Code for autonomous ground vehicle, Data Bus, 3rd place winner in 2012 Sparkfun AVC.

Dependencies:   Watchdog mbed Schedule SimpleFilter LSM303DLM PinDetect DebounceIn Servo

Revision:
0:826c6171fc1b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem/FATFileSystem/Core/ff.c	Wed Jun 20 14:57:48 2012 +0000
@@ -0,0 +1,3555 @@
+/*----------------------------------------------------------------------------/
+/  FatFs - FAT file system module  R0.08                  (C)ChaN, 2010
+/-----------------------------------------------------------------------------/
+/ FatFs module is a generic FAT file system module for small embedded systems.
+/ This is a free software that opened for education, research and commercial
+/ developments under license policy of following terms.
+/
+/  Copyright (C) 2010, ChaN, all right reserved.
+/
+/ * The FatFs module is a free software and there is NO WARRANTY.
+/ * No restriction on use. You can use, modify and redistribute it for
+/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
+/ * Redistributions of source code must retain the above copyright notice.
+/
+/-----------------------------------------------------------------------------/
+/ Feb 26,'06 R0.00  Prototype.
+/
+/ Apr 29,'06 R0.01  First stable version.
+/
+/ Jun 01,'06 R0.02  Added FAT12 support.
+/                   Removed unbuffered mode.
+/                   Fixed a problem on small (<32M) partition.
+/ Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
+/
+/ Sep 22,'06 R0.03  Added f_rename().
+/                   Changed option _FS_MINIMUM to _FS_MINIMIZE.
+/ Dec 11,'06 R0.03a Improved cluster scan algorithm to write files fast.
+/                   Fixed f_mkdir() creates incorrect directory on FAT32.
+/
+/ Feb 04,'07 R0.04  Supported multiple drive system.
+/                   Changed some interfaces for multiple drive system.
+/                   Changed f_mountdrv() to f_mount().
+/                   Added f_mkfs().
+/ Apr 01,'07 R0.04a Supported multiple partitions on a physical drive.
+/                   Added a capability of extending file size to f_lseek().
+/                   Added minimization level 3.
+/                   Fixed an endian sensitive code in f_mkfs().
+/ May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
+/                   Added FSInfo support.
+/                   Fixed DBCS name can result FR_INVALID_NAME.
+/                   Fixed short seek (<= csize) collapses the file object.
+/
+/ Aug 25,'07 R0.05  Changed arguments of f_read(), f_write() and f_mkfs().
+/                   Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
+/                   Fixed f_mkdir() on FAT32 creates incorrect directory.
+/ Feb 03,'08 R0.05a Added f_truncate() and f_utime().
+/                   Fixed off by one error at FAT sub-type determination.
+/                   Fixed btr in f_read() can be mistruncated.
+/                   Fixed cached sector is not flushed when create and close
+/                   without write.
+/
+/ Apr 01,'08 R0.06  Added fputc(), fputs(), fprintf() and fgets().
+/                   Improved performance of f_lseek() on moving to the same
+/                   or following cluster.
+/
+/ Apr 01,'09 R0.07  Merged Tiny-FatFs as a buffer configuration option.
+/                   Added long file name support.
+/                   Added multiple code page support.
+/                   Added re-entrancy for multitask operation.
+/                   Added auto cluster size selection to f_mkfs().
+/                   Added rewind option to f_readdir().
+/                   Changed result code of critical errors.
+/                   Renamed string functions to avoid name collision.
+/ Apr 14,'09 R0.07a Separated out OS dependent code on reentrant cfg.
+/                   Added multiple sector size support.
+/ Jun 21,'09 R0.07c Fixed f_unlink() can return FR_OK on error.
+/                   Fixed wrong cache control in f_lseek().
+/                   Added relative path feature.
+/                   Added f_chdir() and f_chdrive().
+/                   Added proper case conversion to extended char.
+/ Nov 03,'09 R0.07e Separated out configuration options from ff.h to ffconf.h.
+/                   Fixed f_unlink() fails to remove a sub-dir on _FS_RPATH.
+/                   Fixed name matching error on the 13 char boundary.
+/                   Added a configuration option, _LFN_UNICODE.
+/                   Changed f_readdir() to return the SFN with always upper
+/                   case on non-LFN cfg.
+/
+/ May 15,'10 R0.08  Added a memory configuration option. (_USE_LFN)
+/                   Added file lock feature. (_FS_SHARE)
+/                   Added fast seek feature. (_USE_FASTSEEK)
+/                   Changed some types on the API, XCHAR->TCHAR.
+/                   Changed fname member in the FILINFO structure on Unicode cfg.
+/                   String functions support UTF-8 encoding files on Unicode cfg.
+/---------------------------------------------------------------------------*/
+
+//Modified by Thomas Hamilton, Copyright 2010
+
+#include "ff.h"            /* FatFs configurations and declarations */
+#include "diskio.h"        /* Declarations of low level disk I/O functions */
+
+
+/*--------------------------------------------------------------------------
+
+   Module Private Definitions
+
+---------------------------------------------------------------------------*/
+
+#if _FATFS != 8085
+#error Wrong include file (ff.h).
+#endif
+
+
+/* FAT sub-type boundaries */
+/* Note that the FAT spec by Microsoft says 4085 but Windows works with 4087! */
+#define MIN_FAT16    4086    /* Minimum number of clusters for FAT16 */
+#define    MIN_FAT32    65526    /* Minimum number of clusters for FAT32 */
+
+
+/* Definitions corresponds to multiple sector size */
+#if _MAX_SS == 512        /* Single sector size */
+#define    SS(fs)    512U
+#elif _MAX_SS == 1024 || _MAX_SS == 2048 || _MAX_SS == 4096    /* Multiple sector size */
+#define    SS(fs)    ((fs)->ssize)
+#else
+#error Wrong sector size.
+#endif
+
+
+/* Reentrancy related */
+#if _FS_REENTRANT
+#if _USE_LFN == 1
+#error Static LFN work area must not be used in re-entrant configuration.
+#endif
+#define    ENTER_FF(fs)        { if (!lock_fs(fs)) return FR_TIMEOUT; }
+#define    LEAVE_FF(fs, res)    { unlock_fs(fs, res); return res; }
+
+#else
+#define    ENTER_FF(fs)
+#define LEAVE_FF(fs, res)    return res
+
+#endif
+
+#define    ABORT(fs, res)        { fp->flag |= FA__ERROR; LEAVE_FF(fs, res); }
+
+
+/* Character code support macros */
+#define IsUpper(c)    (((c)>='A')&&((c)<='Z'))
+#define IsLower(c)    (((c)>='a')&&((c)<='z'))
+#define IsDigit(c)    (((c)>='0')&&((c)<='9'))
+
+#if _DF1S        /* Code page is DBCS */
+
+#ifdef _DF2S    /* Two 1st byte areas */
+#define IsDBCS1(c)    (((BYTE)(c) >= _DF1S && (BYTE)(c) <= _DF1E) || ((BYTE)(c) >= _DF2S && (BYTE)(c) <= _DF2E))
+#else            /* One 1st byte area */
+#define IsDBCS1(c)    ((BYTE)(c) >= _DF1S && (BYTE)(c) <= _DF1E)
+#endif
+
+#ifdef _DS3S    /* Three 2nd byte areas */
+#define IsDBCS2(c)    (((BYTE)(c) >= _DS1S && (BYTE)(c) <= _DS1E) || ((BYTE)(c) >= _DS2S && (BYTE)(c) <= _DS2E) || ((BYTE)(c) >= _DS3S && (BYTE)(c) <= _DS3E))
+#else            /* Two 2nd byte areas */
+#define IsDBCS2(c)    (((BYTE)(c) >= _DS1S && (BYTE)(c) <= _DS1E) || ((BYTE)(c) >= _DS2S && (BYTE)(c) <= _DS2E))
+#endif
+
+#else            /* Code page is SBCS */
+
+#define IsDBCS1(c)    0
+#define IsDBCS2(c)    0
+
+#endif /* _DF1S */
+
+
+/* Name status flags */
+#define NS            11        /* Offset of name status byte */
+#define NS_LOSS        0x01    /* Out of 8.3 format */
+#define NS_LFN        0x02    /* Force to create LFN entry */
+#define NS_LAST        0x04    /* Last segment */
+#define NS_BODY        0x08    /* Lower case flag (body) */
+#define NS_EXT        0x10    /* Lower case flag (ext) */
+#define NS_DOT        0x20    /* Dot entry */
+
+
+
+/*------------------------------------------------------------*/
+/* Work area                                                  */
+
+#if !_DRIVES
+#error Number of drives must not be 0.
+#endif
+static
+WORD Fsid;                /* File system mount ID */
+static
+FATFS *FatFs[_DRIVES];    /* Pointer to the file system objects (logical drives) */
+
+#if _FS_RPATH
+static
+BYTE Drive;                /* Current drive */
+#endif
+
+
+#if _USE_LFN == 0            /* No LFN */
+#define    DEF_NAMEBUF            BYTE sfn[12]
+#define INIT_BUF(dobj)        (dobj).fn = sfn
+#define    FREE_BUF()
+
+#elif _USE_LFN == 1            /* LFN with static LFN working buffer */
+static WCHAR LfnBuf[_MAX_LFN + 1];
+#define    DEF_NAMEBUF            BYTE sfn[12]
+#define INIT_BUF(dobj)        { (dobj).fn = sfn; (dobj).lfn = LfnBuf; }
+#define    FREE_BUF()
+
+#elif _USE_LFN == 2         /* LFN with dynamic LFN working buffer on the stack */
+#define    DEF_NAMEBUF            BYTE sfn[12]; WCHAR lbuf[_MAX_LFN + 1]
+#define INIT_BUF(dobj)        { (dobj).fn = sfn; (dobj).lfn = lbuf; }
+#define    FREE_BUF()
+
+#elif _USE_LFN == 3         /* LFN with dynamic LFN working buffer on the heap */
+#define    DEF_NAMEBUF            BYTE sfn[12]; WCHAR *lfn
+#define INIT_BUF(dobj)        { lfn = ff_memalloc((_MAX_LFN + 1) * 2); \
+                              if (!lfn) LEAVE_FF((dobj).fs, FR_NOT_ENOUGH_CORE); \
+                              (dobj).lfn = lfn;    (dobj).fn = sfn; }
+#define    FREE_BUF()            ff_memfree(lfn)
+
+#else
+#error Wrong LFN configuration.
+#endif
+
+
+
+
+/*--------------------------------------------------------------------------
+
+   Module Private Functions
+
+---------------------------------------------------------------------------*/
+
+
+/*-----------------------------------------------------------------------*/
+/* String functions                                                      */
+/*-----------------------------------------------------------------------*/
+
+/* Copy memory to memory */
+static
+void mem_cpy (void* dst, const void* src, int cnt) {
+    BYTE *d = (BYTE*)dst;
+    const BYTE *s = (const BYTE*)src;
+
+#if _WORD_ACCESS == 1
+    while (cnt >= sizeof(int)) {
+        *(int*)d = *(int*)s;
+        d += sizeof(int); s += sizeof(int);
+        cnt -= sizeof(int);
+    }
+#endif
+    while (cnt--)
+        *d++ = *s++;
+}
+
+/* Fill memory */
+static
+void mem_set (void* dst, int val, int cnt) {
+    BYTE *d = (BYTE*)dst;
+
+    while (cnt--)
+        *d++ = (BYTE)val;
+}
+
+/* Compare memory to memory */
+static
+int mem_cmp (const void* dst, const void* src, int cnt) {
+    const BYTE *d = (const BYTE *)dst, *s = (const BYTE *)src;
+    int r = 0;
+
+    while (cnt-- && (r = *d++ - *s++) == 0) ;
+    return r;
+}
+
+/* Check if chr is contained in the string */
+static
+int chk_chr (const char* str, int chr) {
+    while (*str && *str != chr) str++;
+    return *str;
+}
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Request/Release grant to access the volume                            */
+/*-----------------------------------------------------------------------*/
+#if _FS_REENTRANT
+
+static
+int lock_fs (
+    FATFS *fs        /* File system object */
+)
+{
+    return ff_req_grant(fs->sobj);
+}
+
+
+static
+void unlock_fs (
+    FATFS *fs,        /* File system object */
+    FRESULT res        /* Result code to be returned */
+)
+{
+    if (res != FR_NOT_ENABLED &&
+        res != FR_INVALID_DRIVE &&
+        res != FR_INVALID_OBJECT &&
+        res != FR_TIMEOUT) {
+        ff_rel_grant(fs->sobj);
+    }
+}
+#endif
+
+
+
+/*-----------------------------------------------------------------------*/
+/* File shareing control functions                                       */
+/*-----------------------------------------------------------------------*/
+#if _FS_SHARE
+
+static
+FRESULT chk_lock (    /* Check if the file can be accessed */
+    FAT_DIR* dj,        /* Directory object pointing the file to be checked */
+    int acc            /* Desired access (0:Read, 1:Write, 2:Delete/Rename) */
+)
+{
+    UINT i, be;
+
+    /* Search file semaphore table */
+    for (i = be = 0; i < _FS_SHARE; i++) {
+        if (dj->fs->flsem[i].ctr) {    /* Existing entry */
+            if (dj->fs->flsem[i].clu == dj->sclust &&     /* The file is found (identified with its location) */
+                dj->fs->flsem[i].idx == dj->index) break;
+        } else {                    /* Blank entry */
+            be++;
+        }
+    }
+    if (i == _FS_SHARE)    /* The file has not been opened */
+        return (be || acc != 2) ? FR_OK : FR_TOO_MANY_OPEN_FILES;    /* Is there a blank entry for new file? */
+
+    /* The file has been opened. Reject any open against writing file and all write mode open */
+    return (acc || dj->fs->flsem[i].ctr == 0x100) ? FR_LOCKED : FR_OK;
+}
+
+
+static
+int enq_lock (    /* Check if an entry is available for a new file */
+    FATFS* fs    /* File system object */
+)
+{
+    UINT i;
+
+    for (i = 0; i < _FS_SHARE && fs->flsem[i].ctr; i++) ;
+    return (i == _FS_SHARE) ? 0 : 1;
+}
+
+
+static
+UINT inc_lock (    /* Increment file open counter and returns its index (0:int error) */
+    FAT_DIR* dj,    /* Directory object pointing the file to register or increment */
+    int acc        /* Desired access mode (0:Read, !0:Write) */
+)
+{
+    UINT i;
+
+
+    for (i = 0; i < _FS_SHARE; i++) {    /* Find the file */
+        if (dj->fs->flsem[i].ctr &&
+            dj->fs->flsem[i].clu == dj->sclust &&
+            dj->fs->flsem[i].idx == dj->index) break;
+    }
+
+    if (i == _FS_SHARE) {                /* Not opened. Register it as new. */
+        for (i = 0; i < _FS_SHARE && dj->fs->flsem[i].ctr; i++) ;
+        if (i == _FS_SHARE) return 0;    /* No space to register (int err) */
+        dj->fs->flsem[i].clu = dj->sclust;
+        dj->fs->flsem[i].idx = dj->index;
+    }
+
+    if (acc && dj->fs->flsem[i].ctr) return 0;    /* Access violation (int err) */
+
+    dj->fs->flsem[i].ctr = acc ? 0x100 : dj->fs->flsem[i].ctr + 1;    /* Set semaphore value */
+
+    return i + 1;
+}
+
+
+static
+FRESULT dec_lock (    /* Decrement file open counter */
+    FATFS* fs,        /* File system object */
+    UINT i            /* Semaphore index */
+)
+{
+    WORD n;
+    FRESULT res;
+
+
+    if (--i < _FS_SHARE) {
+        n = fs->flsem[i].ctr;
+        if (n >= 0x100) n = 0;
+        if (n) n--;
+        fs->flsem[i].ctr = n;
+        res = FR_OK;
+    } else {
+        res = FR_INT_ERR;
+    }
+    return res;
+}
+
+#endif
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Change window offset                                                  */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT move_window (
+    FATFS *fs,        /* File system object */
+    DWORD sector    /* Sector number to make appearance in the fs->win[] */
+)                    /* Move to zero only writes back dirty window */
+{
+    DWORD wsect;
+
+
+    wsect = fs->winsect;
+    if (wsect != sector) {    /* Changed current window */
+#if !_FS_READONLY
+        if (fs->wflag) {    /* Write back dirty window if needed */
+            if (disk_write(fs->drv, fs->win, wsect, 1) != RES_OK)
+                return FR_DISK_ERR;
+            fs->wflag = 0;
+            if (wsect < (fs->fatbase + fs->fsize)) {    /* In FAT area */
+                BYTE nf;
+                for (nf = fs->n_fats; nf > 1; nf--) {    /* Reflect the change to all FAT copies */
+                    wsect += fs->fsize;
+                    disk_write(fs->drv, fs->win, wsect, 1);
+                }
+            }
+        }
+#endif
+        if (sector) {
+            if (disk_read(fs->drv, fs->win, sector, 1) != RES_OK)
+                return FR_DISK_ERR;
+            fs->winsect = sector;
+        }
+    }
+
+    return FR_OK;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Clean-up cached data                                                  */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY
+static
+FRESULT sync (    /* FR_OK: successful, FR_DISK_ERR: failed */
+    FATFS *fs    /* File system object */
+)
+{
+    FRESULT res;
+
+
+    res = move_window(fs, 0);
+    if (res == FR_OK) {
+        /* Update FSInfo sector if needed */
+        if (fs->fs_type == FS_FAT32 && fs->fsi_flag) {
+            fs->winsect = 0;
+            mem_set(fs->win, 0, 512);
