/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Linus Nielsen Feltzing * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include #include #include #include #include #include #include #include "fat.h" #include "ata.h" #include "debug.h" #include "system.h" #define BYTES2INT16(array,pos) \ (array[pos] | (array[pos+1] << 8 )) #define BYTES2INT32(array,pos) \ (array[pos] | (array[pos+1] << 8 ) | \ (array[pos+2] << 16 ) | (array[pos+3] << 24 )) #define NUM_ROOT_DIR_ENTRIES 512 #define NUM_FATS 2 #define NUM_RESERVED_SECTORS 1 #define NUM_BLOCKS 10000 #define FATTYPE_FAT12 0 #define FATTYPE_FAT16 1 #define FATTYPE_FAT32 2 /* BPB offsets; generic */ #define BS_JMPBOOT 0 #define BS_OEMNAME 3 #define BPB_BYTSPERSEC 11 #define BPB_SECPERCLUS 13 #define BPB_RSVDSECCNT 14 #define BPB_NUMFATS 16 #define BPB_ROOTENTCNT 17 #define BPB_TOTSEC16 19 #define BPB_MEDIA 21 #define BPB_FATSZ16 22 #define BPB_SECPERTRK 24 #define BPB_NUMHEADS 26 #define BPB_HIDDSEC 28 #define BPB_TOTSEC32 32 /* fat12/16 */ #define BS_DRVNUM 36 #define BS_RESERVED1 37 #define BS_BOOTSIG 38 #define BS_VOLID 39 #define BS_VOLLAB 43 #define BS_FILSYSTYPE 54 /* fat32 */ #define BPB_FATSZ32 36 #define BPB_EXTFLAGS 40 #define BPB_FSVER 42 #define BPB_ROOTCLUS 44 #define BPB_FSINFO 48 #define BPB_BKBOOTSEC 50 #define BS_32_DRVNUM 64 #define BS_32_BOOTSIG 66 #define BS_32_VOLID 67 #define BS_32_VOLLAB 71 #define BS_32_FILSYSTYPE 82 #define BPB_LAST_WORD 510 /* attributes */ #define FAT_ATTR_LONG_NAME (FAT_ATTR_READ_ONLY | FAT_ATTR_HIDDEN | \ FAT_ATTR_SYSTEM | FAT_ATTR_VOLUME_ID) #define FAT_ATTR_LONG_NAME_MASK (FAT_ATTR_READ_ONLY | FAT_ATTR_HIDDEN | \ FAT_ATTR_SYSTEM | FAT_ATTR_VOLUME_ID | \ FAT_ATTR_DIRECTORY | FAT_ATTR_ARCHIVE ) #define FATDIR_NAME 0 #define FATDIR_ATTR 11 #define FATDIR_NTRES 12 #define FATDIR_CRTTIMETENTH 13 #define FATDIR_CRTTIME 14 #define FATDIR_CRTDATE 16 #define FATDIR_LSTACCDATE 18 #define FATDIR_FSTCLUSHI 20 #define FATDIR_WRTTIME 22 #define FATDIR_WRTDATE 24 #define FATDIR_FSTCLUSLO 26 #define FATDIR_FILESIZE 28 struct fsinfo { int freecount; /* last known free cluster count */ int nextfree; /* first cluster to start looking for free clusters, or 0xffffffff for no hint */ }; /* fsinfo offsets */ #define FSINFO_FREECOUNT 488 #define FSINFO_NEXTFREE 492 static int first_sector_of_cluster(unsigned int cluster); static int bpb_is_sane(void); static void *cache_fat_sector(int secnum); #ifdef DISK_WRITE static unsigned int getcurrdostime(unsigned short *dosdate, unsigned short *dostime, unsigned char *dostenth); static int create_dos_name(unsigned char *name, unsigned char *newname); #endif /* global FAT info struct */ struct bpb fat_bpb; #define FAT_CACHE_SIZE 0x20 #define FAT_CACHE_MASK (FAT_CACHE_SIZE-1) struct fat_cache_entry { unsigned char *ptr; int secnum; int dirty; }; struct fat_cache_entry fat_cache[FAT_CACHE_SIZE]; /* sectors cache for longname use */ static unsigned char lastsector[SECTOR_SIZE]; static unsigned char lastsector2[SECTOR_SIZE]; static unsigned int swap_fat_entry(unsigned int entry) { SWAB32(entry); return