ff.c

stm32-SDIO+FatFS文件系统txt-int-ascii

	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 (
	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 */
	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