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 
00024 #include "pff.h"        /* Petit FatFs configurations and declarations */
00025 #include "diskio.h"        /* Declarations of low level disk I/O functions */
00026 
00027 namespace PFFS {
00028 
00029 /*--------------------------------------------------------------------------
00030 
00031    Private Functions
00032 
00033 ---------------------------------------------------------------------------*/
00034 
00035 static
00036 FATFS *FatFs;    /* Pointer to the file system object (logical drive) */
00037 
00038 
00039 
00040 /*-----------------------------------------------------------------------*/
00041 /* String functions                                                      */
00042 /*-----------------------------------------------------------------------*/
00043 
00044 /* Fill memory */
00045 static
00046 void mem_set (void* dst, int val, int cnt) {
00047     char *d = (char*)dst;
00048     while (cnt--) *d++ = (char)val;
00049 }
00050 
00051 /* Compare memory to memory */
00052 static
00053 int mem_cmp (const void* dst, const void* src, int cnt) {
00054     const char *d = (const char *)dst, *s = (const char *)src;
00055     int r = 0;
00056     while (cnt-- && (r = *d++ - *s++) == 0) ;
00057     return r;
00058 }
00059 
00060 
00061 
00062 /*-----------------------------------------------------------------------*/
00063 /* FAT access - Read value of a FAT entry                                */
00064 /*-----------------------------------------------------------------------*/
00065 
00066 static
00067 CLUST get_fat (    /* 1:IO error, Else:Cluster status */
00068     CLUST clst    /* Cluster# to get the link information */
00069 ) {
00070     WORD wc, bc, ofs;
00071     BYTE buf[4];
00072     FATFS *fs = FatFs;
00073 
00074 
00075     if (clst < 2 || clst >= fs->max_clust)    /* Range check */
00076         return 1;
00077 
00078     switch (fs->fs_type) {
00079         case FS_FAT12 :
00080             bc = (WORD)clst;
00081             bc += bc / 2;
00082             ofs = bc % 512;
00083             bc /= 512;
00084             if (ofs != 511) {
00085                 if (disk_readp(buf, fs->fatbase + bc, ofs, 2)) break;
00086             } else {
00087                 if (disk_readp(buf, fs->fatbase + bc, 511, 1)) break;
00088                 if (disk_readp(buf+1, fs->fatbase + bc + 1, 0, 1)) break;
00089             }
00090             wc = LD_WORD(buf);
00091             return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);
00092 
00093         case FS_FAT16 :
00094             if (disk_readp(buf, fs->fatbase + clst / 256, (WORD)(((WORD)clst % 256) * 2), 2)) break;
00095             return LD_WORD(buf);
00096 #if _FS_FAT32
00097         case FS_FAT32 :
00098             if (disk_readp(buf, fs->fatbase + clst / 128, (WORD)(((WORD)clst % 128) * 4), 4)) break;
00099             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
00100 #endif
00101     }
00102 
00103     return 1;    /* An error occured at the disk I/O layer */
00104 }
00105 
00106 
00107 
00108 
00109 /*-----------------------------------------------------------------------*/
00110 /* Get sector# from cluster#                                             */
00111 /*-----------------------------------------------------------------------*/
00112 
00113 static
00114 DWORD clust2sect (    /* !=0: Sector number, 0: Failed - invalid cluster# */
00115     CLUST clst        /* Cluster# to be converted */
00116 ) {
00117     FATFS *fs = FatFs;
00118 
00119 
00120     clst -= 2;
00121     if (clst >= (fs->max_clust - 2)) return 0;        /* Invalid cluster# */
00122     return (DWORD)clst * fs->csize + fs->database;
00123 }
00124 
00125 
00126 
00127 
00128 /*-----------------------------------------------------------------------*/
00129 /* Directory handling - Rewind directory index                           */
00130 /*-----------------------------------------------------------------------*/
00131 
00132 static
