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if (ofs > 0) {
csize = (DWORD)fp->fs->csize * 512U; /* Cluster size (byte) */
if (ifptr > 0 &&
(ofs - 1) / csize >= (ifptr - 1) / csize) {/* When seek to same or following cluster, */
fp->fptr = (ifptr - 1) & ~(csize - 1); /* start from the current cluster */
ofs -= fp->fptr;
clust = fp->curr_clust;
} else { /* When seek to back cluster, */
clust = fp->org_clust; /* start from the first cluster */
if (clust == 0) { /* If no cluster chain, create a new chain */
clust = create_chain(0);
if (clust == 1) goto fk_error;
fp->org_clust = clust;
}
fp->curr_clust = clust;
}
if (clust != 0) {
while (ofs > csize) { /* Cluster following loop */
if (fp->flag & 0x02) { /* Check if in write mode or not */
clust = create_chain(clust); /* Force streached if in write mode */
if (clust == 0) { /* When disk gets full, clip file size */
ofs = csize; break;
}
} else
clust = get_cluster(clust); /* Follow cluster chain if not in write mode */
if (clust < 2 || clust >= fp->fs->max_clust) goto fk_error;
fp->curr_clust = clust;
fp->fptr += csize;
ofs -= csize;
}
fp->fptr += ofs;
fp->csect = (BYTE)(ofs / 512U); /* Sector offset in the cluster */
if (ofs % 512U) fp->csect++;
}
}
if (fp->fptr > fp->fsize) { /* Set changed flag if the file was extended */
fp->fsize = fp->fptr;
fp->flag |= 0x20;
}
return FR_OK;
fk_error: /* Abort this file due to an unrecoverable error */
fp->flag |= 0x80;
return FR_RW_ERROR;
}
/*-----------------------------------------------------------------------*/
/* 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;
BYTE *dir;
char fn[8+3+1];
res = auto_mount(&path, 0);
if (res == FR_OK) {
res = trace_path(dj, fn, path, &dir); /* Trace the directory path */
if (res == FR_OK) { /* Trace completed */
if (dir) { /* It is not the root dir */
if (dir[11] & 0x10 ) { /* The entry is a directory */
dj->clust =
((DWORD)((WORD)(((WORD)*(volatile BYTE*)((&dir[20])+1)<<8)|(WORD)*(volatile BYTE*)(&dir[20]))) << 16) |
(WORD)(((WORD)*(volatile BYTE*)((&dir[26])+1)<<8)|(WORD)*(volatile BYTE*)(&dir[26]));
dj->sect = clust2sect(dj->clust);
dj->index = 2;
} else { /* The entry is not a directory */
res = FR_NO_FILE;
}
}
dj->id = dj->fs->id;
}
}
return res;
}
/*-----------------------------------------------------------------------*/
/* Read Directory Entry in Sequense */
/*-----------------------------------------------------------------------*/
FRESULT f_readdir (
DIR *dj, /* Pointer to the directory object */
FILINFO *finfo /* Pointer to file information to return */
)
{
FRESULT res;
BYTE *dir, c;
res = validate(dj->fs, dj->id); /* Check validity of the object */
if (res != FR_OK) return res;
finfo->fname[0] = 0;
while (dj->sect) {
if (!move_window(dj->sect))
return FR_RW_ERROR;
dir = &dj->fs->win[(dj->index & 15) * 32]; /* pointer to the directory entry */
c = dir[0];
if (c == 0) break; /* Has it reached to end of dir? */
if (c != 0xE5 && !(dir[11] & 0x08 )) /* Is it a valid entry? */
get_fileinfo(finfo, dir);
if (!next_dir_entry(dj)) dj->sect = 0; /* Next entry */
if (finfo->fname[0]) break; /* Found valid entry */
}
return FR_OK;
}
/*-----------------------------------------------------------------------*/
/* Get File Status */
/*-----------------------------------------------------------------------*/
FRESULT f_stat (
const char *path, /* Pointer to the file path */
FILINFO *finfo /* Pointer to file information to return */
)
{
FRESULT res;
DIR dj;
BYTE *dir;
char fn[8+3+1];
res = auto_mount(&path, 0);
if (res == FR_OK) {
res = trace_path(&dj, 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;
}
/*-----------------------------------------------------------------------*/
/* Truncate File */
/*-----------------------------------------------------------------------*/
FRESULT f_truncate (
FIL *fp /* Pointer to the file object */
)
{
FRESULT res;
CLUST ncl;
res = validate(fp->fs, fp->id); /* Check validity of the object */
if (res != FR_OK) return res;
if (fp->flag & 0x80) return FR_RW_ERROR; /* Check error flag */
if (!(fp->flag & 0x02)) return FR_DENIED; /* Check access mode */
if (fp->fsize > fp->fptr) {
fp->fsize = fp->fptr; /* Set file size to current R/W point */
fp->flag |= 0x20;
if (fp->fptr == 0) { /* When set file size to zero, remove entire cluster chain */
if (!remove_chain(fp->org_clust)) goto ft_error;
fp->org_clust = 0;
} else { /* When truncate a part of the file, remove remaining clusters */
ncl = get_cluster(fp->curr_clust);
if (ncl < 2) goto ft_error;