entry; } static int sec2cluster(unsigned int sec) { if ( sec < fat_bpb.firstdatasector ) { DEBUGF( "sec2cluster() - Bad sector number (%d)\n", sec); return -1; } return ((sec - fat_bpb.firstdatasector) / fat_bpb.bpb_secperclus) + 2; } static int cluster2sec(unsigned int cluster) { int max_cluster = fat_bpb.totalsectors - fat_bpb.firstdatasector / fat_bpb.bpb_secperclus + 1; if(cluster > max_cluster) { DEBUGF( "cluster2sec() - Bad cluster number (%d)\n", cluster); return -1; } return first_sector_of_cluster(cluster); } static int first_sector_of_cluster(unsigned int cluster) { return (cluster - 2) * fat_bpb.bpb_secperclus + fat_bpb.firstdatasector; } int fat_mount(int startsector) { unsigned char buf[SECTOR_SIZE]; int err; int datasec; int countofclusters; int i; /* Clear the cache. Be aware! The bss section MUST have been cleared at boot. Otherwise we will free() garbage pointers here */ for(i = 0;i < FAT_CACHE_SIZE;i++) { if(fat_cache[i].ptr) { free(fat_cache[i].ptr); } fat_cache[i].secnum = 8; /* We use a "safe" sector just in case */ fat_cache[i].dirty = 0; } /* Read the sector */ err = ata_read_sectors(startsector,1,buf); if(err) { DEBUGF( "fat_mount() - Couldn't read BPB (error code %d)\n", err); return -1; } memset(&fat_bpb, 0, sizeof(struct bpb)); fat_bpb.startsector = startsector; strncpy(fat_bpb.bs_oemname, &buf[BS_OEMNAME], 8); fat_bpb.bs_oemname[8] = 0; fat_bpb.bpb_bytspersec = BYTES2INT16(buf,BPB_BYTSPERSEC); fat_bpb.bpb_secperclus = buf[BPB_SECPERCLUS]; fat_bpb.bpb_rsvdseccnt = BYTES2INT16(buf,BPB_RSVDSECCNT); fat_bpb.bpb_numfats = buf[BPB_NUMFATS]; fat_bpb.bpb_rootentcnt = BYTES2INT16(buf,BPB_ROOTENTCNT); fat_bpb.bpb_totsec16 = BYTES2INT16(buf,BPB_TOTSEC16); fat_bpb.bpb_media = buf[BPB_MEDIA]; fat_bpb.bpb_fatsz16 = BYTES2INT16(buf,BPB_FATSZ16); fat_bpb.bpb_fatsz32 = BYTES2INT32(buf,BPB_FATSZ32); fat_bpb.bpb_secpertrk = BYTES2INT16(buf,BPB_SECPERTRK); fat_bpb.bpb_numheads = BYTES2INT16(buf,BPB_NUMHEADS); fat_bpb.bpb_hiddsec = BYTES2INT32(buf,BPB_HIDDSEC); fat_bpb.bpb_totsec32 = BYTES2INT32(buf,BPB_TOTSEC32); fat_bpb.last_word = BYTES2INT16(buf,BPB_LAST_WORD); /* calculate a few commonly used values */ if (fat_bpb.bpb_fatsz16 != 0) fat_bpb.fatsize = fat_bpb.bpb_fatsz16; else fat_bpb.fatsize = fat_bpb.bpb_fatsz32; if (fat_bpb.bpb_totsec16 != 0) fat_bpb.totalsectors = fat_bpb.bpb_totsec16; else fat_bpb.totalsectors = fat_bpb.bpb_totsec32; fat_bpb.firstdatasector = fat_bpb.bpb_rsvdseccnt + fat_bpb.bpb_numfats * fat_bpb.fatsize; /* Determine FAT type */ datasec = fat_bpb.totalsectors - fat_bpb.firstdatasector; countofclusters = datasec / fat_bpb.bpb_secperclus; #ifdef TEST_FAT /* we are sometimes testing with "illegally small" fat32 images, so we don't use the proper fat32 test case for test code */ if ( fat_bpb.bpb_fatsz16 ) #else if ( countofclusters < 65525 ) #endif { DEBUGF("This is not FAT32. Go away!