pff.cpp

00001 /*----------------------------------------------------------------------------/
00002 /  Petit FatFs - FAT file system module  R0.02                 (C)ChaN, 2009
00003 /-----------------------------------------------------------------------------/
00004 / Petit FatFs module is an open source software to implement FAT file system to
00005 / small embedded systems. This is a free software and is opened for education,
00006 / research and commercial developments under license policy of following trems.
00007 /
00008 /  Copyright (C) 2009, ChaN, all right reserved.
00009 /
00010 / * The Petit FatFs module is a free software and there is NO WARRANTY.
00011 / * No restriction on use. You can use, modify and redistribute it for
00012 /   personal, non-profit or commercial use UNDER YOUR RESPONSIBILITY.
00013 / * Redistributions of source code must retain the above copyright notice.
00014 /
00015 /-----------------------------------------------------------------------------/
00016 / Jun 15,'09  R0.01a  First release. (Branched from FatFs R0.07b.)
00017 /
00018 / Dec 14,'09  R0.02   Added multiple code page support.
00019 /                     Added write funciton.
00020 /                     Changed stream read mode interface.
00021 /----------------------------------------------------------------------------*/
00022 
00023 #include "pff.h"        /* Petit FatFs configurations and declarations */
00024 #include "diskio.h"        /* Declarations of low level disk I/O functions */
00025 
00026 
00027 /*--------------------------------------------------------------------------
00028 
00029    Private Functions
00030 
00031 ---------------------------------------------------------------------------*/
00032 
00033 static
00034 FATFS *FatFs;    /* Pointer to the file system object (logical drive) */
00035 
00036 
00037 
00038 /*-----------------------------------------------------------------------*/
00039 /* String functions                                                      */
00040 /*-----------------------------------------------------------------------*/
00041 
00042 /* Fill memory */
00043 static
00044 void mem_set (void* dst, int val, int cnt) {
00045     char *d = (char*)dst;
00046     while (cnt--) *d++ = (char)val;
00047 }
00048 
00049 /* Compare memory to memory */
00050 static
00051 int mem_cmp (const void* dst, const void* src, int cnt) {
00052     const char *d = (const char *)dst, *s = (const char *)src;
00053     int r = 0;
00054     while (cnt-- && (r = *d++ - *s++) == 0) ;
00055     return r;
00056 }
00057 
00058 
00059 
00060 /*-----------------------------------------------------------------------*/
00061 /* FAT access - Read value of a FAT entry                                */
00062 /*-----------------------------------------------------------------------*/
00063 
00064 static
00065 CLUST get_fat (    /* 1:IO error, Else:Cluster status */
00066     CLUST clst    /* Cluster# to get the link information */
00067 ) {
00068     WORD wc, bc, ofs;
00069     BYTE buf[4];
00070     FATFS *fs = FatFs;
00071 
00072 
00073     if (clst < 2 || clst >= fs->max_clust)    /* Range check */
00074         return 1;
00075 
00076     switch (fs->fs_type) {
00077         case FS_FAT12 :
00078             bc = (WORD)clst;
00079             bc += bc / 2;
00080             ofs = bc % 512;
00081             bc /= 512;
00082             if (ofs != 511) {
00083                 if (disk_readp(buf, fs->fatbase + bc, ofs, 2)) break;
00084             } else {
00085                 if (disk_readp(buf, fs->fatbase + bc, 511, 1)) break;
00086                 if (disk_readp(buf+1, fs->fatbase + bc + 1, 0, 1)) break;
00087             }
00088             wc = LD_WORD(buf);
00089             return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);
00090 
00091         case FS_FAT16 :
00092             if (disk_readp(buf, fs->fatbase + clst / 256, (WORD)(((WORD)clst % 256) * 2), 2)) break;
00093             return LD_WORD(buf);
00094 #if _FS_FAT32
00095         case FS_FAT32 :
00096             if (disk_readp(buf, fs->fatbase + clst / 128, (WORD)(((WORD)clst % 128) * 4), 4)) break;
