < ' ') ? 4 : 0;              /* Set last segment flag if end of path */

    if (!i) return FR_INVALID_NAME;     /* Reject null 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 |= 0x10;  /* NT flag (Extension has only small capital) */
    if ((b & 0x0C) == 0x04) c |= 0x08;  /* NT flag (Filename has only small capital) */

    sfn[11] = c;        /* Store NT flag, File name is created */
#endif

    return FR_OK;
}




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


    p = fno->fname;
    if (dj->sect) {
        dir = dj->dir;
        nt = dir[DIR_NTres];        /* NT flag */
        for (i = 0; i < 8; i++) {   /* Copy file name body */
            c = dir[i];
            if (c == ' ') break;
            if (c == 0x05) c = 0xE5;
            if ((nt & 0x08) && IsUpper(c)) c += 0x20;
            *p++ = c;
        }
        if (dir[8] != ' ') {        /* Copy file name extension */
            *p++ = '.';
            for (i = 8; i < 11; i++) {
                c = dir[i];
                if (c == ' ') break;
                if ((nt & 0x10) && IsUpper(c)) c += 0x20;
                *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
    p = fno->lfname;
    if (p) {
        WCHAR wchr, *lfn;

        i = 0;
        if (dj->sect && dj->lfn_idx != 0xFFFF) {/* Get LFN if available */
            lfn = dj->lfn;
            while ((wchr = *lfn++) != 0) {      /* Get an LFN char */
                wchr = ff_convert(wchr, 0);     /* Unicode -> OEM code */
                if (!wchr) { i = 0; break; }    /* Conversion error, no LFN */
                if (_DF1S && wchr >= 0x100)     /* Put 1st byte if it is a DBC */
                    p[i++] = (char)(wchr >> 8);
                p[i++] = (char)wchr;
                if (i >= fno->lfsize) { i = 0; break; } /* Buffer overrun, no LFN */
            }
        }
        p[i] = 0;   /* Terminator */
    }
#endif
}
#endif /* _FS_MINIMIZE <= 1 */




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

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


    if (*path == '/' || *path == '\\' ) path++; /* Strip heading separator */

    dj->sclust =                        /* Set start directory (root dir) */
        (dj->fs->fs_type == FS_FAT32) ? dj->fs->dirbase : 0;

    if ((BYTE)*path < ' ') {            /* Null path means the root directory */
        res = dir_seek(dj, 0);
        dj->dir = NULL;

    } else {                            /* Follow path */
        for (;;) {
            res = create_name(dj, &path);   /* Get a segment */
            if (res != FR_OK) break;
            res = dir_find(dj);             /* Find it */
            last = *(dj->fn+11) & 4;
            if (res != FR_OK) {             /* Could not find the object */
                if (res == FR_NO_FILE && !last)
                    res = FR_NO_PATH;
                break;
            }
            if (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 boot record, 1:Valid boot record but not an FAT, 2:Not a boot record, 3: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->drive, 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 (!mem_cmp(&fs->win[BS_FilSysType], "FAT", 3))        /* Check FAT signature */
        return 0;
    if (!mem_cmp(&fs->win[BS_FilSysType32], "FAT32", 5) && !(fs->win[BPB_ExtFlags] & 0x80))
        return 0;

    return 1;
}




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

static
FRESULT auto_mount (    /* FR_OK(0): successful, !=0: any error occured */
    const char **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 */
)
{
    FRESULT res;
    BYTE vol, fmt, *tbl;
    DSTATUS stat;
    DWORD bsect, fsize, tsect, mclst;
    const char *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] == ':') {
        p += 2;                 /* Found a drive number, get and strip it */
        *path = p;              /* Return pointer to the path name */
    } else {
        vol = 0;                /* No drive number is given, use drive number 0 as default */
    }

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

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

    if (fs->fs_type) {                      /* If the logical drive has been mounted */
        stat = disk_status(fs->drive);
        if (!(stat & STA_NOINIT)) {         /* and 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 re-mounted. Following code attempts to mount the volume */

    fs->fs_type = 0;                    /* Clear the file system object */
    fs->drive = LD2PD(vol);             /* Bind the logical drive and a physical drive */
    stat = disk_initialize(fs->drive);  /* 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->drive, 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 write protection if needed */
        return FR_WRITE_PROTECTED;
#endif
    /* Search FAT partition on the drive */
    fmt = check_fs(fs, bsect = 0);      /* Check sector 0 as an SFD format */
    if (fmt == 1) {                     /* Not an FAT boot record, it may be patitioned */
        /* Check a 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 || LD_WORD(fs->win+BPB_BytsPerSec) != SS(fs))   /* No valid FAT patition is found */
        return FR_NO_FILESYSTEM;