+            ST_WORD(fs->win+BS_55AA, 0xAA55);
+            ST_DWORD(fs->win+FSI_LeadSig, 0x41615252);
+            ST_DWORD(fs->win+FSI_StrucSig, 0x61417272);
+            ST_DWORD(fs->win+FSI_Free_Count, fs->free_clust);
+            ST_DWORD(fs->win+FSI_Nxt_Free, fs->last_clust);
+            disk_write(fs->drv, fs->win, fs->fsi_sector, 1);
+            fs->fsi_flag = 0;
+        }
+        /* Make sure that no pending write process in the physical drive */
+        if (disk_ioctl(fs->drv, CTRL_SYNC, (void*)0) != RES_OK)
+            res = FR_DISK_ERR;
+    }
+
+    return res;
+}
+#endif
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* FAT access - Read value of a FAT entry                                */
+/*-----------------------------------------------------------------------*/
+
+
+DWORD get_fat (    /* 0xFFFFFFFF:Disk error, 1:Internal error, Else:Cluster status */
+    FATFS *fs,    /* File system object */
+    DWORD clst    /* Cluster# to get the link information */
+)
+{
+    UINT wc, bc;
+    BYTE *p;
+
+
+    if (clst < 2 || clst >= fs->n_fatent)    /* Chack range */
+        return 1;
+
+    switch (fs->fs_type) {
+    case FS_FAT12 :
+        bc = (UINT)clst; bc += bc / 2;
+        if (move_window(fs, fs->fatbase + (bc / SS(fs)))) break;
+        wc = fs->win[bc % SS(fs)]; bc++;
+        if (move_window(fs, fs->fatbase + (bc / SS(fs)))) break;
+        wc |= fs->win[bc % SS(fs)] << 8;
+        return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);
+
+    case FS_FAT16 :
+        if (move_window(fs, fs->fatbase + (clst / (SS(fs) / 2)))) break;
+        p = &fs->win[clst * 2 % SS(fs)];
+        return LD_WORD(p);
+
+    case FS_FAT32 :
+        if (move_window(fs, fs->fatbase + (clst / (SS(fs) / 4)))) break;
+        p = &fs->win[clst * 4 % SS(fs)];
+        return LD_DWORD(p) & 0x0FFFFFFF;
+    }
+
+    return 0xFFFFFFFF;    /* An error occurred at the disk I/O layer */
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* FAT access - Change value of a FAT entry                              */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY
+
+FRESULT put_fat (
+    FATFS *fs,    /* File system object */
+    DWORD clst,    /* Cluster# to be changed in range of 2 to fs->n_fatent - 1 */
+    DWORD val    /* New value to mark the cluster */
+)
+{
+    UINT bc;
+    BYTE *p;
+    FRESULT res;
+
+
+    if (clst < 2 || clst >= fs->n_fatent) {    /* Check range */
+        res = FR_INT_ERR;
+
+    } else {
+        switch (fs->fs_type) {
+        case FS_FAT12 :
+            bc = clst; bc += bc / 2;
+            res = move_window(fs, fs->fatbase + (bc / SS(fs)));
+            if (res != FR_OK) break;
+            p = &fs->win[bc % SS(fs)];
+            *p = (clst & 1) ? ((*p & 0x0F) | ((BYTE)val << 4)) : (BYTE)val;
+            bc++;
+            fs->wflag = 1;
+            res = move_window(fs, fs->fatbase + (bc / SS(fs)));
+            if (res != FR_OK) break;
+            p = &fs->win[bc % SS(fs)];
+            *p = (clst & 1) ? (BYTE)(val >> 4) : ((*p & 0xF0) | ((BYTE)(val >> 8) & 0x0F));
+            break;
+
+        case FS_FAT16 :
+            res = move_window(fs, fs->fatbase + (clst / (SS(fs) / 2)));
+            if (res != FR_OK) break;
+            p = &fs->win[clst * 2 % SS(fs)];
+            ST_WORD(p, (WORD)val);
+            break;
+
+        case FS_FAT32 :
+            res = move_window(fs, fs->fatbase + (clst / (SS(fs) / 4)));
+            if (res != FR_OK) break;
+            p = &fs->win[clst * 4 % SS(fs)];
+            val |= LD_DWORD(p) & 0xF0000000;
+            ST_DWORD(p, val);
+            break;
+
+        default :
+            res = FR_INT_ERR;
+        }
+        fs->wflag = 1;
+    }
+
+    return res;
+}
+#endif /* !_FS_READONLY */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* FAT handling - Remove a cluster chain                                 */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY
+static
+FRESULT remove_chain (
+    FATFS *fs,            /* File system object */
+    DWORD clst            /* Cluster# to remove a chain from */
+)
+{
+    FRESULT res;
+    DWORD nxt;
+
+
+    if (clst < 2 || clst >= fs->n_fatent) {    /* Check range */
+        res = FR_INT_ERR;
+
+    } else {
+        res = FR_OK;
+        while (clst < fs->n_fatent) {            /* Not a last link? */
+            nxt = get_fat(fs, clst);            /* Get cluster status */
+            if (nxt == 0) break;                /* Empty cluster? */
+            if (nxt == 1) { res = FR_INT_ERR; break; }    /* Internal error? */
+            if (nxt == 0xFFFFFFFF) { res = FR_DISK_ERR; break; }    /* Disk error? */
+            res = put_fat(fs, clst, 0);            /* Mark the cluster "empty" */
+            if (res != FR_OK) break;
+            if (fs->free_clust != 0xFFFFFFFF) {    /* Update FSInfo */
+                fs->free_clust++;
+                fs->fsi_flag = 1;
+            }
+            clst = nxt;    /* Next cluster */
+        }
+    }
+
+    return res;
+}
+#endif
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* FAT handling - Stretch or Create a cluster chain                      */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY
+static
+DWORD create_chain (    /* 0:No free cluster, 1:Internal error, 0xFFFFFFFF:Disk error, >=2:New cluster# */
+    FATFS *fs,            /* File system object */
+    DWORD clst            /* Cluster# to stretch. 0 means create a new chain. */
+)
+{
+    DWORD cs, ncl, scl;
+
+
+    if (clst == 0) {        /* Create a new chain */
+        scl = fs->last_clust;            /* Get suggested start point */
+        if (!scl || scl >= fs->n_fatent) scl = 1;
+    }
+    else {                    /* Stretch the current chain */
+        cs = get_fat(fs, clst);            /* Check the cluster status */
+        if (cs < 2) return 1;            /* It is an invalid cluster */
+        if (cs < fs->n_fatent) return cs;    /* It is already followed by next cluster */
+        scl = clst;
+    }
+
+    ncl = scl;                /* Start cluster */
+    for (;;) {
+        ncl++;                            /* Next cluster */
+        if (ncl >= fs->n_fatent) {        /* Wrap around */
+            ncl = 2;
+            if (ncl > scl) return 0;    /* No free cluster */
+        }
+        cs = get_fat(fs, ncl);            /* Get the cluster status */
+        if (cs == 0) break;                /* Found a free cluster */
+        if (cs == 0xFFFFFFFF || cs == 1)/* An error occurred */
+            return cs;
+        if (ncl == scl) return 0;        /* No free cluster */
+    }
+
+    if (put_fat(fs, ncl, 0x0FFFFFFF))    /* Mark the new cluster "last link" */
+        return 0xFFFFFFFF;
+    if (clst != 0) {                    /* Link it to the previous one if needed */
+        if (put_fat(fs, clst, ncl))
+            return 0xFFFFFFFF;
+    }
+
+    fs->last_clust = ncl;                /* Update FSINFO */
+    if (fs->free_clust != 0xFFFFFFFF) {
+        fs->free_clust--;
+        fs->fsi_flag = 1;
+    }
+
+    return ncl;        /* Return new cluster number */
+}
+#endif /* !_FS_READONLY */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Get sector# from cluster#                                             */
+/*-----------------------------------------------------------------------*/
+
+
+DWORD clust2sect (    /* !=0: Sector number, 0: Failed - invalid cluster# */
+    FATFS *fs,        /* File system object */
+    DWORD clst        /* Cluster# to be converted */
+)
+{
+    clst -= 2;
+    if (clst >= (fs->n_fatent - 2)) return 0;        /* Invalid cluster# */
+    return clst * fs->csize + fs->database;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Directory handling - Set directory index                              */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT dir_sdi (
+    FAT_DIR *dj,        /* Pointer to directory object */
+    WORD idx        /* Directory index number */
+)
+{
+    DWORD clst;
+    WORD ic;
+
+
+    dj->index = idx;
+    clst = dj->sclust;
+    if (clst == 1 || clst >= dj->fs->n_fatent)    /* Check start cluster range */
+        return FR_INT_ERR;
+    if (!clst && dj->fs->fs_type == FS_FAT32)    /* Replace cluster# 0 with root cluster# if in FAT32 */
+        clst = dj->fs->dirbase;
+
+    if (clst == 0) {    /* Static table */
+        dj->clust = clst;
+        if (idx >= dj->fs->n_rootdir)        /* Index is out of range */
+            return FR_INT_ERR;
+        dj->sect = dj->fs->dirbase + idx / (SS(dj->fs) / 32);    /* Sector# */
+    }
+    else {                /* Dynamic table */
+        ic = SS(dj->fs) / 32 * dj->fs->csize;    /* Entries per cluster */
+        while (idx >= ic) {    /* Follow cluster chain */
+            clst = get_fat(dj->fs, clst);                /* Get next cluster */
+            if (clst == 0xFFFFFFFF) return FR_DISK_ERR;    /* Disk error */
+            if (clst < 2 || clst >= dj->fs->n_fatent)    /* Reached to end of table or int error */
+                return FR_INT_ERR;
+            idx -= ic;
+        }
+        dj->clust = clst;
+        dj->sect = clust2sect(dj->fs, clst) + idx / (SS(dj->fs) / 32);    /* Sector# */
+    }
+
+    dj->dir = dj->fs->win + (idx % (SS(dj->fs) / 32)) * 32;    /* Ptr to the entry in the sector */
+
+    return FR_OK;    /* Seek succeeded */
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Directory handling - Move directory index next                        */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT dir_next (    /* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not stretch */
+    FAT_DIR *dj,        /* Pointer to directory object */
+    int stretch        /* 0: Do not stretch table, 1: Stretch table if needed */
+)
+{
+    DWORD clst;
+    WORD i;
+
+
+    i = dj->index + 1;
+    if (!i || !dj->sect)    /* Report EOT when index has reached 65535 */
+        return FR_NO_FILE;
+
+    if (!(i % (SS(dj->fs) / 32))) {    /* Sector changed? */
+        dj->sect++;                    /* Next sector */
+
+        if (dj->clust == 0) {    /* Static table */
+            if (i >= dj->fs->n_rootdir)    /* Report EOT when end of table */
+                return FR_NO_FILE;
+        }
+        else {                    /* Dynamic table */
+            if (((i / (SS(dj->fs) / 32)) & (dj->fs->csize - 1)) == 0) {    /* Cluster changed? */
+                clst = get_fat(dj->fs, dj->clust);                /* Get next cluster */
+                if (clst <= 1) return FR_INT_ERR;
+                if (clst == 0xFFFFFFFF) return FR_DISK_ERR;
+                if (clst >= dj->fs->n_fatent) {                    /* When it reached end of dynamic table */
+#if !_FS_READONLY
+                    BYTE c;
+                    if (!stretch) return FR_NO_FILE;            /* When do not stretch, report EOT */
+                    clst = create_chain(dj->fs, dj->clust);        /* Stretch cluster chain */
+                    if (clst == 0) return FR_DENIED;            /* No free cluster */
+                    if (clst == 1) return FR_INT_ERR;
+                    if (clst == 0xFFFFFFFF) return FR_DISK_ERR;
+                    /* Clean-up stretched table */
+                    if (move_window(dj->fs, 0)) return FR_DISK_ERR;    /* Flush active window */
+                    mem_set(dj->fs->win, 0, SS(dj->fs));            /* Clear window buffer */
+                    dj->fs->winsect = clust2sect(dj->fs, clst);    /* Cluster start sector */
+                    for (c = 0; c < dj->fs->csize; c++) {        /* Fill the new cluster with 0 */
+                        dj->fs->wflag = 1;
+                        if (move_window(dj->fs, 0)) return FR_DISK_ERR;
+                        dj->fs->winsect++;
+                    }
+                    dj->fs->winsect -= c;                        /* Rewind window address */
+#else
+                    return FR_NO_FILE;            /* Report EOT */
+#endif
+                }
+                dj->clust = clst;                /* Initialize data for new cluster */
+                dj->sect = clust2sect(dj->fs, clst);
+            }
+        }
+    }
+
+    dj->index = i;
+    dj->dir = dj->fs->win + (i % (SS(dj->fs) / 32)) * 32;
+
+    return FR_OK;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* LFN handling - Test/Pick/Fit an LFN segment from/to directory entry   */
+/*-----------------------------------------------------------------------*/
+#if _USE_LFN
+static
+const BYTE LfnOfs[] = {1,3,5,7,9,14,16,18,20,22,24,28,30};    /* Offset of LFN chars in the directory entry */
+
+
+static
+int cmp_lfn (            /* 1:Matched, 0:Not matched */
+    WCHAR *lfnbuf,        /* Pointer to the LFN to be compared */
+    BYTE *dir            /* Pointer to the directory entry containing a part of LFN */
+)
+{
+    int i, s;
+    WCHAR wc, uc;
+
+
+    i = ((dir[LDIR_Ord] & 0xBF) - 1) * 13;    /* Get offset in the LFN buffer */
+    s = 0; wc = 1;
+    do {
+        uc = LD_WORD(dir+LfnOfs[s]);    /* Pick an LFN character from the entry */
+        if (wc) {    /* Last char has not been processed */
+            wc = ff_wtoupper(uc);        /* Convert it to upper case */
+            if (i >= _MAX_LFN || wc != ff_wtoupper(lfnbuf[i++]))    /* Compare it */
+                return 0;                /* Not matched */
+        } else {
+            if (uc != 0xFFFF) return 0;    /* Check filler */
+        }
+    } while (++s < 13);                /* Repeat until all chars in the entry are checked */
+
+    if ((dir[LDIR_Ord] & 0x40) && wc && lfnbuf[i])    /* Last segment matched but different length */
+        return 0;
+
+    return 1;                        /* The part of LFN matched */
+}
+
+
+
+static
+int pick_lfn (            /* 1:Succeeded, 0:Buffer overflow */
+    WCHAR *lfnbuf,        /* Pointer to the Unicode-LFN buffer */
+    BYTE *dir            /* Pointer to the directory entry */
+)
+{
+    int i, s;
+    WCHAR wc, uc;
+
+
+    i = ((dir[LDIR_Ord] & 0x3F) - 1) * 13;    /* Offset in the LFN buffer */
+
+    s = 0; wc = 1;
+    do {
+        uc = LD_WORD(dir+LfnOfs[s]);        /* Pick an LFN character from the entry */
+        if (wc) {    /* Last char has not been processed */
+            if (i >= _MAX_LFN) return 0;    /* Buffer overflow? */
+            lfnbuf[i++] = wc = uc;            /* Store it */
+        } else {
+            if (uc != 0xFFFF) return 0;        /* Check filler */
+        }
+    } while (++s < 13);                        /* Read all character in the entry */
+
+    if (dir[LDIR_Ord] & 0x40) {                /* Put terminator if it is the last LFN part */
+        if (i >= _MAX_LFN) return 0;        /* Buffer overflow? */
+        lfnbuf[i] = 0;
+    }
+
+    return 1;
+}
+
+
+#if !_FS_READONLY
+static
+void fit_lfn (
+    const WCHAR *lfnbuf,    /* Pointer to the LFN buffer */
+    BYTE *dir,                /* Pointer to the directory entry */
+    BYTE ord,                /* LFN order (1-20) */
+    BYTE sum                /* SFN sum */
+)
+{
+    int i, s;
+    WCHAR wc;
+
+
+    dir[LDIR_Chksum] = sum;            /* Set check sum */
+    dir[LDIR_Attr] = AM_LFN;        /* Set attribute. LFN entry */
+    dir[LDIR_Type] = 0;
+    ST_WORD(dir+LDIR_FstClusLO, 0);
+
+    i = (ord - 1) * 13;                /* Get offset in the LFN buffer */
+    s = wc = 0;
+    do {
+        if (wc != 0xFFFF) wc = lfnbuf[i++];    /* Get an effective char */
+        ST_WORD(dir+LfnOfs[s], wc);    /* Put it */
+        if (!wc) wc = 0xFFFF;        /* Padding chars following last char */
+    } while (++s < 13);
+    if (wc == 0xFFFF || !lfnbuf[i]) ord |= 0x40;    /* Bottom LFN part is the start of LFN sequence */
+    dir[LDIR_Ord] = ord;            /* Set the LFN order */
+}
+
+#endif
+#endif
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Create numbered name                                                  */
+/*-----------------------------------------------------------------------*/
+#if _USE_LFN
+void gen_numname (
+    BYTE *dst,            /* Pointer to generated SFN */
+    const BYTE *src,    /* Pointer to source SFN to be modified */
+    const WCHAR *lfn,    /* Pointer to LFN */
+    WORD seq            /* Sequence number */
+)
+{
+    BYTE ns[8], c;
+    int i, j;
+
+
+    mem_cpy(dst, src, 11);
+
+    if (seq > 5) {    /* On many collisions, generate a hash number instead of sequential number */