00097             return ((WORD)(((WORD)*(BYTE*)((buf)+1)<<8)|(WORD)*(BYTE*)(buf))) & 0x0FFFFFFF; //return LD_DWORD(buf) & 0x0FFFFFFF; //get rid of out of bounds warning in online IDE
00098 #endif
00099     }
00100 
00101     return 1;    /* An error occured at the disk I/O layer */
00102 }
00103 
00104 
00105 
00106 
00107 /*-----------------------------------------------------------------------*/
00108 /* Get sector# from cluster#                                             */
00109 /*-----------------------------------------------------------------------*/
00110 
00111 static
00112 DWORD clust2sect (    /* !=0: Sector number, 0: Failed - invalid cluster# */
00113     CLUST clst        /* Cluster# to be converted */
00114 ) {
00115     FATFS *fs = FatFs;
00116 
00117 
00118     clst -= 2;
00119     if (clst >= (fs->max_clust - 2)) return 0;        /* Invalid cluster# */
00120     return (DWORD)clst * fs->csize + fs->database;
00121 }
00122 
00123 
00124 
00125 
00126 /*-----------------------------------------------------------------------*/
00127 /* Directory handling - Rewind directory index                           */
00128 /*-----------------------------------------------------------------------*/
00129 
00130 static
00131 FRESULT dir_rewind (
00132     FATDIR *dj            /* Pointer to directory object */
00133 ) {
00134     CLUST clst;
00135     FATFS *fs = FatFs;
00136 
00137 
00138     dj->index = 0;
00139     clst = dj->sclust;
00140     if (clst == 1 || clst >= fs->max_clust)    /* Check start cluster range */
00141         return FR_DISK_ERR;
00142 #if _FS_FAT32
00143     if (!clst && fs->fs_type == FS_FAT32)    /* Replace cluster# 0 with root cluster# if in FAT32 */
00144         clst = fs->dirbase;
00145 #endif
00146     dj->clust = clst;                        /* Current cluster */
00147     dj->sect = clst ? clust2sect(clst) : fs->dirbase;    /* Current sector */
00148 
00149     return FR_OK;    /* Seek succeeded */
00150 }
00151 
00152 
00153 
00154 
00155 /*-----------------------------------------------------------------------*/
00156 /* Directory handling - Move directory index next                        */
00157 /*-----------------------------------------------------------------------*/
00158 
00159 static
00160 FRESULT dir_next (    /* FR_OK:Succeeded, FR_NO_FILE:End of table */
00161     FATDIR *dj            /* Pointer to directory object */
00162 ) {
00163     CLUST clst;
00164     WORD i;
00165     FATFS *fs = FatFs;
00166 
00167 
00168     i = dj->index + 1;
00169     if (!i || !dj->sect)    /* Report EOT when index has reached 65535 */
00170         return FR_NO_FILE;
00171 
00172     if (!(i & (16-1))) {    /* Sector changed? */
00173         dj->sect++;            /* Next sector */
00174 
00175         if (dj->clust == 0) {    /* Static table */
00176             if (i >= fs->n_rootdir)    /* Report EOT when end of table */
00177                 return FR_NO_FILE;
00178         } else {                   /* Dynamic table */
00179             if (((i / 16) & (fs->csize-1)) == 0) {    /* Cluster changed? */
00180                 clst = get_fat(dj->clust);        /* Get next cluster */
00181                 if (clst <= 1) return FR_DISK_ERR;
00182                 if (clst >= fs->max_clust)        /* When it reached end of dynamic table */
00183                     return FR_NO_FILE;            /* Report EOT */
00184                 dj->clust = clst;                /* Initialize data for new cluster */
00185                 dj->sect = clust2sect(clst);
00186             }
00187         }
00188     }
00189 
00190     dj->index = i;
00191 
00192     return FR_OK;
00193 }
00194 
00195 
00196 
00197 
00198 /*-----------------------------------------------------------------------*/
00199 /* Directory handling - Find an object in the directory                  */
00200 /*-----------------------------------------------------------------------*/
00201 
00202 static
00203 FRESULT dir_find (
00204     FATDIR *dj            /* Pointer to the directory object linked to the file name */
00205 ) {
00206     FRESULT res;
00207     BYTE c, *dir;
00208 
00209 
00210     res = dir_rewind(dj);            /* Rewind directory object */
00211     if (res != FR_OK) return res;
