Automaticfullbackup

#!/usr/bin/python
import os
import sys
import collections
import struct
import sys
import uuid
# GUID Partition Table - Wikipedia
GPT_HEADER_FORMAT = """
8s signature
4s revision
L header_size
L crc32
4x _
Q current_lba
Q backup_lba
Q first_usable_lba
Q last_usable_lba
16s disk_guid
Q part_entry_start_lba
L num_part_entries
L part_entry_size
L crc32_part_array
"""
# GUID Partition Table - Wikipedia
GPT_PARTITION_FORMAT = """
16s type
16s unique
Q first_lba
Q last_lba
Q flags
72s name
"""
def _make_fmt(name, format, extras=[]):
type_and_name = [l.split(None, 1) for l in format.strip().splitlines()]
fmt = ''.join(t for (t,n) in type_and_name)
fmt = '<'+fmt
tupletype = collections.namedtuple(name, [n for (t,n) in type_and_name if n!='_']+extras)
return (fmt, tupletype)
class GPTError(Exception):
pass
def read_header(fp, lba_size=512):
# skip MBR
fp.seek(1*lba_size)
fmt, GPTHeader = _make_fmt('GPTHeader', GPT_HEADER_FORMAT)
data = fp.read(struct.calcsize(fmt))
header = GPTHeader._make(struct.unpack(fmt, data))
if header.signature != 'EFI PART':
raise GPTError('Bad signature: %r' % header.signature)
if header.revision != '\x00\x00\x01\x00':
raise GPTError('Bad revision: %r' % header.revision)
if header.header_size < 92:
raise GPTError('Bad header size: %r' % header.header_size)
header = header._replace(
disk_guid=str(uuid.UUID(bytes_le=header.disk_guid)),
)
return header
def read_partitions(fp, header, lba_size=512):
fp.seek(header.part_entry_start_lba * lba_size)
fmt, GPTPartition = _make_fmt('GPTPartition', GPT_PARTITION_FORMAT, extras=['index'])
for idx in xrange(1, 1+header.num_part_entries):
data = fp.read(header.part_entry_size)
if len(data) < struct.calcsize(fmt):
raise GPTError('Short partition entry')
part = GPTPartition._make(struct.unpack(fmt, data) + (idx,))
if part.type == 16*'\x00':
continue
part = part._replace(
type=str(uuid.UUID(bytes_le=part.type)),
unique=str(uuid.UUID(bytes_le=part.unique)),
name=part.name.decode('utf-16').split('\0', 1)[0],
)
yield part
def find_kernel_device_udevadm(kernelpartition):
try:
for partition in os.listdir('/sys/block/mmcblk0'):
if partition.startswith('mmcblk0p'):

if kernelpartition == name:
return '/dev/' + partition
return ''
except:
return ''
def find_kernel_device_gpt(kernelpartition):
try:
p = 1
header = read_header(open('/dev/mmcblk0', 'r'))
for part in read_partitions(open('/dev/mmcblk0', 'r'), header):
if kernelpartition == part.name:
return '/dev/mmcblk0p' + str(p)
p += 1
return ''
except:
return ''
try:
kerneldev = open('/sys/firmware/devicetree/base/chosen/kerneldev', 'r').readline().split('.')
if 'emmcflash0' in kerneldev[0]:
kerneldevice = find_kernel_device_udevadm(kerneldev[1].strip('\0'))
if kerneldevice == '':
kerneldevice = find_kernel_device_gpt(kerneldev[1].strip('\0'))
if kerneldevice != '':
os.symlink(kerneldevice, '/dev/kernel')
except:
pass