Files
diplomarbeit/Tester/SW/Eclipse/lib/MmcFilesystem/fat_intern.c
T
Matthias 6cc948eef8 Moved remotely
git-svn-id: file:///srv/dev-disk-by-uuid-17e88007-4d0c-45e0-8757-cacfcc458630/repositories/svn/Diplomarbeit@113 9fe90eed-be63-e94b-8204-d34ff4c2ff93
2009-01-12 08:38:14 +00:00

990 lines
32 KiB
C

/* ---------------------------------------------------------------------------
* FAT_intern.c (C)ChaN, 2008
* ---------------------------------------------------------------------------
* Micro-key bv
* Industrieweg 28, 9804 TG Noordhorn
* Postbus 92, 9800 AB Zuidhorn
* The Netherlands
* Tel: +31 594 503020
* Fax: +31 594 505825
* Email: support@microkey.nl
* Web: www.microkey.nl
* ---------------------------------------------------------------------------
* Description: FatFs - FAT file system module R0.06
*
* 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) 2008, 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
* commercial use without restriction under your responsibility.
* Redistributions of source code must retain the above copyright notice.
* ---------------------------------------------------------------------------
* Last Change: 0.2, Aug 11, 2008, MMi
* Edited to fit into LAN_2636 Project
*
*----------------------------------------------------------------------------
* Feb 26,'06 R0.00 Prototype.
*
* Apr 29,'06 R0.01 First stable version.
*
* Jun 01,'06 R0.02 Added FAT12 support.
* Removed unbuffered mode.
* Fixed a problem on small (<32M) patition.
* Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
*
* Sep 22,'06 R0.03 Added f_rename().
* Changed option _FS_MINIMUM to _FS_MINIMIZE.
* Dec 11,'06 R0.03a Improved cluster scan algolithm to write files fast.
* Fixed f_mkdir() creates incorrect directory on FAT32.
*
* Feb 04,'07 R0.04 Supported multiple drive system.
* Changed some interfaces for multiple drive system.
* Changed f_mountdrv() to f_mount().
* Added f_mkfs().
* Apr 01,'07 R0.04a Supported multiple partitions on a plysical drive.
* Added a capability of extending file size to f_lseek().
* Added minimization level 3.
* Fixed an endian sensitive code in f_mkfs().
* May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
* Added FSInfo support.
* Fixed DBCS name can result FR_INVALID_NAME.
* Fixed short seek (<= csize) collapses the file object.
*
* Aug 25,'07 R0.05 Changed arguments of f_read(), f_write() and f_mkfs().
* Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
* Fixed f_mkdir() on FAT32 creates incorrect directory.
* Feb 03,'08 R0.05a Added f_truncate() and f_utime().
* Fixed off by one error at FAT sub-type determination.
* Fixed btr in f_read() can be mistruncated.
* Fixed cached sector is not flushed when create and close
* without write.
*
* Apr 01,'08 R0.06 Added fputc(), fputs(), fprintf() and fgets().
* Improved performance of f_lseek() on moving to the same
* or following cluster.
*---------------------------------------------------------------------------
*/
/* ---------------------------------------------------------------------------
* System include files
* ---------------------------------------------------------------------------
*/
/* Compiler includes */
#include <string.h>
#include "LPC23xx.h"
#include "types.h"
/* FreeRTOS includes */
#include "FreeRTOS.h"
#include "task.h"
/* ---------------------------------------------------------------------------
* Application include files
* ---------------------------------------------------------------------------
*/
#include "fat_intern.h" /* FatFs declarations */
#include "fat_public.h"
#include "fat_diskio.h" /* Include file for user provided disk functions */
#include "fat_time.h" /* Get time from RTC */