    /* Initialize the file system object */
    fsize = LD_WORD(fs->win+BPB_FATSz16);               /* Number of sectors per FAT */
    if (!fsize) fsize = LD_DWORD(fs->win+BPB_FATSz32);
    fs->sects_fat = fsize;
    fs->n_fats = fs->win[BPB_NumFATs];                  /* Number of FAT copies */
    fsize *= fs->n_fats;                                /* (Number of sectors in FAT area) */
    fs->fatbase = bsect + LD_WORD(fs->win+BPB_RsvdSecCnt); /* FAT start sector (lba) */
    fs->csize = fs->win[BPB_SecPerClus];                /* Number of sectors per cluster */
    fs->n_rootdir = LD_WORD(fs->win+BPB_RootEntCnt);    /* Nmuber of root directory entries */
    tsect = LD_WORD(fs->win+BPB_TotSec16);              /* Number of sectors on the file system */
    if (!tsect) tsect = LD_DWORD(fs->win+BPB_TotSec32);
    fs->max_clust = mclst = (tsect                      /* Last cluster# + 1 */
        - LD_WORD(fs->win+BPB_RsvdSecCnt) - fsize - fs->n_rootdir / (SS(fs)/32)
        ) / fs->csize + 2;

    fmt = FS_FAT12;                                     /* Determine the FAT sub type */
    if (mclst >= 0xFF7) fmt = FS_FAT16;             /* Number of clusters >= 0xFF5 */
    if (mclst >= 0xFFF7) fmt = FS_FAT32;            /* Number of clusters >= 0xFFF5 */

    if (fmt == FS_FAT32)
        fs->dirbase = LD_DWORD(fs->win+BPB_RootClus);   /* Root directory start cluster */
    else
        fs->dirbase = fs->fatbase + fsize;              /* Root directory start sector (lba) */
    fs->database = fs->fatbase + fsize + fs->n_rootdir / (SS(fs)/32);   /* Data start sector (lba) */

#if !_FS_READONLY
    /* Initialize allocation information */
    fs->free_clust = 0xFFFFFFFF;
    fs->wflag = 0;
    /* Get fsinfo if needed */
    if (fmt == FS_FAT32) {
        fs->fsi_sector = bsect + LD_WORD(fs->win+BPB_FSInfo);
        fs->fsi_flag = 0;
        if (disk_read(fs->drive, 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->winsect = 0;
    fs->fs_type = fmt;          /* FAT syb-type */
    fs->id = ++Fsid;            /* File system mount ID */
    res = FR_OK;

    return res;
}




/*-----------------------------------------------------------------------*/
/* 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->drive) & STA_NOINIT)
        return FR_NOT_READY;

    return FR_OK;
}




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

   Public Functions

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



/*-----------------------------------------------------------------------*/
/* Mount/Unmount a Locical 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 state */

    if (rfs) {
#if _FS_REENTRANT                   /* Discard sync object of the current volume */
        if (!ff_del_syncobj(fs->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 (
    FIL *fp,            /* Pointer to the blank file object */
    const char *path,   /* Pointer to the file name */
    BYTE mode           /* Access mode and file open mode flags */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    fp->fs = NULL;      /* Clear file object */
#if !_FS_READONLY
    mode &= (FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW);
    res = auto_mount(&path, &dj.fs, (BYTE)(mode & (FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)));
#else
    mode &= FA_READ;
    res = auto_mount(&path, &dj.fs, 0);
#endif
    if (res != FR_OK) LEAVE_FF(dj.fs, res);
    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);   /* Follow the file path */

#if !_FS_READONLY
    /* Create or Open a file */
    if (mode & (FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)) {
        DWORD ps, cl;

        if (res != FR_OK) {     /* No file, create new */
            if (res == FR_NO_FILE)
                res = dir_register(&dj);
            if (res != FR_OK) LEAVE_FF(dj.fs, res);
            mode |= FA_CREATE_ALWAYS;
            dir = dj.dir;
        }
        else {                  /* Any object is already existing */
            if (mode & FA_CREATE_NEW)           /* Cannot create new */
                LEAVE_FF(dj.fs, FR_EXIST);
            dir = dj.dir;
            if (!dir || (dir[DIR_Attr] & (AM_RDO | AM_DIR)))    /* Cannot overwrite it (R/O or DIR) */
                LEAVE_FF(dj.fs, FR_DENIED);
            if (mode & FA_CREATE_ALWAYS) {      /* Resize it to zero if needed */
                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);
                ST_DWORD(dir+DIR_FileSize, 0);  /* size = 0 */
                dj.fs->wflag = 1;
                ps = dj.fs->winsect;            /* Remove the cluster chain */
                if (cl) {
                    res = remove_chain(dj.fs, cl);
                    if (res) LEAVE_FF(dj.fs, res);
                    dj.fs->last_clust = cl - 1; /* Reuse the cluster hole */
                }
                res = move_window(dj.fs, ps);
                if (res != FR_OK) LEAVE_FF(dj.fs, res);
            }
        }
        if (mode & FA_CREATE_ALWAYS) {
            dir[DIR_Attr] = 0;                  /* Reset attribute */
            ps = get_fattime();
            ST_DWORD(dir+DIR_CrtTime, ps);      /* Created time */
            dj.fs->wflag = 1;
            mode |= FA__WRITTEN;                /* Set file changed flag */
        }
    }
    /* Open an existing file */
    else {
#endif /* !_FS_READONLY */
        if (res != FR_OK) LEAVE_FF(dj.fs, res); /* Follow failed */
        dir = dj.dir;
        if (!dir || (dir[DIR_Attr] & AM_DIR))   /* It is a directory */
            LEAVE_FF(dj.fs, FR_NO_FILE);
#if !_FS_READONLY
        if ((mode & FA_WRITE) && (dir[DIR_Attr] & AM_RDO)) /* R/O violation */
            LEAVE_FF(dj.fs, FR_DENIED);
    }
    fp->dir_sect = dj.fs->winsect;      /* Pointer to the directory entry */
    fp->dir_ptr = dj.dir;
#endif
    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; fp->csect = 255;      /* File pointer */
    fp->dsect = 0;
    fp->fs = dj.fs; fp->id = dj.fs->id; /* Owner file system object of the file */