00212 
00213     dir = FatFs->buf;
00214     do {
00215         res = disk_readp(dir, dj->sect, (WORD)((dj->index % 16) * 32), 32)    /* Read an entry */
00216               ? FR_DISK_ERR : FR_OK;
00217         if (res != FR_OK) break;
00218         c = dir[DIR_Name];    /* First character */
00219         if (c == 0) {
00220             res = FR_NO_FILE;    /* Reached to end of table */
00221             break;
00222         }
00223         if (!(dir[DIR_Attr] & AM_VOL) && !mem_cmp(dir, dj->fn, 11)) /* Is it a valid entry? */
00224             break;
00225         res = dir_next(dj);                            /* Next entry */
00226     } while (res == FR_OK);
00227 
00228     return res;
00229 }
00230 
00231 
00232 
00233 
00234 /*-----------------------------------------------------------------------*/
00235 /* Read an object from the directory                                     */
00236 /*-----------------------------------------------------------------------*/
00237 #if _USE_DIR
00238 static
00239 FRESULT dir_read (
00240     FATDIR *dj            /* Pointer to the directory object to store read object name */
00241 ) {
00242     FRESULT res;
00243     BYTE a, c, *dir;
00244 
00245 
00246     res = FR_NO_FILE;
00247     dir = FatFs->buf;
00248     while (dj->sect) {
00249         res = disk_readp(dir, dj->sect, (WORD)((dj->index % 16) * 32), 32)    /* Read an entry */
00250               ? FR_DISK_ERR : FR_OK;
00251         if (res != FR_OK) break;
00252         c = dir[DIR_Name];
00253         if (c == 0) {
00254             res = FR_NO_FILE;    /* Reached to end of table */
00255             break;
00256         }
00257         a = dir[DIR_Attr] & AM_MASK;
00258         if (c != 0xE5 && c != '.' && !(a & AM_VOL))    /* Is it a valid entry? */
00259             break;
00260         res = dir_next(dj);                /* Next entry */
00261         if (res != FR_OK) break;
00262     }
00263 
00264     if (res != FR_OK) dj->sect = 0;
00265 
00266     return res;
00267 }
00268 #endif
00269 
00270 
00271 
00272 /*-----------------------------------------------------------------------*/
00273 /* Pick a segment and create the object name in directory form           */
00274 /*-----------------------------------------------------------------------*/
00275 
00276 #ifdef _EXCVT
00277 static const BYTE cvt[] = _EXCVT;
00278 #endif
00279 
00280 static
00281 FRESULT create_name (
00282     FATDIR *dj,            /* Pointer to the directory object */
00283     const char **path    /* Pointer to pointer to the segment in the path string */
00284 ) {
00285     BYTE c, d, ni, si, i, *sfn;
00286     const char *p;
00287 
00288     /* Create file name in directory form */
00289     sfn = dj->fn;
00290     mem_set(sfn, ' ', 11);
00291     si = i = 0;
00292     ni = 8;
00293     p = *path;
00294     for (;;) {
00295         c = p[si++];
00296         if (c <= ' ' || c == '/') break;    /* Break on end of segment */
00297         if (c == '.' || i >= ni) {
00298             if (ni != 8 || c != '.') break;
00299             i = 8;
00300             ni = 11;
00301             continue;
00302         }
00303 #ifdef _EXCVT
00304         if (c >= 0x80)                    /* To upper extended char (SBCS) */
00305             c = cvt[c - 0x80];
00306 #endif
00307         if (IsDBCS1(c) && i >= ni - 1) {    /* DBC 1st byte? */
00308             d = p[si++];                    /* Get 2nd byte */
00309             sfn[i++] = c;
00310             sfn[i++] = d;
00311         } else {                        /* Single byte code */
00312             if (IsLower(c)) c -= 0x20;    /* toupper */
00313             sfn[i++] = c;
00314         }
00315     }
00316     *path = &p[si];                        /* Rerurn pointer to the next segment */
00317 
00318     sfn[11] = (c <= ' ') ? 1 : 0;        /* Set last segment flag if end of path */
00319 
00320     return FR_OK;
00321 }
00322 
00323 
00324 
00325 
00326 /*-----------------------------------------------------------------------*/
00327 /* Get file information from directory entry                             */
00328 /*-----------------------------------------------------------------------*/
00329 #if _USE_DIR
