/*--------------------------------------------------------------------------/
/  FatFs - Tiny FAT file system module  R0.04b                (C)ChaN, 2007
/---------------------------------------------------------------------------/
/ The FatFs module is an experimenal project to implement FAT file system to
/ cheap microcontrollers. This is a free software and is opened for education,
/ research and development under license policy of following trems.
/
/  Copyright (C) 2007, ChaN, all right reserved.
/
/ * The FatFs module is a free software and there is no warranty.
/ * You can use, modify and/or redistribute it for personal, non-profit or
/   profit use without any restriction under your responsibility.
/ * Redistributions of source code must retain the above copyright notice.
/
/---------------------------------------------------------------------------/
/  Feb 26, 2006  R0.00  Prototype.
/  Apr 29, 2006  R0.01  First stable version.
/  Jun 01, 2006  R0.02  Added FAT12 support.
/                       Removed unbuffered mode.
/                       Fixed a problem on small (<32M) patition.
/  Jun 10, 2006  R0.02a Added a configuration option (_FS_MINIMUM).
/  Sep 22, 2006  R0.03  Added f_rename().
/                       Changed option _FS_MINIMUM to _FS_MINIMIZE.
/  Dec 09, 2006  R0.03a Improved cluster scan algolithm to write files fast.
/  Feb 04, 2007  R0.04  Added FAT32 supprt.
/                       Changed some interfaces incidental to FatFs.
/                       Changed f_mountdrv() to f_mount().
/  Apr 01, 2007  R0.04a Added a capability of extending file size to f_lseek().
/                       Added minimization level 3.
/                       Fixed a problem in FAT32 support.
/  xxx xx, 2007  R0.04b Added a configuration option _USE_NTFLAG.
/                       Added FSInfo support.
/                       Fixed some problems corresponds to FAT32 support.
/                       Fixed DBCS name can result FR_INVALID_NAME.
/                       Fixed short seek (<= csize) collapses the file object.
/---------------------------------------------------------------------------*/

#include <string.h>
#include "tff.h"                /* Tiny-FatFs declarations */
#include "diskio.h"             /* Include file for user provided disk functions */


static
FATFS *FatFs;                   /* Pointer to the file system objects (logical drive) */
static
WORD fsid;                              /* File system mount ID */


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

  Module Private Functions

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


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

static
BOOL move_window (              /* TRUE: successful, FALSE: failed */
        DWORD sector            /* Sector number to make apperance in the FatFs->win */
)                                               /* Move to zero only writes back dirty window */
{
        DWORD wsect;
        FATFS *fs = FatFs;


        wsect = fs->winsect;
        if (wsect != sector) {  /* Changed current window */
#if !_FS_READONLY
                BYTE n;
                if (fs->winflag) {      /* Write back dirty window if needed */
                        if (disk_write(0, fs->win, wsect, 1) != RES_OK)
                                return FALSE;
                        fs->winflag = 0;
                        if (wsect < (fs->fatbase + fs->sects_fat)) {    /* In FAT area */
                                for (n = fs->n_fats; n >= 2; n--) {     /* Refrect the change to all FAT copies */
                                        wsect += fs->sects_fat;
                                        disk_write(0, fs->win, wsect, 1);
                                }
                        }
                }
#endif
                if (sector) {
                        if (disk_read(0, fs->win, sector, 1) != RES_OK)
                                return FALSE;
                        fs->winsect = sector;
                }
        }
        return TRUE;
}




/*-----------------------------------------------------------------------*/
/* Clean-up cached data                                                  */
/*-----------------------------------------------------------------------*/

#if !_FS_READONLY
static
FRESULT sync (void)             /* FR_OK: successful, FR_RW_ERROR: failed */
{
        FATFS *fs = FatFs;


        fs->winflag = 1;
        if (!move_window(0)) return FR_RW_ERROR;
#if _USE_FSINFO
        if (fs->fs_type == FS_FAT32 && fs->fsi_flag) {          /* Update FSInfo sector if needed */
                fs->winsect = 0;
                memset(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(0, fs->win, fs->fsi_sector, 1);
                fs->fsi_flag = 0;
        }
#endif
        if (disk_ioctl(0, CTRL_SYNC, NULL) != RES_OK) return FR_RW_ERROR;
        return FR_OK;
}
#endif




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

static
CLUST get_cluster (             /* 0,>=2: successful, 1: failed */
        CLUST clust                     /* Cluster# to get the link information */
)
{
        WORD wc, bc;
        DWORD fatsect;
        FATFS *fs = FatFs;


        if (clust >= 2 && clust < fs->max_clust) {              /* Valid cluster# */
                fatsect = fs->fatbase;
                switch (fs->fs_type) {
                case FS_FAT12 :
                        bc = (WORD)clust * 3 / 2;
                        if (!move_window(fatsect + bc / 512)) break;
                        wc = fs->win[bc % 512]; bc++;
                        if (!move_window(fatsect + bc / 512)) break;
                        wc |= (WORD)fs->win[bc % 512] << 8;
                        return (clust & 1) ? (wc >> 4) : (wc & 0xFFF);

                case FS_FAT16 :
                        if (!move_window(fatsect + clust / 256)) break;
                        return LD_WORD(&fs->win[((WORD)clust * 2) % 512]);
#if _FAT32
                case FS_FAT32 :
                        if (!move_window(fatsect + clust / 128)) break;
                        return LD_DWORD(&fs->win[((WORD)clust * 4) % 512]) & 0x0FFFFFFF;
#endif
                }
        }

        return 1;       /* There is no cluster information, or an error occured */
}




/*-----------------------------------------------------------------------*/
/* Change a cluster status                                               */
/*-----------------------------------------------------------------------*/