+        do seq = (seq >> 1) + (seq << 15) + (WORD)*lfn++; while (*lfn);
+    }
+
+    /* itoa */
+    i = 7;
+    do {
+        c = (seq % 16) + '0';
+        if (c > '9') c += 7;
+        ns[i--] = c;
+        seq /= 16;
+    } while (seq);
+    ns[i] = '~';
+
+    /* Append the number */
+    for (j = 0; j < i && dst[j] != ' '; j++) {
+        if (IsDBCS1(dst[j])) {
+            if (j == i - 1) break;
+            j++;
+        }
+    }
+    do {
+        dst[j++] = (i < 8) ? ns[i++] : ' ';
+    } while (j < 8);
+}
+#endif
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Calculate sum of an SFN                                               */
+/*-----------------------------------------------------------------------*/
+#if _USE_LFN
+static
+BYTE sum_sfn (
+    const BYTE *dir        /* Ptr to directory entry */
+)
+{
+    BYTE sum = 0;
+    int n = 11;
+
+    do sum = (sum >> 1) + (sum << 7) + *dir++; while (--n);
+    return sum;
+}
+#endif
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Directory handling - Find an object in the directory                  */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT dir_find (
+    FAT_DIR *dj            /* Pointer to the directory object linked to the file name */
+)
+{
+    FRESULT res;
+    BYTE c, *dir;
+#if _USE_LFN
+    BYTE a, ord, sum;
+#endif
+
+    res = dir_sdi(dj, 0);            /* Rewind directory object */
+    if (res != FR_OK) return res;
+
+#if _USE_LFN
+    ord = sum = 0xFF;
+#endif
+    do {
+        res = move_window(dj->fs, dj->sect);
+        if (res != FR_OK) break;
+        dir = dj->dir;                    /* Ptr to the directory entry of current index */
+        c = dir[DIR_Name];
+        if (c == 0) { res = FR_NO_FILE; break; }    /* Reached to end of table */
+#if _USE_LFN    /* LFN configuration */
+        a = dir[DIR_Attr] & AM_MASK;
+        if (c == 0xE5 || ((a & AM_VOL) && a != AM_LFN)) {    /* An entry without valid data */
+            ord = 0xFF;
+        } else {
+            if (a == AM_LFN) {            /* An LFN entry is found */
+                if (dj->lfn) {
+                    if (c & 0x40) {        /* Is it start of LFN sequence? */
+                        sum = dir[LDIR_Chksum];
+                        c &= 0xBF; ord = c;    /* LFN start order */
+                        dj->lfn_idx = dj->index;
+                    }
+                    /* Check validity of the LFN entry and compare it with given name */
+                    ord = (c == ord && sum == dir[LDIR_Chksum] && cmp_lfn(dj->lfn, dir)) ? ord - 1 : 0xFF;
+                }
+            } else {                    /* An SFN entry is found */
+                if (!ord && sum == sum_sfn(dir)) break;    /* LFN matched? */
+                ord = 0xFF; dj->lfn_idx = 0xFFFF;    /* Reset LFN sequence */
+                if (!(dj->fn[NS] & NS_LOSS) && !mem_cmp(dir, dj->fn, 11)) break;    /* SFN matched? */
+            }
+        }
+#else        /* Non LFN configuration */
+        if (!(dir[DIR_Attr] & AM_VOL) && !mem_cmp(dir, dj->fn, 11)) /* Is it a valid entry? */
+            break;
+#endif
+        res = dir_next(dj, 0);        /* Next entry */
+    } while (res == FR_OK);
+
+    return res;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Read an object from the directory                                     */
+/*-----------------------------------------------------------------------*/
+#if _FS_MINIMIZE <= 1
+static
+FRESULT dir_read (
+    FAT_DIR *dj            /* Pointer to the directory object that pointing the entry to be read */
+)
+{
+    FRESULT res;
+    BYTE c, *dir;
+#if _USE_LFN
+    BYTE a, ord = 0xFF, sum = 0xFF;
+#endif
+
+    res = FR_NO_FILE;
+    while (dj->sect) {
+        res = move_window(dj->fs, dj->sect);
+        if (res != FR_OK) break;
+        dir = dj->dir;                    /* Ptr to the directory entry of current index */
+        c = dir[DIR_Name];
+        if (c == 0) { res = FR_NO_FILE; break; }    /* Reached to end of table */
+#if _USE_LFN    /* LFN configuration */
+        a = dir[DIR_Attr] & AM_MASK;
+        if (c == 0xE5 || (!_FS_RPATH && c == '.') || ((a & AM_VOL) && a != AM_LFN)) {    /* An entry without valid data */
+            ord = 0xFF;
+        } else {
+            if (a == AM_LFN) {            /* An LFN entry is found */
+                if (c & 0x40) {            /* Is it start of LFN sequence? */
+                    sum = dir[LDIR_Chksum];
+                    c &= 0xBF; ord = c;
+                    dj->lfn_idx = dj->index;
+                }
+                /* Check LFN validity and capture it */
+                ord = (c == ord && sum == dir[LDIR_Chksum] && pick_lfn(dj->lfn, dir)) ? ord - 1 : 0xFF;
+            } else {                    /* An SFN entry is found */
+                if (ord || sum != sum_sfn(dir))    /* Is there a valid LFN? */
+                    dj->lfn_idx = 0xFFFF;        /* It has no LFN. */
+                break;
+            }
+        }
+#else        /* Non LFN configuration */
+        if (c != 0xE5 && (_FS_RPATH || c != '.') && !(dir[DIR_Attr] & AM_VOL))    /* Is it a valid entry? */
+            break;
+#endif
+        res = dir_next(dj, 0);                /* Next entry */
+        if (res != FR_OK) break;
+    }
+
+    if (res != FR_OK) dj->sect = 0;
+
+    return res;
+}
+#endif
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Register an object to the directory                                   */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY
+static
+FRESULT dir_register (    /* FR_OK:Successful, FR_DENIED:No free entry or too many SFN collision, FR_DISK_ERR:Disk error */
+    FAT_DIR *dj                /* Target directory with object name to be created */
+)
+{
+    FRESULT res;
+    BYTE c, *dir;
+#if _USE_LFN    /* LFN configuration */
+    WORD n, ne, is;
+    BYTE sn[12], *fn, sum;
+    WCHAR *lfn;
+
+
+    fn = dj->fn; lfn = dj->lfn;
+    mem_cpy(sn, fn, 12);
+
+    if (_FS_RPATH && (sn[NS] & NS_DOT)) return FR_INVALID_NAME;    /* Cannot create dot entry */
+
+    if (sn[NS] & NS_LOSS) {            /* When LFN is out of 8.3 format, generate a numbered name */
+        fn[NS] = 0; dj->lfn = 0;            /* Find only SFN */
+        for (n = 1; n < 100; n++) {
+            gen_numname(fn, sn, lfn, n);    /* Generate a numbered name */
+            res = dir_find(dj);                /* Check if the name collides with existing SFN */
+            if (res != FR_OK) break;
+        }
+        if (n == 100) return FR_DENIED;        /* Abort if too many collisions */
+        if (res != FR_NO_FILE) return res;    /* Abort if the result is other than 'not collided' */
+        fn[NS] = sn[NS]; dj->lfn = lfn;
+    }
+
+    if (sn[NS] & NS_LFN) {            /* When LFN is to be created, reserve an SFN + LFN entries. */
+        for (ne = 0; lfn[ne]; ne++) ;
+        ne = (ne + 25) / 13;
+    } else {                        /* Otherwise reserve only an SFN entry. */
+        ne = 1;
+    }
+
+    /* Reserve contiguous entries */
+    res = dir_sdi(dj, 0);
+    if (res != FR_OK) return res;
+    n = is = 0;
+    do {
+        res = move_window(dj->fs, dj->sect);
+        if (res != FR_OK) break;
+        c = *dj->dir;                /* Check the entry status */
+        if (c == 0xE5 || c == 0) {    /* Is it a blank entry? */
+            if (n == 0) is = dj->index;    /* First index of the contiguous entry */
+            if (++n == ne) break;    /* A contiguous entry that required count is found */
+        } else {
+            n = 0;                    /* Not a blank entry. Restart to search */
+        }
+        res = dir_next(dj, 1);        /* Next entry with table stretch */
+    } while (res == FR_OK);
+
+    if (res == FR_OK && ne > 1) {    /* Initialize LFN entry if needed */
+        res = dir_sdi(dj, is);
+        if (res == FR_OK) {
+            sum = sum_sfn(dj->fn);    /* Sum of the SFN tied to the LFN */
+            ne--;
+            do {                    /* Store LFN entries in bottom first */
+                res = move_window(dj->fs, dj->sect);
+                if (res != FR_OK) break;
+                fit_lfn(dj->lfn, dj->dir, (BYTE)ne, sum);
+                dj->fs->wflag = 1;
+                res = dir_next(dj, 0);    /* Next entry */
+            } while (res == FR_OK && --ne);
+        }
+    }
+
+#else    /* Non LFN configuration */
+    res = dir_sdi(dj, 0);
+    if (res == FR_OK) {
+        do {    /* Find a blank entry for the SFN */
+            res = move_window(dj->fs, dj->sect);
+            if (res != FR_OK) break;
+            c = *dj->dir;
+            if (c == 0xE5 || c == 0) break;    /* Is it a blank entry? */
+            res = dir_next(dj, 1);            /* Next entry with table stretch */
+        } while (res == FR_OK);
+    }
+#endif
+
+    if (res == FR_OK) {        /* Initialize the SFN entry */
+        res = move_window(dj->fs, dj->sect);
+        if (res == FR_OK) {
+            dir = dj->dir;
+            mem_set(dir, 0, 32);        /* Clean the entry */
+            mem_cpy(dir, dj->fn, 11);    /* Put SFN */
+#if _USE_LFN
+            dir[DIR_NTres] = *(dj->fn+NS) & (NS_BODY | NS_EXT);    /* Put NT flag */
+#endif
+            dj->fs->wflag = 1;
+        }
+    }
+
+    return res;
+}
+#endif /* !_FS_READONLY */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Remove an object from the directory                                   */
+/*-----------------------------------------------------------------------*/
+#if !_FS_READONLY && !_FS_MINIMIZE
+static
+FRESULT dir_remove (    /* FR_OK: Successful, FR_DISK_ERR: A disk error */
+    FAT_DIR *dj                /* Directory object pointing the entry to be removed */
+)
+{
+    FRESULT res;
+#if _USE_LFN    /* LFN configuration */
+    WORD i;
+
+    i = dj->index;    /* SFN index */
+    res = dir_sdi(dj, (WORD)((dj->lfn_idx == 0xFFFF) ? i : dj->lfn_idx));    /* Goto the SFN or top of the LFN entries */
+    if (res == FR_OK) {
+        do {
+            res = move_window(dj->fs, dj->sect);
+            if (res != FR_OK) break;
+            *dj->dir = 0xE5;            /* Mark the entry "deleted" */
+            dj->fs->wflag = 1;
+            if (dj->index >= i) break;    /* When reached SFN, all entries of the object has been deleted. */
+            res = dir_next(dj, 0);        /* Next entry */
+        } while (res == FR_OK);
+        if (res == FR_NO_FILE) res = FR_INT_ERR;
+    }
+
+#else            /* Non LFN configuration */
+    res = dir_sdi(dj, dj->index);
+    if (res == FR_OK) {
+        res = move_window(dj->fs, dj->sect);
+        if (res == FR_OK) {
+            *dj->dir = 0xE5;            /* Mark the entry "deleted" */
+            dj->fs->wflag = 1;
+        }
+    }
+#endif
+
+    return res;
+}
+#endif /* !_FS_READONLY */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Pick a segment and create the object name in directory form           */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT create_name (
+    FAT_DIR *dj,            /* Pointer to the directory object */
+    const TCHAR **path    /* Pointer to pointer to the segment in the path string */
+)
+{
+#ifdef _EXCVT
+    static const BYTE excvt[] = _EXCVT;    /* Upper conversion table for extended chars */
+#endif
+
+#if _USE_LFN    /* LFN configuration */
+    BYTE b, cf;
+    WCHAR w, *lfn;
+    int i, ni, si, di;
+    const TCHAR *p;
+
+    /* Create LFN in Unicode */
+    si = di = 0;
+    p = *path;
+    lfn = dj->lfn;
+    for (;;) {
+        w = p[si++];                    /* Get a character */
+        if (w < ' ' || w == '/' || w == '\\') break;    /* Break on end of segment */
+        if (di >= _MAX_LFN)                /* Reject too long name */
+            return FR_INVALID_NAME;
+#if !_LFN_UNICODE
+        w &= 0xFF;
+        if (IsDBCS1(w)) {                /* If it is a DBC 1st byte */
+            b = p[si++];                /* Get 2nd byte */
+            if (!IsDBCS2(b))            /* Reject invalid code for DBC */
+                return FR_INVALID_NAME;
+            w = (w << 8) + b;
+        }
+        w = ff_convert(w, 1);            /* Convert OEM to Unicode */
+        if (!w) return FR_INVALID_NAME;    /* Reject invalid code */
+#endif
+        if (w < 0x80 && chk_chr("\"*:<>\?|\x7F", w)) /* Reject illegal chars for LFN */
+            return FR_INVALID_NAME;
+        lfn[di++] = w;                    /* Store the Unicode char */
+    }
+    *path = &p[si];                        /* Return pointer to the next segment */
+    cf = (w < ' ') ? NS_LAST : 0;        /* Set last segment flag if end of path */
+#if _FS_RPATH
+    if ((di == 1 && lfn[di - 1] == '.') || /* Is this a dot entry? */
+        (di == 2 && lfn[di - 1] == '.' && lfn[di - 2] == '.')) {
+        lfn[di] = 0;
+        for (i = 0; i < 11; i++)
+            dj->fn[i] = (i < di) ? '.' : ' ';
+        dj->fn[i] = cf | NS_DOT;        /* This is a dot entry */
+        return FR_OK;
+    }
+#endif
+    while (di) {                        /* Strip trailing spaces and dots */
+        w = lfn[di - 1];
+        if (w != ' ' && w != '.') break;
+        di--;
+    }
+    if (!di) return FR_INVALID_NAME;    /* Reject nul string */
+
+    lfn[di] = 0;                        /* LFN is created */
+
+    /* Create SFN in directory form */
+    mem_set(dj->fn, ' ', 11);
+    for (si = 0; lfn[si] == ' ' || lfn[si] == '.'; si++) ;    /* Strip leading spaces and dots */
+    if (si) cf |= NS_LOSS | NS_LFN;
+    while (di && lfn[di - 1] != '.') di--;    /* Find extension (di<=si: no extension) */
+
+    b = i = 0; ni = 8;
+    for (;;) {
+        w = lfn[si++];                    /* Get an LFN char */
+        if (!w) break;                    /* Break on end of the LFN */
+        if (w == ' ' || (w == '.' && si != di)) {    /* Remove spaces and dots */
+            cf |= NS_LOSS | NS_LFN; continue;
+        }
+
+        if (i >= ni || si == di) {        /* Extension or end of SFN */
+            if (ni == 11) {                /* Long extension */
+                cf |= NS_LOSS | NS_LFN; break;
+            }
+            if (si != di) cf |= NS_LOSS | NS_LFN;    /* Out of 8.3 format */
+            if (si > di) break;            /* No extension */
+            si = di; i = 8; ni = 11;    /* Enter extension section */
+            b <<= 2; continue;
+        }
+
+        if (w >= 0x80) {                /* Non ASCII char */
+#ifdef _EXCVT
+            w = ff_convert(w, 0);        /* Unicode -> OEM code */
+            if (w) w = excvt[w - 0x80];    /* Convert extended char to upper (SBCS) */
+#else
+            w = ff_convert(ff_wtoupper(w), 0);    /* Upper converted Unicode -> OEM code */
+#endif
+            cf |= NS_LFN;                /* Force create LFN entry */
+        }
+
+        if (_DF1S && w >= 0x100) {        /* Double byte char */
+            if (i >= ni - 1) {
+                cf |= NS_LOSS | NS_LFN; i = ni; continue;
+            }
+            dj->fn[i++] = (BYTE)(w >> 8);
+        } else {                        /* Single byte char */
+            if (!w || chk_chr("+,;=[]", w)) {        /* Replace illegal chars for SFN */
+                w = '_'; cf |= NS_LOSS | NS_LFN;    /* Lossy conversion */
+            } else {
+                if (IsUpper(w)) {        /* ASCII large capital */
+                    b |= 2;
+                } else {
+                    if (IsLower(w)) {    /* ASCII small capital */
+                        b |= 1; w -= 0x20;
+                    }
+                }
+            }
+        }
+        dj->fn[i++] = (BYTE)w;
+    }
+
+    if (dj->fn[0] == 0xE5) dj->fn[0] = 0x05;    /* If the first char collides with deleted mark, replace it with 0x05 */
+
+    if (ni == 8) b <<= 2;
+    if ((b & 0x0C) == 0x0C || (b & 0x03) == 0x03)    /* Create LFN entry when there are composite capitals */
+        cf |= NS_LFN;
+    if (!(cf & NS_LFN)) {                        /* When LFN is in 8.3 format without extended char, NT flags are created */
+        if ((b & 0x03) == 0x01) cf |= NS_EXT;    /* NT flag (Extension has only small capital) */
+        if ((b & 0x0C) == 0x04) cf |= NS_BODY;    /* NT flag (Filename has only small capital) */
+    }
+
+    dj->fn[NS] = cf;    /* SFN is created */
+
+    return FR_OK;
+
+
+#else    /* Non-LFN configuration */
+    BYTE b, c, d, *sfn;
+    int ni, si, i;
+    const char *p;
+
+    /* Create file name in directory form */
+    sfn = dj->fn;