00330 static
00331 void get_fileinfo (        /* No return code */
00332     FATDIR *dj,            /* Pointer to the directory object */
00333     FILINFO *fno         /* Pointer to store the file information */
00334 ) {
00335     BYTE i, c, *dir;
00336     char *p;
00337 
00338 
00339     p = fno->fname;
00340     if (dj->sect) {
00341         dir = FatFs->buf;
00342         for (i = 0; i < 8; i++) {    /* Copy file name body */
00343             c = dir[i];
00344             if (c == ' ') break;
00345             if (c == 0x05) c = 0xE5;
00346             *p++ = c;
00347         }
00348         if (dir[8] != ' ') {        /* Copy file name extension */
00349             *p++ = '.';
00350             for (i = 8; i < 11; i++) {
00351                 c = dir[i];
00352                 if (c == ' ') break;
00353                 *p++ = c;
00354             }
00355         }
00356         fno->fattrib = dir[DIR_Attr];                /* Attribute */
00357         fno->fsize = LD_DWORD(dir+DIR_FileSize);    /* Size */
00358         fno->fdate = LD_WORD(dir+DIR_WrtDate);        /* Date */
00359         fno->ftime = LD_WORD(dir+DIR_WrtTime);        /* Time */
00360     }
00361     *p = 0;
00362 }
00363 #endif /* _USE_DIR */
00364 
00365 
00366 
00367 /*-----------------------------------------------------------------------*/
00368 /* Follow a file path                                                    */
00369 /*-----------------------------------------------------------------------*/
00370 
00371 static
00372 FRESULT follow_path (    /* FR_OK(0): successful, !=0: error code */
00373     FATDIR *dj,            /* Directory object to return last directory and found object */
00374     const char *path    /* Full-path string to find a file or directory */
00375 ) {
00376     FRESULT res;
00377     BYTE *dir;
00378 
00379 
00380     while (*path == ' ') path++;        /* Skip leading spaces */
00381     if (*path == '/') path++;            /* Strip heading separator */
00382     dj->sclust = 0;                        /* Set start directory (always root dir) */
00383 
00384     if ((BYTE)*path <= ' ') {            /* Null path means the root directory */
00385         res = dir_rewind(dj);
00386         FatFs->buf[0] = 0;
00387 
00388     } else {                            /* Follow path */
00389         for (;;) {
00390             res = create_name(dj, &path);    /* Get a segment */
00391             if (res != FR_OK) break;
00392             res = dir_find(dj);                /* Find it */
00393             if (res != FR_OK) {                /* Could not find the object */
00394                 if (res == FR_NO_FILE && !*(dj->fn+11))
00395                     res = FR_NO_PATH;
00396                 break;
00397             }
00398             if (*(dj->fn+11)) break;        /* Last segment match. Function completed. */
00399             dir = FatFs->buf;                /* There is next segment. Follow the sub directory */
00400             if (!(dir[DIR_Attr] & AM_DIR)) { /* Cannot follow because it is a file */
00401                 res = FR_NO_PATH;
00402                 break;
00403             }
00404             dj->sclust =
00405 #if _FS_FAT32
00406                 ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00407 #endif
00408                 LD_WORD(dir+DIR_FstClusLO);
00409         }
00410     }
00411 
00412     return res;
00413 }
00414 
00415 
00416 
00417 
00418 /*-----------------------------------------------------------------------*/
00419 /* Check a sector if it is an FAT boot record                            */
00420 /*-----------------------------------------------------------------------*/
00421 
00422 static
00423 __attribute__((section(".SD_Code"))) BYTE check_fs (    /* 0:The FAT boot record, 1:Valid boot record but not an FAT, 2:Not a boot record, 3:Error */
00424     BYTE *buf,    /* Working buffer */
00425     DWORD sect    /* Sector# (lba) to check if it is an FAT boot record or not */
00426 ) {
00427     if (disk_readp(buf, sect, 510, 2))        /* Read the boot sector */
00428         return 3;
00429     if (LD_WORD(buf) != 0xAA55)                /* Check record signature */
00430         return 2;
