| #!/usr/bin/python |
| |
| # Copyright 2016, The Android Open Source Project |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| |
| """Command-line tool for partitioning Brillo images.""" |
| |
| |
| import argparse |
| import copy |
| import json |
| import math |
| import numbers |
| import struct |
| import sys |
| import uuid |
| import zlib |
| |
| |
| # Keywords used in JSON files. |
| JSON_KEYWORD_SETTINGS = 'settings' |
| JSON_KEYWORD_SETTINGS_AB_SUFFIXES = 'ab_suffixes' |
| JSON_KEYWORD_SETTINGS_DISK_SIZE = 'disk_size' |
| JSON_KEYWORD_SETTINGS_DISK_ALIGNMENT = 'disk_alignment' |
| JSON_KEYWORD_SETTINGS_DISK_GUID = 'disk_guid' |
| JSON_KEYWORD_PARTITIONS = 'partitions' |
| JSON_KEYWORD_PARTITIONS_LABEL = 'label' |
| JSON_KEYWORD_PARTITIONS_OFFSET = 'offset' |
| JSON_KEYWORD_PARTITIONS_SIZE = 'size' |
| JSON_KEYWORD_PARTITIONS_GROW = 'grow' |
| JSON_KEYWORD_PARTITIONS_GUID = 'guid' |
| JSON_KEYWORD_PARTITIONS_TYPE_GUID = 'type_guid' |
| JSON_KEYWORD_PARTITIONS_FLAGS = 'flags' |
| JSON_KEYWORD_PARTITIONS_IGNORE = 'ignore' |
| JSON_KEYWORD_PARTITIONS_AB = 'ab' |
| JSON_KEYWORD_PARTITIONS_AB_EXPANDED = 'ab_expanded' |
| JSON_KEYWORD_PARTITIONS_POSITION = 'position' |
| JSON_KEYWORD_AUTO = 'auto' |
| |
| # Possible values for the --type option of the query_partition |
| # sub-command. |
| QUERY_PARTITION_TYPES = ['size', |
| 'offset', |
| 'guid', |
| 'type_guid', |
| 'flags'] |
| |
| BPT_VERSION_MAJOR = 1 |
| BPT_VERSION_MINOR = 0 |
| |
| DISK_SECTOR_SIZE = 512 |
| |
| GPT_NUM_LBAS = 33 |
| |
| GPT_MIN_PART_NUM = 1 |
| GPT_MAX_PART_NUM = 128 |
| |
| KNOWN_TYPE_GUIDS = { |
| 'brillo_boot': 'bb499290-b57e-49f6-bf41-190386693794', |
| 'brillo_system': '0f2778c4-5cc1-4300-8670-6c88b7e57ed6', |
| 'brillo_odm': 'e99d84d7-2c1b-44cf-8c58-effae2dc2558', |
| 'brillo_oem': 'aa3434b2-ddc3-4065-8b1a-18e99ea15cb7', |
| 'brillo_userdata': '0bb7e6ed-4424-49c0-9372-7fbab465ab4c', |
| 'brillo_misc': '6b2378b0-0fbc-4aa9-a4f6-4d6e17281c47', |
| 'brillo_vbmeta': 'b598858a-5fe3-418e-b8c4-824b41f4adfc', |
| 'brillo_vendor_specific': '314f99d5-b2bf-4883-8d03-e2f2ce507d6a', |
| 'linux_fs': '0fc63daf-8483-4772-8e79-3d69d8477de4', |
| 'ms_basic_data': 'ebd0a0a2-b9e5-4433-87c0-68b6b72699c7' |
| } |
| |
| |
| def RoundToMultiple(number, size, round_down=False): |
| """Rounds a number up (or down) to nearest multiple of another number. |
| |
| Args: |
| number: The number to round up. |
| size: The multiple to round up to. |
| round_down: If True, the number will be rounded down. |
| |
| Returns: |
| If |number| is a multiple of |size|, returns |number|, otherwise |
| returns |number| + |size| - |remainder| (if |round_down| is False) or |
| |number| - |remainder| (if |round_down| is True). Always returns |
| an integer. |
| """ |
| remainder = number % size |
| if remainder == 0: |
| return int(number) |
| if round_down: |
| return int(number - remainder) |
| return int(number + size - remainder) |
| |
| |
| def ParseNumber(arg): |
| """Number parser. |
| |
| If |arg| is an integer, that value is returned. Otherwise int(arg, 0) |
| is returned. |
| |
| This function is suitable for use in the |type| parameter of |
