| 35,6 → 35,38 |
|---|
| import random |
| import xstruct |
| |
| def align_up(size, alignment): |
| "Return size aligned up to alignment" |
| |
| if (size % alignment == 0): |
| return size |
| |
| return (((size / alignment) + 1) * alignment) |
| |
| def subtree_size(root, cluster_size): |
| "Recursive directory walk and calculate size" |
| |
| size = 0 |
| files = 0 |
| |
| for name in os.listdir(root): |
| canon = os.path.join(root, name) |
| |
| if (os.path.isfile(canon)): |
| size += align_up(os.path.getsize(canon), cluster_size) |
| files += 1 |
| |
| if (os.path.isdir(canon)): |
| size += subtree_size(canon, cluster_size) |
| files += 1 |
| |
| return size + align_up(files * 32, cluster_size) |
| |
| def root_entries(root): |
| "Return number of root directory entries" |
| |
| return len(os.listdir(root)) |
| |
| BOOT_SECTOR = """little: |
| uint8_t jmp[3] /* jump instruction */ |
| char oem[8] /* OEM string */ |
| 76,25 → 108,34 |
|---|
| print "<PATH> must be a directory" |
| return |
| |
| sector_size = 512 |
| cluster_size = 4096 |
| |
| 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) |
| |
| sectors = (cluster_size + 2 * fat_size + root_size + size) / sector_size |
| |
| outf = file(sys.argv[2], "w") |
| |
| boot_sector = xstruct.create(BOOT_SECTOR) |
| boot_sector.jmp = [0xEB, 0x3C, 0x90] |
| boot_sector.oem = "MSDOS5.0" |
| boot_sector.sector = 512 |
| boot_sector.cluster = 8 # 4096 bytes per cluster |
| boot_sector.reserved = 1 |
| 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 = 224 # FIXME: root directory should be sector aligned |
| boot_sector.sectors = 0 # FIXME |
| boot_sector.rootdir = root_size / 32 |
| boot_sector.sectors = (sectors if (sectors <= 65535) else 0) |
| boot_sector.descriptor = 0xF8 |
| boot_sector.fat_sectors = 0 # FIXME |
| boot_sector.track_sectors = 0 # FIXME |
| boot_sector.heads = 0 # FIXME |
| boot_sector.fat_sectors = fat_size / sector_size |
| boot_sector.track_sectors = 63 |
| boot_sector.heads = 6 |
| boot_sector.hidden = 0 |
| boot_sector.sectors_big = 0 # FIXME |
| boot_sector.sectors_big = (sectors if (sectors > 65535) else 0) |
| |
| boot_sector.drive = 0 |
| boot_sector.drive = 0x80 |
| boot_sector.extboot_signature = 0x29 |
| boot_sector.serial = random.randint(0, 0xFFFFFFFF) |
| boot_sector.label = "HELENOS" |