\n"); return -1; } fat_bpb.bpb_extflags = BYTES2INT16(buf,BPB_EXTFLAGS); fat_bpb.bpb_fsver = BYTES2INT16(buf,BPB_FSVER); fat_bpb.bpb_rootclus = BYTES2INT32(buf,BPB_ROOTCLUS); fat_bpb.bpb_fsinfo = BYTES2INT16(buf,BPB_FSINFO); fat_bpb.bpb_bkbootsec = BYTES2INT16(buf,BPB_BKBOOTSEC); fat_bpb.bs_drvnum = buf[BS_32_DRVNUM]; fat_bpb.bs_bootsig = buf[BS_32_BOOTSIG]; if(fat_bpb.bs_bootsig == 0x29) { fat_bpb.bs_volid = BYTES2INT32(buf,BS_32_VOLID); strncpy(fat_bpb.bs_vollab, &buf[BS_32_VOLLAB], 11); strncpy(fat_bpb.bs_filsystype, &buf[BS_32_FILSYSTYPE], 8); } if (bpb_is_sane() < 0) { DEBUGF( "fat_mount() - BPB is not sane\n"); return -1; } fat_bpb.rootdirsector = cluster2sec(fat_bpb.bpb_rootclus); return 0; } static int bpb_is_sane(void) { if(fat_bpb.bpb_bytspersec != 512) { DEBUGF( "bpb_is_sane() - Error: sector size is not 512 (%d)\n", fat_bpb.bpb_bytspersec); return -1; } if(fat_bpb.bpb_secperclus * fat_bpb.bpb_bytspersec > 32768) { DEBUGF( "bpb_is_sane() - Warning: cluster size is larger than 32K " "(%d * %d = %d)\n", fat_bpb.bpb_bytspersec, fat_bpb.bpb_secperclus, fat_bpb.bpb_bytspersec * fat_bpb.bpb_secperclus); } if(fat_bpb.bpb_rsvdseccnt != 1) { DEBUGF( "bpb_is_sane() - Warning: Reserved sectors is not 1 (%d)\n", fat_bpb.bpb_rsvdseccnt); } if(fat_bpb.bpb_numfats != 2) { DEBUGF( "bpb_is_sane() - Warning: NumFATS is not 2 (%d)\n", fat_bpb.bpb_numfats); } if(fat_bpb.bpb_rootentcnt != 512) { DEBUGF( "bpb_is_sane() - Warning: RootEntCnt is not 512 (%d)\n", fat_bpb.bpb_rootentcnt); } if(fat_bpb.bpb_media != 0xf0 && fat_bpb.bpb_media < 0xf8) { DEBUGF( "bpb_is_sane() - Warning: Non-standard " "media type (0x%02x)\n", fat_bpb.bpb_media); } if(fat_bpb.last_word != 0xaa55) { DEBUGF( "bpb_is_sane() - Error: Last word is not " "0xaa55 (0x%04x)\n", fat_bpb.last_word); return -1; } return 0; } static void *cache_fat_sector(int secnum) { int cache_index = secnum & FAT_CACHE_MASK; unsigned char *sec; sec = fat_cache[cache_index].ptr; /* Delete the cache entry if it isn't the sector we want */ if(sec && fat_cache[cache_index].secnum != secnum) { #ifdef WRITE /* Write back if it is dirty */ if(fat_cache[cache_index].dirty) { if(ata_write_sectors(secnum + fat_bpb.startsector, 1, sec)) { panic("cache_fat_sector() - Could" " not write sector %d\n", secnum); } } #endif free(sec); fat_cache[cache_index].ptr = NULL; fat_cache[cache_index].secnum = 8; /* Normally an unused sector */ fat_cache[cache_index].dirty = 0; sec = NULL; } /* Load the sector if it is not cached */ if(!sec) { sec = malloc(fat_bpb.bpb_bytspersec); if(!sec) { DEBUGF( "cache_fat_sector() - Out of memory\n"); return NULL; } if(ata_read_sectors(secnum + fat_bpb.startsector,1,sec)) { DEBUGF( "cache_fat_sector() - Could" " not read sector %d\n", secnum); free(sec); return NULL; } fat_cache[cache_index].ptr = sec; fat_cache[cache_index].secnum = secnum; } return sec; } #ifdef DISK_WRITE static int update_entry(int entry, unsigned int val) { unsigned long *sec; int fatoffset; int thisfatsecnum; int thisfatentoffset; fatoffset = entry * 4; thisfatsecnum = fatoffset / fat_bpb.bpb_bytspersec + fat_bpb.bpb_rsvdseccnt; thisfatentoffset = fatoffset % fat_bpb.bpb_bytspersec; /* Load the sector if it is not cached */ sec = cache_fat_sector(thisfatsecnum); if(!sec) { DEBUGF( "update_entry() - Could