ff.c

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	fp->dsect = 0;
	fp->fs = dj.fs; fp->id = dj.fs->id;	/* Owner file system object of the file */

	LEAVE_FF(dj.fs, FR_OK);
}




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

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


	*br = 0;

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

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


	LEAVE_FF(fp->fs, FR_OK);
}




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

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


	*bw = 0;

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

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

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

	LEAVE_FF(fp->fs, FR_OK);
}




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

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


	res = validate(fp->fs, fp->id);		/* Check validity of the object */
	if (res == FR_OK) {
		if (fp->flag & FA__WRITTEN) {	/* Has the file been written? */
#if !_FS_TINY	/* Write-back dirty buffer */
			if (fp->flag & FA__DIRTY) {
				if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
					LEAVE_FF(fp->fs, FR_DISK_ERR);
				fp->flag &= (BYTE)~FA__DIRTY;
			}
#endif
			/* Update the directory entry */
			res = move_window(fp->fs, fp->dir_sect);
			if (res == FR_OK) {
				dir = fp->dir_ptr;
				dir[DIR_Attr] |= AM_ARC;					/* Set archive bit */
				ST_DWORD(dir+DIR_FileSize, fp->fsize);		/* Update file size */
				ST_WORD(dir+DIR_FstClusLO, fp->org_clust);	/* Update start cluster */
				ST_WORD(dir+DIR_FstClusHI, fp->org_clust >> 16);
				tim = get_fattime();					/* Updated time */
				ST_DWORD(dir+DIR_WrtTime, tim);
				fp->flag &= (BYTE)~FA__WRITTEN;
				fp->fs->wflag = 1;
				res = sync(fp->fs);
			}
		}
	}

	LEAVE_FF(fp->fs, res);
}

#endif /* !_FS_READONLY */




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

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


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




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

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


	res = validate(fp->fs, fp->id);		/* Check validity of the object */
	if (res != FR_OK) LEAVE_FF(fp->fs, res);
	if (fp->flag & FA__ERROR)			/* Check abort flag */
		LEAVE_FF(fp->fs, FR_INT_ERR);
	if (ofs > fp->fsize					/* In read-only mode, clip offset with the file size */
#if !_FS_READONLY
		 && !(fp->flag & FA_WRITE)
#endif
		) ofs = fp->fsize;

	ifptr = fp->fptr;
	fp->fptr = 0; fp->csect = 255;
	nsect = 0;
	if (ofs > 0) {
		bcs = (DWORD)fp->fs->csize * SS(fp->fs);	/* Cluster size (byte) */
		if (ifptr > 0 &&
			(ofs - 1) / bcs >= (ifptr - 1) / bcs) {	/* When seek to same or following cluster, */
			fp->fptr = (ifptr - 1) & ~(bcs - 1);	/* start from the current cluster */
			ofs -= fp->fptr;
			clst = fp->curr_clust;
		} else {									/* When seek to back cluster, */
			clst = fp->org_clust;					/* start from the first cluster */
#if !_FS_READONLY
			if (clst == 0) {						/* If no cluster chain, create a new chain */
				clst = create_chain(fp->fs, 0);
				if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
				if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
				fp->org_clust = clst;
			}
#endif
			fp->curr_clust = clst;
		}
		if (clst != 0) {
			while (ofs > bcs) {						/* Cluster following loop */
#if !_FS_READONLY
				if (fp->flag & FA_WRITE) {			/* Check if in write mode or not */
					clst = create_chain(fp->fs, clst);	/* Force streached if in write mode */
					if (clst == 0) {				/* When disk gets full, clip file size */
						ofs = bcs; break;
					}
				} else
#endif
					clst = get_cluster(fp->fs, clst);	/* Follow cluster chain if not in write mode */
				if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
				if (clst <= 1 || clst >= fp->fs->max_clust) ABORT(fp->fs, FR_INT_ERR);
				fp->curr_clust = clst;
				fp->fptr += bcs;
				ofs -= bcs;
			}
			fp->fptr += ofs;
			fp->csect = (BYTE)(ofs / SS(fp->fs));	/* Sector offset in the cluster */
			if (ofs % SS(fp->fs)) {
				nsect = clust2sect(fp->fs, clst);	/* Current sector */
				if (!nsect) ABORT(fp->fs, FR_INT_ERR);
				nsect += fp->csect;
				fp->csect++;
			}
		}
	}
	if (nsect && nsect != fp->dsect && fp->fptr % SS(fp->fs)) {
#if !_FS_TINY
#if !_FS_READONLY
		if (fp->flag & FA__DIRTY) {			/* Write-back dirty buffer if needed */
			if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
				ABORT(fp->fs, FR_DISK_ERR);
			fp->flag &= (BYTE)~FA__DIRTY;
		}
#endif
		if (disk_read(fp->fs->drive, fp->buf, nsect, 1) != RES_OK)
			ABORT(fp->fs, FR_DISK_ERR);
#endif
		fp->dsect = nsect;
	}
#if !_FS_READONLY
	if (fp->fptr > fp->fsize) {			/* Set changed flag if the file size is extended */
		fp->fsize = fp->fptr;
		fp->flag |= FA__WRITTEN;
	}
#endif

	LEAVE_FF(fp->fs, res);
}




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

FRESULT f_opendir (
	DIR *dj,			/* Pointer to directory object to create */
	const char *path	/* Pointer to the directory path */
)
{
	FRESULT res;
	NAMEBUF(sfn, lfn);
	BYTE *dir;


	res = auto_mount(&path, &dj->fs, 0);
	if (res == FR_OK) {
		INITBUF((*dj), sfn, lfn);
		res = follow_path(dj, path);			/* Follow the path to the directory */
		if (res == FR_OK) {						/* Follow completed */
			dir = dj->dir;
			if (dir) {							/* It is not the root dir */
				if (dir[DIR_Attr] & AM_DIR) {	/* The object is a directory */
					dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
				} else {						/* The object is not a directory */
					res = FR_NO_PATH;
				}
			} else {							/* It is the root dir */
				dj->sclust = (dj->fs->fs_type == FS_FAT32) ? dj->fs->dirbase : 0;
			}
			if (res == FR