    LEAVE_FF(dj.fs, FR_OK);
}




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

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


    *br = 0;

    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? */
            if (fp->csect >= fp->fs->csize) {       /* On the cluster boundary? */
                clst = (fp->fptr == 0) ?            /* On the top of the file? */
                    fp->org_clust : get_cluster(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 */
                fp->csect = 0;                      /* Reset sector offset in the cluster */
            }
            sect = clust2sect(fp->fs, fp->curr_clust);  /* Get current sector */
            if (!sect) ABORT(fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btr / SS(fp->fs);                  /* When remaining bytes >= sector size, */
            if (cc) {                               /* Read maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_read(fp->fs->drive, rbuff, sect, (BYTE)cc) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
                fp->csect += (BYTE)cc;              /* Next sector address in the cluster */
                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->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
                fp->flag &= (BYTE)~FA__DIRTY;
            }
#endif
            if (fp->dsect != sect) {            /* Fill sector buffer with file data */
                if (disk_read(fp->fs->drive, fp->buf, sect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
            }
#endif
            fp->dsect = sect;
            fp->csect++;                            /* Next sector address in the cluster */
        }
        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 (
    FIL *fp,            /* Pointer to the file object */
    const void *buff,   /* Pointer to the data to be written */
    UINT btw,           /* Number of bytes to write */
    UINT *bw            /* Pointer to number of bytes written */
)
{
    FRESULT res;
    DWORD clst, sect;
    UINT wcnt, cc;
    const BYTE *wbuff = buff;


    *bw = 0;

    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? */
            if (fp->csect >= fp->fs->csize) {       /* 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 streach 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 */
                fp->csect = 0;                      /* Reset sector address in the 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->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
                fp->flag &= (BYTE)~FA__DIRTY;
            }
#endif
            sect = clust2sect(fp->fs, fp->curr_clust);  /* Get current sector */
            if (!sect) ABORT(fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btw / SS(fp->fs);                  /* When remaining bytes >= sector size, */
            if (cc) {                               /* Write maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_write(fp->fs->drive, 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          
                fp->csect += (BYTE)cc;              /* Next sector address in the cluster */
                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->drive, fp->buf, sect, 1) != RES_OK)
                        ABORT(fp->fs, FR_DISK_ERR);
            }
#endif
            fp->dsect = sect;
            fp->csect++;                            /* Next sector address in the cluster */
        }
        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 (
    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->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    LEAVE_FF(fp->fs, FR_DISK_ERR);
                fp->flag &= (BYTE)~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();                    /* Updated time */
                ST_DWORD(dir+DIR_WrtTime, tim);
                fp->flag &= (BYTE)~FA__WRITTEN;
                fp->fs->wflag = 1;
                res = sync(fp->fs);
            }
        }
    }

    LEAVE_FF(fp->fs, res);
}

#endif /* !_FS_READONLY */




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

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


#if _FS_READONLY
    res = validate(fp->fs, fp->id);
    if (res == FR_OK) fp->fs = NULL;
    LEAVE_FF(fp->fs, res);
#else
    res = f_sync(fp);
    if (res == FR_OK) fp->fs = NULL;
    return res;
#endif
}