not cache sector %d\n", thisfatsecnum); return -1; } /* We can safely assume that the correct sector is in the cache, so we mark it dirty without checking the sector number */ fat_cache[thisfatsecnum & FAT_CACHE_MASK].dirty = 1; /* don't change top 4 bits */ sec[thisfatentoffset/sizeof(int)] &= 0xf000000; sec[thisfatentoffset/sizeof(int)] |= val & 0x0fffffff; return 0; } #endif static int read_entry(int entry) { unsigned long *sec; int fatoffset; int thisfatsecnum; int thisfatentoffset; int val = -1; fatoffset = entry * 4; thisfatsecnum = fatoffset / fat_bpb.bpb_bytspersec + fat_bpb.bpb_rsvdseccnt; thisfatentoffset = fatoffset % fat_bpb.bpb_bytspersec; /* Load the sector if it is not cached */ sec = cache_fat_sector(thisfatsecnum); if(!sec) { DEBUGF( "read_entry() - Could not cache sector %d\n", thisfatsecnum); return -1; } val = sec[thisfatentoffset/sizeof(int)]; val = SWAB32(val); return val; } static int get_next_cluster(unsigned int cluster) { int next_cluster; next_cluster = read_entry(cluster); /* is this last cluster in chain? */ if ( next_cluster >= 0x0ffffff8 ) return 0; else return next_cluster; } #ifdef DISK_WRITE static int flush_fat(struct bpb *bpb) { int i; int err; unsigned char *sec; int secnum; int fatsz; unsigned short d, t; char m; fatsz = fat_bpb.fatsize; for(i = 0;i < FAT_CACHE_SIZE;i++) { if(fat_cache[i].ptr && fat_cache[i].dirty) { secnum = fat_cache[i].secnum + fat_bpb.bpb_rsvdseccnt + fat_bpb.startsector; DEBUGF("Flushing FAT sector %d\n", secnum); sec = fat_cache[i].ptr; /* Write to the first FAT */ err = ata_write_sectors(secnum, 1, sec); if(err) { DEBUGF( "flush_fat() - Couldn't write" " sector (%d)\n", secnum); return -1; } /* Write to the second FAT */ err = ata_write_sectors(secnum + fatsz, 1, sec); if(err) { DEBUGF( "flush_fat() - Couldn't write" " sector (%d)\n", secnum + fatsz); return -1; } fat_cache[i].dirty = 0; } } getcurrdostime(&d, &t, &m); return 0; } static unsigned int getcurrdostime(unsigned short *dosdate, unsigned short *dostime, unsigned char *dostenth) { struct timeb tb; struct tm *tm; ftime(&tb); tm = localtime(&tb.time); *dosdate = ((tm->tm_year - 80) << 9) | ((tm->tm_mon + 1) << 5) | (tm->tm_mday); *dostime = (tm->tm_hour << 11) | (tm->tm_min << 5) | (tm->tm_sec >> 1); *dostenth = (tm->tm_sec & 1) * 100 + tb.millitm / 10; return 0; } static int add_dir_entry(unsigned int currdir, struct fat_direntry *de) { unsigned char buf[SECTOR_SIZE]; unsigned char *eptr; int i; int err; unsigned int sec; unsigned int sec_cnt; int need_to_update_last_empty_marker = 0; int is_rootdir = (currdir == 0); int done = 0; unsigned char firstbyte; if(is_rootdir) { sec = fat_bpb.rootdirsector; } else { sec = first_sector_of_cluster(currdir); } sec_cnt = 0; while(!done) { /* The root dir has a fixed size */ if(is_rootdir) { if(sec_cnt >= fat_bpb.bpb_rootentcnt * 32 / fat_bpb.bpb_bytspersec) { /* We have reached the last sector of the root dir */ if(need_to_update_last_empty_marker) { /* Since the directory is full, there is no room for a marker, so we just exit */ return 0; } else { DEBUGF( "add_dir_entry() -" " Root dir is full\n"); return -1; } } } else { if(sec_cnt >= fat_bpb.bpb_secperclus) { /* We have reached the end of this cluster */ DEBUGF("Moving to the next cluster..."); currdir = get_next_cluster(currdir); DEBUGF("new cluster is %d\n", currdir); if(!currdir) { /* This was the last in the chain, we have to allocate a new cluster */ /* TODO */ } } } DEBUGF("Reading sector %d...