#if !_FS_READONLY
static
BOOL put_cluster (              /* TRUE: successful, FALSE: failed */
        CLUST clust,            /* Cluster# to change */
        CLUST val                       /* New value to mark the cluster */
)
{
        WORD bc;
        BYTE *p;
        DWORD fatsect;
        FATFS *fs = FatFs;


        fatsect = fs->fatbase;
        switch (fs->fs_type) {
        case FS_FAT12 :
                bc = (WORD)clust * 3 / 2;
                if (!move_window(fatsect + bc / 512)) return FALSE;
                p = &fs->win[bc % 512];
                *p = (clust & 1) ? ((*p & 0x0F) | ((BYTE)val << 4)) : (BYTE)val;
                bc++;
                fs->winflag = 1; 
                if (!move_window(fatsect + bc / 512)) return FALSE;
                p = &fs->win[bc % 512];
                *p = (clust & 1) ? (BYTE)(val >> 4) : ((*p & 0xF0) | ((BYTE)(val >> 8) & 0x0F));
                break;

        case FS_FAT16 :
                if (!move_window(fatsect + clust / 256)) return FALSE;
                ST_WORD(&fs->win[((WORD)clust * 2) % 512], (WORD)val);
                break;
#if _FAT32
        case FS_FAT32 :
                if (!move_window(fatsect + clust / 128)) return FALSE;
                ST_DWORD(&fs->win[((WORD)clust * 4) % 512], val);
                break;
#endif
        default :
                return FALSE;
        }
        fs->winflag = 1;
        return TRUE;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Remove a cluster chain                                                */
/*-----------------------------------------------------------------------*/

#if !_FS_READONLY
static
BOOL remove_chain (             /* TRUE: successful, FALSE: failed */
        CLUST clust                     /* Cluster# to remove chain from */
)
{
        CLUST nxt;
        FATFS *fs = FatFs;


        while (clust >= 2 && clust < fs->max_clust) {
                nxt = get_cluster(clust);
                if (nxt == 1) return FALSE;
                if (!put_cluster(clust, 0)) return FALSE;
                if (fs->free_clust != (CLUST)0xFFFFFFFF) {
                        fs->free_clust++;
#if _USE_FSINFO
                        fs->fsi_flag = 1;
#endif
                }
                clust = nxt;
        }
        return TRUE;
}
#endif




/*-----------------------------------------------------------------------*/
/* Stretch or create a cluster chain                                     */
/*-----------------------------------------------------------------------*/

#if !_FS_READONLY
static
CLUST create_chain (    /* 0: no free cluster, 1: error, >=2: new cluster number */
        CLUST clust                     /* Cluster# to stretch, 0 means create new */
)
{
        CLUST cstat, ncl, scl, mcl;
        FATFS *fs = FatFs;


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

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

        if (!put_cluster(ncl, (CLUST)0x0FFFFFFF)) return 1;     /* Mark the new cluster "in use" */
        if (clust && !put_cluster(clust, ncl)) return 1;        /* Link it to previous one if needed */

        fs->last_clust = ncl;                           /* Update fsinfo */
        if (fs->free_clust != (CLUST)0xFFFFFFFF) {
                fs->free_clust--;
#if _USE_FSINFO
                fs->fsi_flag = 1;
#endif
        }

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




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

static
DWORD clust2sect (      /* !=0: sector number, 0: failed - invalid cluster# */
        CLUST clust             /* Cluster# to be converted */
)
{
        FATFS *fs = FatFs;


        clust -= 2;
        if (clust >= (fs->max_clust - 2)) return 0;             /* Invalid cluster# */
        return (DWORD)clust * fs->sects_clust + fs->database;
}




/*-----------------------------------------------------------------------*/
/* Move directory pointer to next                                        */
/*-----------------------------------------------------------------------*/

static
BOOL next_dir_entry (   /* TRUE: successful, FALSE: could not move next */
        DIR *dirobj                     /* Pointer to directory object */
)
{
        CLUST clust;
        WORD idx;
        FATFS *fs = FatFs;


        idx = dirobj->index + 1;
        if ((idx & 15) == 0) {          /* Table sector changed? */
                dirobj->sect++;                 /* Next sector */
                if (!dirobj->clust) {           /* In static table */
                        if (idx >= fs->n_rootdir) return FALSE; /* Reached to end of table */
                } else {                                        /* In dynamic table */
                        if (((idx / 16) & (fs->sects_clust - 1)) == 0) {        /* Cluster changed? */
                                clust = get_cluster(dirobj->clust);                     /* Get next cluster */
                                if (clust < 2 || clust >= fs->max_clust)        /* Reached to end of table */
                                        return FALSE;
                                dirobj->clust = clust;                          /* Initialize for new cluster */
                                dirobj->sect = clust2sect(clust);
                        }
                }
        }
        dirobj->index = idx;    /* Lower 4 bit of dirobj->index indicates offset in dirobj->sect */
        return TRUE;
}




/*-----------------------------------------------------------------------*/
/* Get file status from directory entry                                  */
/*-----------------------------------------------------------------------*/

#if _FS_MINIMIZE <= 1
static
void get_fileinfo (             /* No return code */
        FILINFO *finfo,         /* Ptr to store the File Information */
        const BYTE *dir         /* Ptr to the directory entry */
)
{
        BYTE n, c, a;
        char *p;


        p = &finfo->fname[0];
        a = _USE_NTFLAG ? dir[DIR_NTres] : 0;   /* NT flag */
        for (n = 0; n < 8; n++) {       /* Convert file name (body) */
                c = dir[n];
                if (c == ' ') break;
                if (c == 0x05) c = 0xE5;
                if (a & 0x08 && c >= 'A' && c <= 'Z') c += 0x20;
                *p++ = c;
        }
        if (dir[8] != ' ') {            /* Convert file name (extension) */
                *p++ = '.';
                for (n = 8; n < 11; n++) {
                        c = dir[n];
                        if (c == ' ') break;
                        if (a & 0x10 && c >= 'A' && c <= 'Z') c += 0x20;
                        *p++ = c;
                }
        }
        *p = '\0';

        finfo->fattrib = dir[DIR_Attr];                 /* Attribute */
        finfo->fsize = LD_DWORD(&dir[DIR_FileSize]);    /* Size */
        finfo->fdate = LD_WORD(&dir[DIR_WrtDate]);      /* Date */
        finfo->ftime = LD_WORD(&dir[DIR_WrtTime]);      /* Time */
}
#endif /* _FS_MINIMIZE <= 1 */