00133 FRESULT dir_rewind (
00134     FATDIR *dj            /* Pointer to directory object */
00135 ) {
00136     CLUST clst;
00137     FATFS *fs = FatFs;
00138 
00139 
00140     dj->index = 0;
00141     clst = dj->sclust;
00142     if (clst == 1 || clst >= fs->max_clust)    /* Check start cluster range */
00143         return FR_DISK_ERR;
00144 #if _FS_FAT32
00145     if (!clst && fs->fs_type == FS_FAT32)    /* Replace cluster# 0 with root cluster# if in FAT32 */
00146         clst = fs->dirbase;
00147 #endif
00148     dj->clust = clst;                        /* Current cluster */
00149     dj->sect = clst ? clust2sect(clst) : fs->dirbase;    /* Current sector */
00150 
00151     return FR_OK;    /* Seek succeeded */
00152 }
00153 
00154 
00155 
00156 
00157 /*-----------------------------------------------------------------------*/
00158 /* Directory handling - Move directory index next                        */
00159 /*-----------------------------------------------------------------------*/
00160 
00161 static
00162 FRESULT dir_next (    /* FR_OK:Succeeded, FR_NO_FILE:End of table */
00163     FATDIR *dj            /* Pointer to directory object */
00164 ) {
00165     CLUST clst;
00166     WORD i;
00167     FATFS *fs = FatFs;
00168 
00169 
00170     i = dj->index + 1;
00171     if (!i || !dj->sect)    /* Report EOT when index has reached 65535 */
00172         return FR_NO_FILE;
00173 
00174     if (!(i & (16-1))) {    /* Sector changed? */
00175         dj->sect++;            /* Next sector */
00176 
00177         if (dj->clust == 0) {    /* Static table */
00178             if (i >= fs->n_rootdir)    /* Report EOT when end of table */
00179                 return FR_NO_FILE;
00180         } else {                   /* Dynamic table */
00181             if (((i / 16) & (fs->csize-1)) == 0) {    /* Cluster changed? */
00182                 clst = get_fat(dj->clust);        /* Get next cluster */
00183                 if (clst <= 1) return FR_DISK_ERR;
00184                 if (clst >= fs->max_clust)        /* When it reached end of dynamic table */
00185                     return FR_NO_FILE;            /* Report EOT */
00186                 dj->clust = clst;                /* Initialize data for new cluster */
00187                 dj->sect = clust2sect(clst);
00188             }
00189         }
00190     }
00191 
00192     dj->index = i;
00193 
00194     return FR_OK;
00195 }
00196 
00197 
00198 
00199 
00200 /*-----------------------------------------------------------------------*/
00201 /* Directory handling - Find an object in the directory                  */
00202 /*-----------------------------------------------------------------------*/
00203 
00204 static
00205 FRESULT dir_find (
00206     FATDIR *dj            /* Pointer to the directory object linked to the file name */
00207 ) {
00208     FRESULT res;
00209     BYTE c, *dir;
00210 
00211 
00212     res = dir_rewind(dj);            /* Rewind directory object */
00213     if (res != FR_OK) return res;
00214 
00215     dir = FatFs->buf;
00216     do {
00217         res = disk_readp(dir, dj->sect, (WORD)((dj->index % 16) * 32), 32)    /* Read an entry */
00218               ? FR_DISK_ERR : FR_OK;
00219         if (res != FR_OK) break;
00220         c = dir[DIR_Name];    /* First character */
00221         if (c == 0) {
00222             res = FR_NO_FILE;    /* Reached to end of table */
00223             break;
00224         }
00225         if (!(dir[DIR_Attr] & AM_VOL) && !mem_cmp(dir, dj->fn, 11)) /* Is it a valid entry? */
00226             break;
00227         res = dir_next(dj);                            /* Next entry */
00228     } while (res == FR_OK);
00229 
00230     return res;
00231 }
00232 
00233 
00234 
00235 
00236 /*-----------------------------------------------------------------------*/
00237 /* Read an object from the directory                                     */
00238 /*-----------------------------------------------------------------------*/
00239 #if _USE_DIR
00240 static