+    mem_set(sfn, ' ', 11);
+    si = i = b = 0; ni = 8;
+    p = *path;
+#if _FS_RPATH
+    if (p[si] == '.') { /* Is this a dot entry? */
+        for (;;) {
+            c = (BYTE)p[si++];
+            if (c != '.' || si >= 3) break;
+            sfn[i++] = c;
+        }
+        if (c != '/' && c != '\\' && c > ' ') return FR_INVALID_NAME;
+        *path = &p[si];                                    /* Return pointer to the next segment */
+        sfn[NS] = (c <= ' ') ? NS_LAST | NS_DOT : NS_DOT;    /* Set last segment flag if end of path */
+        return FR_OK;
+    }
+#endif
+    for (;;) {
+        c = (BYTE)p[si++];
+        if (c <= ' ' || c == '/' || c == '\\') break;    /* Break on end of segment */
+        if (c == '.' || i >= ni) {
+            if (ni != 8 || c != '.') return FR_INVALID_NAME;
+            i = 8; ni = 11;
+            b <<= 2; continue;
+        }
+        if (c >= 0x80) {                /* Extended char */
+#ifdef _EXCVT
+            c = excvt[c - 0x80];        /* Convert extend char (SBCS) */
+#else
+            b |= 3;                        /* Eliminate NT flag if extended char is exist */
+#if !_DF1S    /* ASCII only cfg */
+            return FR_INVALID_NAME;
+#endif
+#endif
+        }
+        if (IsDBCS1(c)) {                /* DBC 1st byte? */
+            d = (BYTE)p[si++];            /* Get 2nd byte */
+            if (!IsDBCS2(d) || i >= ni - 1)    /* Reject invalid DBC */
+                return FR_INVALID_NAME;
+            sfn[i++] = c;
+            sfn[i++] = d;
+        } else {                        /* Single byte code */
+            if (chk_chr("\"*+,:<=>\?[]|\x7F", c))    /* Reject illegal chrs for SFN */
+                return FR_INVALID_NAME;
+            if (IsUpper(c)) {            /* ASCII large capital? */
+                b |= 2;
+            } else {
+                if (IsLower(c)) {        /* ASCII small capital? */
+                    b |= 1; c -= 0x20;
+                }
+            }
+            sfn[i++] = c;
+        }
+    }
+    *path = &p[si];                        /* Return pointer to the next segment */
+    c = (c <= ' ') ? NS_LAST : 0;        /* Set last segment flag if end of path */
+
+    if (!i) return FR_INVALID_NAME;        /* Reject nul string */
+    if (sfn[0] == 0xE5) sfn[0] = 0x05;    /* When first char collides with 0xE5, replace it with 0x05 */
+
+    if (ni == 8) b <<= 2;
+    if ((b & 0x03) == 0x01) c |= NS_EXT;    /* NT flag (Name extension has only small capital) */
+    if ((b & 0x0C) == 0x04) c |= NS_BODY;    /* NT flag (Name body has only small capital) */
+
+    sfn[NS] = c;        /* Store NT flag, File name is created */
+
+    return FR_OK;
+#endif
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Get file information from directory entry                             */
+/*-----------------------------------------------------------------------*/
+#if _FS_MINIMIZE <= 1
+static
+void get_fileinfo (        /* No return code */
+    FAT_DIR *dj,            /* Pointer to the directory object */
+    FILINFO *fno         /* Pointer to the file information to be filled */
+)
+{
+    int i;
+    BYTE nt, *dir;
+    TCHAR *p, c;
+
+
+    p = fno->fname;
+    if (dj->sect) {
+        dir = dj->dir;
+        nt = dir[DIR_NTres];        /* NT flag */
+        for (i = 0; i < 8; i++) {    /* Copy name body */
+            c = dir[i];
+            if (c == ' ') break;
+            if (c == 0x05) c = (TCHAR)0xE5;
+            if (_USE_LFN && (nt & NS_BODY) && IsUpper(c)) c += 0x20;
+#if _LFN_UNICODE
+            if (IsDBCS1(c) && i < 7 && IsDBCS2(dir[i + 1]))
+                c = (c << 8) | dir[++i];
+            c = ff_convert(c, 1);
+            if (!c) c = '?';
+#endif
+            *p++ = c;
+        }
+        if (dir[8] != ' ') {        /* Copy name extension */
+            *p++ = '.';
+            for (i = 8; i < 11; i++) {
+                c = dir[i];
+                if (c == ' ') break;
+                if (_USE_LFN && (nt & NS_EXT) && IsUpper(c)) c += 0x20;
+#if _LFN_UNICODE
+                if (IsDBCS1(c) && i < 10 && IsDBCS2(dir[i + 1]))
+                    c = (c << 8) | dir[++i];
+                c = ff_convert(c, 1);
+                if (!c) c = '?';
+#endif
+                *p++ = c;
+            }
+        }
+        fno->fattrib = dir[DIR_Attr];                /* Attribute */
+        fno->fsize = LD_DWORD(dir+DIR_FileSize);    /* Size */
+        fno->fdate = LD_WORD(dir+DIR_WrtDate);        /* Date */
+        fno->ftime = LD_WORD(dir+DIR_WrtTime);        /* Time */
+    }
+    *p = 0;
+
+#if _USE_LFN
+    if (fno->lfname) {
+        TCHAR *tp = fno->lfname;
+        WCHAR w, *lfn;
+
+        i = 0;
+        if (dj->sect && dj->lfn_idx != 0xFFFF) {/* Get LFN if available */
+            lfn = dj->lfn;
+            while ((w = *lfn++) != 0) {            /* Get an LFN char */
+#if !_LFN_UNICODE
+                w = ff_convert(w, 0);            /* Unicode -> OEM conversion */
+                if (!w) { i = 0; break; }        /* Could not convert, no LFN */
+                if (_DF1S && w >= 0x100)        /* Put 1st byte if it is a DBC */
+                    tp[i++] = (TCHAR)(w >> 8);
+#endif
+                if (i >= fno->lfsize - 1) { i = 0; break; }    /* Buffer overrun, no LFN */
+                tp[i++] = (TCHAR)w;
+            }
+        }
+        tp[i] = 0;    /* Terminator */
+    }
+#endif
+}
+#endif /* _FS_MINIMIZE <= 1 */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Follow a file path                                                    */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT follow_path (    /* FR_OK(0): successful, !=0: error code */
+    FAT_DIR *dj,            /* Directory object to return last directory and found object */
+    const TCHAR *path    /* Full-path string to find a file or directory */
+)
+{
+    FRESULT res;
+    BYTE *dir, ns;
+
+
+#if _FS_RPATH
+    if (*path == '/' || *path == '\\') { /* There is a heading separator */
+        path++;    dj->sclust = 0;        /* Strip it and start from the root dir */
+    } else {                            /* No heading separator */
+        dj->sclust = dj->fs->cdir;    /* Start from the current dir */
+    }
+#else
+    if (*path == '/' || *path == '\\')    /* Strip heading separator if exist */
+        path++;
+    dj->sclust = 0;                        /* Start from the root dir */
+#endif
+
+    if ((UINT)*path < ' ') {            /* Nul path means the start directory itself */
+        res = dir_sdi(dj, 0);
+        dj->dir = 0;
+
+    } else {                            /* Follow path */
+        for (;;) {
+            res = create_name(dj, &path);    /* Get a segment */
+            if (res != FR_OK) break;
+            res = dir_find(dj);                /* Find it */
+            ns = *(dj->fn+NS);
+            if (res != FR_OK) {                /* Failed to find the object */
+                if (res != FR_NO_FILE) break;    /* Abort if any hard error occured */
+                /* Object not found */
+                if (_FS_RPATH && (ns & NS_DOT)) {    /* If dot entry is not exit */
+                    dj->sclust = 0; dj->dir = 0;    /* It is the root dir */
+                    res = FR_OK;
+                    if (!(ns & NS_LAST)) continue;
+                } else {                            /* Could not find the object */
+                    if (!(ns & NS_LAST)) res = FR_NO_PATH;
+                }
+                break;
+            }
+            if (ns & NS_LAST) break;            /* Last segment match. Function completed. */
+            dir = dj->dir;                        /* There is next segment. Follow the sub directory */
+            if (!(dir[DIR_Attr] & AM_DIR)) {    /* Cannot follow because it is a file */
+                res = FR_NO_PATH; break;
+            }
+            dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
+        }
+    }
+
+    return res;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Load boot record and check if it is an FAT boot record                */
+/*-----------------------------------------------------------------------*/
+
+static
+BYTE check_fs (    /* 0:The FAT BR, 1:Valid BR but not an FAT, 2:Not a BR, 3:Disk error */
+    FATFS *fs,    /* File system object */
+    DWORD sect    /* Sector# (lba) to check if it is an FAT boot record or not */
+)
+{
+    if (disk_read(fs->drv, fs->win, sect, 1) != RES_OK)    /* Load boot record */
+        return 3;
+    if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55)        /* Check record signature (always placed at offset 510 even if the sector size is >512) */
+        return 2;
+
+    if ((LD_DWORD(&fs->win[BS_FilSysType]) & 0xFFFFFF) == 0x544146)    /* Check "FAT" string */
+        return 0;
+    if ((LD_DWORD(&fs->win[BS_FilSysType32]) & 0xFFFFFF) == 0x544146)
+        return 0;
+
+    return 1;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Make sure that the file system is valid                               */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT chk_mounted (    /* FR_OK(0): successful, !=0: any error occurred */
+    const TCHAR **path,    /* Pointer to pointer to the path name (drive number) */
+    FATFS **rfs,        /* Pointer to pointer to the found file system object */
+    BYTE chk_wp            /* !=0: Check media write protection for write access */
+)
+{
+    BYTE fmt, b, *tbl;
+    UINT vol;
+    DSTATUS stat;
+    DWORD bsect, fasize, tsect, sysect, nclst, szbfat;
+    WORD nrsv;
+    const TCHAR *p = *path;
+    FATFS *fs;
+
+    /* Get logical drive number from the path name */
+    vol = p[0] - '0';                /* Is there a drive number? */
+    if (vol <= 9 && p[1] == ':') {    /* Found a drive number, get and strip it */
+        p += 2; *path = p;            /* Return pointer to the path name */
+    } else {                        /* No drive number is given */
+#if _FS_RPATH
+        vol = Drive;                /* Use current drive */
+#else
+        vol = 0;                    /* Use drive 0 */
+#endif
+    }
+
+    /* Check if the logical drive is valid or not */
+    if (vol >= _DRIVES)             /* Is the drive number valid? */
+        return FR_INVALID_DRIVE;
+    *rfs = fs = FatFs[vol];            /* Return pointer to the corresponding file system object */
+    if (!fs) return FR_NOT_ENABLED;    /* Is the file system object available? */
+
+    ENTER_FF(fs);                    /* Lock file system */
+
+    if (fs->fs_type) {                /* If the logical drive has been mounted */
+        stat = disk_status(fs->drv);
+        if (!(stat & STA_NOINIT)) {    /* and the physical drive is kept initialized (has not been changed), */
+#if !_FS_READONLY
+            if (chk_wp && (stat & STA_PROTECT))    /* Check write protection if needed */
+                return FR_WRITE_PROTECTED;
+#endif
+            return FR_OK;            /* The file system object is valid */
+        }
+    }
+
+    /* The logical drive must be mounted. Following code attempts to mount the volume (initialize the file system object) */
+
+    fs->fs_type = 0;                    /* Clear the file system object */
+    fs->drv = (BYTE)LD2PD(vol);            /* Bind the logical drive and a physical drive */
+    stat = disk_initialize(fs->drv);    /* Initialize low level disk I/O layer */
+    if (stat & STA_NOINIT)                /* Check if the drive is ready */
+        return FR_NOT_READY;
+#if _MAX_SS != 512                        /* Get disk sector size if needed */
+    if (disk_ioctl(fs->drv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK || SS(fs) > _MAX_SS)
+        return FR_NO_FILESYSTEM;
+#endif
+#if !_FS_READONLY
+    if (chk_wp && (stat & STA_PROTECT))    /* Check disk write protection if needed */
+        return FR_WRITE_PROTECTED;
+#endif
+    /* Search FAT partition on the drive (Supports only generic partitionings, FDISK and SFD) */
+    fmt = check_fs(fs, bsect = 0);        /* Check sector 0 if it is a VBR */
+    if (fmt == 1) {                        /* Not an FAT-VBR, the disk may be partitioned */
+        /* Check the partition listed in top of the partition table */
+        tbl = &fs->win[MBR_Table + LD2PT(vol) * 16];    /* Partition table */
+        if (tbl[4]) {                                    /* Is the partition existing? */
+            bsect = LD_DWORD(&tbl[8]);                    /* Partition offset in LBA */
+            fmt = check_fs(fs, bsect);                    /* Check the partition */
+        }
+    }
+    if (fmt == 3) return FR_DISK_ERR;
+    if (fmt) return FR_NO_FILESYSTEM;                    /* No FAT volume is found */
+
+    /* Following code initializes the file system object */
+
+    if (LD_WORD(fs->win+BPB_BytsPerSec) != SS(fs))        /* (BPB_BytsPerSec must be equal to the physical sector size) */
+        return FR_NO_FILESYSTEM;
+
+    fasize = LD_WORD(fs->win+BPB_FATSz16);                /* Number of sectors per FAT */
+    if (!fasize) fasize = LD_DWORD(fs->win+BPB_FATSz32);
+    fs->fsize = fasize;
+
+    fs->n_fats = b = fs->win[BPB_NumFATs];                /* Number of FAT copies */
+    if (b != 1 && b != 2) return FR_NO_FILESYSTEM;        /* (Must be 1 or 2) */
+    fasize *= b;                                        /* Number of sectors for FAT area */
+
+    fs->csize = b = fs->win[BPB_SecPerClus];            /* Number of sectors per cluster */
+    if (!b || (b & (b - 1))) return FR_NO_FILESYSTEM;    /* (Must be 1,2,4...128) */
+
+    fs->n_rootdir = LD_WORD(fs->win+BPB_RootEntCnt);    /* Number of root directory entries */
+    if (fs->n_rootdir % (SS(fs) / 32)) return FR_NO_FILESYSTEM;    /* (BPB_RootEntCnt must be sector aligned) */
+
+    tsect = LD_WORD(fs->win+BPB_TotSec16);                /* Number of sectors on the volume */
+    if (!tsect) tsect = LD_DWORD(fs->win+BPB_TotSec32);
+
+    nrsv = LD_WORD(fs->win+BPB_RsvdSecCnt);                /* Number of reserved sectors */
+    if (!nrsv) return FR_NO_FILESYSTEM;                    /* (BPB_RsvdSecCnt must not be 0) */
+
+    /* Determine the FAT sub type */
+    sysect = nrsv + fasize + fs->n_rootdir / (SS(fs) / 32);    /* RSV+FAT+DIR */
+    if (tsect < sysect) return FR_NO_FILESYSTEM;        /* (Invalid volume size) */
+    nclst = (tsect - sysect) / fs->csize;                /* Number of clusters */
+    if (!nclst) return FR_NO_FILESYSTEM;                /* (Invalid volume size) */
+    fmt = FS_FAT12;
+    if (nclst >= MIN_FAT16) fmt = FS_FAT16;
+    if (nclst >= MIN_FAT32) fmt = FS_FAT32;
+
+    /* Boundaries and Limits */
+    fs->n_fatent = nclst + 2;                            /* Number of FAT entries */
+    fs->database = bsect + sysect;                        /* Data start sector */
+    fs->fatbase = bsect + nrsv;                         /* FAT start sector */
+    if (fmt == FS_FAT32) {
+        if (fs->n_rootdir) return FR_NO_FILESYSTEM;        /* (BPB_RootEntCnt must be 0) */
+        fs->dirbase = LD_DWORD(fs->win+BPB_RootClus);    /* Root directory start cluster */
+        szbfat = fs->n_fatent * 4;                        /* (Required FAT size) */
+    } else {
+        if (!fs->n_rootdir)    return FR_NO_FILESYSTEM;    /* (BPB_RootEntCnt must not be 0) */
+        fs->dirbase = fs->fatbase + fasize;                /* Root directory start sector */
+        szbfat = (fmt == FS_FAT16) ?                    /* (Required FAT size) */
+            fs->n_fatent * 2 : fs->n_fatent * 3 / 2 + (fs->n_fatent & 1);
+    }
+    if (fs->fsize < (szbfat + (SS(fs) - 1)) / SS(fs))    /* (FAT size must not be less than FAT sectors */
+        return FR_NO_FILESYSTEM;
+
+#if !_FS_READONLY
+    /* Initialize cluster allocation information */
+    fs->free_clust = 0xFFFFFFFF;
+    fs->last_clust = 0;
+
+    /* Get fsinfo if available */
+    if (fmt == FS_FAT32) {
+         fs->fsi_flag = 0;
+        fs->fsi_sector = bsect + LD_WORD(fs->win+BPB_FSInfo);
+        if (disk_read(fs->drv, fs->win, fs->fsi_sector, 1) == RES_OK &&
+            LD_WORD(fs->win+BS_55AA) == 0xAA55 &&
+            LD_DWORD(fs->win+FSI_LeadSig) == 0x41615252 &&
+            LD_DWORD(fs->win+FSI_StrucSig) == 0x61417272) {
+                fs->last_clust = LD_DWORD(fs->win+FSI_Nxt_Free);
+                fs->free_clust = LD_DWORD(fs->win+FSI_Free_Count);
+        }
+    }
+#endif
+    fs->fs_type = fmt;        /* FAT sub-type */
