diff options
| -rw-r--r-- | tools/pygrub/src/pygrub | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/tools/pygrub/src/pygrub b/tools/pygrub/src/pygrub index 5815e0ee7e..a0475a30cb 100644 --- a/tools/pygrub/src/pygrub +++ b/tools/pygrub/src/pygrub @@ -40,15 +40,20 @@ def enable_cursor(ison): except _curses.error: pass -def is_disk_image(file): +DISK_TYPE_RAW, DISK_TYPE_HYBRIDISO, DISK_TYPE_DOS = range(3) +def identify_disk_image(file): + """Detect DOS partition table or HybridISO format.""" fd = os.open(file, os.O_RDONLY) - buf = os.read(fd, 512) + buf = os.read(fd, 0x8006) os.close(fd) if len(buf) >= 512 and \ struct.unpack("H", buf[0x1fe: 0x200]) == (0xaa55,): - return True - return False + # HybridISO contains a DOS partition table for booting from USB devices, but really is an ISO image + if len(buf) >= 0x8006 and buf[0x8001:0x8006] == 'CD001': + return DISK_TYPE_HYBRIDISO + return DISK_TYPE_DOS + return DISK_TYPE_RAW SECTOR_SIZE=512 DK_LABEL_LOC=1 @@ -94,12 +99,19 @@ FDISK_PART_SOLARIS_OLD=0x82 FDISK_PART_GPT=0xee def get_partition_offsets(file): - if not is_disk_image(file): + image_type = identify_disk_image(file) + if image_type == DISK_TYPE_RAW: # No MBR: assume whole disk filesystem, which is like a # single partition starting at 0 return [0] - - part_offs = [] + elif image_type == DISK_TYPE_HYBRIDISO: + # A HybridISO contains an ISO filesystem at 0 in addition + # to the DOS partition table + part_offs = [0] + elif image_type == DISK_TYPE_DOS: + part_offs = [] + else: + raise ValueError('Unhandled image type returnd by identify_disk_image(): %d' % (image_type,)) fd = os.open(file, os.O_RDONLY) buf = os.read(fd, 512) |