/*-----------------------------------------------------------------------*/
/* Pick a paragraph and create the name in format of directory entry     */
/*-----------------------------------------------------------------------*/

static
char make_dirfile (                     /* 1: error - detected an invalid format, '\0'or'/': next character */
        const char **path,              /* Pointer to the file path pointer */
        char *dirname                   /* Pointer to directory name buffer {Name(8), Ext(3), NT flag(1)} */
)
{
        BYTE n, t, c, a, b;


        memset(dirname, ' ', 8+3);      /* Fill buffer with spaces */
        a = 0; b = 0x18;        /* NT flag */
        n = 0; t = 8;
        for (;;) {
                c = *(*path)++;
                if (c == '\0' || c == '/') {            /* Reached to end of str or directory separator */
                        if (n == 0) break;
                        dirname[11] = _USE_NTFLAG ? (a & b) : 0;
                        return c;
                }
                if (c <= ' ' || c == 0x7F) break;               /* Reject invisible chars */
                if (c == '.') {
                        if (!(a & 1) && n >= 1 && n <= 8) {     /* Enter extension part */
                                n = 8; t = 11; continue;
                        }
                        break;
                }
                if (_USE_SJIS && 
                        ((c >= 0x81 && c <= 0x9F) ||            /* Accept S-JIS code */
                    (c >= 0xE0 && c <= 0xFC))) {
                        if (n == 0 && c == 0xE5)                /* Change heading \xE5 to \x05 */
                                c = 0x05;
                        a ^= 1; goto md_l2;
                }
                if (c == '"') break;                            /* Reject " */
                if (c <= ')') goto md_l1;                       /* Accept ! # $ % & ' ( ) */
                if (c <= ',') break;                            /* Reject * + , */
                if (c <= '9') goto md_l1;                       /* Accept - 0-9 */
                if (c <= '?') break;                            /* Reject : ; < = > ? */
                if (!(a & 1)) { /* These checks are not applied to S-JIS 2nd byte */
                        if (c == '|') break;                    /* Reject | */
                        if (c >= '[' && c <= ']') break;/* Reject [ \ ] */
                        if (_USE_NTFLAG && c >= 'A' && c <= 'Z')
                                (t == 8) ? (b &= ~0x08) : (b &= ~0x10);
                        if (c >= 'a' && c <= 'z') {             /* Convert to upper case */
                                c -= 0x20;
                                if (_USE_NTFLAG) (t == 8) ? (a |= 0x08) : (a |= 0x10);
                        }
                }
        md_l1:
                a &= ~1;
        md_l2:
                if (n >= t) break;
                dirname[n++] = c;
        }
        return 1;
}



/*-----------------------------------------------------------------------*/
/* Trace a file path                                                     */
/*-----------------------------------------------------------------------*/

static
FRESULT trace_path (    /* FR_OK(0): successful, !=0: error code */
        DIR *dirobj,            /* Pointer to directory object to return last directory */
        char *fn,                       /* Pointer to last segment name to return */
        const char *path,       /* Full-path string to trace a file or directory */
        BYTE **dir                      /* Directory pointer in Win[] to retutn */
)
{
        CLUST clust;
        char ds;
        BYTE *dptr = NULL;
        FATFS *fs = FatFs;

        /* Initialize directory object */
        clust = fs->dirbase;
#if _FAT32
        if (fs->fs_type == FS_FAT32) {
                dirobj->clust = dirobj->sclust = clust;
                dirobj->sect = clust2sect(clust);
        } else
#endif
        {
                dirobj->clust = dirobj->sclust = 0;
                dirobj->sect = clust;
        }
        dirobj->index = 0;
        dirobj->fs = fs;

        if (*path == '\0') {                                                    /* Null path means the root directory */
                *dir = NULL; return FR_OK;
        }

        for (;;) {
                ds = make_dirfile(&path, fn);                                   /* Get a paragraph into fn[] */
                if (ds == 1) return FR_INVALID_NAME;
                for (;;) {
                        if (!move_window(dirobj->sect)) return FR_RW_ERROR;
                        dptr = &fs->win[(dirobj->index & 15) * 32];             /* Pointer to the directory entry */
                        if (dptr[DIR_Name] == 0)                                                /* Has it reached to end of dir? */
                                return !ds ? FR_NO_FILE : FR_NO_PATH;
                        if (dptr[DIR_Name] != 0xE5                                              /* Matched? */
                                && !(dptr[DIR_Attr] & AM_VOL)
                                && !memcmp(&dptr[DIR_Name], fn, 8+3) ) break;
                        if (!next_dir_entry(dirobj))                                    /* Next directory pointer */
                                return !ds ? FR_NO_FILE : FR_NO_PATH;
                }
                if (!ds) { *dir = dptr; return FR_OK; }                         /* Matched with end of path */
                if (!(dptr[DIR_Attr] & AM_DIR)) return FR_NO_PATH;      /* Cannot trace because it is a file */
                clust =                                                                                         /* Get cluster# of the directory */
#if _FAT32
                        ((DWORD)LD_WORD(&dptr[DIR_FstClusHI]) << 16) |
#endif
                        LD_WORD(&dptr[DIR_FstClusLO]);
                dirobj->clust = dirobj->sclust = clust;                         /* Restart scannig with the new directory */
                dirobj->sect = clust2sect(clust);
                dirobj->index = 2;
        }
}



/*-----------------------------------------------------------------------*/
/* Reserve a directory entry                                             */
/*-----------------------------------------------------------------------*/

#if !_FS_READONLY
static
FRESULT reserve_direntry (      /* FR_OK: successful, FR_DENIED: no free entry, FR_RW_ERROR: a disk error occured */
        DIR *dirobj,                    /* Target directory to create new entry */
        BYTE **dir                              /* Pointer to pointer to created entry to retutn */
)
{
        CLUST clust;
        DWORD sector;
        BYTE c, n, *dptr;
        FATFS *fs = FatFs;


        /* Re-initialize directory object */
        clust = dirobj->sclust;
        if (clust) {    /* Dyanmic directory table */
                dirobj->clust = clust;
                dirobj->sect = clust2sect(clust);
        } else {                /* Static directory table */
                dirobj->sect = fs->dirbase;
        }
        dirobj->index = 0;

        do {
                if (!move_window(dirobj->sect)) return FR_RW_ERROR;
                dptr = &fs->win[(dirobj->index & 15) * 32];     /* Pointer to the directory entry */
                c = dptr[DIR_Name];
                if (c == 0 || c == 0xE5) {                      /* Found an empty entry! */
                        *dir = dptr; return FR_OK;
                }
        } while (next_dir_entry(dirobj));                               /* Next directory pointer */
        /* Reached to end of the directory table */