+    fs->id = ++Fsid;        /* File system mount ID */
+    fs->winsect = 0;        /* Invalidate sector cache */
+    fs->wflag = 0;
+#if _FS_RPATH
+    fs->cdir = 0;            /* Current directory (root dir) */
+#endif
+#if _FS_SHARE                /* Clear file lock semaphores */
+    for (vol = 0; vol < _FS_SHARE; vol++)
+        fs->flsem[vol].ctr = 0;
+#endif
+
+    return FR_OK;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Check if the file/dir object is valid or not                          */
+/*-----------------------------------------------------------------------*/
+
+static
+FRESULT validate (    /* FR_OK(0): The object is valid, !=0: Invalid */
+    FATFS *fs,        /* Pointer to the file system object */
+    WORD id            /* Member id of the target object to be checked */
+)
+{
+    if (!fs || !fs->fs_type || fs->id != id)
+        return FR_INVALID_OBJECT;
+
+    ENTER_FF(fs);        /* Lock file system */
+
+    if (disk_status(fs->drv) & STA_NOINIT)
+        return FR_NOT_READY;
+
+    return FR_OK;
+}
+
+
+
+
+/*--------------------------------------------------------------------------
+
+   Public Functions
+
+--------------------------------------------------------------------------*/
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Mount/Unmount a Logical Drive                                         */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_mount (
+    BYTE vol,        /* Logical drive number to be mounted/unmounted */
+    FATFS *fs        /* Pointer to new file system object (NULL for unmount)*/
+)
+{
+    FATFS *rfs;
+
+
+    if (vol >= _DRIVES)                /* Check if the drive number is valid */
+        return FR_INVALID_DRIVE;
+    rfs = FatFs[vol];                /* Get current fs object */
+
+    if (rfs) {
+#if _FS_REENTRANT                    /* Discard sync object of the current volume */
+        if (!ff_del_syncobj(rfs->sobj)) return FR_INT_ERR;
+#endif
+        rfs->fs_type = 0;            /* Clear old fs object */
+    }
+
+    if (fs) {
+        fs->fs_type = 0;            /* Clear new fs object */
+#if _FS_REENTRANT                    /* Create sync object for the new volume */
+        if (!ff_cre_syncobj(vol, &fs->sobj)) return FR_INT_ERR;
+#endif
+    }
+    FatFs[vol] = fs;                /* Register new fs object */
+
+    return FR_OK;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Open or Create a File                                                 */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_open (
+    FAT_FIL *fp,            /* Pointer to the blank file object */
+    const TCHAR *path,    /* Pointer to the file name */
+    BYTE mode            /* Access mode and file open mode flags */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    BYTE *dir;
+    DEF_NAMEBUF;
+
+
+    fp->fs = 0;            /* Clear file object */
+
+#if !_FS_READONLY
+    mode &= FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW;
+    res = chk_mounted(&path, &dj.fs, (BYTE)(mode & ~FA_READ));
+#else
+    mode &= FA_READ;
+    res = chk_mounted(&path, &dj.fs, 0);
+#endif
+    INIT_BUF(dj);
+    if (res == FR_OK)
+        res = follow_path(&dj, path);    /* Follow the file path */
+    dir = dj.dir;
+
+#if !_FS_READONLY    /* R/W configuration */
+    if (res == FR_OK) {
+        if (!dir)    /* Current dir itself */
+            res = FR_INVALID_NAME;
+#if _FS_SHARE
+        else
+            res = chk_lock(&dj, (mode & ~FA_READ) ? 1 : 0);
+#endif
+    }
+    /* Create or Open a file */
+    if (mode & (FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)) {
+        DWORD dw, cl;
+
+        if (res != FR_OK) {                /* No file, create new */
+            if (res == FR_NO_FILE)        /* There is no file to open, create a new entry */
+#if _FS_SHARE
+                res = enq_lock(dj.fs) ? dir_register(&dj) : FR_TOO_MANY_OPEN_FILES;
+#else
+                res = dir_register(&dj);
+#endif
+            mode |= FA_CREATE_ALWAYS;
+            dir = dj.dir;                /* New entry */
+        }
+        else {                            /* Any object is already existing */
+            if (mode & FA_CREATE_NEW) {            /* Cannot create new */
+                res = FR_EXIST;
+            } else {
+                if (dir[DIR_Attr] & (AM_RDO | AM_DIR))    /* Cannot overwrite it (R/O or DIR) */
+                    res = FR_DENIED;
+            }
+        }
+        if (res == FR_OK && (mode & FA_CREATE_ALWAYS)) {    /* Truncate it if overwrite mode */
+            dw = get_fattime();                        /* Created time */
+            ST_DWORD(dir+DIR_CrtTime, dw);
+            dir[DIR_Attr] = 0;                    /* Reset attribute */
+            ST_DWORD(dir+DIR_FileSize, 0);        /* size = 0 */
+            cl = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);    /* Get start cluster */
+            ST_WORD(dir+DIR_FstClusHI, 0);        /* cluster = 0 */
+            ST_WORD(dir+DIR_FstClusLO, 0);
+            dj.fs->wflag = 1;
+            if (cl) {                            /* Remove the cluster chain if exist */
+                dw = dj.fs->winsect;
+                res = remove_chain(dj.fs, cl);
+                if (res == FR_OK) {
+                    dj.fs->last_clust = cl - 1;    /* Reuse the cluster hole */
+                    res = move_window(dj.fs, dw);
+                }
+            }
+        }
+    }
+    else {    /* Open an existing file */
+        if (res == FR_OK) {                        /* Follow succeeded */
+            if (dir[DIR_Attr] & AM_DIR) {        /* It is a directory */
+                res = FR_NO_FILE;
+            } else {
+                if ((mode & FA_WRITE) && (dir[DIR_Attr] & AM_RDO)) /* R/O violation */
+                    res = FR_DENIED;
+            }
+        }
+    }
+    if (res == FR_OK) {
+        if (mode & (FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW))
+            mode |= FA__WRITTEN;                /* Set file changed flag */
+        fp->dir_sect = dj.fs->winsect;            /* Pointer to the directory entry */
+        fp->dir_ptr = dir;
+#if _FS_SHARE
+        fp->lockid = inc_lock(&dj, (mode & ~FA_READ) ? 1 : 0);
+        if (!fp->lockid) res = FR_INT_ERR;
+#endif
+    }
+
+#else                /* R/O configuration */
+    if (res == FR_OK) {                    /* Follow succeeded */
+        if (!dir) {                        /* Current dir itself */
+            res = FR_INVALID_NAME;
+        } else {
+            if (dir[DIR_Attr] & AM_DIR)    /* It is a directory */
+                res = FR_NO_FILE;
+        }
+    }
+#endif
+    FREE_BUF();
+
+    if (res == FR_OK) {
+        fp->flag = mode;                    /* File access mode */
+        fp->org_clust =                        /* File start cluster */
+            ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
+        fp->fsize = LD_DWORD(dir+DIR_FileSize);    /* File size */
+        fp->fptr = 0;                        /* File pointer */
+        fp->dsect = 0;
+#if _USE_FASTSEEK
+        fp->cltbl = 0;                        /* No cluster link map table */
+#endif
+        fp->fs = dj.fs; fp->id = dj.fs->id;    /* Validate file object */
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Read File                                                             */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_read (
+    FAT_FIL *fp,         /* Pointer to the file object */
+    void *buff,        /* Pointer to data buffer */
+    UINT btr,        /* Number of bytes to read */
+    UINT *br        /* Pointer to number of bytes read */
+)
+{
+    FRESULT res;
+    DWORD clst, sect, remain;
+    UINT rcnt, cc;
+    BYTE csect, *rbuff = (BYTE*)buff;
+
+
+    *br = 0;    /* Initialize byte counter */
+
+    res = validate(fp->fs, fp->id);                    /* Check validity of the object */
+    if (res != FR_OK) LEAVE_FF(fp->fs, res);
+    if (fp->flag & FA__ERROR)                        /* Check abort flag */
+        LEAVE_FF(fp->fs, FR_INT_ERR);
+    if (!(fp->flag & FA_READ))                         /* Check access mode */
+        LEAVE_FF(fp->fs, FR_DENIED);
+    remain = fp->fsize - fp->fptr;
+    if (btr > remain) btr = (UINT)remain;            /* Truncate btr by remaining bytes */
+
+    for ( ;  btr;                                    /* Repeat until all data transferred */
+        rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt) {
+        if ((fp->fptr % SS(fp->fs)) == 0) {            /* On the sector boundary? */
+            csect = (BYTE)(fp->fptr / SS(fp->fs) & (fp->fs->csize - 1));    /* Sector offset in the cluster */
+            if (!csect) {                            /* On the cluster boundary? */
+                clst = (fp->fptr == 0) ?            /* On the top of the file? */
+                    fp->org_clust : get_fat(fp->fs, fp->curr_clust);
+                if (clst <= 1) ABORT(fp->fs, FR_INT_ERR);
+                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                fp->curr_clust = clst;                /* Update current cluster */
+            }
+            sect = clust2sect(fp->fs, fp->curr_clust);    /* Get current sector */
+            if (!sect) ABORT(fp->fs, FR_INT_ERR);
+            sect += csect;
+            cc = btr / SS(fp->fs);                    /* When remaining bytes >= sector size, */
+            if (cc) {                                /* Read maximum contiguous sectors directly */
+                if (csect + cc > fp->fs->csize)        /* Clip at cluster boundary */
+                    cc = fp->fs->csize - csect;
+                if (disk_read(fp->fs->drv, rbuff, sect, (BYTE)cc) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+#if !_FS_READONLY && _FS_MINIMIZE <= 2                /* Replace one of the read sectors with cached data if it contains a dirty sector */
+#if _FS_TINY
+                if (fp->fs->wflag && fp->fs->winsect - sect < cc)
+                    mem_cpy(rbuff + ((fp->fs->winsect - sect) * SS(fp->fs)), fp->fs->win, SS(fp->fs));
+#else
+                if ((fp->flag & FA__DIRTY) && fp->dsect - sect < cc)
+                    mem_cpy(rbuff + ((fp->dsect - sect) * SS(fp->fs)), fp->buf, SS(fp->fs));
+#endif
+#endif
+                rcnt = SS(fp->fs) * cc;                /* Number of bytes transferred */
+                continue;
+            }
+#if !_FS_TINY
+#if !_FS_READONLY
+            if (fp->flag & FA__DIRTY) {            /* Write sector I/O buffer if needed */
+                if (disk_write(fp->fs->drv, fp->buf, fp->dsect, 1) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+                fp->flag &= ~FA__DIRTY;
+            }
+#endif
+            if (fp->dsect != sect) {            /* Fill sector buffer with file data */
+                if (disk_read(fp->fs->drv, fp->buf, sect, 1) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+            }
+#endif
+            fp->dsect = sect;
+        }
+        rcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs));    /* Get partial sector data from sector buffer */
+        if (rcnt > btr) rcnt = btr;
+#if _FS_TINY
+        if (move_window(fp->fs, fp->dsect))            /* Move sector window */
+            ABORT(fp->fs, FR_DISK_ERR);
+        mem_cpy(rbuff, &fp->fs->win[fp->fptr % SS(fp->fs)], rcnt);    /* Pick partial sector */
+#else
+        mem_cpy(rbuff, &fp->buf[fp->fptr % SS(fp->fs)], rcnt);    /* Pick partial sector */
+#endif
+    }
+
+    LEAVE_FF(fp->fs, FR_OK);
+}
+
+
+
+
+#if !_FS_READONLY
+/*-----------------------------------------------------------------------*/
+/* Write File                                                            */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_write (
+    FAT_FIL *fp,            /* Pointer to the file object */
+    const void *buff,    /* Pointer to the data to be written */
+    UINT btw,            /* Number of bytes to write */
+    UINT *bw            /* Pointer to number of bytes written */
+)
+{
+    FRESULT res;
+    DWORD clst, sect;
+    UINT wcnt, cc;
+    const BYTE *wbuff = (const BYTE*)buff;
+    BYTE csect;
+
+
+    *bw = 0;    /* Initialize byte counter */
+
+    res = validate(fp->fs, fp->id);                    /* Check validity of the object */
+    if (res != FR_OK) LEAVE_FF(fp->fs, res);
+    if (fp->flag & FA__ERROR)                        /* Check abort flag */
+        LEAVE_FF(fp->fs, FR_INT_ERR);
+    if (!(fp->flag & FA_WRITE))                        /* Check access mode */
+        LEAVE_FF(fp->fs, FR_DENIED);
+    if (fp->fsize + btw < fp->fsize) btw = 0;        /* File size cannot reach 4GB */
+
+    for ( ;  btw;                                    /* Repeat until all data transferred */
+        wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt) {
+        if ((fp->fptr % SS(fp->fs)) == 0) {            /* On the sector boundary? */
+            csect = (BYTE)(fp->fptr / SS(fp->fs) & (fp->fs->csize - 1));    /* Sector offset in the cluster */
+            if (!csect) {                            /* On the cluster boundary? */
+                if (fp->fptr == 0) {                /* On the top of the file? */
+                    clst = fp->org_clust;            /* Follow from the origin */
+                    if (clst == 0)                    /* When there is no cluster chain, */
+                        fp->org_clust = clst = create_chain(fp->fs, 0);    /* Create a new cluster chain */
+                } else {                            /* Middle or end of the file */
+                    clst = create_chain(fp->fs, fp->curr_clust);            /* Follow or stretch cluster chain */
+                }
+                if (clst == 0) break;                /* Could not allocate a new cluster (disk full) */
+                if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
+                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                fp->curr_clust = clst;                /* Update current cluster */
+            }
+#if _FS_TINY
+            if (fp->fs->winsect == fp->dsect && move_window(fp->fs, 0))    /* Write back data buffer prior to following direct transfer */
+                ABORT(fp->fs, FR_DISK_ERR);
+#else
+            if (fp->flag & FA__DIRTY) {        /* Write back data buffer prior to following direct transfer */
+                if (disk_write(fp->fs->drv, fp->buf, fp->dsect, 1) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+                fp->flag &= ~FA__DIRTY;
+            }
+#endif
+            sect = clust2sect(fp->fs, fp->curr_clust);    /* Get current sector */
+            if (!sect) ABORT(fp->fs, FR_INT_ERR);
+            sect += csect;
+            cc = btw / SS(fp->fs);                    /* When remaining bytes >= sector size, */
+            if (cc) {                                /* Write maximum contiguous sectors directly */
+                if (csect + cc > fp->fs->csize)        /* Clip at cluster boundary */
+                    cc = fp->fs->csize - csect;
+                if (disk_write(fp->fs->drv, wbuff, sect, (BYTE)cc) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+#if _FS_TINY
+                if (fp->fs->winsect - sect < cc) {    /* Refill sector cache if it gets dirty by the direct write */
+                    mem_cpy(fp->fs->win, wbuff + ((fp->fs->winsect - sect) * SS(fp->fs)), SS(fp->fs));
+                    fp->fs->wflag = 0;
+                }
+#else
+                if (fp->dsect - sect < cc) {        /* Refill sector cache if it gets dirty by the direct write */
+                    mem_cpy(fp->buf, wbuff + ((fp->dsect - sect) * SS(fp->fs)), SS(fp->fs));
+                    fp->flag &= ~FA__DIRTY;
+                }
+#endif
+                wcnt = SS(fp->fs) * cc;                /* Number of bytes transferred */
+                continue;
+            }
+#if _FS_TINY
+            if (fp->fptr >= fp->fsize) {            /* Avoid silly buffer filling at growing edge */
+                if (move_window(fp->fs, 0)) ABORT(fp->fs, FR_DISK_ERR);
+                fp->fs->winsect = sect;
+            }
+#else
+            if (fp->dsect != sect) {                /* Fill sector buffer with file data */
+                if (fp->fptr < fp->fsize &&
+                    disk_read(fp->fs->drv, fp->buf, sect, 1) != RES_OK)
+                        ABORT(fp->fs, FR_DISK_ERR);
+            }
+#endif