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

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


    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 (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 = 0; fp->csect = 255;
    nsect = 0;
    if (ofs > 0) {
        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 streached if in write mode */
                    if (clst == 0) {                /* When disk gets full, clip file size */
                        ofs = bcs; break;
                    }
                } else
#endif
                    clst = get_cluster(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->max_clust) ABORT(fp->fs, FR_INT_ERR);
                fp->curr_clust = clst;
                fp->fptr += bcs;
                ofs -= bcs;
            }
            fp->fptr += ofs;
            fp->csect = (BYTE)(ofs / SS(fp->fs));   /* Sector offset in the cluster */
            if (ofs % SS(fp->fs)) {
                nsect = clust2sect(fp->fs, clst);   /* Current sector */
                if (!nsect) ABORT(fp->fs, FR_INT_ERR);
                nsect += fp->csect;
                fp->csect++;
            }
        }
    }
    if (nsect && nsect != fp->dsect && fp->fptr % SS(fp->fs)) {
#if !_FS_TINY
#if !_FS_READONLY
        if (fp->flag & FA__DIRTY) {         /* Write-back dirty buffer if needed */
            if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                ABORT(fp->fs, FR_DISK_ERR);
            fp->flag &= (BYTE)~FA__DIRTY;
        }
#endif
        if (disk_read(fp->fs->drive, 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 (
    DIR *dj,            /* Pointer to directory object to create */
    const char *path    /* Pointer to the directory path */
)
{
    FRESULT res;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = auto_mount(&path, &dj->fs, 0);
    if (res == FR_OK) {
        INITBUF((*dj), sfn, lfn);
        res = follow_path(dj, path);            /* Follow the path to the directory */
        if (res == FR_OK) {                     /* Follow completed */
            dir = dj->dir;
            if (dir) {                          /* It is not the root 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;
                }
            } else {                            /* It is the root dir */
                dj->sclust = (dj->fs->fs_type == FS_FAT32) ? dj->fs->dirbase : 0;
            }
            if (res == FR_OK) res = dir_seek(dj, 0);
            dj->id = dj->fs->id;
        } else {
            if (res == FR_NO_FILE) res = FR_NO_PATH;
        }
    }

    LEAVE_FF(dj->fs, res);
}




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

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


    res = validate(dj->fs, dj->id);         /* Check validity of the object */
    if (res == FR_OK) {
        INITBUF((*dj), sfn, lfn);
        if (!fno) {
            res = dir_seek(dj, 0);
        } else {
            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, FALSE);  /* Increment index for next */
                if (res == FR_NO_FILE) {
                    dj->sect = 0;
                    res = FR_OK;
                }
            }
        }
    }

    LEAVE_FF(dj->fs, res);
}



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

FRESULT f_stat (
    const char *path,   /* Pointer to the file path */
    FILINFO *fno        /* Pointer to file information to return */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);


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

    LEAVE_FF(dj.fs, res);
}



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

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


    res = validate(fp->fs, fp->id);     /* Check validity of the object */
    if (res != FR_OK) 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 > 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_cluster(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->max_clust) {
                res = put_cluster(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);
}




/*-----------------------------------------------------------------------*/
/* Get Number of Free Clusters                                           */
/*-----------------------------------------------------------------------*/

FRESULT f_getfree (
    const char *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;
    BYTE fat, f, *p;


    /* Get drive number */
    res = auto_mount(&path, fatfs, 0);
    if (res != FR_OK) LEAVE_FF(*fatfs, res);

    /* If number of free cluster is valid, return it without cluster scan. */
    if ((*fatfs)->free_clust <= (*fatfs)->max_clust - 2) {
        *nclst = (*fatfs)->free_clust;
        LEAVE_FF(*fatfs, FR_OK);
    }

    /* Get number of free clusters */
    fat = (*fatfs)->fs_type;
    n = 0;
    if (fat == FS_FAT12) {
        clst = 2;
        do {
            if ((WORD)get_cluster(*fatfs, clst) == 0) n++;
        } while (++clst < (*fatfs)->max_clust);
    } else {
        clst = (*fatfs)->max_clust;
        sect = (*fatfs)->fatbase;
        f = 0; p = 0;
        do {
            if (!f) {
                res = move_window(*fatfs, sect++);
                if (res != FR_OK)
                    LEAVE_FF(*fatfs, res);
                p = (*fatfs)->win;
            }
            if (fat == FS_FAT16) {
                if (LD_WORD(p) == 0) n++;
                p += 2; f += 1;
            } else {
                if (LD_DWORD(p) == 0) n++;
                p += 4; f += 2;
            }
        } while (--clst);
    }
    (*fatfs)->free_clust = n;
    if (fat == FS_FAT32) (*fatfs)->fsi_flag = 1;
    *nclst = n;

    LEAVE_FF(*fatfs, FR_OK);
}




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

FRESULT f_unlink (
    const char *path        /* Pointer to the file or directory path */
)
{
    FRESULT res;
    DIR dj, sdj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;
    DWORD dclst;


    res = auto_mount(&path, &dj.fs, 1);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);