        /* Abort when static table or could not stretch dynamic table */
        if (!clust || !(clust = create_chain(dirobj->clust))) return FR_DENIED;
        if (clust == 1 || !move_window(0)) return FR_RW_ERROR;

        fs->winsect = sector = clust2sect(clust);                       /* Cleanup the expanded table */
        memset(fs->win, 0, 512);
        for (n = fs->sects_clust; n; n--) {
                if (disk_write(0, fs->win, sector, 1) != RES_OK)
                        return FR_RW_ERROR;
                sector++;
        }
        fs->winflag = 1;
        *dir = fs->win;
        return FR_OK;
}
#endif /* !_FS_READONLY */




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

static
BYTE check_fs (         /* 0:The FAT boot record, 1:Valid boot record but not an FAT, 2:Not a boot record or error */
        DWORD sect              /* Sector# to check if it is a FAT boot record or not */
)
{
        FATFS *fs = FatFs;

        if (disk_read(0, fs->win, sect, 1) != RES_OK)   /* Load boot record */
                return 2;
        if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55)               /* Check record signature */
                return 2;

        if (!memcmp(&fs->win[BS_FilSysType], "FAT", 3)) /* Check FAT signature */
                return 0;
#if _FAT32
        if (!memcmp(&fs->win[BS_FilSysType32], "FAT32", 5) && !(fs->win[BPB_ExtFlags] & 0x80))
                return 0;
#endif
        return 1;
}




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

static
FRESULT auto_mount (            /* FR_OK(0): successful, !=0: any error occured */
        const char **path,              /* Pointer to pointer to the path name (drive number) */
        BYTE chk_wp                             /* !=0: Check media write protection for wrinting fuctions */
)
{
        BYTE fmt;
        DSTATUS stat;
        DWORD bootsect, fatsize, totalsect, maxclust;
        const char *p = *path;
        FATFS *fs = FatFs;



        while (*p == ' ') p++;  /* Strip leading spaces */
        if (*p == '/') p++;             /* Strip heading slash */
        *path = p;                              /* Return pointer to the path name */

        /* Is the file system object registered? */
        if (!fs) return FR_NOT_ENABLED;

        /* Chekck if the logical drive has been mounted or not */
        if (fs->fs_type) {
                stat = disk_status(0);
                if (!(stat & STA_NOINIT)) {                             /* If the physical drive is kept initialized */
#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 has not been mounted, following code attempts to mount the logical drive */

        memset(fs, 0, sizeof(FATFS));           /* Clean-up the file system object */
        stat = disk_initialize(0);                      /* Initialize low level disk I/O layer */
        if (stat & STA_NOINIT)                          /* Check if the drive is ready */
                return FR_NOT_READY;
#if !_FS_READONLY
        if (chk_wp && (stat & STA_PROTECT))     /* Check write protection if needed */
                return FR_WRITE_PROTECTED;
#endif

        /* Search FAT partition on the drive */
        fmt = check_fs(bootsect = 0);           /* Check sector 0 as an SFD format */
        if (fmt == 1) {                                         /* Not a FAT boot record, it may be patitioned */
                /* Check a partition listed in top of the partition table */
                if (fs->win[MBR_Table+4]) {                                     /* Is the 1st partition existing? */
                        bootsect = LD_DWORD(&fs->win[MBR_Table+8]);     /* Partition offset in LBA */
                        fmt = check_fs(bootsect);                               /* Check the partition */
                }
        }
        if (fmt || LD_WORD(&fs->win[BPB_BytsPerSec]) != 512)    /* No valid FAT patition is found */
                return FR_NO_FILESYSTEM;

        /* Initialize the file system object */
        fatsize = LD_WORD(&fs->win[BPB_FATSz16]);                       /* Number of sectors per FAT */
        if (!fatsize) fatsize = LD_DWORD(&fs->win[BPB_FATSz32]);
        fs->sects_fat = (CLUST)fatsize;
        fs->n_fats = fs->win[BPB_NumFATs];                                      /* Number of FAT copies */
        fatsize *= fs->n_fats;                                                          /* (Number of sectors in FAT area) */
        fs->fatbase = bootsect + LD_WORD(&fs->win[BPB_RsvdSecCnt]);     /* FAT start sector (lba) */
        fs->sects_clust = fs->win[BPB_SecPerClus];                      /* Number of sectors per cluster */
        fs->n_rootdir = LD_WORD(&fs->win[BPB_RootEntCnt]);      /* Nmuber of root directory entries */
        totalsect = LD_WORD(&fs->win[BPB_TotSec16]);            /* Number of sectors on the file system */
        if (!totalsect) totalsect = LD_DWORD(&fs->win[BPB_TotSec32]);
        fs->max_clust = maxclust = (totalsect                           /* Last cluster# + 1 */
                - LD_WORD(&fs->win[BPB_RsvdSecCnt]) - fatsize - fs->n_rootdir / 16
                ) / fs->sects_clust + 2;

        fmt = FS_FAT12;                                                                         /* Determine the FAT sub type */
        if (maxclust > 0xFF7) fmt = FS_FAT16;
        if (maxclust > 0xFFF7)
#if !_FAT32
                return FR_NO_FILESYSTEM;
#else
                fmt = FS_FAT32;
        if (fmt == FS_FAT32)
                fs->dirbase = LD_DWORD(&fs->win[BPB_RootClus]); /* Root directory start cluster */
        else
#endif
                fs->dirbase = fs->fatbase + fatsize;                    /* Root directory start sector (lba) */
        fs->database = fs->fatbase + fatsize + fs->n_rootdir / 16;      /* Data start sector (lba) */
        fs->fs_type = fmt;                                                                      /* FAT sub-type */

#if !_FS_READONLY
        fs->free_clust = (CLUST)0xFFFFFFFF;
#if _USE_FSINFO
        /* Load fsinfo sector if needed */
        if (fmt == FS_FAT32) {
                fs->fsi_sector = bootsect + LD_WORD(&fs->win[BPB_FSInfo]);
                if (disk_read(0, 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
#endif
        fs->id = ++fsid;                                                                        /* File system mount ID */
        return FR_OK;
}




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

static
FRESULT validate (              /* FR_OK(0): The id is valid, !=0: Not valid */
        const FATFS *fs,        /* Pointer to the file system object */
        WORD id                         /* id member of the target object to be checked */
)
{
        if (!fs || fs->id != id)
                return FR_INVALID_OBJECT;
        if (disk_status(0) & STA_NOINIT)
                return FR_NOT_READY;

        return FR_OK;
}




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

   Public Functions

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


/*-----------------------------------------------------------------------*/
/* Mount/Unmount a Locical Drive                                         */
/*-----------------------------------------------------------------------*/