+            fp->dsect = sect;
+        }
+        wcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs));    /* Put partial sector into file I/O buffer */
+        if (wcnt > btw) wcnt = btw;
+#if _FS_TINY
+        if (move_window(fp->fs, fp->dsect))            /* Move sector window */
+            ABORT(fp->fs, FR_DISK_ERR);
+        mem_cpy(&fp->fs->win[fp->fptr % SS(fp->fs)], wbuff, wcnt);    /* Fit partial sector */
+        fp->fs->wflag = 1;
+#else
+        mem_cpy(&fp->buf[fp->fptr % SS(fp->fs)], wbuff, wcnt);    /* Fit partial sector */
+        fp->flag |= FA__DIRTY;
+#endif
+    }
+
+    if (fp->fptr > fp->fsize) fp->fsize = fp->fptr;    /* Update file size if needed */
+    fp->flag |= FA__WRITTEN;                        /* Set file changed flag */
+
+    LEAVE_FF(fp->fs, FR_OK);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Synchronize the File Object                                           */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_sync (
+    FAT_FIL *fp        /* Pointer to the file object */
+)
+{
+    FRESULT res;
+    DWORD tim;
+    BYTE *dir;
+
+
+    res = validate(fp->fs, fp->id);        /* Check validity of the object */
+    if (res == FR_OK) {
+        if (fp->flag & FA__WRITTEN) {    /* Has the file been written? */
+#if !_FS_TINY    /* Write-back dirty buffer */
+            if (fp->flag & FA__DIRTY) {
+                if (disk_write(fp->fs->drv, fp->buf, fp->dsect, 1) != RES_OK)
+                    LEAVE_FF(fp->fs, FR_DISK_ERR);
+                fp->flag &= ~FA__DIRTY;
+            }
+#endif
+            /* Update the directory entry */
+            res = move_window(fp->fs, fp->dir_sect);
+            if (res == FR_OK) {
+                dir = fp->dir_ptr;
+                dir[DIR_Attr] |= AM_ARC;                    /* Set archive bit */
+                ST_DWORD(dir+DIR_FileSize, fp->fsize);        /* Update file size */
+                ST_WORD(dir+DIR_FstClusLO, fp->org_clust);    /* Update start cluster */
+                ST_WORD(dir+DIR_FstClusHI, fp->org_clust >> 16);
+                tim = get_fattime();                        /* Update updated time */
+                ST_DWORD(dir+DIR_WrtTime, tim);
+                fp->flag &= ~FA__WRITTEN;
+                fp->fs->wflag = 1;
+                res = sync(fp->fs);
+            }
+        }
+    }
+
+    LEAVE_FF(fp->fs, res);
+}
+
+#endif /* !_FS_READONLY */
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Close File                                                            */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_close (
+    FAT_FIL *fp        /* Pointer to the file object to be closed */
+)
+{
+    FRESULT res;
+
+#if _FS_READONLY
+    FATFS *fs = fp->fs;
+    res = validate(fs, fp->id);
+    if (res == FR_OK) fp->fs = 0;    /* Discard file object */
+    LEAVE_FF(fs, res);
+
+#else
+    res = f_sync(fp);        /* Flush cached data */
+#if _FS_SHARE
+    if (res == FR_OK) {        /* Decrement open counter */
+#if _FS_REENTRANT
+        res = validate(fp->fs, fp->id);
+        if (res == FR_OK) {
+            res = dec_lock(fp->fs, fp->lockid);    
+            unlock_fs(fp->fs, FR_OK);
+        }
+#else
+        res = dec_lock(fp->fs, fp->lockid);
+#endif
+    }
+#endif
+    if (res == FR_OK) fp->fs = 0;    /* Discard file object */
+    return res;
+#endif
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Change Current Drive/Directory                                        */
+/*-----------------------------------------------------------------------*/
+
+#if _FS_RPATH
+
+FRESULT f_chdrive (
+    BYTE drv        /* Drive number */
+)
+{
+    if (drv >= _DRIVES) return FR_INVALID_DRIVE;
+
+    Drive = drv;
+
+    return FR_OK;
+}
+
+
+
+
+FRESULT f_chdir (
+    const TCHAR *path    /* Pointer to the directory path */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    BYTE *dir;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 0);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);        /* Follow the path */
+        FREE_BUF();
+        if (res == FR_OK) {                    /* Follow completed */
+            dir = dj.dir;                    /* Pointer to the entry */
+            if (!dir) {
+                dj.fs->cdir = dj.sclust;    /* Start directory itself */
+            } else {
+                if (dir[DIR_Attr] & AM_DIR)    /* Reached to the directory */
+                    dj.fs->cdir = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
+                else
+                    res = FR_NO_PATH;        /* Reached but a file */
+            }
+        }
+        if (res == FR_NO_FILE) res = FR_NO_PATH;
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+#endif
+
+
+
+#if _FS_MINIMIZE <= 2
+/*-----------------------------------------------------------------------*/
+/* Seek File R/W Pointer                                                 */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_lseek (
+    FAT_FIL *fp,        /* Pointer to the file object */
+    DWORD ofs        /* File pointer from top of file */
+)
+{
+    FRESULT res;
+
+
+    res = validate(fp->fs, fp->id);        /* Check validity of the object */
+    if (res != FR_OK) LEAVE_FF(fp->fs, res);
+    if (fp->flag & FA__ERROR)            /* Check abort flag */
+        LEAVE_FF(fp->fs, FR_INT_ERR);
+
+#if _USE_FASTSEEK
+    if (fp->cltbl) {    /* Fast seek */
+        DWORD cl, pcl, ncl, tcl, dsc, tlen, *tbl = fp->cltbl;
+        BYTE csc;
+
+        tlen = *tbl++;
+        if (ofs == CREATE_LINKMAP) {    /* Create link map table */
+            cl = fp->org_clust;
+            if (cl) {
+                do {
+                    if (tlen < 4) {    /* Not enough table items */
+                        res = FR_NOT_ENOUGH_CORE; break;
+                    }
+                    tcl = cl; ncl = 0;
+                    do {        /* Get a fragment and store the top and length */
+                        pcl = cl; ncl++;
+                        cl = get_fat(fp->fs, cl);
+                        if (cl <= 1) ABORT(fp->fs, FR_INT_ERR);
+                        if (cl == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                    } while (cl == pcl + 1);
+                    *tbl++ = ncl; *tbl++ = tcl;
+                    tlen -= 2;
+                } while (cl < fp->fs->n_fatent);
+            }
+            *tbl = 0;    /* Terminate table */
+
+        } else {                        /* Fast seek */
+            if (ofs > fp->fsize)        /* Clip offset at the file size */
+                ofs = fp->fsize;
+            fp->fptr = ofs;                /* Set file pointer */
+            if (ofs) {
+                dsc = (ofs - 1) / SS(fp->fs);
+                cl = dsc / fp->fs->csize;
+                for (;;) {
+                    ncl = *tbl++;
+                    if (!ncl) ABORT(fp->fs, FR_INT_ERR);
+                    if (cl < ncl) break;
+                    cl -= ncl; tbl++;
+                }
+                fp->curr_clust = cl + *tbl;
+                csc = (BYTE)(dsc & (fp->fs->csize - 1));
+                dsc = clust2sect(fp->fs, fp->curr_clust);
+                if (!dsc) ABORT(fp->fs, FR_INT_ERR);
+                dsc += csc;
+                if (fp->fptr % SS(fp->fs) && dsc != fp->dsect) {
+#if !_FS_TINY
+#if !_FS_READONLY
+                    if (fp->flag & FA__DIRTY) {        /* Flush dirty buffer if needed */
+                        if (disk_write(fp->fs->drv, fp->buf, fp->dsect, 1) != RES_OK)
+                            ABORT(fp->fs, FR_DISK_ERR);
+                        fp->flag &= ~FA__DIRTY;
+                    }
+#endif
+                    if (disk_read(fp->fs->drv, fp->buf, dsc, 1) != RES_OK)
+                        ABORT(fp->fs, FR_DISK_ERR);
+#endif
+                    fp->dsect = dsc;
+                }
+            }
+        }
+    } else
+#endif
+
+    /* Normal Seek */
+    {
+        DWORD clst, bcs, nsect, ifptr;
+
+        if (ofs > fp->fsize                    /* In read-only mode, clip offset with the file size */
+#if !_FS_READONLY
+             && !(fp->flag & FA_WRITE)
+#endif
+            ) ofs = fp->fsize;
+
+        ifptr = fp->fptr;
+        fp->fptr = nsect = 0;
+        if (ofs) {
+            bcs = (DWORD)fp->fs->csize * SS(fp->fs);    /* Cluster size (byte) */
+            if (ifptr > 0 &&
+                (ofs - 1) / bcs >= (ifptr - 1) / bcs) {    /* When seek to same or following cluster, */
+                fp->fptr = (ifptr - 1) & ~(bcs - 1);    /* start from the current cluster */
+                ofs -= fp->fptr;
+                clst = fp->curr_clust;
+            } else {                                    /* When seek to back cluster, */
+                clst = fp->org_clust;                    /* start from the first cluster */
+#if !_FS_READONLY
+                if (clst == 0) {                        /* If no cluster chain, create a new chain */
+                    clst = create_chain(fp->fs, 0);
+                    if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
+                    if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                    fp->org_clust = clst;
+                }
+#endif
+                fp->curr_clust = clst;
+            }
+            if (clst != 0) {
+                while (ofs > bcs) {                        /* Cluster following loop */
+#if !_FS_READONLY
+                    if (fp->flag & FA_WRITE) {            /* Check if in write mode or not */
+                        clst = create_chain(fp->fs, clst);    /* Force stretch if in write mode */
+                        if (clst == 0) {                /* When disk gets full, clip file size */
+                            ofs = bcs; break;
+                        }
+                    } else
+#endif
+                        clst = get_fat(fp->fs, clst);    /* Follow cluster chain if not in write mode */
+                    if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                    if (clst <= 1 || clst >= fp->fs->n_fatent) ABORT(fp->fs, FR_INT_ERR);
+                    fp->curr_clust = clst;
+                    fp->fptr += bcs;
+                    ofs -= bcs;
+                }
+                fp->fptr += ofs;
+                if (ofs % SS(fp->fs)) {
+                    nsect = clust2sect(fp->fs, clst);    /* Current sector */
+                    if (!nsect) ABORT(fp->fs, FR_INT_ERR);
+                    nsect += ofs / SS(fp->fs);
+                }
+            }
+        }
+        if (fp->fptr % SS(fp->fs) && nsect != fp->dsect) {
+#if !_FS_TINY
+#if !_FS_READONLY
+            if (fp->flag & FA__DIRTY) {            /* Flush dirty buffer if needed */
+                if (disk_write(fp->fs->drv, fp->buf, fp->dsect, 1) != RES_OK)
+                    ABORT(fp->fs, FR_DISK_ERR);
+                fp->flag &= ~FA__DIRTY;
+            }
+#endif
+            if (disk_read(fp->fs->drv, fp->buf, nsect, 1) != RES_OK)
+                ABORT(fp->fs, FR_DISK_ERR);
+#endif
+            fp->dsect = nsect;
+        }
+#if !_FS_READONLY
+        if (fp->fptr > fp->fsize) {            /* Set changed flag if the file size is extended */
+            fp->fsize = fp->fptr;
+            fp->flag |= FA__WRITTEN;
+        }
+#endif
+    }
+
+    LEAVE_FF(fp->fs, res);
+}
+
+
+
+#if _FS_MINIMIZE <= 1
+/*-----------------------------------------------------------------------*/
+/* Create a Directroy Object                                             */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_opendir (
+    FAT_DIR *dj,            /* Pointer to directory object to create */
+    const TCHAR *path    /* Pointer to the directory path */
+)
+{
+    FRESULT res;
+    BYTE *dir;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj->fs, 0);
+    if (res == FR_OK) {
+        INIT_BUF(*dj);
+        res = follow_path(dj, path);            /* Follow the path to the directory */
+        FREE_BUF();
+        if (res == FR_OK) {                        /* Follow completed */
+            dir = dj->dir;
+            if (dir) {                            /* It is not the current dir */
+                if (dir[DIR_Attr] & AM_DIR) {    /* The object is a directory */
+                    dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
+                } else {                        /* The object is not a directory */
+                    res = FR_NO_PATH;
+                }
+            }
+            if (res == FR_OK) {
+                dj->id = dj->fs->id;
+                res = dir_sdi(dj, 0);            /* Rewind dir */
+            }
+        }
+        if (res == FR_NO_FILE) res = FR_NO_PATH;
+    }
+
+    LEAVE_FF(dj->fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Read Directory Entry in Sequense                                      */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_readdir (
+    FAT_DIR *dj,            /* Pointer to the open directory object */
+    FILINFO *fno        /* Pointer to file information to return */
+)
+{
+    FRESULT res;
+    DEF_NAMEBUF;
+
+
+    res = validate(dj->fs, dj->id);            /* Check validity of the object */
+    if (res == FR_OK) {
+        if (!fno) {
+            res = dir_sdi(dj, 0);
+        } else {
+            INIT_BUF(*dj);
+            res = dir_read(dj);
+            if (res == FR_NO_FILE) {
+                dj->sect = 0;
+                res = FR_OK;
+            }
+            if (res == FR_OK) {                /* A valid entry is found */
+                get_fileinfo(dj, fno);        /* Get the object information */
+                res = dir_next(dj, 0);        /* Increment index for next */
+                if (res == FR_NO_FILE) {
+                    dj->sect = 0;
+                    res = FR_OK;
+                }
+            }
+            FREE_BUF();
+        }
+    }
+
+    LEAVE_FF(dj->fs, res);
+}
+
+
+
+#if _FS_MINIMIZE == 0
+/*-----------------------------------------------------------------------*/
+/* Get File Status                                                       */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_stat (
+    const TCHAR *path,    /* Pointer to the file path */
+    FILINFO *fno        /* Pointer to file information to return */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 0);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);    /* Follow the file path */
+        if (res == FR_OK) {                /* Follow completed */
+            if (dj.dir)        /* Found an object */
+                get_fileinfo(&dj, fno);
+            else            /* It is root dir */
+                res = FR_INVALID_NAME;
+        }
+        FREE_BUF();
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+#if !_FS_READONLY
+/*-----------------------------------------------------------------------*/
+/* Get Number of Free Clusters                                           */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_getfree (
+    const TCHAR *path,    /* Pointer to the logical drive number (root dir) */
+    DWORD *nclst,        /* Pointer to the variable to return number of free clusters */
+    FATFS **fatfs        /* Pointer to pointer to corresponding file system object to return */
+)
+{
+    FRESULT res;
+    DWORD n, clst, sect, stat;
+    UINT i;
+    BYTE fat, *p;
+
+
+    /* Get drive number */
+    res = chk_mounted(&path, fatfs, 0);
+    if (res == FR_OK) {
+        /* If free_clust is valid, return it without full cluster scan */
+        if ((*fatfs)->free_clust <= (*fatfs)->n_fatent - 2) {
+            *nclst = (*fatfs)->free_clust;
+        } else {
+            /* Get number of free clusters */
+            fat = (*fatfs)->fs_type;
+            n = 0;
+            if (fat == FS_FAT12) {
+                clst = 2;
+                do {
+                    stat = get_fat(*fatfs, clst);
+                    if (stat == 0xFFFFFFFF) { res = FR_DISK_ERR; break; }
+                    if (stat == 1) { res = FR_INT_ERR; break; }
+                    if (stat == 0) n++;
+                } while (++clst < (*fatfs)->n_fatent);
+            } else {
+                clst = (*fatfs)->n_fatent;
+                sect = (*fatfs)->fatbase;
+                i = 0; p = 0;
+                do {
+                    if (!i) {
+                        res = move_window(*fatfs, sect++);
+                        if (res != FR_OK) break;
+                        p = (*fatfs)->win;
