?? tff.c
字號:
/*--------------------------------------------------------------------------/
/ FatFs - Tiny FAT file system module R0.05 (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.
/ May 05, 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.
/ Aug 25, 2007 R0.05 Changed arguments of f_read() and f_write().
/---------------------------------------------------------------------------*/
#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
/* 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(0, 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(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;
}
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