00431 
00432     if (!disk_readp(buf, sect, BS_FilSysType, 2) && LD_WORD(buf) == 0x4146)    /* Check FAT12/16 */
00433         return 0;
00434 #if _FS_FAT32
00435     if (!disk_readp(buf, sect, BS_FilSysType32, 2) && LD_WORD(buf) == 0x4146)    /* Check FAT32 */
00436         return 0;
00437 #endif
00438     return 1;
00439 }
00440 
00441 
00442 
00443 
00444 /*--------------------------------------------------------------------------
00445 
00446    Public Functions
00447 
00448 --------------------------------------------------------------------------*/
00449 
00450 
00451 
00452 /*-----------------------------------------------------------------------*/
00453 /* Mount/Unmount a Locical Drive                                         */
00454 /*-----------------------------------------------------------------------*/
00455 
00456 __attribute__((section(".SD_Code"))) FRESULT pf_mount (
00457     FATFS *fs        /* Pointer to new file system object (NULL: Unmount) */
00458 ) {
00459     BYTE fmt, buf[36];
00460     DWORD bsect, fsize, tsect, mclst;
00461 
00462 
00463     FatFs = 0;
00464     if (!fs) return FR_OK;                /* Unregister fs object */
00465 
00466     if (disk_initialize() & STA_NOINIT)    /* Check if the drive is ready or not */
00467         return FR_NOT_READY;
00468 
00469     /* Search FAT partition on the drive */
00470     bsect = 0;
00471     fmt = check_fs(buf, bsect);            /* Check sector 0 as an SFD format */
00472     if (fmt == 1) {                        /* Not an FAT boot record, it may be FDISK format */
00473         /* Check a partition listed in top of the partition table */
00474         if (disk_readp(buf, bsect, MBR_Table, 16)) {    /* 1st partition entry */
00475             fmt = 3;
00476         } else {
00477             if (buf[4]) {                    /* Is the partition existing? */
00478                 bsect = LD_DWORD(&buf[8]);    /* Partition offset in LBA */
00479                 fmt = check_fs(buf, bsect);    /* Check the partition */
00480             }
00481         }
00482     }
00483     if (fmt == 3) return FR_DISK_ERR;
00484     if (fmt) return FR_NO_FILESYSTEM;    /* No valid FAT patition is found */
00485 
00486     /* Initialize the file system object */
00487     if (disk_readp(buf, bsect, 13, sizeof(buf))) return FR_DISK_ERR;
00488 
00489     fsize = LD_WORD(buf+BPB_FATSz16-13);                /* Number of sectors per FAT */
00490     if (!fsize) fsize = LD_DWORD(buf+BPB_FATSz32-13);
00491 
00492     fsize *= buf[BPB_NumFATs-13];                        /* Number of sectors in FAT area */
00493     fs->fatbase = bsect + LD_WORD(buf+BPB_RsvdSecCnt-13); /* FAT start sector (lba) */
00494     fs->csize = buf[BPB_SecPerClus-13];                    /* Number of sectors per cluster */
00495     fs->n_rootdir = LD_WORD(buf+BPB_RootEntCnt-13);        /* Nmuber of root directory entries */
00496     tsect = LD_WORD(buf+BPB_TotSec16-13);                /* Number of sectors on the file system */
00497     if (!tsect) tsect = LD_DWORD(buf+BPB_TotSec32-13);
00498     mclst = (tsect                        /* Last cluster# + 1 */
00499              - LD_WORD(buf+BPB_RsvdSecCnt-13) - fsize - fs->n_rootdir / 16
00500             ) / fs->csize + 2;
00501     fs->max_clust = (CLUST)mclst;
00502 
00503     fmt = FS_FAT12;                            /* Determine the FAT sub type */
00504     if (mclst >= 0xFF7) fmt = FS_FAT16;        /* Number of clusters >= 0xFF5 */
00505     if (mclst >= 0xFFF7)                    /* Number of clusters >= 0xFFF5 */
00506 #if _FS_FAT32
00507         fmt = FS_FAT32;
00508 #else
00509         return FR_NO_FILESYSTEM;
00510 #endif
00511 
00512     fs->fs_type = fmt;        /* FAT sub-type */
00513 #if _FS_FAT32
00514     if (fmt == FS_FAT32)
00515         fs->dirbase = LD_DWORD(buf+(BPB_RootClus-13));    /* Root directory start cluster */
00516     else
00517 #endif
00518         fs->dirbase = fs->fatbase + fsize;                /* Root directory start sector (lba) */
00519     fs->database = fs->fatbase + fsize + fs->n_rootdir / 16;    /* Data start sector (lba) */
00520 
00521     fs->flag = 0;
00522     FatFs = fs;
00523 
00524     return FR_OK;