    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);           /* Follow the file path */
    if (res != FR_OK) LEAVE_FF(dj.fs, res); /* Follow failed */

    dir = dj.dir;
    if (!dir)                               /* Is it the root directory? */
        LEAVE_FF(dj.fs, FR_INVALID_NAME);
    if (dir[DIR_Attr] & AM_RDO)             /* Is it a R/O object? */
        LEAVE_FF(dj.fs, FR_DENIED);
    dclst = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);

    if (dir[DIR_Attr] & AM_DIR) {           /* It is a sub-directory */
        if (dclst < 2) LEAVE_FF(dj.fs, FR_INT_ERR);
        mem_cpy(&sdj, &dj, sizeof(DIR));        /* Check if the sub-dir is empty or not */
        sdj.sclust = dclst;
        res = dir_seek(&sdj, 0);
        if (res != FR_OK) LEAVE_FF(dj.fs, res);
        res = dir_read(&sdj);
        if (res == FR_OK) res = FR_DENIED;  /* Not empty sub-dir */
        if (res != FR_NO_FILE) LEAVE_FF(dj.fs, res);
    }

    res = dir_remove(&dj);                  /* Remove directory entry */
    if (res == FR_OK) {
        if (dclst)
            res = remove_chain(dj.fs, dclst);   /* Remove the cluster chain */
        if (res == FR_OK) res = sync(dj.fs);
    }

    LEAVE_FF(dj.fs, res);
}




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

FRESULT f_mkdir (
    const char *path        /* Pointer to the directory path */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir, n;
    DWORD dsect, dclst, pclst, tim;


    res = auto_mount(&path, &dj.fs, 1);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);

    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);           /* Follow the file path */
    if (res == FR_OK) res = FR_EXIST;       /* Any file or directory is already existing */
    if (res != FR_NO_FILE)                  /* Any error occured */
        LEAVE_FF(dj.fs, res);

    dclst = create_chain(dj.fs, 0);         /* Allocate a new cluster for new directory table */
    res = FR_OK;
    if (dclst == 0) res = FR_DENIED;
    if (dclst == 1) res = FR_INT_ERR;
    if (dclst == 0xFFFFFFFF) res = FR_DISK_ERR;
    if (res == FR_OK)
        res = move_window(dj.fs, 0);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);
    dsect = clust2sect(dj.fs, dclst);

    dir = dj.fs->win;                       /* Initialize the new directory table */
    mem_set(dir, 0, SS(dj.fs));
    mem_set(dir+DIR_Name, ' ', 8+3);        /* Create "." entry */
    dir[DIR_Name] = '.';
    dir[DIR_Attr] = AM_DIR;
    tim = get_fattime();
    ST_DWORD(dir+DIR_WrtTime, tim);
    ST_WORD(dir+DIR_FstClusLO, dclst);
    ST_WORD(dir+DIR_FstClusHI, dclst >> 16);
    mem_cpy(dir+32, dir, 32);           /* Create ".." entry */
    dir[33] = '.';
    pclst = dj.sclust;
    if (dj.fs->fs_type == FS_FAT32 && pclst == dj.fs->dirbase)
        pclst = 0;
    ST_WORD(dir+32+DIR_FstClusLO, pclst);
    ST_WORD(dir+32+DIR_FstClusHI, pclst >> 16);
    for (n = 0; n < dj.fs->csize; n++) {    /* Write dot entries and clear left sectors */
        dj.fs->winsect = dsect++;
        dj.fs->wflag = 1;
        res = move_window(dj.fs, 0);
        if (res) LEAVE_FF(dj.fs, res);
        mem_set(dir, 0, SS(dj.fs));
    }

    res = dir_register(&dj);
    if (res != FR_OK) {
        remove_chain(dj.fs, dclst);
    } else {
        dir = dj.dir;
        dir[DIR_Attr] = AM_DIR;                 /* Attribute */
        ST_DWORD(dir+DIR_WrtTime, tim);         /* Crated time */
        ST_WORD(dir+DIR_FstClusLO, dclst);      /* Table start cluster */
        ST_WORD(dir+DIR_FstClusHI, dclst >> 16);
        dj.fs->wflag = 1;
        res = sync(dj.fs);
    }

    LEAVE_FF(dj.fs, res);
}




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

FRESULT f_chmod (
    const char *path,   /* Pointer to the file path */
    BYTE value,         /* Attribute bits */
    BYTE mask           /* Attribute mask to change */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = auto_mount(&path, &dj.fs, 1);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);       /* Follow the file path */
        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 char *path,   /* Pointer to the file/directory name */
    const FILINFO *fno  /* Pointer to the timestamp to be set */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = auto_mount(&path, &dj.fs, 1);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);   /* Follow the file path */
        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 char *path_old,   /* Pointer to the old name */
    const char *path_new    /* Pointer to the new name */
)
{
    FRESULT res;
    DIR dj_old, dj_new;
    NAMEBUF(sfn, lfn);
    BYTE buf[21], *dir;
    DWORD dw;


