| 34,6 → 34,7 |
|---|
| import os |
| import random |
| import xstruct |
| import array |
| |
| def align_up(size, alignment): |
| "Return size aligned up to alignment" |
| 43,7 → 44,7 |
|---|
| |
| return (((size / alignment) + 1) * alignment) |
| |
| def subtree_size(root, cluster_size): |
| def subtree_size(root, cluster_size, dirent_size): |
| "Recursive directory walk and calculate size" |
| |
| size = 0 |
| 57,10 → 58,10 |
|---|
| files += 1 |
| |
| if (os.path.isdir(canon)): |
| size += subtree_size(canon, cluster_size) |
| size += subtree_size(canon, cluster_size, dirent_size) |
| files += 1 |
| |
| return size + align_up(files * 32, cluster_size) |
| return size + align_up(files * dirent_size, cluster_size) |
| |
| def root_entries(root): |
| "Return number of root directory entries" |
| 67,6 → 68,99 |
|---|
| |
| return len(os.listdir(root)) |
| |
| def write_file(path, outf, cluster_size, data_start, fat): |
| "Store the contents of a file" |
| |
| size = os.path.getsize(path) |
| prev = -1 |
| first = -1 |
| |
| inf = file(path, "r") |
| rd = 0; |
| while (rd < size): |
| data = inf.read(cluster_size); |
| |
| empty_cluster = fat.index(0) |
| |
| fat[empty_cluster] = 0xffff |
| if (prev != -1): |
| fat[prev] = empty_cluster |
| else: |
| first = empty_cluster |
| |
| prev = empty_cluster |
| |
| outf.seek(data_start + empty_cluster * cluster_size) |
| outf.write(data) |
| rd += len(data) |
| inf.close() |
| |
| return first, size |
| |
| DIR_ENTRY = """little: |
| char name[8] /* file name */ |
| char ext[3] /* file extension */ |
| uint8_t attr /* file attributes */ |
| padding[1] /* reserved for NT */ |
| uint8_t ctime_fine /* create time (fine resolution) */ |
| uint16_t ctime /* create time */ |
| uint16_t cdate /* create date */ |
| uint16_t adate /* access date */ |
| padding[2] /* EA-index */ |
| uint16_t mtime /* modification time */ |
| uint16_t mdate /* modification date */ |
| uint16_t cluster /* first cluster */ |
| uint32_t size /* file size */ |
| """ |
| |
| def mangle_fname(name): |
| # FIXME: filter illegal characters |
| fname = (name.split('.')[0] + ' ').upper()[0:8] |
| return fname |
| |
| def mangle_ext(name): |
| # FIXME: filter illegal characters |
| ext = (name.split('.')[1] + ' ').upper()[0:3] |
| return ext |
| |
| def create_dirent(name, directory, cluster, size): |
| dir_entry = xstruct.create(DIR_ENTRY) |
| |
| dir_entry.name = mangle_fname(name) |
| dir_entry.ext = mangle_ext(name) |
| |
| if (directory): |
| dir_entry.attr = 0x30 |
| else: |
| dir_entry.attr = 0x20 |
| |
| dir_entry.ctime_fine = 0 # FIXME |
| dir_entry.ctime = 0 # FIXME |
| dir_entry.cdate = 0 # FIXME |
| dir_entry.adate = 0 # FIXME |
| dir_entry.mtime = 0 # FIXME |
| dir_entry.mdate = 0 # FIXME |
| dir_entry.cluster = cluster |
| dir_entry.size = size |
| |
| return dir_entry |
| |
| def recursion(head, root, outf, cluster_size, root_start, data_start, fat): |
| "Recursive directory walk" |
| |
| directory = [] |
| for name in os.listdir(root): |
| canon = os.path.join(root, name) |
| |
| if (os.path.isfile(canon)): |
| rv = write_file(canon, outf, cluster_size, data_start, fat) |
| directory.append(create_dirent(name, False, rv[0], rv[1])) |
| |
| if (head): |
| outf.seek(root_start) |
| for dir_entry in directory: |
| outf.write(dir_entry.pack()) |
| |