00525 }
00526 
00527 
00528 
00529 
00530 /*-----------------------------------------------------------------------*/
00531 /* Open or Create a File                                                 */
00532 /*-----------------------------------------------------------------------*/
00533 
00534 FRESULT pf_open (
00535     const char *path    /* Pointer to the file name */
00536 ) {
00537     FRESULT res;
00538     FATDIR dj;
00539     BYTE sp[12], dir[32];
00540     FATFS *fs = FatFs;
00541 
00542 
00543     if (!fs)                        /* Check file system */
00544         return FR_NOT_ENABLED;
00545 
00546     fs->flag = 0;
00547     fs->buf = dir;
00548     dj.fn = sp;
00549     res = follow_path(&dj, path);    /* Follow the file path */
00550     if (res != FR_OK) return res;    /* Follow failed */
00551     if (!dir[0] || (dir[DIR_Attr] & AM_DIR))    /* It is a directory */
00552         return FR_NO_FILE;
00553 
00554     fs->org_clust =                        /* File start cluster */
00555 #if _FS_FAT32
00556         ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00557 #endif
00558         LD_WORD(dir+DIR_FstClusLO);
00559     fs->fsize = LD_DWORD(dir+DIR_FileSize);    /* File size */
00560     fs->fptr = 0;                        /* File pointer */
00561     fs->flag = FA_OPENED;
00562 
00563     return FR_OK;
00564 }
00565 
00566 
00567 
00568 
00569 /*-----------------------------------------------------------------------*/
00570 /* Read File                                                             */
00571 /*-----------------------------------------------------------------------*/
00572 #if _USE_READ
00573 
00574 FRESULT pf_read (
00575     void* buff,        /* Pointer to the read buffer (NULL:Forward data to the stream)*/
00576     WORD btr,        /* Number of bytes to read */
00577     WORD* br        /* Pointer to number of bytes read */
00578 ) {
00579     DRESULT dr;
00580     CLUST clst;
00581     DWORD sect, remain;
00582     BYTE *rbuff = (BYTE *)buff;
00583     WORD rcnt;
00584     FATFS *fs = FatFs;
00585 
00586 
00587     *br = 0;
00588     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00589     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00590         return FR_NOT_OPENED;
00591 
00592     remain = fs->fsize - fs->fptr;
00593     if (btr > remain) btr = (WORD)remain;            /* Truncate btr by remaining bytes */
00594 
00595     while (btr)    {                                    /* Repeat until all data transferred */
00596         if ((fs->fptr % 512) == 0) {                /* On the sector boundary? */
00597             if ((fs->fptr / 512 % fs->csize) == 0) {    /* On the cluster boundary? */
00598                 clst = (fs->fptr == 0) ?            /* On the top of the file? */
00599                        fs->org_clust : get_fat(fs->curr_clust);
00600                 if (clst <= 1) goto fr_abort;
00601                 fs->curr_clust = clst;                /* Update current cluster */
00602                 fs->csect = 0;                        /* Reset sector offset in the cluster */
00603             }
00604             sect = clust2sect(fs->curr_clust);        /* Get current sector */
00605             if (!sect) goto fr_abort;
00606             fs->dsect = sect + fs->csect++;
00607         }
00608         rcnt = 512 - ((WORD)fs->fptr % 512);        /* Get partial sector data from sector buffer */
00609         if (rcnt > btr) rcnt = btr;
00610         dr = disk_readp(!buff ? 0 : rbuff, fs->dsect, (WORD)(fs->fptr % 512), rcnt);
00611         if (dr) goto fr_abort;
00612         fs->fptr += rcnt;
00613         rbuff += rcnt;            /* Update pointers and counters */
00614         btr -= rcnt;
00615         *br += rcnt;
00616     }
00617 
00618     return FR_OK;
00619 
00620 fr_abort:
00621     fs->flag = 0;
00622     return FR_DISK_ERR;
00623 }
00624 #endif
00625 
00626 
00627 
00628 /*-----------------------------------------------------------------------*/
00629 /* Write File                                                            */
00630 /*-----------------------------------------------------------------------*/
00631 #if _USE_WRITE
00632 