/* ---------------------------------------------------------------------------
* Local constant and macro definitions
* ---------------------------------------------------------------------------
*/
/* ---------------------------------------------------------------------------
* Global variable definitions
* ---------------------------------------------------------------------------
*/
/* ---------------------------------------------------------------------------
* Local variable definitions
* ---------------------------------------------------------------------------
*/
FATFS *FatFs[_DRIVES] = {0,0}; /* Pointer to file system objects */
/* (logical drives) */
UINT16 fsid; /* File system mount ID */
/* ---------------------------------------------------------------------------
* Local function definitions
* ---------------------------------------------------------------------------
*/
BOOLEAN move_window (FATFS *fs, UINT32 sector)
{
UINT32 wsect;
wsect = fs->winsect;
if (wsect != sector)
{
/* Changed current window */
#if !_FS_READONLY /* If write-access granted */
UINT8 n;
if (fs->winflag)
{
/* Write back dirty window if needed */
if (disk_write(fs->drive, 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 FAT copy */
wsect += fs->sects_fat;
disk_write(fs->drive, fs->win, wsect, 1);
}
}
}
#endif
if (sector)
{
if (disk_read(fs->drive, fs->win, sector, 1) != RES_OK)
{
return FALSE;
}
fs->winsect = sector;
}
}
return TRUE;
}
#if !_FS_READONLY
FRESULT sync (FATFS *fs)
{
fs->winflag = 1;
if (!move_window(fs, 0))
return FR_RW_ERROR;
#if _USE_FSINFO
/* Update FSInfo sector if needed */
if (fs->fs_type == FS_FAT32 && fs->fsi_flag)
{
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(fs->drive, fs->win, fs->fsi_sector, 1);
fs->fsi_flag = 0;
}
#endif
/* Make sure that no pending write process in the physical drive */
if (disk_ioctl(fs->drive, CTRL_SYNC, NULL) != RES_OK)
return FR_RW_ERROR;
return FR_OK;
}
#endif
UINT32 get_cluster (FATFS *fs, UINT32 clust)
{
UINT16 wc, bc;
UINT32 fatsect;
if (clust >= 2 && clust < fs->max_clust)
{
/* Is it a valid cluster number? */
fatsect = fs->fatbase;
switch (fs->fs_type)
{
case FS_FAT12:
bc = (UINT16)clust * 3 / 2;
if (!move_window(fs, fatsect + (bc / SS(fs))))
break;
wc = fs->win[bc & (SS(fs) - 1)];
bc++;
if (!move_window(fs, fatsect + (bc / SS(fs))))
break;
wc |= (UINT16)fs->win[bc & (SS(fs) - 1)] << 8;
return (clust & 1) ? (wc >> 4) : (wc & 0xFFF);
case FS_FAT16:
if (!move_window(fs, fatsect + (clust / (SS(fs) / 2))))
break;
return LD_WORD(&fs->win[((UINT16)clust * 2) & (SS(fs) - 1)]);
case FS_FAT32:
if (!move_window(fs, fatsect + (clust / (SS(fs) / 4))))
break;
return LD_DWORD(&fs->win[((UINT16)clust * 4) & (SS(fs) - 1)]) & 0x0FFFFFFF;
}
}
return 1; /* Out of cluster range, or an error occured */
}
#if !_FS_READONLY
BOOLEAN put_cluster(FATFS *fs, UINT32 clust, UINT32 val)
{
UINT32 fatsect;
UINT16 bc;
UINT8 *p;
fatsect = fs->fatbase;
switch (fs->fs_type)
{
case FS_FAT12:
bc = (UINT16)clust * 3 / 2;
if (!move_window(fs, fatsect + (bc / SS(fs))))
{
return FALSE;
}
p = &fs->win[bc & (SS(fs) - 1)];
*p = (clust & 1) ? ((*p & 0x0F) | ((UINT8)val << 4)) : (UINT8)val;
bc++;
fs->winflag = 1;
if (!move_window(fs, fatsect + (bc / SS(fs))))
{
return FALSE;
}
p = &fs->win[bc & (SS(fs) - 1)];
*p = (clust & 1) ? (UINT8)(val >> 4) : ((*p & 0xF0) | ((UINT8)(val
>> 8) & 0x0F));
break;
case FS_FAT16:
if (!move_window(fs, fatsect + (clust / (SS(fs) / 2))))
{
return FALSE;
}
ST_WORD(&fs->win[((UINT16)clust * 2) & (SS(fs) - 1)], (UINT16)val);
break;
case FS_FAT32:
if (!move_window(fs, fatsect + (clust / (SS(fs) / 4))))
{
return FALSE;
}
ST_DWORD(&fs->win[((UINT16)clust * 4) & (SS(fs) - 1)], val);