if (ncl < fp->fs->max_clust) {
if (!put_cluster(fp->curr_clust, (CLUST)0x0FFFFFFF)) goto ft_error;
if (!remove_chain(ncl)) goto ft_error;
}
}
}
return FR_OK;
ft_error: /* Abort this file due to an unrecoverable error */
fp->flag |= 0x80;
return FR_RW_ERROR;
}
/*-----------------------------------------------------------------------*/
/* Get Number of Free Clusters */
/*-----------------------------------------------------------------------*/
FRESULT f_getfree (
const char *drv, /* Pointer to the logical drive number (root dir) */
DWORD *nclust, /* Pointer to the variable to return number of free clusters */
FATFS **fatfs /* Pointer to pointer to corresponding file system object to return */
)
{
FRESULT res;
FATFS *fs;
DWORD n, sect;
CLUST clust;
BYTE fat, f, *p;
/* 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;
}
/* Get number of free clusters */
fat = fs->fs_type;
n = 0;
if (fat == 1) {
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 (!1 || fat == 2) {
if ((WORD)(((WORD)*(volatile BYTE*)((p)+1)<<8)|(WORD)*(volatile BYTE*)(p)) == 0) n++;
p += 2; f += 1;
} else {
if ((DWORD)(((DWORD)*(volatile BYTE*)((p)+3)<<24)|((DWORD)*(volatile BYTE*)((p)+2)<<16)|((WORD)*(volatile BYTE*)((p)+1)<<8)|*(volatile BYTE*)(p)) == 0) n++;
p += 4; f += 2;
}
} while (--clust);
}
fs->free_clust = n;
if (fat == 3) fs->fsi_flag = 1;
*nclust = n;
return FR_OK;
}
/*-----------------------------------------------------------------------*/
/* Delete a File or Directory */
/*-----------------------------------------------------------------------*/
FRESULT f_unlink (
const char *path /* Pointer to the file or directory path */
)
{
FRESULT res;
DIR dj;
BYTE *dir, *sdir;
DWORD dsect;
char fn[8+3+1];
CLUST dclust;
res = auto_mount(&path, 1);
if (res != FR_OK) return res;
res = trace_path(&dj, fn, path, &dir); /* Trace the file path */
if (res != FR_OK) return res; /* Trace failed */
if (!dir) return FR_INVALID_NAME; /* It is the root directory */
if (dir[11] & 0x01 ) return FR_DENIED; /* It is a R/O object */
dsect = dj.fs->winsect;
dclust =
((DWORD)((WORD)(((WORD)*(volatile BYTE*)((&dir[20])+1)<<8)|(WORD)*(volatile BYTE*)(&dir[20]))) << 16) |
(WORD)(((WORD)*(volatile BYTE*)((&dir[26])+1)<<8)|(WORD)*(volatile BYTE*)(&dir[26]));
if (dir[11] & 0x10 ) { /* It is a sub-directory */
dj.clust = dclust; /* Check if the sub-dir is empty or not */
dj.sect = clust2sect(dclust);
dj.index = 2;
do {
if (!move_window(dj.sect)) return FR_RW_ERROR;
sdir = &dj.fs->win[(dj.index & 15) * 32];
if (sdir[0] == 0) break;
if (sdir[0] != 0xE5 && !(sdir[11] & 0x08 ))
return FR_DENIED; /* The directory is not empty */
} while (next_dir_entry(&dj));
}
if (!move_window(dsect)) return FR_RW_ERROR; /* Mark the directory entry 'deleted' */
dir[0] = 0xE5;
dj.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 */
)
{
FRESULT res;
DIR dj;
BYTE *dir, *fw, n;
char fn[8+3+1];
DWORD sect, dsect, tim;
CLUST dclust, pclust;
res = auto_mount(&path, 1);
if (res != FR_OK) return res;
res = trace_path(&dj, 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(&dj, &dir); /* Reserve a directory entry */
if (res != FR_OK) return res;
sect = dj.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 = dj.fs->win;
memset(fw, 0, 512U); /* Clear the directory table */
for (n = 1; n < dj.fs->csize; n++) {
if (disk_write(0, fw, ++dsect, 1) != RES_OK)
return FR_RW_ERROR;
}
memset(&fw[0], ' ', 8+3); /* Create "." entry */
fw[0] = '.';
fw[11] = 0x10 ;
tim = get_fattime();
*(volatile BYTE*)(&fw[22])=(BYTE)(tim); *(volatile BYTE*)((&fw[22])+1)=(BYTE)((WORD)(tim)>>8); *(volatile BYTE*)((&fw[22])+2)=(BYTE)((DWORD)(tim)>>16); *(volatile BYTE*)((&fw[22])+3)=(BYTE)((DWORD)(tim)>>24);
memcpy(&fw[32], &fw[0], 32); fw[33] = '.'; /* Create ".." entry */
pclust = dj.sclust;
*(volatile BYTE*)(&fw[ 20])=(BYTE)(dclust >> 16); *(volatile BYTE*)((&fw[ 20])+1)=(BYTE)((WORD)(dclust >> 16)>>8);
if (dj.fs->fs_type == 3 && pclust == dj.fs->dirbase) pclust = 0;
*(volatile BYTE*)(&fw[32+20])=(BYTE)(pclust >> 16); *(volatile BYTE*)((&fw[32+20])+1)=(BYTE)((WORD)(pclust >> 16)>>8);
*(volatile BYTE*)(&fw[ 26])=(BYTE)(dclust); *(volatile BYTE*)((&fw[ 26])+1)=(BYTE)((WORD)(dclust)>>8);
*(volatile BYTE*)(&fw[32+26])=(BYTE)(pclust); *(volatile BYTE*)((&fw[32+26])+1)=(BYTE)((WORD)(pclust)>>8);
dj.fs->winflag = 1;
if (!move_window(sect)) return FR_RW_ERROR;
memset(&dir[0], 0, 32); /* Clean-up the new entry */
memcpy(&dir[0], fn, 8+3); /* Name */
dir[12] = fn[11];
dir[11] =
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