+                        i = SS(*fatfs);
+                    }
+                    if (fat == FS_FAT16) {
+                        if (LD_WORD(p) == 0) n++;
+                        p += 2; i -= 2;
+                    } else {
+                        if ((LD_DWORD(p) & 0x0FFFFFFF) == 0) n++;
+                        p += 4; i -= 4;
+                    }
+                } while (--clst);
+            }
+            (*fatfs)->free_clust = n;
+            if (fat == FS_FAT32) (*fatfs)->fsi_flag = 1;
+            *nclst = n;
+        }
+    }
+    LEAVE_FF(*fatfs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Truncate File                                                         */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_truncate (
+    FAT_FIL *fp        /* Pointer to the file object */
+)
+{
+    FRESULT res;
+    DWORD ncl;
+
+
+    res = validate(fp->fs, fp->id);        /* Check validity of the object */
+    if (res == FR_OK) {
+        if (fp->flag & FA__ERROR) {            /* Check abort flag */
+            res = FR_INT_ERR;
+        } else {
+            if (!(fp->flag & FA_WRITE))        /* Check access mode */
+                res = FR_DENIED;
+        }
+    }
+    if (res == FR_OK) {
+        if (fp->fsize > fp->fptr) {
+            fp->fsize = fp->fptr;    /* Set file size to current R/W point */
+            fp->flag |= FA__WRITTEN;
+            if (fp->fptr == 0) {    /* When set file size to zero, remove entire cluster chain */
+                res = remove_chain(fp->fs, fp->org_clust);
+                fp->org_clust = 0;
+            } else {                /* When truncate a part of the file, remove remaining clusters */
+                ncl = get_fat(fp->fs, fp->curr_clust);
+                res = FR_OK;
+                if (ncl == 0xFFFFFFFF) res = FR_DISK_ERR;
+                if (ncl == 1) res = FR_INT_ERR;
+                if (res == FR_OK && ncl < fp->fs->n_fatent) {
+                    res = put_fat(fp->fs, fp->curr_clust, 0x0FFFFFFF);
+                    if (res == FR_OK) res = remove_chain(fp->fs, ncl);
+                }
+            }
+        }
+        if (res != FR_OK) fp->flag |= FA__ERROR;
+    }
+
+    LEAVE_FF(fp->fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Delete a File or Directory                                            */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_unlink (
+    const TCHAR *path        /* Pointer to the file or directory path */
+)
+{
+    FRESULT res;
+    FAT_DIR dj, sdj;
+    BYTE *dir;
+    DWORD dclst;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 1);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);        /* Follow the file path */
+        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
+            res = FR_INVALID_NAME;            /* Cannot remove dot entry */
+#if _FS_SHARE
+        if (res == FR_OK) res = chk_lock(&dj, 2);    /* Cannot remove open file */
+#endif
+        if (res == FR_OK) {                    /* The object is accessible */
+            dir = dj.dir;
+            if (!dir) {
+                res = FR_INVALID_NAME;        /* Cannot remove the start directory */
+            } else {
+                if (dir[DIR_Attr] & AM_RDO)
+                    res = FR_DENIED;        /* Cannot remove R/O object */
+            }
+            dclst = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
+            if (res == FR_OK && (dir[DIR_Attr] & AM_DIR)) {    /* Is it a sub-dir? */
+                if (dclst < 2) {
+                    res = FR_INT_ERR;
+                } else {
+                    mem_cpy(&sdj, &dj, sizeof(FAT_DIR));    /* Check if the sub-dir is empty or not */
+                    sdj.sclust = dclst;
+                    res = dir_sdi(&sdj, 2);        /* Exclude dot entries */
+                    if (res == FR_OK) {
+                        res = dir_read(&sdj);
+                        if (res == FR_OK            /* Not empty dir */
+#if _FS_RPATH
+                        || dclst == sdj.fs->cdir    /* Current dir */
+#endif
+                        ) res = FR_DENIED;
+                        if (res == FR_NO_FILE) res = FR_OK;    /* Empty */
+                    }
+                }
+            }
+            if (res == FR_OK) {
+                res = dir_remove(&dj);        /* Remove the directory entry */
+                if (res == FR_OK) {
+                    if (dclst)                /* Remove the cluster chain if exist */
+                        res = remove_chain(dj.fs, dclst);
+                    if (res == FR_OK) res = sync(dj.fs);
+                }
+            }
+        }
+        FREE_BUF();
+    }
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Create a Directory                                                    */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_mkdir (
+    const TCHAR *path        /* Pointer to the directory path */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    BYTE *dir, n;
+    DWORD dsc, dcl, pcl, tim = get_fattime();
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 1);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);            /* Follow the file path */
+        if (res == FR_OK) res = FR_EXIST;        /* Any object with same name is already existing */
+        if (_FS_RPATH && res == FR_NO_FILE && (dj.fn[NS] & NS_DOT))
+            res = FR_INVALID_NAME;
+        if (res == FR_NO_FILE) {                /* Can create a new directory */
+            dcl = create_chain(dj.fs, 0);        /* Allocate a cluster for the new directory table */
+            res = FR_OK;
+            if (dcl == 0) res = FR_DENIED;        /* No space to allocate a new cluster */
+            if (dcl == 1) res = FR_INT_ERR;
+            if (dcl == 0xFFFFFFFF) res = FR_DISK_ERR;
+            if (res == FR_OK)                    /* Flush FAT */
+                res = move_window(dj.fs, 0);
+            if (res == FR_OK) {                    /* Initialize the new directory table */
+                dsc = clust2sect(dj.fs, dcl);
+                dir = dj.fs->win;
+                mem_set(dir, 0, SS(dj.fs));
+                mem_set(dir+DIR_Name, ' ', 8+3);    /* Create "." entry */
+                dir[DIR_Name] = '.';
+                dir[DIR_Attr] = AM_DIR;
+                ST_DWORD(dir+DIR_WrtTime, tim);
+                ST_WORD(dir+DIR_FstClusLO, dcl);
+                ST_WORD(dir+DIR_FstClusHI, dcl >> 16);
+                mem_cpy(dir+32, dir, 32);             /* Create ".." entry */
+                dir[33] = '.'; pcl = dj.sclust;
+                if (dj.fs->fs_type == FS_FAT32 && pcl == dj.fs->dirbase)
+                    pcl = 0;
+                ST_WORD(dir+32+DIR_FstClusLO, pcl);
+                ST_WORD(dir+32+DIR_FstClusHI, pcl >> 16);
+                for (n = dj.fs->csize; n; n--) {    /* Write dot entries and clear following sectors */
+                    dj.fs->winsect = dsc++;
+                    dj.fs->wflag = 1;
+                    res = move_window(dj.fs, 0);
+                    if (res != FR_OK) break;
+                    mem_set(dir, 0, SS(dj.fs));
+                }
+            }
+            if (res == FR_OK) res = dir_register(&dj);    /* Register the object to the directoy */
+            if (res != FR_OK) {
+                remove_chain(dj.fs, dcl);                /* Could not register, remove cluster chain */
+            } else {
+                dir = dj.dir;
+                dir[DIR_Attr] = AM_DIR;                    /* Attribute */
+                ST_DWORD(dir+DIR_WrtTime, tim);            /* Created time */
+                ST_WORD(dir+DIR_FstClusLO, dcl);        /* Table start cluster */
+                ST_WORD(dir+DIR_FstClusHI, dcl >> 16);
+                dj.fs->wflag = 1;
+                res = sync(dj.fs);
+            }
+        }
+        FREE_BUF();
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Change Attribute                                                      */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_chmod (
+    const TCHAR *path,    /* Pointer to the file path */
+    BYTE value,            /* Attribute bits */
+    BYTE mask            /* Attribute mask to change */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    BYTE *dir;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 1);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);        /* Follow the file path */
+        FREE_BUF();
+        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
+            res = FR_INVALID_NAME;
+        if (res == FR_OK) {
+            dir = dj.dir;
+            if (!dir) {                        /* Is it a root directory? */
+                res = FR_INVALID_NAME;
+            } else {                        /* File or sub directory */
+                mask &= AM_RDO|AM_HID|AM_SYS|AM_ARC;    /* Valid attribute mask */
+                dir[DIR_Attr] = (value & mask) | (dir[DIR_Attr] & (BYTE)~mask);    /* Apply attribute change */
+                dj.fs->wflag = 1;
+                res = sync(dj.fs);
+            }
+        }
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Change Timestamp                                                      */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_utime (
+    const TCHAR *path,    /* Pointer to the file/directory name */
+    const FILINFO *fno    /* Pointer to the time stamp to be set */
+)
+{
+    FRESULT res;
+    FAT_DIR dj;
+    BYTE *dir;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path, &dj.fs, 1);
+    if (res == FR_OK) {
+        INIT_BUF(dj);
+        res = follow_path(&dj, path);    /* Follow the file path */
+        FREE_BUF();
+        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
+            res = FR_INVALID_NAME;
+        if (res == FR_OK) {
+            dir = dj.dir;
+            if (!dir) {                    /* Root directory */
+                res = FR_INVALID_NAME;
+            } else {                    /* File or sub-directory */
+                ST_WORD(dir+DIR_WrtTime, fno->ftime);
+                ST_WORD(dir+DIR_WrtDate, fno->fdate);
+                dj.fs->wflag = 1;
+                res = sync(dj.fs);
+            }
+        }
+    }
+
+    LEAVE_FF(dj.fs, res);
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Rename File/Directory                                                 */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_rename (
+    const TCHAR *path_old,    /* Pointer to the old name */
+    const TCHAR *path_new    /* Pointer to the new name */
+)
+{
+    FRESULT res;
+    FAT_DIR djo, djn;
+    BYTE buf[21], *dir;
+    DWORD dw;
+    DEF_NAMEBUF;
+
+
+    res = chk_mounted(&path_old, &djo.fs, 1);
+    if (res == FR_OK) {
+        djn.fs = djo.fs;
+        INIT_BUF(djo);
+        res = follow_path(&djo, path_old);        /* Check old object */
+        if (_FS_RPATH && res == FR_OK && (djo.fn[NS] & NS_DOT))
+            res = FR_INVALID_NAME;
+#if _FS_SHARE
+        if (res == FR_OK) res = chk_lock(&djo, 2);
+#endif
+        if (res == FR_OK) {                        /* Old object is found */
+            if (!djo.dir) {                        /* Is root dir? */
+                res = FR_NO_FILE;
+            } else {
+                mem_cpy(buf, djo.dir+DIR_Attr, 21);        /* Save the object information except for name */
+                mem_cpy(&djn, &djo, sizeof(FAT_DIR));        /* Check new object */
+                res = follow_path(&djn, path_new);
+                if (res == FR_OK) res = FR_EXIST;            /* The new object name is already existing */
+                if (res == FR_NO_FILE) {                     /* Is it a valid path and no name collision? */
+/* Start critical section that any interruption or error can cause cross-link */
+                    res = dir_register(&djn);            /* Register the new entry */
+                    if (res == FR_OK) {
+                        dir = djn.dir;                    /* Copy object information except for name */
+                        mem_cpy(dir+13, buf+2, 19);
+                        dir[DIR_Attr] = buf[0] | AM_ARC;
+                        djo.fs->wflag = 1;
+                        if (djo.sclust != djn.sclust && (dir[DIR_Attr] & AM_DIR)) {        /* Update .. entry in the directory if needed */
+                            dw = clust2sect(djn.fs, (DWORD)LD_WORD(dir+DIR_FstClusHI) | LD_WORD(dir+DIR_FstClusLO));
+                            if (!dw) {
+                                res = FR_INT_ERR;
+                            } else {
+                                res = move_window(djn.fs, dw);
+                                dir = djn.fs->win+32;    /* .. entry */
+                                if (res == FR_OK && dir[1] == '.') {
+                                    dw = (djn.fs->fs_type == FS_FAT32 && djn.sclust == djn.fs->dirbase) ? 0 : djn.sclust;
+                                    ST_WORD(dir+DIR_FstClusLO, dw);
+                                    ST_WORD(dir+DIR_FstClusHI, dw >> 16);
+                                    djn.fs->wflag = 1;
+                                }
+                            }
+                        }
+                        if (res == FR_OK) {
+                            res = dir_remove(&djo);        /* Remove old entry */
+                            if (res == FR_OK)
+                                res = sync(djo.fs);
+                        }
+                    }
+/* End critical section */
+                }
+            }
+        }
+        FREE_BUF();
+    }
+    LEAVE_FF(djo.fs, res);
+}
+
+#endif /* !_FS_READONLY */
+#endif /* _FS_MINIMIZE == 0 */
+#endif /* _FS_MINIMIZE <= 1 */
+#endif /* _FS_MINIMIZE <= 2 */
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Forward data to the stream directly (available on only tiny cfg)      */
+/*-----------------------------------------------------------------------*/
+#if _USE_FORWARD && _FS_TINY
+
+FRESULT f_forward (
+    FAT_FIL *fp,                         /* Pointer to the file object */
+    UINT (*func)(const BYTE*,UINT),    /* Pointer to the streaming function */
+    UINT btr,                        /* Number of bytes to forward */
+    UINT *bf                        /* Pointer to number of bytes forwarded */
+)
+{
+    FRESULT res;
+    DWORD remain, clst, sect;
+    UINT rcnt;
+    BYTE csect;
+
+
+    *bf = 0;    /* Initialize byte counter */
+
+    res = validate(fp->fs, fp->id);                    /* Check validity of the object */
+    if (res != FR_OK) LEAVE_FF(fp->fs, res);
+    if (fp->flag & FA__ERROR)                        /* Check error flag */
+        LEAVE_FF(fp->fs, FR_INT_ERR);
+    if (!(fp->flag & FA_READ))                        /* Check access mode */
+        LEAVE_FF(fp->fs, FR_DENIED);
+
+    remain = fp->fsize - fp->fptr;
+    if (btr > remain) btr = (UINT)remain;            /* Truncate btr by remaining bytes */
+
+    for ( ;  btr && (*func)(0, 0);                    /* Repeat until all data transferred or stream becomes busy */
+        fp->fptr += rcnt, *bf += rcnt, btr -= rcnt) {
+        csect = (BYTE)(fp->fptr / SS(fp->fs) & (fp->fs->csize - 1));    /* Sector offset in the cluster */
+        if ((fp->fptr % SS(fp->fs)) == 0) {            /* On the sector boundary? */
+            if (!csect) {                            /* On the cluster boundary? */
+                clst = (fp->fptr == 0) ?            /* On the top of the file? */
+                    fp->org_clust : get_fat(fp->fs, fp->curr_clust);
+                if (clst <= 1) ABORT(fp->fs, FR_INT_ERR);
+                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
+                fp->curr_clust = clst;                /* Update current cluster */
+            }
+        }
+        sect = clust2sect(fp->fs, fp->curr_clust);    /* Get current data sector */
+        if (!sect) ABORT(fp->fs, FR_INT_ERR);
+        sect += csect;
+        if (move_window(fp->fs, sect))                /* Move sector window */
+            ABORT(fp->fs, FR_DISK_ERR);
+        fp->dsect = sect;
+        rcnt = SS(fp->fs) - (WORD)(fp->fptr % SS(fp->fs));    /* Forward data from sector window */
+        if (rcnt > btr) rcnt = btr;
+        rcnt = (*func)(&fp->fs->win[(WORD)fp->fptr % SS(fp->fs)], rcnt);
+        if (!rcnt) ABORT(fp->fs, FR_INT_ERR);
+    }
+
+    LEAVE_FF(fp->fs, FR_OK);
+}
+#endif /* _USE_FORWARD */
+
+
+