| BOOT_SECTOR = """little: |
| uint8_t jmp[3] /* jump instruction */ |
| char oem[8] /* OEM string */ |
| 95,9 → 189,13 |
|---|
| """ |
| |
| EMPTY_SECTOR = """little: |
| padding[512] |
| padding[512] /* empty sector data */ |
| """ |
| |
| FAT_ENTRY = """little: |
| uint16_t next /* FAT16 entry */ |
| """ |
| |
| def usage(prname): |
| "Print usage syntax" |
| print prname + " <PATH> <IMAGE>" |
| 112,15 → 210,32 |
|---|
| print "<PATH> must be a directory" |
| return |
| |
| fat16_clusters = 4096 |
| |
| sector_size = 512 |
| cluster_size = 4096 |
| dirent_size = 32 |
| fatent_size = 2 |
| fat_count = 2 |
| reserved_clusters = 2 |
| |
| root_size = align_up(root_entries(sys.argv[1]) * 32, sector_size) |
| size = subtree_size(sys.argv[1], cluster_size) |
| fat_size = align_up(size / cluster_size * 2, sector_size) |
| # Make sure the filesystem is large enought for FAT16 |
| size = subtree_size(path, cluster_size, dirent_size) + reserved_clusters * cluster_size |
| while (size / cluster_size < fat16_clusters): |
| if (cluster_size > sector_size): |
| cluster_size /= 2 |
| size = subtree_size(path, cluster_size, dirent_size) + reserved_clusters * cluster_size |
| else: |
| size = fat16_clusters * cluster_size + reserved_clusters * cluster_size |
| |
| sectors = (cluster_size + 2 * fat_size + root_size + size) / sector_size |
| root_size = align_up(root_entries(path) * dirent_size, cluster_size) |
| |
| fat_size = align_up(align_up(size, cluster_size) / cluster_size * fatent_size, sector_size) |
| |
| sectors = (cluster_size + fat_count * fat_size + root_size + size) / sector_size |
| root_start = cluster_size + fat_count * fat_size |
| data_start = root_start + root_size |
| |
| outf = file(sys.argv[2], "w") |
| |
| boot_sector = xstruct.create(BOOT_SECTOR) |
| 129,8 → 244,8 |
|---|
| boot_sector.sector = sector_size |
| boot_sector.cluster = cluster_size / sector_size |
| boot_sector.reserved = cluster_size / sector_size |
| boot_sector.fats = 2 |
| boot_sector.rootdir = root_size / 32 |
| boot_sector.fats = fat_count |
| boot_sector.rootdir = root_size / dirent_size |
| boot_sector.sectors = (sectors if (sectors <= 65535) else 0) |
| boot_sector.descriptor = 0xF8 |
| boot_sector.fat_sectors = fat_size / sector_size |
| 150,12 → 265,12 |
|---|
| |
| empty_sector = xstruct.create(EMPTY_SECTOR) |
| |
| # Reserved sectors (boot_sector.reserved - boot_sector) |
| for i in range(1, boot_sector.reserved): |
| # Reserved sectors |
| for i in range(1, cluster_size / sector_size): |
| outf.write(empty_sector.pack()) |
| |
| # FAT tables |
| for i in range(0, boot_sector.fats): |
| for i in range(0, fat_count): |
| for j in range(0, boot_sector.fat_sectors): |
| outf.write(empty_sector.pack()) |
| |
| 167,6 → 282,20 |
|---|
| for i in range(0, size / sector_size): |
| outf.write(empty_sector.pack()) |
| |
| fat = array.array('L', [0] * (fat_size / fatent_size)) |
| fat[0] = 0xfff8 |
| fat[1] = 0xffff |
| |
| recursion(True, path, outf, cluster_size, root_start, data_start, fat) |
| |
| # Store FAT |
| fat_entry = xstruct.create(FAT_ENTRY) |
| for i in range(0, fat_count): |
| outf.seek(cluster_size + i * fat_size) |
| for j in range(0, fat_size / fatent_size): |
| fat_entry.next = fat[j] |
| outf.write(fat_entry.pack()) |
| |
| outf.close() |
| |
| if __name__ == '__main__': |