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


        if (drv) return FR_INVALID_DRIVE;
        fsobj = FatFs;
        FatFs = fs;
        if (fsobj) memset(fsobj, 0, sizeof(FATFS));
        if (fs) memset(fs, 0, sizeof(FATFS));

        return FR_OK;
}




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

FRESULT f_open (
        FIL *fp,                        /* Pointer to the blank file object */
        const char *path,       /* Pointer to the file name */
        BYTE mode                       /* Access mode and file open mode flags */
)
{
        FRESULT res;
        BYTE *dir;
        DIR dirobj;
        char fn[8+3+1];
        FATFS *fs = FatFs;


        fp->fs = NULL;
#if !_FS_READONLY
        mode &= (FA_READ|FA_WRITE|FA_CREATE_ALWAYS|FA_OPEN_ALWAYS|FA_CREATE_NEW);
        res = auto_mount(&path, (BYTE)(mode & (FA_WRITE|FA_CREATE_ALWAYS|FA_OPEN_ALWAYS|FA_CREATE_NEW)));
#else
        mode &= FA_READ;
        res = auto_mount(&path, 0);
#endif
        if (res != FR_OK) return res;

        /* Trace the file path */
        res = trace_path(&dirobj, fn, path, &dir);      /* Trace the file path */

#if !_FS_READONLY
        /* Create or Open a File */
        if (mode & (FA_CREATE_ALWAYS|FA_OPEN_ALWAYS|FA_CREATE_NEW)) {
                CLUST rs;
                DWORD dw;
                if (res != FR_OK) {             /* No file, create new */
                        if (res != FR_NO_FILE) return res;
                        res = reserve_direntry(&dirobj, &dir);
                        if (res != FR_OK) return res;
                        memset(dir, 0, 32);             /* Initialize the new entry */
                        memcpy(&dir[DIR_Name], fn, 8+3);
                        dir[DIR_NTres] = fn[11];
                        mode |= FA_CREATE_ALWAYS;
                } else {                                /* Any object is already existing */
                        if (mode & FA_CREATE_NEW)                       /* Cannot create new */
                                return FR_EXIST;
                        if (dir == NULL || (dir[DIR_Attr] & (AM_RDO|AM_DIR)))   /* Cannot overwrite (R/O or DIR) */
                                return FR_DENIED;
                        if (mode & FA_CREATE_ALWAYS) {          /* Resize it to zero */
#if _FAT32
                                rs = ((DWORD)LD_WORD(&dir[DIR_FstClusHI]) << 16) | LD_WORD(&dir[DIR_FstClusLO]);
                                ST_WORD(&dir[DIR_FstClusHI], 0);
#else
                                rs = LD_WORD(&dir[DIR_FstClusLO]);
#endif
                                ST_WORD(&dir[DIR_FstClusLO], 0);        /* cluster = 0 */
                                ST_DWORD(&dir[DIR_FileSize], 0);        /* size = 0 */
                                fs->winflag = 1;
                                dw = fs->winsect;                               /* Remove the cluster chain */
                                if (!remove_chain(rs) || !move_window(dw))
                                        return FR_RW_ERROR;
                                fs->last_clust = rs - 1;                /* Reuse the cluster hole */
                        }
                }
                if (mode & FA_CREATE_ALWAYS) {
                        dir[DIR_Attr] = AM_ARC;         /* New attribute */
                        dw = get_fattime();
                        ST_DWORD(&dir[DIR_WrtTime], dw);        /* Updated time */
                        ST_DWORD(&dir[DIR_CrtTime], dw);        /* Created time */
                        fs->winflag = 1;
                }
        }
        /* Open a File */
        else {
#endif /* !_FS_READONLY */
                if (res != FR_OK) return res;           /* Trace failed */
                if (dir == NULL || (dir[DIR_Attr] & AM_DIR))    /* It is a directory */
                        return FR_NO_FILE;
#if !_FS_READONLY
                if ((mode & FA_WRITE) && (dir[DIR_Attr] & AM_RDO)) /* R/O violation */
                        return FR_DENIED;
        }

        fp->dir_sect = fs->winsect;                     /* Pointer to the directory entry */
        fp->dir_ptr = dir;
#endif
        fp->flag = mode;                                                        /* File access mode */
        fp->org_clust =                                                         /* File start cluster */
#if _FAT32
                ((DWORD)LD_WORD(&dir[DIR_FstClusHI]) << 16) |
#endif
                LD_WORD(&dir[DIR_FstClusLO]);
        fp->fsize = LD_DWORD(&dir[DIR_FileSize]);       /* File size */
        fp->fptr = 0;                                                           /* File ptr */
        fp->sect_clust = 1;                                                     /* Sector counter */
        fp->fs = fs; fp->id = fs->id;                           /* Owner file system object of the file */

        return FR_OK;
}




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

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


        *br = 0;
        res = validate(fs, fp->id);                                             /* Check validity of the object */
        if (res) return res;
        if (fp->flag & FA__ERROR) return FR_RW_ERROR;   /* Check error flag */
        if (!(fp->flag & FA_READ)) return FR_DENIED;    /* Check access mode */
        remain = fp->fsize - fp->fptr;
        if (btr > remain) btr = (WORD)remain;                   /* Truncate read count by number of bytes left */

        for ( ;  btr;                                                                   /* Repeat until all data transferred */
                rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt) {
                if ((fp->fptr % 512) == 0) {                            /* On the sector boundary */
                        if (--fp->sect_clust) {                                 /* Decrement left sector counter */
                                sect = fp->curr_sect + 1;                       /* Get current sector */
                        } else {                                                                /* On the cluster boundary, get next cluster */
                                clust = (fp->fptr == 0) ?
                                        fp->org_clust : get_cluster(fp->curr_clust);
                                if (clust < 2 || clust >= fs->max_clust)
                                        goto fr_error;
                                fp->curr_clust = clust;                         /* Current cluster */
                                sect = clust2sect(clust);                       /* Get current sector */
                                fp->sect_clust = fs->sects_clust;       /* Re-initialize the left sector counter */
                        }
                        fp->curr_sect = sect;                                   /* Update current sector */
                        cc = btr / 512;                                                 /* When left bytes >= 512, */
                        if (cc) {                                                               /* Read maximum contiguous sectors directly */
                                if (cc > fp->sect_clust) cc = fp->sect_clust;
                                if (disk_read(0, rbuff, sect, cc) != RES_OK)
                                        goto fr_error;
                                fp->sect_clust -= cc - 1;
                                fp->curr_sect += cc - 1;
                                rcnt = cc * 512; continue;
                        }
                }
                if (!move_window(fp->curr_sect)) goto fr_error; /* Move sector window */
                rcnt = 512 - (WORD)(fp->fptr % 512);                    /* Copy fractional bytes from sector window */
                if (rcnt > btr) rcnt = btr;
                memcpy(rbuff, &fs->win[(WORD)fp->fptr % 512], rcnt);
        }

        return FR_OK;

fr_error:       /* Abort this function due to an unrecoverable error */
        fp->flag |= FA__ERROR;
        return FR_RW_ERROR;
}