00633 FRESULT pf_write (
00634     const void* buff,    /* Pointer to the data to be written */
00635     WORD btw,            /* Number of bytes to write (0:Finalize the current write operation) */
00636     WORD* bw            /* Pointer to number of bytes written */
00637 ) {
00638     CLUST clst;
00639     DWORD sect, remain;
00640     const BYTE *p = (const BYTE *)buff;
00641     WORD wcnt;
00642     FATFS *fs = FatFs;
00643 
00644 
00645     *bw = 0;
00646     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00647     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00648         return FR_NOT_OPENED;
00649 
00650     if (!btw) {        /* Finalize request */
00651         if ((fs->flag & FA__WIP) && disk_writep(0, 0)) goto fw_abort;
00652         fs->flag &= ~FA__WIP;
00653         return FR_OK;
00654     } else {        /* Write data request */
00655         if (!(fs->flag & FA__WIP))        /* Round down fptr to the sector boundary */
00656             fs->fptr &= 0xFFFFFE00;
00657     }
00658     remain = fs->fsize - fs->fptr;
00659     if (btw > remain) btw = (WORD)remain;            /* Truncate btw by remaining bytes */
00660 
00661     while (btw)    {                                    /* Repeat until all data transferred */
00662         if (((WORD)fs->fptr % 512) == 0) {                /* On the sector boundary? */
00663             if ((fs->fptr / 512 % fs->csize) == 0) {    /* On the cluster boundary? */
00664                 clst = (fs->fptr == 0) ?            /* On the top of the file? */
00665                        fs->org_clust : get_fat(fs->curr_clust);
00666                 if (clst <= 1) goto fw_abort;
00667                 fs->curr_clust = clst;                /* Update current cluster */
00668                 fs->csect = 0;                        /* Reset sector offset in the cluster */
00669             }
00670             sect = clust2sect(fs->curr_clust);        /* Get current sector */
00671             if (!sect) goto fw_abort;
00672             fs->dsect = sect + fs->csect++;
00673             if (disk_writep(0, fs->dsect)) goto fw_abort;    /* Initiate a sector write operation */
00674             fs->flag |= FA__WIP;
00675         }
00676         wcnt = 512 - ((WORD)fs->fptr % 512);        /* Number of bytes to write to the sector */
00677         if (wcnt > btw) wcnt = btw;
00678         if (disk_writep(p, wcnt)) goto fw_abort;    /* Send data to the sector */
00679         fs->fptr += wcnt;
00680         p += wcnt;                /* Update pointers and counters */
00681         btw -= wcnt;
00682         *bw += wcnt;
00683         if (((WORD)fs->fptr % 512) == 0) {
00684             if (disk_writep(0, 0)) goto fw_abort;    /* Finalize the currtent secter write operation */
00685             fs->flag &= ~FA__WIP;
00686         }
00687     }
00688 
00689     return FR_OK;
00690 
00691 fw_abort:
00692     fs->flag = 0;
00693     return FR_DISK_ERR;
00694 }
00695 #endif
00696 
00697 
00698 
00699 /*-----------------------------------------------------------------------*/
00700 /* Seek File R/W Pointer                                                 */
00701 /*-----------------------------------------------------------------------*/
00702 #if _USE_LSEEK
00703 
00704 FRESULT pf_lseek (
00705     DWORD ofs        /* File pointer from top of file */
00706 ) {
00707     CLUST clst;
00708     DWORD bcs, sect, ifptr;
00709     FATFS *fs = FatFs;
00710 
00711 
00712     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00713     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00714         return FR_NOT_OPENED;
00715 
00716     if (ofs > fs->fsize) ofs = fs->fsize;    /* Clip offset with the file size */
00717     ifptr = fs->fptr;
00718     fs->fptr = 0;
00719     if (ofs > 0) {
00720         bcs = (DWORD)fs->csize * 512;    /* Cluster size (byte) */
00721         if (ifptr > 0 &&
00722                 (ofs - 1) / bcs >= (ifptr - 1) / bcs) {    /* When seek to same or following cluster, */
00723             fs->fptr = (ifptr - 1) & ~(bcs - 1);    /* start from the current cluster */
00724             ofs -= fs->fptr;
00725             clst = fs->curr_clust;
00726         } else {                            /* When seek to back cluster, */