00241 FRESULT dir_read (
00242     FATDIR *dj            /* Pointer to the directory object to store read object name */
00243 ) {
00244     FRESULT res;
00245     BYTE a, c, *dir;
00246 
00247 
00248     res = FR_NO_FILE;
00249     dir = FatFs->buf;
00250     while (dj->sect) {
00251         res = disk_readp(dir, dj->sect, (WORD)((dj->index % 16) * 32), 32)    /* Read an entry */
00252               ? FR_DISK_ERR : FR_OK;
00253         if (res != FR_OK) break;
00254         c = dir[DIR_Name];
00255         if (c == 0) {
00256             res = FR_NO_FILE;    /* Reached to end of table */
00257             break;
00258         }
00259         a = dir[DIR_Attr] & AM_MASK;
00260         if (c != 0xE5 && c != '.' && !(a & AM_VOL))    /* Is it a valid entry? */
00261             break;
00262         res = dir_next(dj);                /* Next entry */
00263         if (res != FR_OK) break;
00264     }
00265 
00266     if (res != FR_OK) dj->sect = 0;
00267 
00268     return res;
00269 }
00270 #endif
00271 
00272 
00273 
00274 /*-----------------------------------------------------------------------*/
00275 /* Pick a segment and create the object name in directory form           */
00276 /*-----------------------------------------------------------------------*/
00277 
00278 #ifdef _EXCVT
00279 static const BYTE cvt[] = _EXCVT;
00280 #endif
00281 
00282 static
00283 FRESULT create_name (
00284     FATDIR *dj,            /* Pointer to the directory object */
00285     const char **path    /* Pointer to pointer to the segment in the path string */
00286 ) {
00287     BYTE c, d, ni, si, i, *sfn;
00288     const char *p;
00289 
00290     /* Create file name in directory form */
00291     sfn = dj->fn;
00292     mem_set(sfn, ' ', 11);
00293     si = i = 0;
00294     ni = 8;
00295     p = *path;
00296     for (;;) {
00297         c = p[si++];
00298         if (c <= ' ' || c == '/') break;    /* Break on end of segment */
00299         if (c == '.' || i >= ni) {
00300             if (ni != 8 || c != '.') break;
00301             i = 8;
00302             ni = 11;
00303             continue;
00304         }
00305 #ifdef _EXCVT
00306         if (c >= 0x80)                    /* To upper extended char (SBCS) */
00307             c = cvt[c - 0x80];
00308 #endif
00309         if (IsDBCS1(c) && i >= ni - 1) {    /* DBC 1st byte? */
00310             d = p[si++];                    /* Get 2nd byte */
00311             sfn[i++] = c;
00312             sfn[i++] = d;
00313         } else {                        /* Single byte code */
00314             if (IsLower(c)) c -= 0x20;    /* toupper */
00315             sfn[i++] = c;
00316         }
00317     }
00318     *path = &p[si];                        /* Rerurn pointer to the next segment */
00319 
00320     sfn[11] = (c <= ' ') ? 1 : 0;        /* Set last segment flag if end of path */
00321 
00322     return FR_OK;
00323 }
00324 
00325 
00326 
00327 
00328 /*-----------------------------------------------------------------------*/
00329 /* Get file information from directory entry                             */
00330 /*-----------------------------------------------------------------------*/
00331 #if _USE_DIR
00332 static
00333 void get_fileinfo (        /* No return code */
00334     FATDIR *dj,            /* Pointer to the directory object */
00335     FILINFO *fno         /* Pointer to store the file information */
00336 ) {
00337     BYTE i, c, *dir;
00338     char *p;
00339 
00340 
00341     p = fno->fname;
00342     if (dj->sect) {
00343         dir = FatFs->buf;
00344         for (i = 0; i < 8; i++) {    /* Copy file name body */
00345             c = dir[i];
00346             if (c == ' ') break;
00347             if (c == 0x05) c = 0xE5;
00348             *p++ = c;
00349         }
00350         if (dir[8] != ' ') {        /* Copy file name extension */
00351             *p++ = '.';
00352             for (i = 8; i < 11; i++) {
00353                 c = dir[i];
00354                 if (c == ' ') break;
00355                 *p++ = c;