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

FRESULT f_write (
        FIL *fp,                        /* Pointer to the file object */
        const void *buff,       /* Pointer to the data to be written */
        WORD btw,                       /* Number of bytes to write */
        WORD *bw                        /* Pointer to number of bytes written */
)
{
        DWORD sect;
        WORD wcnt;
        CLUST clust;
        BYTE cc;
        FRESULT res;
        const BYTE *wbuff = buff;
        FATFS *fs = fp->fs;


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

        for ( ;  btw;                                                                   /* Repeat until all data transferred */
                wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt) {
                if ((fp->fptr % 512) == 0) {                            /* On the sector boundary */
                        if (--(fp->sect_clust)) {                               /* Decrement left sector counter */
                                sect = fp->curr_sect + 1;                       /* Get current sector */
                        } else {                                                                /* On the cluster boundary, get next cluster */
                                if (fp->fptr == 0) {                            /* Is top of the file */
                                        clust = fp->org_clust;
                                        if (clust == 0)                                 /* No cluster is created yet */
                                                fp->org_clust = clust = create_chain(0);        /* Create a new cluster chain */
                                } else {                                                        /* Middle or end of file */
                                        clust = create_chain(fp->curr_clust);                   /* Trace or streach cluster chain */
                                }
                                if (clust == 0) break;                          /* Disk full */
                                if (clust == 1 || clust >= fs->max_clust) goto fw_error;
                                fp->curr_clust = clust;                         /* Current cluster */
                                sect = clust2sect(clust);                       /* Get current sector */
                                fp->sect_clust = fs->sects_clust;       /* Re-initialize the left sector counter */
                        }
                        fp->curr_sect = sect;                                   /* Update current sector */
                        cc = btw / 512;                                                 /* When left bytes >= 512, */
                        if (cc) {                                                               /* Write maximum contiguous sectors directly */
                                if (cc > fp->sect_clust) cc = fp->sect_clust;
                                if (disk_write(0, wbuff, sect, cc) != RES_OK)
                                        goto fw_error;
                                fp->sect_clust -= cc - 1;
                                fp->curr_sect += cc - 1;
                                wcnt = cc * 512; continue;
                        }
                        if (fp->fptr >= fp->fsize) {                    /* Flush R/W window if needed */
                                if (!move_window(0)) goto fw_error;
                                fs->winsect = fp->curr_sect;
                        }
                }
                if (!move_window(fp->curr_sect))                        /* Move sector window */
                        goto fw_error;
                wcnt = 512 - (WORD)(fp->fptr % 512);                    /* Copy fractional bytes bytes to sector window */
                if (wcnt > btw) wcnt = btw;
                memcpy(&fs->win[(WORD)fp->fptr % 512], wbuff, wcnt);
                fs->winflag = 1;
        }

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

fw_error:       /* Abort this function due to an unrecoverable error */
        fp->flag |= FA__ERROR;
        return FR_RW_ERROR;
}




/*-----------------------------------------------------------------------*/
/* Synchronize between File and Disk                                     */
/*-----------------------------------------------------------------------*/

FRESULT f_sync (
        FIL *fp         /* Pointer to the file object */
)
{
        DWORD tim;
        BYTE *dir;
        FRESULT res;
        FATFS *fs = fp->fs;


        res = validate(fs, fp->id);                             /* Check validity of the object */
        if (res == FR_OK) {
                if (fp->flag & FA__WRITTEN) {           /* Has the file been written? */
                        /* Update the directory entry */
                        if (!move_window(fp->dir_sect))
                                return FR_RW_ERROR;
                        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 */
#if _FAT32
                        ST_WORD(&dir[DIR_FstClusHI], fp->org_clust >> 16);
#endif
                        tim = get_fattime();                                    /* Updated time */
                        ST_DWORD(&dir[DIR_WrtTime], tim);
                        fp->flag &= ~FA__WRITTEN;
                        res = sync();
                }
        }
        return res;
}

#endif /* !_FS_READONLY */




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

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


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

        return res;
}




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

FRESULT f_lseek (
        FIL *fp,                /* Pointer to the file object */
        DWORD ofs               /* File pointer from top of file */
)
{
        CLUST clust;
        DWORD csize;
        BYTE csect;
        FRESULT res;
        FATFS *fs = fp->fs;


        res = validate(fs, fp->id);                     /* Check validity of the object */
        if (res) return res;

        if (fp->flag & FA__ERROR) return FR_RW_ERROR;
#if !_FS_READONLY
        if (ofs > fp->fsize && !(fp->flag & FA_WRITE))
#else
        if (ofs > fp->fsize)
#endif
                ofs = fp->fsize;
        fp->fptr = 0; fp->sect_clust = 1;               /* Set file R/W pointer to top of the file */