00727             clst = fs->org_clust;            /* start from the first cluster */
00728             fs->curr_clust = clst;
00729         }
00730         while (ofs > bcs) {                /* Cluster following loop */
00731             clst = get_fat(clst);        /* Follow cluster chain */
00732             if (clst <= 1 || clst >= fs->max_clust) goto fe_abort;
00733             fs->curr_clust = clst;
00734             fs->fptr += bcs;
00735             ofs -= bcs;
00736         }
00737         fs->fptr += ofs;
00738         sect = clust2sect(clst);        /* Current sector */
00739         if (!sect) goto fe_abort;
00740         fs->csect = (BYTE)(ofs / 512);    /* Sector offset in the cluster */
00741         if (ofs % 512)
00742             fs->dsect = sect + fs->csect++;
00743     }
00744 
00745     return FR_OK;
00746 
00747 fe_abort:
00748     fs->flag = 0;
00749     return FR_DISK_ERR;
00750 }
00751 #endif
00752 
00753 
00754 
00755 /*-----------------------------------------------------------------------*/
00756 /* Create a Directroy Object                                             */
00757 /*-----------------------------------------------------------------------*/
00758 #if _USE_DIR
00759 
00760 FRESULT pf_opendir (
00761     FATDIR *dj,            /* Pointer to directory object to create */
00762     const char *path    /* Pointer to the directory path */
00763 ) {
00764     FRESULT res;
00765     BYTE sp[12], dir[32];
00766     FATFS *fs = FatFs;
00767 
00768 
00769     if (!fs) {                /* Check file system */
00770         res = FR_NOT_ENABLED;
00771     } else {
00772         fs->buf = dir;
00773         dj->fn = sp;
00774         res = follow_path(dj, path);            /* Follow the path to the directory */
00775         if (res == FR_OK) {                        /* Follow completed */
00776             if (dir[0]) {                        /* It is not the root dir */
00777                 if (dir[DIR_Attr] & AM_DIR) {    /* The object is a directory */
00778                     dj->sclust =
00779 #if _FS_FAT32
00780                         ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00781 #endif
00782                         LD_WORD(dir+DIR_FstClusLO);
00783                 } else {                        /* The object is not a directory */
00784                     res = FR_NO_PATH;
00785                 }
00786             }
00787             if (res == FR_OK)
00788                 res = dir_rewind(dj);            /* Rewind dir */
00789         }
00790         if (res == FR_NO_FILE) res = FR_NO_PATH;
00791     }
00792 
00793     return res;
00794 }
00795 
00796 
00797 
00798 
00799 /*-----------------------------------------------------------------------*/
00800 /* Read Directory Entry in Sequense                                      */
00801 /*-----------------------------------------------------------------------*/
00802 
00803 FRESULT pf_readdir (
00804     FATDIR *dj,            /* Pointer to the open directory object */
00805     FILINFO *fno        /* Pointer to file information to return */
00806 ) {
00807     FRESULT res;
00808     BYTE sp[12], dir[32];
00809     FATFS *fs = FatFs;
00810 
00811 
00812     if (!fs) {                /* Check file system */
00813         res = FR_NOT_ENABLED;
00814     } else {
00815         fs->buf = dir;
00816         dj->fn = sp;
00817         if (!fno) {
00818             res = dir_rewind(dj);
00819         } else {
00820             res = dir_read(dj);
00821             if (res == FR_NO_FILE) {
00822                 dj->sect = 0;
00823                 res = FR_OK;
00824             }
00825             if (res == FR_OK) {                /* A valid entry is found */
00826                 get_fileinfo(dj, fno);        /* Get the object information */
00827                 res = dir_next(dj);            /* Increment index for next */
00828                 if (res == FR_NO_FILE) {
00829                     dj->sect = 0;
00830                     res = FR_OK;
00831                 }
00832             }
00833         }
00834     }
00835 
00836     return res;
00837 }
00838 
00839 #endif /* _USE_DIR */
00840 
00841