    INITBUF(dj_old, sfn, lfn);
    res = auto_mount(&path_old, &dj_old.fs, 1);
    if (res == FR_OK) {
        dj_new.fs = dj_old.fs;
        res = follow_path(&dj_old, path_old);   /* Check old object */
    }
    if (res != FR_OK) LEAVE_FF(dj_old.fs, res); /* The old object is not found */

    if (!dj_old.dir) LEAVE_FF(dj_old.fs, FR_NO_FILE);   /* Is root dir? */
    mem_cpy(buf, dj_old.dir+DIR_Attr, 21);      /* Save the object information */

    mem_cpy(&dj_new, &dj_old, sizeof(DIR));
    res = follow_path(&dj_new, path_new);       /* Check new object */
    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? */
        res = dir_register(&dj_new);            /* Register the new object */
        if (res == FR_OK) {
            dir = dj_new.dir;                   /* Copy object information into new entry */
            mem_cpy(dir+13, buf+2, 19);
            dir[DIR_Attr] = buf[0];
            dj_old.fs->wflag = 1;
            if (dir[DIR_Attr] & AM_DIR) {       /* Update .. entry in the directory if needed */
                dw = clust2sect(dj_new.fs, (DWORD)LD_WORD(dir+DIR_FstClusHI) | LD_WORD(dir+DIR_FstClusLO));
                if (!dw) {
                    res = FR_INT_ERR;
                } else {
                    res = move_window(dj_new.fs, dw);
                    dir = dj_new.fs->win+32;
                    if (res == FR_OK && dir[1] == '.') {
                        dw = (dj_new.fs->fs_type == FS_FAT32 && dj_new.sclust == dj_new.fs->dirbase) ? 0 : dj_new.sclust;
                        ST_WORD(dir+DIR_FstClusLO, dw);
                        ST_WORD(dir+DIR_FstClusHI, dw >> 16);
                        dj_new.fs->wflag = 1;
                    }
                }
            }
            if (res == FR_OK) {
                res = dir_remove(&dj_old);          /* Remove old entry */
                if (res == FR_OK)
                    res = sync(dj_old.fs);
            }
        }
    }

    LEAVE_FF(dj_old.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 _FS_TINY cfg)  */
/*-----------------------------------------------------------------------*/
#if _USE_FORWARD && _FS_TINY

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


    *bf = 0;

    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)(NULL, 0);               /* Repeat until all data transferred or stream becomes busy */
        fp->fptr += rcnt, *bf += rcnt, btr -= rcnt) {
        if ((fp->fptr % SS(fp->fs)) == 0) {         /* On the sector boundary? */
            if (fp->csect >= fp->fs->csize) {       /* On the cluster boundary? */
                clst = (fp->fptr == 0) ?            /* On the top of the file? */
                    fp->org_clust : get_cluster(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 */
                fp->csect = 0;                      /* Reset sector address in the cluster */
            }
            fp->csect++;                            /* Next sector address in the cluster */
        }
        sect = clust2sect(fp->fs, fp->curr_clust);  /* Get current data sector */
        if (!sect) ABORT(fp->fs, FR_INT_ERR);
        sect += fp->csect - 1;
        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 and <= 2048 */
#define N_FATS      1           /* 1 or 2 */
#define MAX_SECTOR  131072000UL /* Maximum partition size */
#define MIN_SECTOR  2000UL      /* Minimum partition size */


FRESULT f_mkfs (
    BYTE drv,           /* Logical drive number */
    BYTE partition,     /* Partitioning rule 0:FDISK, 1:SFD */
    WORD allocsize      /* Allocation unit size [bytes] */
)
{
    static const DWORD sstbl[] = { 2048000, 1024000, 512000, 256000, 128000, 64000, 32000, 16000, 8000, 4000,   0 };
    static const WORD cstbl[] =  {   32768,   16384,   8192,   4096,   2048, 16384,  8192,  4096, 2048, 1024, 512 };
    BYTE fmt, m, *tbl;
    DWORD b_part, b_fat, b_dir, b_data;     /* Area offset (LBA) */
    DWORD n_part, n_rsv, n_fat, n_dir;      /* Area size */
    DWORD n_clst, n;
    WORD as;
    FATFS *fs;
    DSTATUS stat;


    /* Check validity of the parameters */
    if (drv >= _DRIVES) return FR_INVALID_DRIVE;
    if (partition >= 2) return FR_MKFS_ABORTED;

    /* Check mounted drive and clear work area */
    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 (disk_ioctl(drv, GET_SECTOR_COUNT, &n_part) != RES_OK || n_part < MIN_SECTOR)
        return FR_MKFS_ABORTED;
    if (n_part > MAX_SECTOR) n_part = MAX_SECTOR;
    b_part = (!partition) ? 63 : 0;     /* Boot sector */
    n_part -= b_part;
#if _MAX_SS == 512
    if (!allocsize) {                   /* Auto selection of cluster size */
        for (n = 0; n_part < sstbl[n]; n++) ;
        allocsize = cstbl[n];
    }
#endif
    for (as = 512; as <= 32768U && as != allocsize; as <<= 1);
    if (as != allocsize) return FR_MKFS_ABORTED;
#if _MAX_SS != 512                      /* Check disk sector size */
    if (disk_ioctl(drv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK
        || SS(fs) > _MAX_SS
        || SS(fs) > allocsize)
        return FR_MKFS_ABORTED;
#endif
    allocsize /= SS(fs);        /* Number of sectors per cluster */