        /* Move file R/W pointer if needed */
        if (ofs) {
                clust = fp->org_clust;  /* Get start cluster */
#if !_FS_READONLY
                if (!clust) {                   /* If the file does not have a cluster chain, create new cluster chain */
                        clust = create_chain(0);
                        if (clust == 1) goto fk_error;
                        fp->org_clust = clust;
                }
#endif
                if (clust) {                    /* If the file has a cluster chain, it can be followed */
                        csize = (DWORD)fs->sects_clust * 512;           /* Cluster size in unit of byte */
                        for (;;) {                                                                      /* Loop to skip leading clusters */
                                fp->curr_clust = clust;                                 /* Update current cluster */
                                if (ofs <= csize) break;
#if !_FS_READONLY
                                if (fp->flag & FA_WRITE)                                /* Check if in write mode or not */
                                        clust = create_chain(clust);            /* Force streached if in write mode */
                                else
#endif
                                        clust = get_cluster(clust);                     /* Only follow cluster chain if not in write mode */
                                if (clust == 0) {                                               /* Stop if could not follow the cluster chain */
                                        ofs = csize; break;
                                }
                                if (clust == 1 || clust >= fs->max_clust) goto fk_error;
                                fp->fptr += csize;                                              /* Update R/W pointer */
                                ofs -= csize;
                        }
                        csect = (BYTE)((ofs - 1) / 512);                        /* Sector offset in the cluster */
                        fp->curr_sect = clust2sect(clust) + csect;      /* Current sector */
                        fp->sect_clust = fs->sects_clust - csect;       /* Left sector counter in the cluster */
                        fp->fptr += ofs;                                                        /* Update file R/W pointer */
                }
        }
#if !_FS_READONLY
        if ((fp->flag & FA_WRITE) && fp->fptr > fp->fsize) {    /* Set updated flag if in write mode */
                fp->fsize = fp->fptr;
                fp->flag |= FA__WRITTEN;
        }
#endif

        return FR_OK;

fk_error:       /* Abort this function due to an unrecoverable error */
        fp->flag |= FA__ERROR;
        return FR_RW_ERROR;
}




#if _FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Open a directroy                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_opendir (
        DIR *dirobj,            /* Pointer to directory object to create */
        const char *path        /* Pointer to the directory path */
)
{
        BYTE *dir;
        char fn[8+3+1];
        FRESULT res;
        FATFS *fs = FatFs;


        res = auto_mount(&path, 0);
        if (res != FR_OK) return res;

        res = trace_path(dirobj, fn, path, &dir);       /* Trace the directory path */
        if (res == FR_OK) {                                                     /* Trace completed */
                if (dir != NULL) {                                              /* It is not the root dir */
                        if (dir[DIR_Attr] & AM_DIR) {           /* The entry is a directory */
                                dirobj->clust =
#if _FAT32
                                        ((DWORD)LD_WORD(&dir[DIR_FstClusHI]) << 16) |
#endif
                                        LD_WORD(&dir[DIR_FstClusLO]);
                                dirobj->sect = clust2sect(dirobj->clust);
                                dirobj->index = 2;
                        } else {                                                /* The entry is not a directory */
                                res = FR_NO_FILE;
                        }
                }
                dirobj->id = fs->id;
        }
        return res;
}




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

FRESULT f_readdir (
        DIR *dirobj,            /* Pointer to the directory object */
        FILINFO *finfo          /* Pointer to file information to return */
)
{
        BYTE *dir, c;
        FRESULT res;
        FATFS *fs = dirobj->fs;


        res = validate(fs, dirobj->id);                 /* Check validity of the object */
        if (res) return res;

        finfo->fname[0] = 0;
        while (dirobj->sect) {
                if (!move_window(dirobj->sect))
                        return FR_RW_ERROR;
                dir = &fs->win[(dirobj->index & 15) * 32];              /* pointer to the directory entry */
                c = dir[DIR_Name];
                if (c == 0) break;                                                              /* Has it reached to end of dir? */
                if (c != 0xE5 && !(dir[DIR_Attr] & AM_VOL))             /* Is it a valid entry? */
                        get_fileinfo(finfo, dir);
                if (!next_dir_entry(dirobj)) dirobj->sect = 0;  /* Next entry */
                if (finfo->fname[0]) break;                                             /* Found valid entry */
        }

        return FR_OK;
}




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

FRESULT f_stat (
        const char *path,       /* Pointer to the file path */
        FILINFO *finfo          /* Pointer to file information to return */
)
{
        BYTE *dir;
        char fn[8+3+1];
        FRESULT res;
        DIR dirobj;


        res = auto_mount(&path, 0);
        if (res != FR_OK) return res;

        res = trace_path(&dirobj, fn, path, &dir);      /* Trace the file path */
        if (res == FR_OK) {                                                     /* Trace completed */
                if (dir)        /* Found an object */
                        get_fileinfo(finfo, dir);
                else            /* It is root dir */
                        res = FR_INVALID_NAME;
        }

        return res;
}




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

FRESULT f_getfree (
        const char *drv,        /* Logical drive number */
        DWORD *nclust,          /* Pointer to the double word to return number of free clusters */
        FATFS **fatfs           /* Pointer to pointer to the file system object to return */
)
{
        DWORD n, sect;
        CLUST clust;
        BYTE fat, f, *p;
        FRESULT res;
        FATFS *fs;


        /* Get drive number */
        res = auto_mount(&drv, 0);
        if (res != FR_OK) return res;
        *fatfs = fs = FatFs;

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

        /* Count number of free clusters */
        fat = fs->fs_type;
        n = 0;
        if (fat == FS_FAT12) {
                clust = 2;
                do {
                        if ((WORD)get_cluster(clust) == 0) n++;
                } while (++clust < fs->max_clust);
        } else {
                clust = fs->max_clust;
                sect = fs->fatbase;
                f = 0; p = 0;
                do {
                        if (!f) {
                                if (!move_window(sect++)) return FR_RW_ERROR;
                                p = fs->win;
                        }
                        if (!_FAT32 || fat == FS_FAT16) {
                                if (LD_WORD(p) == 0) n++;
                                p += 2; f += 1;
                        } else {
                                if (LD_DWORD(p) == 0) n++;
                                p += 4; f += 2;
                        }
                } while (--clust);
        }
        fs->free_clust = n;
#if _USE_FSINFO
        if (fat == FS_FAT32) fs->fsi_flag = 1;
#endif