00356             }
00357         }
00358         fno->fattrib = dir[DIR_Attr];                /* Attribute */
00359         fno->fsize = LD_DWORD(dir+DIR_FileSize);    /* Size */
00360         fno->fdate = LD_WORD(dir+DIR_WrtDate);        /* Date */
00361         fno->ftime = LD_WORD(dir+DIR_WrtTime);        /* Time */
00362     }
00363     *p = 0;
00364 }
00365 #endif /* _USE_DIR */
00366 
00367 
00368 
00369 /*-----------------------------------------------------------------------*/
00370 /* Follow a file path                                                    */
00371 /*-----------------------------------------------------------------------*/
00372 
00373 static
00374 FRESULT follow_path (    /* FR_OK(0): successful, !=0: error code */
00375     FATDIR *dj,            /* Directory object to return last directory and found object */
00376     const char *path    /* Full-path string to find a file or directory */
00377 ) {
00378     FRESULT res;
00379     BYTE *dir;
00380 
00381 
00382     while (*path == ' ') path++;        /* Skip leading spaces */
00383     if (*path == '/') path++;            /* Strip heading separator */
00384     dj->sclust = 0;                        /* Set start directory (always root dir) */
00385 
00386     if ((BYTE)*path <= ' ') {            /* Null path means the root directory */
00387         res = dir_rewind(dj);
00388         FatFs->buf[0] = 0;
00389 
00390     } else {                            /* Follow path */
00391         for (;;) {
00392             res = create_name(dj, &path);    /* Get a segment */
00393             if (res != FR_OK) break;
00394             res = dir_find(dj);                /* Find it */
00395             if (res != FR_OK) {                /* Could not find the object */
00396                 if (res == FR_NO_FILE && !*(dj->fn+11))
00397                     res = FR_NO_PATH;
00398                 break;
00399             }
00400             if (*(dj->fn+11)) break;        /* Last segment match. Function completed. */
00401             dir = FatFs->buf;                /* There is next segment. Follow the sub directory */
00402             if (!(dir[DIR_Attr] & AM_DIR)) { /* Cannot follow because it is a file */
00403                 res = FR_NO_PATH;
00404                 break;
00405             }
00406             dj->sclust =
00407 #if _FS_FAT32
00408                 ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00409 #endif
00410                 LD_WORD(dir+DIR_FstClusLO);
00411         }
00412     }
00413 
00414     return res;
00415 }
00416 
00417 
00418 
00419 
00420 /*-----------------------------------------------------------------------*/
00421 /* Check a sector if it is an FAT boot record                            */
00422 /*-----------------------------------------------------------------------*/
00423 
00424 static
00425 __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 */
00426     BYTE *buf,    /* Working buffer */
00427     DWORD sect    /* Sector# (lba) to check if it is an FAT boot record or not */
00428 ) {
00429     if (disk_readp(buf, sect, 510, 2))        /* Read the boot sector */
00430         return 3;
00431     if (LD_WORD(buf) != 0xAA55)                /* Check record signature */
00432         return 2;
00433 
00434     if (!disk_readp(buf, sect, BS_FilSysType, 2) && LD_WORD(buf) == 0x4146)    /* Check FAT12/16 */
00435         return 0;
00436 #if _FS_FAT32
00437     if (!disk_readp(buf, sect, BS_FilSysType32, 2) && LD_WORD(buf) == 0x4146)    /* Check FAT32 */
00438         return 0;
00439 #endif
00440     return 1;
00441 }
00442 
00443 
00444 
00445 
00446 /*--------------------------------------------------------------------------
00447 
00448    Public Functions
00449 
00450 --------------------------------------------------------------------------*/
00451 
00452 
00453 
00454 /*-----------------------------------------------------------------------*/
00455 /* Mount/Unmount a Locical Drive                                         */