    /* Pre-compute number of clusters and FAT type */
    n_clst = n_part / allocsize;
    fmt = FS_FAT12;
    if (n_clst >= 0xFF5) fmt = FS_FAT16;
    if (n_clst >= 0xFFF5) fmt = FS_FAT32;

    /* Determine offset and size of FAT structure */
    switch (fmt) {
    case FS_FAT12:
        n_fat = ((n_clst * 3 + 1) / 2 + 3 + SS(fs) - 1) / SS(fs);
        n_rsv = 1 + partition;
        n_dir = N_ROOTDIR * 32 / SS(fs);
        break;
    case FS_FAT16:
        n_fat = ((n_clst * 2) + 4 + SS(fs) - 1) / SS(fs);
        n_rsv = 1 + partition;
        n_dir = N_ROOTDIR * 32 / SS(fs);
        break;
    default:
        n_fat = ((n_clst * 4) + 8 + SS(fs) - 1) / SS(fs);
        n_rsv = 33 - partition;
        n_dir = 0;
    }
    b_fat = b_part + n_rsv;         /* FATs start sector */
    b_dir = b_fat + n_fat * N_FATS; /* Directory start sector */
    b_data = b_dir + n_dir;         /* Data start sector */

    /* Align data start sector to erase block boundary (for flash memory media) */
    if (disk_ioctl(drv, GET_BLOCK_SIZE, &n) != RES_OK) return FR_MKFS_ABORTED;
    n = (b_data + n - 1) & ~(n - 1);
    n_fat += (n - b_data) / N_FATS;
    /* b_dir and b_data are no longer used below */

    /* Determine number of cluster and final check of validity of the FAT type */
    n_clst = (n_part - n_rsv - n_fat * N_FATS - n_dir) / allocsize;
    if (   (fmt == FS_FAT16 && n_clst < 0xFF5)
        || (fmt == FS_FAT32 && n_clst < 0xFFF5))
        return FR_MKFS_ABORTED;

    /* Create partition table if needed */
    if (!partition) {
        DWORD n_disk = b_part + n_part;

        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_part < 0x10000) ? 0x04 : 0x06;
        else
            tbl[4] = 0x0c;
        ST_DWORD(tbl+8, 63);            /* Partition start in LBA */
        ST_DWORD(tbl+12, n_part);       /* Partition size in LBA */
        ST_WORD(tbl+64, 0xAA55);        /* Signature */
        if (disk_write(drv, fs->win, 0, 1) != RES_OK)
            return FR_DISK_ERR;
    }

    /* Create boot record */
    tbl = fs->win;                              /* Clear buffer */
    mem_set(tbl, 0, SS(fs));
    ST_DWORD(tbl+BS_jmpBoot, 0x90FEEB);         /* Boot code (jmp $, nop) */
    ST_WORD(tbl+BPB_BytsPerSec, SS(fs));        /* Sector size */
    tbl[BPB_SecPerClus] = (BYTE)allocsize;      /* Sectors per cluster */
    ST_WORD(tbl+BPB_RsvdSecCnt, n_rsv);         /* Reserved sectors */
    tbl[BPB_NumFATs] = N_FATS;                  /* Number of FATs */
    ST_WORD(tbl+BPB_RootEntCnt, SS(fs) / 32 * n_dir); /* Number of rootdir entries */
    if (n_part < 0x10000) {                     /* Number of total sectors */
        ST_WORD(tbl+BPB_TotSec16, n_part);
    } else {
        ST_DWORD(tbl+BPB_TotSec32, n_part);
    }
    tbl[BPB_Media] = 0xF8;                      /* Media descripter */
    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_part);          /* Hidden sectors */
    n = get_fattime();                          /* Use current time as a VSN */
    if (fmt != FS_FAT32) {
        ST_DWORD(tbl+BS_VolID, n);              /* Volume serial number */
        ST_WORD(tbl+BPB_FATSz16, n_fat);        /* Number of secters 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 lavel, FAT signature */
    } else {
        ST_DWORD(tbl+BS_VolID32, n);            /* Volume serial number */
        ST_DWORD(tbl+BPB_FATSz32, n_fat);       /* Number of secters per FAT */
        ST_DWORD(tbl+BPB_RootClus, 2);          /* Root directory cluster (2) */
        ST_WORD(tbl+BPB_FSInfo, 1);             /* FSInfo record offset (bs+1) */
        ST_WORD(tbl+BPB_BkBootSec, 6);          /* Backup boot record offset (bs+6) */
        tbl[BS_DrvNum32] = 0x80;                /* Drive number */
        tbl[BS_BootSig32] = 0x29;               /* Extended boot signature */
        mem_cpy(tbl+BS_VolLab32, "NO NAME    FAT32   ", 19);    /* Volume lavel, FAT signature */
    }
    ST_WORD(tbl+BS_55AA, 0xAA55);               /* Signature */
    if (disk_write(drv, tbl, b_part+0, 1) != RES_OK)
        return FR_DISK_ERR;
    if (fmt == FS_FAT32)
        disk_write(drv, tbl, b_part+6, 1);