break;
default:
return FALSE;
}
fs->winflag = 1;
return TRUE;
}
#endif /* !_FS_READONLY */
#if !_FS_READONLY
BOOLEAN remove_chain (FATFS *fs, UINT32 clust)
{
UINT32 nxt;
while (clust >= 2 && clust < fs->max_clust)
{
nxt = get_cluster(fs, clust);
if (nxt == 1)
{
return FALSE;
}
if (!put_cluster(fs, clust, 0))
{
return FALSE;
}
if (fs->free_clust != 0xFFFFFFFF)
{
fs->free_clust++;
#if _USE_FSINFO
fs->fsi_flag = 1;
#endif
}
clust = nxt;
}
return TRUE;
}
#endif
#if !_FS_READONLY
UINT32 create_chain (FATFS *fs, UINT32 clust)
{
UINT32 cstat;
UINT32 ncl;
UINT32 scl;
UINT32 mcl = fs->max_clust;
if (clust == 0)
{
/* Create new chain */
scl = fs->last_clust; /* Get suggested start point */
if (scl == 0 || scl >= mcl)
scl = 1;
}
else
{
/* Stretch existing chain */
cstat = get_cluster(fs, clust); /* Check the cluster status */
if (cstat < 2)
{
return 1; /* It is an invalid cluster */
}
if (cstat < mcl)
{
return cstat; /* Is already followed by 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(fs, 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(fs, ncl, 0x0FFFFFFF))
{
return 1; /* Mark the new cluster "in use" */
}
if (clust != 0 && !put_cluster(fs, clust, ncl))
{
return 1; /* Link it to previous one if needed*/
}
fs->last_clust = ncl; /* Update fsinfo */
if (fs->free_clust != 0xFFFFFFFF)
{
fs->free_clust--;
#if _USE_FSINFO
fs->fsi_flag = 1;
#endif
}
return ncl; /* Return new cluster number */
}
#endif /* !_FS_READONLY */
UINT32 clust2sect(FATFS *fs, UINT32 clust)
{
clust -= 2;
if (clust >= (fs->max_clust - 2))
{
return 0; /* Invalid cluster number */
}
return (clust * fs->csize + fs->database);
}
BOOLEAN next_dir_entry(DIR *dj)
{
UINT32 clust;
UINT16 idx;
idx = dj->index + 1;
if ((idx & ((SS(dj->fs) - 1) / 32)) == 0)
{
/* Table sector changed? */
dj->sect++; /* Next sector */
if (dj->clust == 0)
{
/* In static table */
if (idx >= dj->fs->n_rootdir)
{
return FALSE; /* Reached to end of table */
}
}
else
{
/* In dynamic table */
if (((idx / (SS(dj->fs) / 32)) & (dj->fs->csize - 1)) == 0)
{
/* Cluster changed? */
clust = get_cluster(dj->fs, dj->clust); /* Get next cluster */
if (clust < 2 || clust >= dj->fs->max_clust)
{
/* Reached to end of table */
return FALSE;
}
dj->clust = clust; /* Initialize for new cluster */
dj->sect = clust2sect(dj->fs, clust);
}
}
}
dj->index = idx; /* Lower bits of dj->index indicates*/
/* offset in dj->sect */
return TRUE;
}
#if _FS_MINIMIZE <= 1
void get_fileinfo (FILINFO *finfo, const UINT8 *dir)
{
UINT8 n;
UINT8 c;
UINT8 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 */
char make_dirfile(const char **path, char *dirname)
{
UINT8 n;
UINT8 t;
UINT8 c;
UINT8 a;
UINT8 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 ^= 0x01;
goto md_l2; /* LABEL SEE END OF FUNCTION */
}
if (c == '"')
{
break; /* Reject " */
}
if (c <= ')')
{
goto md_l1; /* LABEL SEE END OF FUNCTION */
}
/* 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 &= 0xF7) : (b &= 0xEF);
}
if (c >= 'a' && c <= 'z')
{
/* Convert to upper case */
c -= 0x20;
if (_USE_NTFLAG)
{
(t == 8) ? (a |= 0x08) : (a |= 0x10);
}
}
}
/* GOTO LABELS */
md_l1: a &= 0xFE;
md_l2: if (n >= t)
{
break;
}
dirname[n++] = c;
}
return 1;
}
FRESULT trace_path (DIR *dj, char *fn, const char *path, UINT8 **dir)
{
UINT32 clust;
char ds;
UINT8 *dptr = NULL;
FATFS *fs = dj->fs;
/* Initialize directory object */
clust = fs->dirbase;
if (fs->fs_type == FS_FAT32)
{
dj->clust = dj->sclust = clust;
dj->sect = clust2sect(fs, clust);
}
else
{
dj->clust = dj->sclust = 0;
dj->sect = clust;
}
dj->index = 0;
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(fs, dj->sect))
{
return FR_RW_ERROR;
}
/* Pointer to the directory entry */
