diff options
| -rw-r--r-- | firmware/drivers/fat.c | 52 |
1 files changed, 22 insertions, 30 deletions
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c index a60a017..89b322e 100644 --- a/firmware/drivers/fat.c +++ b/firmware/drivers/fat.c @@ -996,32 +996,21 @@ int fat_readwrite( struct fat_file *file, int sectorcount, if ( sector == -1 ) return 0; - if ( write && !cluster) { - /* new file */ - cluster = find_free_cluster(fat_bpb.fsinfo.nextfree); - if (!cluster) { - cluster = find_free_cluster(0); - if (!cluster) { - DEBUGF("fat_readwrite(): Disk full!\n"); - return -3; - } - } - file->firstcluster = cluster; - sector = cluster2sec(cluster); - if (sector<0) - return -1; - } + if (!write) + first = last = sector; /* find sequential sectors and read/write them all at once */ for (i=0; i<sectorcount && sector>=0; i++ ) { - if ( numsec >= fat_bpb.bpb_secperclus ) { + numsec++; + if ( numsec >= fat_bpb.bpb_secperclus || !cluster) { int oldcluster = cluster; cluster = get_next_cluster(cluster); if (!cluster) { if ( write ) { - /* writing past end-of-file, - find a new free cluster to use. */ - cluster = find_free_cluster(oldcluster+1); + if (!oldcluster) /* new file */ + cluster = find_free_cluster(fat_bpb.fsinfo.nextfree); + else /* writing past end-of-file */ + cluster = find_free_cluster(oldcluster+1); if (!cluster) { /* no free cluster found after last, search from beginning */ @@ -1032,8 +1021,12 @@ int fat_readwrite( struct fat_file *file, int sectorcount, DEBUGF("fat_readwrite(): Disk full!\n"); } } - if ( cluster ) - update_fat_entry(oldcluster, cluster); + if ( cluster ) { + if ( !oldcluster ) + file->firstcluster = cluster; + else + update_fat_entry(oldcluster, cluster); + } } else { /* reading past end-of-file */ @@ -1051,21 +1044,20 @@ int fat_readwrite( struct fat_file *file, int sectorcount, } else sector++; - numsec++; - - if (!first) - first = sector; - if (!last) - last = sector; + if (write && !first) + first = last = sector; + if ( (sector != last+1) || /* not sequential any more? */ (i == sectorcount-1) || /* last sector requested? */ (last-first+1 == 256) ) { /* max 256 sectors per ata request */ - int count = last-first+1; + int count = last - first + 1; + int start = first + fat_bpb.startsector; + LDEBUGF("s=%x, l=%x, f=%x, i=%d\n",sector,last,first,i); if (write) - err = ata_write_sectors(first + fat_bpb.startsector, count, buf); + err = ata_write_sectors(start, count, buf); else - err = ata_read_sectors(first + fat_bpb.startsector, count, buf); + err = ata_read_sectors(start, count, buf); if (err) { DEBUGF( "fat_readwrite() - Couldn't read sector %d" " (error code %d)\n", sector,err); |