00456 /*-----------------------------------------------------------------------*/
00457 
00458 __attribute__((section(".SD_Code"))) FRESULT pf_mount (
00459     FATFS *fs        /* Pointer to new file system object (NULL: Unmount) */
00460 ) {
00461     BYTE fmt, buf[36];
00462     DWORD bsect, fsize, tsect, mclst;
00463 
00464 
00465     FatFs = 0;
00466     if (!fs) return FR_OK;                /* Unregister fs object */
00467 
00468     if (disk_initialize() & STA_NOINIT)    /* Check if the drive is ready or not */
00469         return FR_NOT_READY;
00470 
00471     /* Search FAT partition on the drive */
00472     bsect = 0;
00473     fmt = check_fs(buf, bsect);            /* Check sector 0 as an SFD format */
00474     if (fmt == 1) {                        /* Not an FAT boot record, it may be FDISK format */
00475         /* Check a partition listed in top of the partition table */
00476         if (disk_readp(buf, bsect, MBR_Table, 16)) {    /* 1st partition entry */
00477             fmt = 3;
00478         } else {
00479             if (buf[4]) {                    /* Is the partition existing? */
00480                 bsect = LD_DWORD(&buf[8]);    /* Partition offset in LBA */
00481                 fmt = check_fs(buf, bsect);    /* Check the partition */
00482             }
00483         }
00484     }
00485     if (fmt == 3) return FR_DISK_ERR;
00486     if (fmt) return FR_NO_FILESYSTEM;    /* No valid FAT patition is found */
00487 
00488     /* Initialize the file system object */
00489     if (disk_readp(buf, bsect, 13, sizeof(buf))) return FR_DISK_ERR;
00490 
00491     fsize = LD_WORD(buf+BPB_FATSz16-13);                /* Number of sectors per FAT */
00492     if (!fsize) fsize = LD_DWORD(buf+BPB_FATSz32-13);
00493 
00494     fsize *= buf[BPB_NumFATs-13];                        /* Number of sectors in FAT area */
00495     fs->fatbase = bsect + LD_WORD(buf+BPB_RsvdSecCnt-13); /* FAT start sector (lba) */
00496     fs->csize = buf[BPB_SecPerClus-13];                    /* Number of sectors per cluster */
00497     fs->n_rootdir = LD_WORD(buf+BPB_RootEntCnt-13);        /* Nmuber of root directory entries */
00498     tsect = LD_WORD(buf+BPB_TotSec16-13);                /* Number of sectors on the file system */
00499     if (!tsect) tsect = LD_DWORD(buf+BPB_TotSec32-13);
00500     mclst = (tsect                        /* Last cluster# + 1 */
00501              - LD_WORD(buf+BPB_RsvdSecCnt-13) - fsize - fs->n_rootdir / 16
00502             ) / fs->csize + 2;
00503     fs->max_clust = (CLUST)mclst;
00504 
00505     fmt = FS_FAT12;                            /* Determine the FAT sub type */
00506     if (mclst >= 0xFF7) fmt = FS_FAT16;        /* Number of clusters >= 0xFF5 */
00507     if (mclst >= 0xFFF7)                    /* Number of clusters >= 0xFFF5 */
00508 #if _FS_FAT32
00509         fmt = FS_FAT32;
00510 #else
00511         return FR_NO_FILESYSTEM;
00512 #endif
00513 
00514     fs->fs_type = fmt;        /* FAT sub-type */
00515 #if _FS_FAT32
00516     if (fmt == FS_FAT32)
00517         fs->dirbase = LD_DWORD(buf+(BPB_RootClus-13));    /* Root directory start cluster */
00518     else
00519 #endif
00520         fs->dirbase = fs->fatbase + fsize;                /* Root directory start sector (lba) */
00521     fs->database = fs->fatbase + fsize + fs->n_rootdir / 16;    /* Data start sector (lba) */
00522 
00523     fs->flag = 0;
00524     FatFs = fs;
00525 
00526     return FR_OK;
00527 }
00528 
00529 
00530 
00531 
00532 /*-----------------------------------------------------------------------*/
00533 /* Open or Create a File                                                 */
00534 /*-----------------------------------------------------------------------*/
00535 
00536 FRESULT pf_open (
00537     const char *path    /* Pointer to the file name */
00538 ) {
00539     FRESULT res;
00540     FATDIR dj;
00541     BYTE sp[12], dir[32];
00542     FATFS *fs = FatFs;
00543 
00544 
00545     if (!fs)                        /* Check file system */