dptr = &fs->win[(dj->index & ((SS(fs) - 1) / 32)) * 32];
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] & AR_VOL)
&& !memcmp(&dptr[DIR_Name], fn, 8+3))
{
break;
}
if (!next_dir_entry(dj)) /* 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] & AR_DIR))
{
return FR_NO_PATH; /* Cannot trace because it is a file*/
}
/* Get cluster# of the directory */
clust = ((UINT32)LD_WORD(&dptr[DIR_FstClusHI]) << 16)
| LD_WORD(&dptr[DIR_FstClusLO]);
/* Restart scanning at the new directory */
dj->clust = dj->sclust = clust;
dj->sect = clust2sect(fs, clust);
dj->index = 2;
}
}
#if !_FS_READONLY
FRESULT reserve_direntry (DIR *dj, UINT8 **dir)
{
UINT32 clust;
UINT32 sector;
UINT8 c;
UINT8 n;
UINT8 *dptr;
FATFS *fs = dj->fs;
/* Re-initialize directory object */
clust = dj->sclust;
if (clust != 0)
{
/* Dyanmic directory table */
dj->clust = clust;
dj->sect = clust2sect(fs, clust);
}
else
{
/* Static directory table */
dj->sect = fs->dirbase;
}
dj->index = 0;
do
{
if (!move_window(fs, dj->sect))
{
return FR_RW_ERROR;
}
/* Pointer to the directory entry */
dptr = &fs->win[(dj->index & ((SS(dj->fs) - 1) / 32)) * 32];
c = dptr[DIR_Name];
if (c == 0 || c == 0xE5)
{
/* Found an empty entry */
*dir = dptr;
return FR_OK;
}
} while (next_dir_entry(dj)); /* Next directory pointer */
/* Reached to end of the directory table */
/* Abort when it is a static table or could not stretch dynamic table */
if (clust == 0 || !(clust = create_chain(fs, dj->clust)))
{
return FR_DENIED;
}
if (clust == 1 || !move_window(fs, 0))
{
return FR_RW_ERROR;
}
/* Cleanup the expanded table */
fs->winsect = sector = clust2sect(fs, clust);
memset(fs->win, 0, SS(fs));
for (n = fs->csize; n; n--)
{
if (disk_write(fs->drive, fs->win, sector, 1) != RES_OK)
{
return FR_RW_ERROR;
}
sector++;
}
fs->winflag = 1;
*dir = fs->win;
return FR_OK;
}
#endif
UINT8 check_fs (FATFS *fs, UINT32 sect)
{
/* Load boot record */
if (disk_read(fs->drive, fs->win, sect, 1) != RES_OK)
{
return 2;
}
/* Check record signature (always placed at offset 510 even if the sector
* size is >512)
*/
if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55)
{
return 2;
}
/* Check FAT signature */
if (!memcmp(&fs->win[BS_FilSysType], "FAT", 3))
{
return 0;
}
if (!memcmp(&fs->win[BS_FilSysType32], "FAT32", 5)
&& !(fs->win[BPB_ExtFlags] & 0x80))
{
return 0;
}
return 1;
}
FRESULT auto_mount (const char **path, FATFS **rfs, UINT8 chk_wp)
{
UINT32 bootsect;
UINT32 fatsize;
UINT32 totalsect;
UINT32 maxclust;
UINT8 drv;
UINT8 fmt;
UINT8 *tbl;
DSTATUS stat;
const char *p = *path;
FATFS *fs;
/* Get drive number from the path name */
while (*p == ' ')
{
p++; /* Strip leading spaces */
}
drv = p[0] - '0'; /* Is there a drive number? */
if (drv <= 9 && p[1] == ':')
{
p += 2; /* Found drive number, get&strip it */
}
else
{
drv = 0; /* No drive number is given, use */
/* drive number 0 as default */
}
if (*p == '/')
{
p++; /* Strip heading slash */
}
*path = p; /* Return pointer to the path name */
/* Check if the drive number is valid or not */
if (drv >= _DRIVES)
{
return FR_INVALID_DRIVE; /* Is the drive number valid? */
}
*rfs = fs = FatFs[drv]; /* Returen pointer to the */
/* corresponding file system object */
if (!fs)
{
return FR_NOT_ENABLED; /* Is file system object registered?*/
}
if (fs->fs_type)
{
/* If the logical drive has been mounted */
stat = disk_status(fs->drive);
if (!(stat & STA_NOINIT))
{
/* and physical drive is kept initialized (has not been changed)*/
#if !_FS_READONLY
/* Check write protection if needed */
if (chk_wp && (stat & STA_PROTECT))
{
return FR_WRITE_PROTECTED;
}
#endif
return FR_OK; /* The file system object is valid */
}
}
/* The logical drive must be re-mounted.