        *nclust = n;
        return FR_OK;
}




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

FRESULT f_unlink (
        const char *path                        /* Pointer to the file or directory path */
)
{
        BYTE *dir, *sdir;
        DWORD dsect;
        char fn[8+3+1];
        CLUST dclust;
        FRESULT res;
        DIR dirobj;
        FATFS *fs = FatFs;


        res = auto_mount(&path, 1);
        if (res != FR_OK) return res;

        res = trace_path(&dirobj, fn, path, &dir);      /* Trace the file path */
        if (res != FR_OK) return res;                           /* Trace failed */
        if (dir == NULL) return FR_INVALID_NAME;        /* It is the root directory */
        if (dir[DIR_Attr] & AM_RDO) return FR_DENIED;   /* It is a R/O object */
        dsect = fs->winsect;
        dclust =
#if _FAT32
                ((DWORD)LD_WORD(&dir[DIR_FstClusHI]) << 16) |
#endif
                LD_WORD(&dir[DIR_FstClusLO]);
        if (dir[DIR_Attr] & AM_DIR) {                           /* It is a sub-directory */
                dirobj.clust = dclust;                                  /* Check if the sub-dir is empty or not */
                dirobj.sect = clust2sect(dclust);
                dirobj.index = 2;
                do {
                        if (!move_window(dirobj.sect)) return FR_RW_ERROR;
                        sdir = &fs->win[(dirobj.index & 15) * 32];
                        if (sdir[DIR_Name] == 0) break;
                        if (sdir[DIR_Name] != 0xE5 && !(sdir[DIR_Attr] & AM_VOL))
                                return FR_DENIED;       /* The directory is not empty */
                } while (next_dir_entry(&dirobj));
        }

        if (!move_window(dsect)) return FR_RW_ERROR;    /* Mark the directory entry 'deleted' */
        dir[DIR_Name] = 0xE5;
        fs->winflag = 1;
        if (!remove_chain(dclust)) return FR_RW_ERROR;  /* Remove the cluster chain */

        return sync();
}




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

FRESULT f_mkdir (
        const char *path                /* Pointer to the directory path */
)
{
        BYTE *dir, *fw, n;
        char fn[8+3+1];
        DWORD sect, dsect, tim;
        CLUST dclust, pclust;
        FRESULT res;
        DIR dirobj;
        FATFS *fs = FatFs;


        res = auto_mount(&path, 1);
        if (res != FR_OK) return res;

        res = trace_path(&dirobj, fn, path, &dir);      /* Trace the file path */
        if (res == FR_OK) return FR_EXIST;                      /* Any file or directory is already existing */
        if (res != FR_NO_FILE) return res;

        res = reserve_direntry(&dirobj, &dir);          /* Reserve a directory entry */
        if (res != FR_OK) return res;
        sect = fs->winsect;
        dclust = create_chain(0);                                       /* Allocate a cluster for new directory table */
        if (dclust == 1) return FR_RW_ERROR;
        dsect = clust2sect(dclust);
        if (!dsect) return FR_DENIED;
        if (!move_window(dsect)) return FR_RW_ERROR;

        fw = fs->win;
        memset(fw, 0, 512);                                                     /* Clear the directory table */
        for (n = 1; n < fs->sects_clust; n++) {
                if (disk_write(0, fw, ++dsect, 1) != RES_OK)
                        return FR_RW_ERROR;
        }

        memset(&fw[DIR_Name], ' ', 8+3);                        /* Create "." entry */
        fw[DIR_Name] = '.';
        fw[DIR_Attr] = AM_DIR;
        tim = get_fattime();
        ST_DWORD(&fw[DIR_WrtTime], tim);
        memcpy(&fw[32], &fw[0], 32); fw[33] = '.';      /* Create ".." entry */
        pclust = dirobj.sclust;
#if _FAT32
        ST_WORD(&fw[   DIR_FstClusHI], dclust >> 16);
        if (fs->fs_type == FS_FAT32 && pclust == fs->dirbase) pclust = 0;
        ST_WORD(&fw[32+DIR_FstClusHI], pclust >> 16);
#endif
        ST_WORD(&fw[   DIR_FstClusLO], dclust);
        ST_WORD(&fw[32+DIR_FstClusLO], pclust);
        fs->winflag = 1;

        if (!move_window(sect)) return FR_RW_ERROR;
        memset(&dir[0], 0, 32);                                         /* Clean-up the new entry */
        memcpy(&dir[DIR_Name], fn, 8+3);                        /* Name */
        dir[DIR_NTres] = fn[11];
        dir[DIR_Attr] = AM_DIR;                                         /* Attribute */
        ST_DWORD(&dir[DIR_WrtTime], tim);                       /* Crated time */
        ST_WORD(&dir[DIR_FstClusLO], dclust);           /* Table start cluster */
#if _FAT32
        ST_WORD(&dir[DIR_FstClusHI], dclust >> 16);
#endif

        return sync();
}




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

FRESULT f_chmod (
        const char *path,       /* Pointer to the file path */
        BYTE value,                     /* Attribute bits */
        BYTE mask                       /* Attribute mask to change */
)
{
        FRESULT res;
        BYTE *dir;
        DIR dirobj;
        char fn[8+3+1];


        res = auto_mount(&path, 1);
        if (res == FR_OK) {
                res = trace_path(&dirobj, fn, path, &dir);      /* Trace the file path */
                if (res == FR_OK) {                     /* Trace completed */
                        if (dir == NULL) {
                                res = FR_INVALID_NAME;
                        } else {
                                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 */
                                res = sync();
                        }
                }
        }
        return res;
}




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

FRESULT f_rename (
        const char *path_old,   /* Pointer to the old name */
        const char *path_new    /* Pointer to the new name */
)
{
        FRESULT res;
        DWORD sect_old;
        BYTE *dir_old, *dir_new, direntry[32-11];
        DIR dirobj;
        char fn[8+3+1];
        FATFS *fs = FatFs;


        res = auto_mount(&path_old, 1);
        if (res != FR_OK) return res;

        res = trace_path(&dirobj, fn, path_old, &dir_old);      /* Check old object */
        if (res != FR_OK) return res;                   /* The old object is not found */
        if (!dir_old) return FR_NO_FILE;
        sect_old = fs->winsect;                                 /* Save the object information */
        memcpy(direntry, &dir_old[11], 32-11);

        res = trace_path(&dirobj, fn, path_new, &dir_new);      /* Check new object */
        if (res == FR_OK) return FR_EXIST;                      /* The new object name is already existing */
        if (res != FR_NO_FILE) return res;                      /* Is there no old name? */
        res = reserve_direntry(&dirobj, &dir_new);      /* Reserve a directory entry */
        if (res != FR_OK) return res;

        memcpy(&dir_new[DIR_Attr], direntry, 32-11);    /* Create new entry */
        memcpy(&dir_new[DIR_Name], fn, 8+3);
        dir_new[DIR_NTres] = fn[11];
        fs->winflag = 1;

        if (!move_window(sect_old)) return FR_RW_ERROR; /* Remove old entry */
        dir_old[DIR_Name] = 0xE5;

        return sync();
}

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