00546         return FR_NOT_ENABLED;
00547 
00548     fs->flag = 0;
00549     fs->buf = dir;
00550     dj.fn = sp;
00551     res = follow_path(&dj, path);    /* Follow the file path */
00552     if (res != FR_OK) return res;    /* Follow failed */
00553     if (!dir[0] || (dir[DIR_Attr] & AM_DIR))    /* It is a directory */
00554         return FR_NO_FILE;
00555 
00556     fs->org_clust =                        /* File start cluster */
00557 #if _FS_FAT32
00558         ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00559 #endif
00560         LD_WORD(dir+DIR_FstClusLO);
00561     fs->fsize = LD_DWORD(dir+DIR_FileSize);    /* File size */
00562     fs->fptr = 0;                        /* File pointer */
00563     fs->flag = FA_OPENED;
00564 
00565     return FR_OK;
00566 }
00567 
00568 
00569 
00570 
00571 /*-----------------------------------------------------------------------*/
00572 /* Read File                                                             */
00573 /*-----------------------------------------------------------------------*/
00574 #if _USE_READ
00575 
00576 FRESULT pf_read (
00577     void* buff,        /* Pointer to the read buffer (NULL:Forward data to the stream)*/
00578     WORD btr,        /* Number of bytes to read */
00579     WORD* br        /* Pointer to number of bytes read */
00580 ) {
00581     DRESULT dr;
00582     CLUST clst;
00583     DWORD sect, remain;
00584     BYTE *rbuff = (BYTE *)buff;
00585     WORD rcnt;
00586     FATFS *fs = FatFs;
00587 
00588 
00589     *br = 0;
00590     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00591     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00592         return FR_NOT_OPENED;
00593 
00594     remain = fs->fsize - fs->fptr;
00595     if (btr > remain) btr = (WORD)remain;            /* Truncate btr by remaining bytes */
00596 
00597     while (btr)    {                                    /* Repeat until all data transferred */
00598         if ((fs->fptr % 512) == 0) {                /* On the sector boundary? */
00599             if ((fs->fptr / 512 % fs->csize) == 0) {    /* On the cluster boundary? */
00600                 clst = (fs->fptr == 0) ?            /* On the top of the file? */
00601                        fs->org_clust : get_fat(fs->curr_clust);
00602                 if (clst <= 1) goto fr_abort;
00603                 fs->curr_clust = clst;                /* Update current cluster */
00604                 fs->csect = 0;                        /* Reset sector offset in the cluster */
00605             }
00606             sect = clust2sect(fs->curr_clust);        /* Get current sector */
00607             if (!sect) goto fr_abort;
00608             fs->dsect = sect + fs->csect++;
00609         }
00610         rcnt = 512 - ((WORD)fs->fptr % 512);        /* Get partial sector data from sector buffer */
00611         if (rcnt > btr) rcnt = btr;
00612         dr = disk_readp(!buff ? 0 : rbuff, fs->dsect, (WORD)(fs->fptr % 512), rcnt);
00613         if (dr) goto fr_abort;
00614         fs->fptr += rcnt;
00615         rbuff += rcnt;            /* Update pointers and counters */
00616         btr -= rcnt;
00617         *br += rcnt;
00618     }
00619 
00620     return FR_OK;
00621 
00622 fr_abort:
00623     fs->flag = 0;
00624     return FR_DISK_ERR;
00625 }
00626 #endif
00627 
00628 
00629 
00630 /*-----------------------------------------------------------------------*/
00631 /* Write File                                                            */
00632 /*-----------------------------------------------------------------------*/
00633 #if _USE_WRITE
00634 
00635 FRESULT pf_write (
00636     const void* buff,    /* Pointer to the data to be written */
00637     WORD btw,            /* Number of bytes to write (0:Finalize the current write operation) */
00638     WORD* bw            /* Pointer to number of bytes written */
00639 ) {
00640     CLUST clst;
00641     DWORD sect, remain;
00642     const BYTE *p = (const BYTE *)buff;
00643     WORD wcnt;
00644     FATFS *fs = FatFs;