* Following code attempts to mount the logical drive
*/
memset(fs, 0, sizeof(FATFS)); /* Clean-up the file system object */
fs->drive = LD2PD(drv); /* Bind logical and physical drive */
stat = disk_initialize(fs->drive); /* Initialize low level I/O layer */
if (stat & STA_NOINIT) /* Check if the drive is ready */
{
return FR_NOT_READY;
}
#if S_MAX_SIZ > 512 /* Get disk sector size if needed */
if (disk_ioctl(drv,GET_SECTOR_SIZE,&SS(fs)) != RES_OK || SS(fs)> S_MAX_SIZ)
{
return FR_NO_FILESYSTEM;
}
#endif
#if !_FS_READONLY
if (chk_wp && (stat & STA_PROTECT)) /* Check write protection if needed */
{
return FR_WRITE_PROTECTED;
}
#endif
/* Search FAT partition on the drive */
fmt = check_fs(fs, bootsect = 0); /* Check sector 0 as an SFD format */
if (fmt == 1)
{
/* Not an FAT boot record, it may be patitioned */
/* Check a partition listed in top of the partition table */
tbl = &fs->win[MBR_Table + LD2PT(drv) * 16]; /* Partition table */
if (tbl[4])
{
/* Is the partition existing? */
bootsect = LD_DWORD(&tbl[8]); /* Partition offset in LBA */
fmt = check_fs(fs, bootsect); /* Check the partition */
}
}
/* No valid FAT patition is found */
if (fmt || LD_WORD(&fs->win[BPB_BytsPerSec]) != SS(fs))
{
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 = fatsize;
/* Number of FAT copies */
fs->n_fats = fs->win[BPB_NumFATs];
/* (Number of sectors in FAT area) */
fatsize *= fs->n_fats;
/* FAT start sector (lba) */
fs->fatbase = bootsect + LD_WORD(&fs->win[BPB_RsvdSecCnt]);
/* Number of sectors per cluster */
fs->csize = fs->win[BPB_SecPerClus];
/* Nmuber of root directory entries */
fs->n_rootdir = LD_WORD(&fs->win[BPB_RootEntCnt]);
/* Number of sectors on the file system */
totalsect = LD_WORD(&fs->win[BPB_TotSec16]);
if (!totalsect)
{
totalsect = LD_DWORD(&fs->win[BPB_TotSec32]);
}
/* max_clust = Last cluster# + 1 */
fs->max_clust = maxclust = (totalsect - LD_WORD(&fs->win[BPB_RsvdSecCnt])
- fatsize - fs->n_rootdir / (SS(fs)/32) ) / fs->csize + 2;
fmt = FS_FAT12; /* Determine the FAT sub type */
if (maxclust >= 0xFF7)
{
fmt = FS_FAT16;
}
if (maxclust >= 0xFFF7)
{
fmt = FS_FAT32;
}
if (fmt == FS_FAT32)
{
/* Root directory start cluster */
fs->dirbase = LD_DWORD(&fs->win[BPB_RootClus]);
}
else
{
/* Root directory start sector (lba) */
fs->dirbase = fs->fatbase + fatsize;
}
/* Data start sector (lba) */
fs->database = fs->fatbase + fatsize + fs->n_rootdir / (SS(fs)/32);
#if !_FS_READONLY
/* Initialize allocation information */
fs->free_clust = 0xFFFFFFFF;
#if _USE_FSINFO
/* Get fsinfo if needed */
if (fmt == FS_FAT32)
{
fs->fsi_sector = bootsect + LD_WORD(&fs->win[BPB_FSInfo]);
if (disk_read(fs->drive, fs->win, fs->fsi_sector, 1) == RES_OK &&
LD_WORD(&fs->win[BS_55AA]) == 0xAA55 &&
LD_DWORD(&fs->win[FSI_LeadSig]) == 0x41615252 &&
LD_DWORD(&fs->win[FSI_StrucSig]) == 0x61417272)
{
fs->last_clust = LD_DWORD(&fs->win[FSI_Nxt_Free]);
fs->free_clust = LD_DWORD(&fs->win[FSI_Free_Count]);
}
}
#endif
#endif
fs->fs_type = fmt; /* FAT syb-type */
fs->id = ++fsid; /* File system mount ID */
return FR_OK;
}
FRESULT validate (const FATFS *fs, UINT16 id)
{
if (!fs || !fs->fs_type || fs->id != id)
{
return FR_INVALID_OBJECT;
}
if (disk_status(fs->drive) & STA_NOINIT)
{
return FR_NOT_READY;
}
return FR_OK;
}