+#if _USE_MKFS && !_FS_READONLY
+/*-----------------------------------------------------------------------*/
+/* Create File System on the Drive                                       */
+/*-----------------------------------------------------------------------*/
+#define N_ROOTDIR    512            /* Multiple of 32 */
+#define N_FATS        1            /* 1 or 2 */
+
+
+FRESULT f_mkfs (
+    BYTE drv,        /* Logical drive number */
+    BYTE sfd,        /* Partitioning rule 0:FDISK, 1:SFD */
+    UINT au            /* Allocation unit size [bytes] */
+)
+{
+    static const WORD vst[] = { 1024,   512,  256,  128,   64,    32,   16,    8,    4,    2,   0};
+    static const WORD cst[] = {32768, 16384, 8192, 4096, 2048, 16384, 8192, 4096, 2048, 1024, 512};
+    BYTE fmt, md, *tbl;
+    DWORD n_clst, vs, n;
+    UINT as, i;
+    DWORD b_vol, b_fat, b_dir, b_data;        /* Area offset (LBA) */
+    DWORD n_vol, n_rsv, n_fat, n_dir;        /* Area size */
+    FATFS *fs;
+    DSTATUS stat;
+
+
+    /* Check mounted drive and clear work area */
+    if (drv >= _DRIVES) return FR_INVALID_DRIVE;
+    fs = FatFs[drv];
+    if (!fs) return FR_NOT_ENABLED;
+    fs->fs_type = 0;
+    drv = LD2PD(drv);
+
+    /* Get disk statics */
+    stat = disk_initialize(drv);
+    if (stat & STA_NOINIT) return FR_NOT_READY;
+    if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;
+#if _MAX_SS != 512                    /* Get disk sector size */
+    if (disk_ioctl(drv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK || SS(fs) > _MAX_SS)
+        return FR_DISK_ERR;
+#endif
+    if (disk_ioctl(drv, GET_SECTOR_COUNT, &n_vol) != RES_OK || n_vol < 128)
+        return FR_DISK_ERR;
+    b_vol = (sfd == 1) ? 0 : 63;    /* Volume start sector */
+    n_vol -= b_vol;
+    if (au & (au - 1)) au = 0;        /* Check validity of the allocation unit size */
+    if (!au) {                        /* AU auto selection */
+        vs = n_vol / (2000 / (SS(fs) / 512));
+        for (i = 0; vs < vst[i]; i++) ;
+        au = cst[i];
+    }
+    if (_MAX_SS != 512 && au < SS(fs)) au = SS(fs);
+    au /= SS(fs);        /* Number of sectors per cluster */
+    if (au == 0) au = 1;
+    if (au > 128) au = 128;
+
+    /* Pre-compute number of clusters and FAT syb-type */
+    n_clst = n_vol / au;
+    fmt = FS_FAT12;
+    if (n_clst >= MIN_FAT16) fmt = FS_FAT16;
+    if (n_clst >= MIN_FAT32) fmt = FS_FAT32;
+
+    /* Determine offset and size of FAT structure */
+    if (fmt == FS_FAT32) {
+        n_fat = ((n_clst * 4) + 8 + SS(fs) - 1) / SS(fs);
+        n_rsv = 32;
+        n_dir = 0;
+    } else {
+        n_fat = (fmt == FS_FAT12) ? (n_clst * 3 + 1) / 2 + 3 : (n_clst * 2) + 4;
+        n_fat = (n_fat + SS(fs) - 1) / SS(fs);
+        n_rsv = 1;
+        n_dir = N_ROOTDIR * 32UL / SS(fs);
+    }
+    b_fat = b_vol + n_rsv;                /* FAT area start sector */
+    b_dir = b_fat + n_fat * N_FATS;        /* Directory area start sector */
+    b_data = b_dir + n_dir;                /* Data area start sector */
+    if (n_vol < b_data + au) return FR_MKFS_ABORTED;    /* Too small volume */
+
+    /* Align data start sector to erase block boundary (for flash memory media) */
+    if (disk_ioctl(drv, GET_BLOCK_SIZE, &n) != RES_OK) return FR_DISK_ERR;
+    if (!n || n > 32768) return FR_MKFS_ABORTED;
+    n = (b_data + n - 1) & ~(n - 1);    /* Next nearest boundary from current data start */
+    n = (n - b_data) / N_FATS;
+    if (fmt == FS_FAT32) {        /* FAT32: Move FAT start */
+        n_rsv += n;
+        b_fat += n;
+    } else {                    /* FAT12/16: Expand FAT size */
+        n_fat += n;
+    }
+    /* b_dir and b_data are no longer used below */
+
+    /* Determine number of cluster and final check of validity of the FAT sub-type */
+    n_clst = (n_vol - n_rsv - n_fat * N_FATS - n_dir) / au;
+    if (   (fmt == FS_FAT16 && n_clst < MIN_FAT16)
+        || (fmt == FS_FAT32 && n_clst < MIN_FAT32))
+        return FR_MKFS_ABORTED;
+
+    /* Create partition table if required */
+    if (sfd == 1) {
+        md = 0xF0;
+    } else {
+        DWORD n_disk = b_vol + n_vol;
+
+        mem_set(fs->win, 0, SS(fs));
+        tbl = fs->win+MBR_Table;
+        ST_DWORD(tbl, 0x00010180);        /* Partition start in CHS */
+        if (n_disk < 63UL * 255 * 1024) {    /* Partition end in CHS */
+            n_disk = n_disk / 63 / 255;
+            tbl[7] = (BYTE)n_disk;
+            tbl[6] = (BYTE)((n_disk >> 2) | 63);
+        } else {
+            ST_WORD(&tbl[6], 0xFFFF);
+        }
+        tbl[5] = 254;
+        if (fmt != FS_FAT32)            /* System ID */
+            tbl[4] = (n_vol < 0x10000) ? 0x04 : 0x06;
+        else
+            tbl[4] = 0x0c;
+        ST_DWORD(tbl+8, 63);            /* Partition start in LBA */
+        ST_DWORD(tbl+12, n_vol);        /* Partition size in LBA */
+        ST_WORD(tbl+64, 0xAA55);        /* Signature */
+        if (disk_write(drv, fs->win, 0, 1) != RES_OK)
+            return FR_DISK_ERR;
+        md = 0xF8;
+    }
+
+    /* Create VBR */
+    tbl = fs->win;                                /* Clear buffer */
+    mem_set(tbl, 0, SS(fs));
+    ST_DWORD(tbl+BS_jmpBoot, 0x90FEEB);            /* Boot code (jmp $, nop) */
+    as = SS(fs);                                /* Sector size */
+    ST_WORD(tbl+BPB_BytsPerSec, as);
+    tbl[BPB_SecPerClus] = (BYTE)au;                /* Sectors per cluster */
+    ST_WORD(tbl+BPB_RsvdSecCnt, n_rsv);            /* Reserved sectors */
+    tbl[BPB_NumFATs] = N_FATS;                    /* Number of FATs */
+    as = (fmt == FS_FAT32) ? 0 : N_ROOTDIR;        /* Number of rootdir entries */
+    ST_WORD(tbl+BPB_RootEntCnt, as);
+    if (n_vol < 0x10000) {                        /* Number of total sectors */
+        ST_WORD(tbl+BPB_TotSec16, n_vol);
+    } else {
+        ST_DWORD(tbl+BPB_TotSec32, n_vol);
+    }
+    tbl[BPB_Media] = md;                        /* Media descriptor */
+    ST_WORD(tbl+BPB_SecPerTrk, 63);                /* Number of sectors per track */
+    ST_WORD(tbl+BPB_NumHeads, 255);                /* Number of heads */
+    ST_DWORD(tbl+BPB_HiddSec, b_vol);            /* Hidden sectors */
+    n = get_fattime();                            /* Use current time as VSN */
+    if (fmt == FS_FAT32) {
+        ST_DWORD(tbl+BS_VolID32, n);            /* VSN */
+        ST_DWORD(tbl+BPB_FATSz32, n_fat);        /* Number of sectors per FAT */
+        ST_DWORD(tbl+BPB_RootClus, 2);            /* Root directory start cluster (2) */
+        ST_WORD(tbl+BPB_FSInfo, 1);                /* FSInfo record offset (VBR+1) */
+        ST_WORD(tbl+BPB_BkBootSec, 6);            /* Backup boot record offset (VBR+6) */
+        tbl[BS_DrvNum32] = 0x80;                /* Drive number */
+        tbl[BS_BootSig32] = 0x29;                /* Extended boot signature */
+        mem_cpy(tbl+BS_VolLab32, "NO NAME    FAT32   ", 19);    /* Volume label, FAT signature */
+    } else {
+        ST_DWORD(tbl+BS_VolID, n);                /* VSN */
+        ST_WORD(tbl+BPB_FATSz16, n_fat);        /* Number of sectors per FAT */
+        tbl[BS_DrvNum] = 0x80;                    /* Drive number */
+        tbl[BS_BootSig] = 0x29;                    /* Extended boot signature */
+        mem_cpy(tbl+BS_VolLab, "NO NAME    FAT     ", 19);    /* Volume label, FAT signature */
+    }
+    ST_WORD(tbl+BS_55AA, 0xAA55);                /* Signature (Offset is fixed here regardless of sector size) */
+    if (disk_write(drv, tbl, b_vol, 1) != RES_OK)    /* Original (VBR) */
+        return FR_DISK_ERR;
+    if (fmt == FS_FAT32)                        /* Backup (VBR+6) */
+        disk_write(drv, tbl, b_vol + 6, 1);
+
+    /* Initialize FAT area */
+    for (i = 0; i < N_FATS; i++) {
+        mem_set(tbl, 0, SS(fs));            /* 1st sector of the FAT  */
+        n = md;                                /* Media descriptor byte */
+        if (fmt != FS_FAT32) {
+            n |= (fmt == FS_FAT12) ? 0x00FFFF00 : 0xFFFFFF00;
+            ST_DWORD(tbl+0, n);                /* Reserve cluster #0-1 (FAT12/16) */
+        } else {
+            n |= 0x0FFFFF00;
+            ST_DWORD(tbl+0, n);                /* Reserve cluster #0-1 (FAT32) */
+            ST_DWORD(tbl+4, 0x0FFFFFFF);
+            ST_DWORD(tbl+8, 0x0FFFFFFF);    /* Reserve cluster #2 for root dir */
+        }
+        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
+            return FR_DISK_ERR;
+        mem_set(tbl, 0, SS(fs));        /* Fill following FAT entries with zero */
+        for (n = 1; n < n_fat; n++) {    /* This loop may take a time on FAT32 volume due to many single sector write */
+            if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
+                return FR_DISK_ERR;
+        }
+    }
+
+    /* Initialize root directory */
+    n = (fmt == FS_FAT32) ? as : n_dir;
+    while (n--) {
+        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
+            return FR_DISK_ERR;
+    }
+
+    /* Create FSInfo record if needed */
+    if (fmt == FS_FAT32) {
+        ST_WORD(tbl+BS_55AA, 0xAA55);
+        ST_DWORD(tbl+FSI_LeadSig, 0x41615252);
+        ST_DWORD(tbl+FSI_StrucSig, 0x61417272);
+        ST_DWORD(tbl+FSI_Free_Count, n_clst - 1);
+        ST_DWORD(tbl+FSI_Nxt_Free, 0xFFFFFFFF);
+        disk_write(drv, tbl, b_vol + 1, 1);    /* Original (VBR+1) */
+        disk_write(drv, tbl, b_vol + 7, 1);    /* Backup  (VBR+7) */
+    }
+
+    return (disk_ioctl(drv, CTRL_SYNC, (void*)0) == RES_OK) ? FR_OK : FR_DISK_ERR;
+}
+
+#endif /* _USE_MKFS && !_FS_READONLY */
+
+
+
+
+#if _USE_STRFUNC
+/*-----------------------------------------------------------------------*/
+/* Get a string from the file                                            */
+/*-----------------------------------------------------------------------*/
+TCHAR* f_gets (
+    TCHAR* buff,    /* Pointer to the string buffer to read */
+    int len,        /* Size of string buffer (characters) */
+    FAT_FIL* fil        /* Pointer to the file object */
+)
+{
+    int n = 0;
+    TCHAR c, *p = buff;
+    BYTE s[2];
+    UINT rc;
+
+
+    while (n < len - 1) {            /* Read bytes until buffer gets filled */
+        f_read(fil, s, 1, &rc);
+        if (rc != 1) break;            /* Break on EOF or error */
+        c = s[0];
+#if _LFN_UNICODE                    /* Read a character in UTF-8 encoding */
+        if (c >= 0x80) {
+            if (c < 0xC0) continue;    /* Skip stray trailer */
+            if (c < 0xE0) {            /* Two-byte sequense */
+                f_read(fil, s, 1, &rc);
+                if (rc != 1) break;
+                c = ((c & 0x1F) << 6) | (s[0] & 0x3F);
+                if (c < 0x80) c = '?';
+            } else {
+                if (c < 0xF0) {        /* Three-byte sequense */
+                    f_read(fil, s, 2, &rc);
+                    if (rc != 2) break;
+                    c = (c << 12) | ((s[0] & 0x3F) << 6) | (s[1] & 0x3F);
+                    if (c < 0x800) c = '?';
+                } else {            /* Reject four-byte sequense */
+                    c = '?';
+                }
+            }
+        }
+#endif
+#if _USE_STRFUNC >= 2
+        if (c == '\r') continue;    /* Strip '\r' */
+#endif
+        *p++ = c;
+        n++;
+        if (c == '\n') break;        /* Break on EOL */
+    }
+    *p = 0;
+    return n ? buff : 0;            /* When no data read (eof or error), return with error. */
+}
+
+
+
+#if !_FS_READONLY
+#include <stdarg.h>
+/*-----------------------------------------------------------------------*/
+/* Put a character to the file                                           */
+/*-----------------------------------------------------------------------*/
+int f_putc (
+    TCHAR c,    /* A character to be output */
+    FAT_FIL* fil    /* Pointer to the file object */
+)
+{
+    UINT bw, btw;
+    BYTE s[3];
+
+
+#if _USE_STRFUNC >= 2
+    if (c == '\n') f_putc ('\r', fil);    /* LF -> CRLF conversion */
+#endif
+
+#if _LFN_UNICODE    /* Write the character in UTF-8 encoding */
+    if (c < 0x80) {            /* 7-bit */
+        s[0] = (BYTE)c;
+        btw = 1;
+    } else {
+        if (c < 0x800) {    /* 11-bit */
+            s[0] = (BYTE)(0xC0 | (c >> 6));
+            s[1] = (BYTE)(0x80 | (c & 0x3F));
+            btw = 2;
+        } else {            /* 16-bit */
+            s[0] = (BYTE)(0xE0 | (c >> 12));
+            s[1] = (BYTE)(0x80 | ((c >> 6) & 0x3F));
+            s[2] = (BYTE)(0x80 | (c & 0x3F));
+            btw = 3;
+        }
+    }
+#else                /* Write the character without conversion */
+    s[0] = (BYTE)c;
+    btw = 1;
+#endif
+    f_write(fil, s, btw, &bw);        /* Write the char to the file */
+    return (bw == btw) ? 1 : EOF;    /* Return the result */
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Put a string to the file                                              */
+/*-----------------------------------------------------------------------*/
+int f_puts (
+    const TCHAR* str,    /* Pointer to the string to be output */
+    FAT_FIL* fil            /* Pointer to the file object */
+)
+{
+    int n;
+
+
+    for (n = 0; *str; str++, n++) {
+        if (f_putc(*str, fil) == EOF) return EOF;
+    }
+    return n;
+}
+
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Put a formatted string to the file                                    */
+/*-----------------------------------------------------------------------*/
+int f_printf (
+    FAT_FIL* fil,            /* Pointer to the file object */
+    const TCHAR* str,    /* Pointer to the format string */
+    ...                    /* Optional arguments... */
+)
+{
+    va_list arp;
+    BYTE f, r;
+    UINT i, w;
+    ULONG val;
+    TCHAR c, d, s[16];
+    int res, cc;
+
+
+    va_start(arp, str);
+
+    for (cc = res = 0; cc != EOF; res += cc) {
+        c = *str++;
+        if (c == 0) break;            /* End of string */
+        if (c != '%') {                /* Non escape character */
+            cc = f_putc(c, fil);
+            if (cc != EOF) cc = 1;
+            continue;
+        }
+        w = f = 0;
+        c = *str++;
+        if (c == '0') {                /* Flag: '0' padding */
+            f = 1; c = *str++;
+        }
+        while (IsDigit(c)) {        /* Precision */
+            w = w * 10 + c - '0';
+            c = *str++;
+        }
+        if (c == 'l' || c == 'L') {    /* Prefix: Size is long int */
+            f |= 2; c = *str++;
+        }
+        if (!c) break;
+        d = c;
+        if (IsLower(d)) d -= 0x20;
+        switch (d) {                /* Type is... */
+        case 'S' :                    /* String */
+            cc = f_puts(va_arg(arp, TCHAR*), fil); continue;
+        case 'C' :                    /* Character */
+            cc = f_putc((TCHAR)va_arg(arp, int), fil); continue;
+        case 'B' :                    /* Binary */
+            r = 2; break;
+        case 'O' :                    /* Octal */
+            r = 8; break;
+        case 'D' :                    /* Signed decimal */
+        case 'U' :                    /* Unsigned decimal */
+            r = 10; break;
+        case 'X' :                    /* Hexdecimal */
+            r = 16; break;
+        default:                    /* Unknown */
+            cc = f_putc(c, fil); continue;
+        }
+
+        /* Get an argument */
+        val = (f & 2) ? va_arg(arp, long) : ((d == 'D') ? (long)va_arg(arp, int) : va_arg(arp, unsigned int));
+        if (d == 'D' && (val & 0x80000000)) {
+            val = 0 - val;
+            f |= 4;
+        }
+        /* Put it in numeral string */
+        i = 0;
+        do {
+            d = (TCHAR)(val % r); val /= r;
+            if (d > 9) {
+                d += 7;
+                if (c == 'x') d += 0x20;
+            }
+            s[i++] = d + '0';
+        } while (val && i < sizeof(s) / sizeof(s[0]));
+        if (f & 4) s[i++] = '-';
+        cc = 0;
+        while (i < w-- && cc != EOF) {
+            cc = f_putc((TCHAR)((f & 1) ? '0' : ' '), fil);
+            res++;
+        }
+        do {
+            cc = f_putc(s[--i], fil); 
+            res++;
+        } while (i && cc != EOF);
+        if (cc != EOF) cc = 0;
+    }
+
+    va_end(arp);
+    return (cc == EOF) ? cc : res;
+}
+
+#endif /* !_FS_READONLY */
+#endif /* _USE_STRFUNC */
\ No newline at end of file