\n", sec); /* Read the next sector in the current dir */ err = ata_read_sectors(sec + fat_bpb.startsector,1,buf); if(err) { DEBUGF( "add_dir_entry() - Couldn't read dir sector" " (error code %d)\n", err); return -1; } if(need_to_update_last_empty_marker) { /* All we need to do is to set the first entry to 0 */ DEBUGF("Clearing the first entry in sector %d\n", sec); buf[0] = 0; done = 1; } else { /* Look for a free slot */ for(i = 0;i < SECTOR_SIZE;i+=32) { firstbyte = buf[i]; if(firstbyte == 0xe5 || firstbyte == 0) { DEBUGF("Found free slot at entry %d in sector %d\n", i/32, sec); eptr = &buf[i]; memset(eptr, 0, 32); strncpy(&eptr[FATDIR_NAME], de->name, 11); eptr[FATDIR_ATTR] = de->attr; eptr[FATDIR_NTRES] = 0; eptr[FATDIR_CRTTIMETENTH] = de->crttimetenth; eptr[FATDIR_CRTDATE] = de->crtdate & 0xff; eptr[FATDIR_CRTDATE+1] = de->crtdate >> 8; eptr[FATDIR_CRTTIME] = de->crttime & 0xff; eptr[FATDIR_CRTTIME+1] = de->crttime >> 8; eptr[FATDIR_WRTDATE] = de->wrtdate & 0xff; eptr[FATDIR_WRTDATE+1] = de->wrtdate >> 8; eptr[FATDIR_WRTTIME] = de->wrttime & 0xff; eptr[FATDIR_WRTTIME+1] = de->wrttime >> 8; eptr[FATDIR_FILESIZE] = de->filesize & 0xff; eptr[FATDIR_FILESIZE+1] = (de->filesize >> 8) & 0xff; eptr[FATDIR_FILESIZE+2] = (de->filesize >> 16) & 0xff; eptr[FATDIR_FILESIZE+3] = (de->filesize >> 24) & 0xff; /* Advance the last_empty_entry marker */ if(firstbyte == 0) { i += 32; if(i < SECTOR_SIZE) { buf[i] = 0; /* We are done */ done = 1; } else { /* We must fill in the first entry in the next sector */ need_to_update_last_empty_marker = 1; } } err = ata_write_sectors(sec + fat_bpb.startsector,1,buf); if(err) { DEBUGF( "add_dir_entry() - " " Couldn't write dir" " sector (error code %d)\n", err); return -1; } break; } } } sec++; sec_cnt++; } return 0; } unsigned char char2dos(unsigned char c) { switch(c) { case 0xe5: /* Special kanji character */ c = 0x05; break; case 0x22: case 0x2a: case 0x2b: case 0x2c: case 0x2e: case 0x3a: case 0x3b: case 0x3c: case 0x3d: case 0x3e: case 0x3f: case 0x5b: case 0x5c: case 0x5d: case 0x7c: /* Illegal name */ c = 0; break; default: if(c < 0x20) { /* Illegal name */ c = 0; } break; } return c; } static int create_dos_name(unsigned char *name, unsigned char *newname) { unsigned char n[12]; unsigned char c; int i; char *ext; if(strlen(name) > 12) { return -1; } strcpy(n, name); ext = strchr(n, '.'); if(ext) { *ext++ = 0; } /* The file name is either empty, or there was only an extension. In either case it is illegal. */ if(n[0] == 0) { return -1; } /* Name part */ for(i = 0;n[i] && (i < 8);i++) { c = char2dos(n[i]); if(c) { newname[i] = toupper(c); } } while(i < 8) { newname[i++] = ' '; } /* Extension