00645 
00646 
00647     *bw = 0;
00648     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00649     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00650         return FR_NOT_OPENED;
00651 
00652     if (!btw) {        /* Finalize request */
00653         if ((fs->flag & FA__WIP) && disk_writep(0, 0)) goto fw_abort;
00654         fs->flag &= ~FA__WIP;
00655         return FR_OK;
00656     } else {        /* Write data request */
00657         if (!(fs->flag & FA__WIP))        /* Round down fptr to the sector boundary */
00658             fs->fptr &= 0xFFFFFE00;
00659     }
00660     remain = fs->fsize - fs->fptr;
00661     if (btw > remain) btw = (WORD)remain;            /* Truncate btw by remaining bytes */
00662 
00663     while (btw)    {                                    /* Repeat until all data transferred */
00664         if (((WORD)fs->fptr % 512) == 0) {                /* On the sector boundary? */
00665             if ((fs->fptr / 512 % fs->csize) == 0) {    /* On the cluster boundary? */
00666                 clst = (fs->fptr == 0) ?            /* On the top of the file? */
00667                        fs->org_clust : get_fat(fs->curr_clust);
00668                 if (clst <= 1) goto fw_abort;
00669                 fs->curr_clust = clst;                /* Update current cluster */
00670                 fs->csect = 0;                        /* Reset sector offset in the cluster */
00671             }
00672             sect = clust2sect(fs->curr_clust);        /* Get current sector */
00673             if (!sect) goto fw_abort;
00674             fs->dsect = sect + fs->csect++;
00675             if (disk_writep(0, fs->dsect)) goto fw_abort;    /* Initiate a sector write operation */
00676             fs->flag |= FA__WIP;
00677         }
00678         wcnt = 512 - ((WORD)fs->fptr % 512);        /* Number of bytes to write to the sector */
00679         if (wcnt > btw) wcnt = btw;
00680         if (disk_writep(p, wcnt)) goto fw_abort;    /* Send data to the sector */
00681         fs->fptr += wcnt;
00682         p += wcnt;                /* Update pointers and counters */
00683         btw -= wcnt;
00684         *bw += wcnt;
00685         if (((WORD)fs->fptr % 512) == 0) {
00686             if (disk_writep(0, 0)) goto fw_abort;    /* Finalize the currtent secter write operation */
00687             fs->flag &= ~FA__WIP;
00688         }
00689     }
00690 
00691     return FR_OK;
00692 
00693 fw_abort:
00694     fs->flag = 0;
00695     return FR_DISK_ERR;
00696 }
00697 #endif
00698 
00699 
00700 
00701 /*-----------------------------------------------------------------------*/
00702 /* Seek File R/W Pointer                                                 */
00703 /*-----------------------------------------------------------------------*/
00704 #if _USE_LSEEK
00705 
00706 FRESULT pf_lseek (
00707     DWORD ofs        /* File pointer from top of file */
00708 ) {
00709     CLUST clst;
00710     DWORD bcs, sect, ifptr;
00711     FATFS *fs = FatFs;
00712 
00713 
00714     if (!fs) return FR_NOT_ENABLED;        /* Check file system */
00715     if (!(fs->flag & FA_OPENED))        /* Check if opened */
00716         return FR_NOT_OPENED;
00717 
00718     if (ofs > fs->fsize) ofs = fs->fsize;    /* Clip offset with the file size */
00719     ifptr = fs->fptr;
00720     fs->fptr = 0;
00721     if (ofs > 0) {
00722         bcs = (DWORD)fs->csize * 512;    /* Cluster size (byte) */
00723         if (ifptr > 0 &&
00724                 (ofs - 1) / bcs >= (ifptr - 1) / bcs) {    /* When seek to same or following cluster, */
00725             fs->fptr = (ifptr - 1) & ~(bcs - 1);    /* start from the current cluster */
00726             ofs -= fs->fptr;
00727             clst = fs->curr_clust;
00728         } else {                            /* When seek to back cluster, */
00729             clst = fs->org_clust;            /* start from the first cluster */
00730             fs->curr_clust = clst;
00731         }