    /* Initialize FAT area */
    for (m = 0; m < N_FATS; m++) {
        mem_set(tbl, 0, SS(fs));        /* 1st sector of the FAT  */
        if (fmt != FS_FAT32) {
            n = (fmt == FS_FAT12) ? 0x00FFFFF8 : 0xFFFFFFF8;
            ST_DWORD(tbl, n);               /* Reserve cluster #0-1 (FAT12/16) */
        } else {
            ST_DWORD(tbl+0, 0xFFFFFFF8);    /* Reserve cluster #0-1 (FAT32) */
            ST_DWORD(tbl+4, 0xFFFFFFFF);
            ST_DWORD(tbl+8, 0x0FFFFFFF);    /* Reserve cluster #2 for root dir */
        }
        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
        mem_set(tbl, 0, SS(fs));        /* Following FAT entries are filled by zero */
        for (n = 1; n < n_fat; n++) {
            if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
                return FR_DISK_ERR;
        }
    }

    /* Initialize Root directory */
    m = (BYTE)((fmt == FS_FAT32) ? allocsize : n_dir);
    do {
        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
    } while (--m);

    /* 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_part+1, 1);
        disk_write(drv, tbl, b_part+7, 1);
    }

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

#endif /* _USE_MKFS && !_FS_READONLY */




#if _USE_STRFUNC
/*-----------------------------------------------------------------------*/
/* Get a string from the file                                            */
/*-----------------------------------------------------------------------*/
char* f_gets (
    char* buff, /* Pointer to the string buffer to read */
    int len,    /* Size of string buffer */
    FIL* fil    /* Pointer to the file object */
)
{
    int i = 0;
    char *p = buff;
    UINT rc;


    while (i < len - 1) {           /* Read bytes until buffer gets filled */
        f_read(fil, p, 1, &rc);
        if (rc != 1) break;         /* Break when no data to read */
#if _USE_STRFUNC >= 2
        if (*p == '\r') continue;   /* Strip '\r' */
#endif
        i++;
        if (*p++ == '\n') break;    /* Break when reached end of line */
    }
    *p = 0;
    return i ? buff : NULL;         /* 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 (
    int chr,    /* A character to be output */
    FIL* fil    /* Ponter to the file object */
)
{
    UINT bw;
    char c;


#if _USE_STRFUNC >= 2
    if (chr == '\n') f_putc ('\r', fil);    /* LF -> CRLF conversion */
#endif
    if (!fil) { /* Special value may be used to switch the destination to any other device */
    /*  put_console(chr);   */
        return chr;
    }
    c = (char)chr;
    f_write(fil, &c, 1, &bw);   /* Write a byte to the file */
    return bw ? chr : EOF;      /* Return the result */
}




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


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




/*-----------------------------------------------------------------------*/
/* Put a formatted string to the file                                    */
/*-----------------------------------------------------------------------*/
int f_printf (
    FIL* fil,           /* Pointer to the file object */
    const char* str,    /* Pointer to the format string */
    ...                 /* Optional arguments... */
)
{
    va_list arp;
    UCHAR c, f, r;
    ULONG val;
    char s[16];
    int i, w, 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 cahracter */
            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 (c >= '0' && c <= '9') {  /* Precision */
            w = w * 10 + (c - '0');
            c = *str++;
        }
        if (c == 'l') {             /* Prefix: Size is long int */
            f |= 2; c = *str++;
        }
        if (c == 's') {             /* Type is string */
            cc = f_puts(va_arg(arp, char*), fil);
            continue;
        }
        if (c == 'c') {             /* Type is character */
            cc = f_putc(va_arg(arp, int), fil);
            if (cc != EOF) cc = 1;
            continue;
        }
        r = 0;
        if (c == 'd') r = 10;       /* Type is signed decimal */
        if (c == 'u') r = 10;       /* Type is unsigned decimal */
        if (c == 'X') r = 16;       /* Type is unsigned hexdecimal */
        if (r == 0) break;          /* Unknown type */
        if (f & 2) {                /* Get the value */
            val = (ULONG)va_arg(arp, long);
        } else {
            val = (c == 'd') ? (ULONG)(long)va_arg(arp, int) : (ULONG)va_arg(arp, unsigned int);
        }
        /* Put numeral string */
        if (c == 'd') {
            if (val & 0x80000000) {
                val = 0 - val;
                f |= 4;
            }
        }
        i = sizeof(s) - 1; s[i] = 0;
        do {
            c = (UCHAR)(val % r + '0');
            if (c > '9') c += 7;
            s[--i] = c;
            val /= r;
        } while (i && val);
        if (i && (f & 4)) s[--i] = '-';
        w = sizeof(s) - 1 - w;
        while (i && i > w) s[--i] = (f & 1) ? '0' : ' ';
        cc = f_puts(&s[i], fil);
    }

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

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