part */ for(i = 0;ext && ext[i] && (i < 3);i++) { c = char2dos(ext[i]); if(c) { newname[8+i] = toupper(c); } } while(i < 3) { newname[8+i++] = ' '; } return 0; } int fat_create_dir(unsigned int currdir, char *name) { struct fat_direntry de; int err; DEBUGF("fat_create_file()\n"); memset(&de, 0, sizeof(struct fat_direntry)); if(create_dos_name(name, de.name) < 0) { DEBUGF( "fat_create_file() - Illegal file name (%s)\n", name); return -1; } getcurrdostime(&de.crtdate, &de.crttime, &de.crttimetenth); de.wrtdate = de.crtdate; de.wrttime = de.crttime; de.filesize = 0; de.attr = FAT_ATTR_DIRECTORY; err = add_dir_entry(currdir, &de); return 0; } int fat_create_file(unsigned int currdir, char *name) { struct fat_direntry de; int err; DEBUGF("fat_create_file()\n"); memset(&de, 0, sizeof(struct fat_direntry)); if(create_dos_name(name, de.name) < 0) { DEBUGF( "fat_create_file() - Illegal file name (%s)\n", name); return -1; } getcurrdostime(&de.crtdate, &de.crttime, &de.crttimetenth); de.wrtdate = de.crtdate; de.wrttime = de.crttime; de.filesize = 0; err = add_dir_entry(currdir, &de); return err; } #endif static int parse_direntry(struct fat_direntry *de, unsigned char *buf) { int i=0,j=0; memset(de, 0, sizeof(struct fat_direntry)); de->attr = buf[FATDIR_ATTR]; de->crttimetenth = buf[FATDIR_CRTTIMETENTH]; de->crtdate = BYTES2INT16(buf,FATDIR_CRTDATE); de->crttime = BYTES2INT16(buf,FATDIR_CRTTIME); de->wrtdate = BYTES2INT16(buf,FATDIR_WRTDATE); de->wrttime = BYTES2INT16(buf,FATDIR_WRTTIME); de->filesize = BYTES2INT32(buf,FATDIR_FILESIZE); de->firstcluster = BYTES2INT16(buf,FATDIR_FSTCLUSLO) | (BYTES2INT16(buf,FATDIR_FSTCLUSHI) << 16); /* fix the name */ for (i=0; (i<8) && (buf[FATDIR_NAME+i] != ' '); i++) de->name[j++] = buf[FATDIR_NAME+i]; if ( buf[FATDIR_NAME+8] != ' ' ) { de->name[j++] = '.'; for (i=8; (i<11) && (buf[FATDIR_NAME+i] != ' '); i++) de->name[j++] = buf[FATDIR_NAME+i]; } return 1; } int fat_open( unsigned int startcluster, struct fat_file *file) { file->firstcluster = startcluster; file->nextcluster = startcluster; file->nextsector = cluster2sec(startcluster); file->sectornum = 0; return 0; } int fat_read( struct fat_file *file, int sectorcount, void* buf ) { int cluster = file->nextcluster; int sector = file->nextsector; int numsec = file->sectornum; int err, i; if ( sector == -1 ) return 0; for ( i=0; i= fat_bpb.bpb_secperclus ) { cluster = get_next_cluster(cluster); if (!cluster) { /* end of file */ sector = -1; break; } sector = cluster2sec(cluster); if (sector<0) return -1; numsec=0; } else sector++; } file->nextcluster = cluster; file->nextsector = sector; file->sectornum = numsec; return sectorcount; } int fat_seek(struct fat_file *file, int seeksector ) { int cluster = file->firstcluster; int sector = seeksector; int numsec = 0; int i; if ( seeksector ) { for (i=0; i= fat_bpb.bpb_secperclus ) { cluster = get_next_cluster(cluster); if (!cluster) /* end of file */ return -1; sector = cluster2sec(cluster); if (sector<0) return -2; numsec=0; } else sector++; } } else { sector = cluster2sec(cluster); if (sector<0) return -2; } file->nextcluster = cluster; file->nextsector = sector; file->sectornum = numsec; return 0; } int fat_opendir(struct fat_dir *dir, unsigned int currdir) { int is_rootdir = (currdir == 0); unsigned int sec; int err; if(is_rootdir) { sec = fat_bpb.rootdirsector; } else { sec = first_sector_of_cluster(currdir); } /* Read the first sector in the current dir */ err = ata_read_sectors(sec + fat_bpb.startsector,1,dir->cached_buf); if(err) { DEBUGF( "fat_opendir() - Couldn't read dir sector" " (error code %d)\n", err); return -1; } dir->entry = 0; dir->cached_sec = sec; dir->num_sec = 0; return 0; } int fat_getnext(struct fat_dir *dir, struct fat_direntry *entry) { int done = 0; int i; int err; unsigned char firstbyte; int longarray[20]; int longs=0; int sectoridx=0; while(!done) { for(i = dir->entry;i < SECTOR_SIZE/32;i++) { firstbyte = dir->cached_buf[i*32]; if(firstbyte == 0xe5) /* free entry */ continue; if(firstbyte == 0) { /* last entry */ entry->name[0] = 0; return 0; } /* longname entry? */ if ( ( dir->cached_buf[i*32 + FATDIR_ATTR] & FAT_ATTR_LONG_NAME_MASK ) == FAT_ATTR_LONG_NAME ) { longarray[longs++] = i*32 + sectoridx; } else { if ( parse_direntry(entry, &dir->cached_buf[i*32]) ) { /* replace shortname with longname? */ if ( longs ) { int j,k,l=0; /* iterate backwards through the dir entries */ for (j=longs-1; j>=0; j--) { unsigned char* ptr = dir->cached_buf; int index = longarray[j]; /* current or cached sector? */ if ( sectoridx >= SECTOR_SIZE ) { if ( sectoridx >= SECTOR_SIZE*2 ) { if ( ( index >= SECTOR_SIZE ) && ( index < SECTOR_SIZE*2 )) ptr = lastsector; else ptr = lastsector2; } else { if ( index < SECTOR_SIZE ) ptr = lastsector; } index &= SECTOR_SIZE-1; } /* piece together the name subcomponents. names are stored in unicode, but we only grab the low byte (iso8859-1). */ for (k=0; k<5; k++) entry->name[l++] = ptr[index + k*2 + 1]; for (k=0; k<6; k++) entry->name[l++] = ptr[index + k*2 + 14]; for (k=0; k<2; k++) entry->name[l++] = ptr[index + k*2 + 28]; } entry->name[l]=0; } done = 1; break; } } } /* save this sector, for longname use */ if ( sectoridx ) memcpy( lastsector2, dir->cached_buf, SECTOR_SIZE ); else memcpy( lastsector, dir->cached_buf, SECTOR_SIZE ); sectoridx += SECTOR_SIZE; /* Next sector? */ if(i < SECTOR_SIZE/32) { i++; } else { dir->num_sec++; /* Do we need to advance one cluster? */ if(dir->num_sec < fat_bpb.bpb_secperclus) { dir->cached_sec++; } else { int cluster = sec2cluster(dir->cached_sec); if ( cluster < 0 ) { DEBUGF("sec2cluster failed\n"); return -1; } dir->num_sec = 0; cluster = get_next_cluster( cluster ); if(!cluster) { DEBUGF("End of cluster chain.\n"); return -1; } dir->cached_sec = cluster2sec(cluster); if ( dir->cached_sec < 0 ) { DEBUGF("Invalid cluster: %d\n",cluster); return -1; } } /* Read the next sector */ err = ata_read_sectors(dir->cached_sec + fat_bpb.startsector, 1, dir->cached_buf); if(err) { DEBUGF( "fat_getnext() - Couldn't read dir sector" " (error code %d)\n", err); return -1; } i = 0; } dir->entry = i; } return 0; }