00732         while (ofs > bcs) {                /* Cluster following loop */
00733             clst = get_fat(clst);        /* Follow cluster chain */
00734             if (clst <= 1 || clst >= fs->max_clust) goto fe_abort;
00735             fs->curr_clust = clst;
00736             fs->fptr += bcs;
00737             ofs -= bcs;
00738         }
00739         fs->fptr += ofs;
00740         sect = clust2sect(clst);        /* Current sector */
00741         if (!sect) goto fe_abort;
00742         fs->csect = (BYTE)(ofs / 512);    /* Sector offset in the cluster */
00743         if (ofs % 512)
00744             fs->dsect = sect + fs->csect++;
00745     }
00746 
00747     return FR_OK;
00748 
00749 fe_abort:
00750     fs->flag = 0;
00751     return FR_DISK_ERR;
00752 }
00753 #endif
00754 
00755 
00756 
00757 /*-----------------------------------------------------------------------*/
00758 /* Create a Directroy Object                                             */
00759 /*-----------------------------------------------------------------------*/
00760 #if _USE_DIR
00761 
00762 FRESULT pf_opendir (
00763     FATDIR *dj,            /* Pointer to directory object to create */
00764     const char *path    /* Pointer to the directory path */
00765 ) {
00766     FRESULT res;
00767     BYTE sp[12], dir[32];
00768     FATFS *fs = FatFs;
00769 
00770 
00771     if (!fs) {                /* Check file system */
00772         res = FR_NOT_ENABLED;
00773     } else {
00774         fs->buf = dir;
00775         dj->fn = sp;
00776         res = follow_path(dj, path);            /* Follow the path to the directory */
00777         if (res == FR_OK) {                        /* Follow completed */
00778             if (dir[0]) {                        /* It is not the root dir */
00779                 if (dir[DIR_Attr] & AM_DIR) {    /* The object is a directory */
00780                     dj->sclust =
00781 #if _FS_FAT32
00782                         ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) |
00783 #endif
00784                         LD_WORD(dir+DIR_FstClusLO);
00785                 } else {                        /* The object is not a directory */
00786                     res = FR_NO_PATH;
00787                 }
00788             }
00789             if (res == FR_OK)
00790                 res = dir_rewind(dj);            /* Rewind dir */
00791         }
00792         if (res == FR_NO_FILE) res = FR_NO_PATH;
00793     }
00794 
00795     return res;
00796 }
00797 
00798 
00799 
00800 
00801 /*-----------------------------------------------------------------------*/
00802 /* Read Directory Entry in Sequense                                      */
00803 /*-----------------------------------------------------------------------*/
00804 
00805 FRESULT pf_readdir (
00806     FATDIR *dj,            /* Pointer to the open directory object */
00807     FILINFO *fno        /* Pointer to file information to return */
00808 ) {
00809     FRESULT res;
00810     BYTE sp[12], dir[32];
00811     FATFS *fs = FatFs;
00812 
00813 
00814     if (!fs) {                /* Check file system */
00815         res = FR_NOT_ENABLED;
00816     } else {
00817         fs->buf = dir;
00818         dj->fn = sp;
00819         if (!fno) {
00820             res = dir_rewind(dj);
00821         } else {
00822             res = dir_read(dj);
00823             if (res == FR_NO_FILE) {
00824                 dj->sect = 0;
00825                 res = FR_OK;
00826             }
00827             if (res == FR_OK) {                /* A valid entry is found */
00828                 get_fileinfo(dj, fno);        /* Get the object information */
00829                 res = dir_next(dj);            /* Increment index for next */
00830                 if (res == FR_NO_FILE) {
00831                     dj->sect = 0;
00832                     res = FR_OK;
00833                 }
00834             }
00835         }
00836     }
00837 
00838     return res;
00839 }
00840 
00841 #endif /* _USE_DIR */
00842 
00843 } // namespace PFFS
00844 
00845