| |ArgumentParser|'s add_argument() function. An improvement to just |
| using type=int is that this function supports numbers in other |
| bases, e.g. "0x1234". |
| |
| Arguments: |
| arg: Argument (int or string) to parse. |
| |
| Returns: |
| The parsed value, as an integer. |
| |
| Raises: |
| ValueError: If the argument could not be parsed. |
| """ |
| if isinstance(arg, numbers.Integral): |
| return arg |
| return int(arg, 0) |
| |
| |
| def ParseGuid(arg): |
| """Parser for RFC 4122 GUIDs. |
| |
| Arguments: |
| arg: The argument, as a string. |
| |
| Returns: |
| UUID in hyphenated format. |
| |
| Raises: |
| ValueError: If the given string cannot be parsed. |
| """ |
| return str(uuid.UUID(arg)) |
| |
| |
| def ParseSize(arg): |
| """Parser for size strings with decimal and binary unit support. |
| |
| This supports both integers and strings. |
| |
| Arguments: |
| arg: The string to parse. |
| |
| Returns: |
| The parsed size in bytes as an integer. |
| |
| Raises: |
| ValueError: If the given string cannot be parsed. |
| """ |
| if isinstance(arg, numbers.Integral): |
| return arg |
| |
| ws_index = arg.find(' ') |
| if ws_index != -1: |
| num = float(arg[0:ws_index]) |
| factor = 1 |
| if arg.endswith('KiB'): |
| factor = 1024 |
| elif arg.endswith('MiB'): |
| factor = 1024*1024 |
| elif arg.endswith('GiB'): |
| factor = 1024*1024*1024 |
| elif arg.endswith('TiB'): |
| factor = 1024*1024*1024*1024 |
| elif arg.endswith('PiB'): |
| factor = 1024*1024*1024*1024*1024 |
| elif arg.endswith('kB'): |
| factor = 1000 |
| elif arg.endswith('MB'): |
| factor = 1000*1000 |
| elif arg.endswith('GB'): |
| factor = 1000*1000*1000 |
| elif arg.endswith('TB'): |
| factor = 1000*1000*1000*1000 |
| elif arg.endswith('PB'): |
| factor = 1000*1000*1000*1000*1000 |
| else: |
| raise ValueError('Cannot parse string "{}"'.format(arg)) |
| value = num*factor |
| # If the resulting value isn't an integer, round up. |
| if not value.is_integer(): |
| value = int(math.ceil(value)) |
| else: |
| value = int(arg, 0) |
| return value |
| |
| |
| class GuidGenerator(object): |
| """An interface for obtaining strings that are GUIDs. |
| |
| To facilitate unit testing, this abstraction is used instead of the |
| directly using the uuid module. |
| """ |
| |
| def dispense_guid(self, partition_number): |
| """Dispenses a GUID. |
| |
| Arguments: |
| partition_number: The partition number or 0 if requesting a GUID |
| for the whole disk. |
| |
| Returns: |
| A RFC 4122 compliant GUID, as a string. |
| """ |
| return str(uuid.uuid4()) |
| |
| |
| class Partition(object): |
| """Object representing a partition. |
| |
| Attributes: |
| label: The partition label. |
| offset: Offset of the partition on the disk, or None. |
| size: Size of the partition or None if not specified. |
| grow: True if partition has been requested to use all remaining space. |
| guid: Instance GUID (RFC 4122 compliant) as a string or None or 'auto' |
| if it should be automatically generated. |
| type_guid: Type GUID (RFC 4122 compliant) as a string or a known type |
| from the |KNOWN_TYPE_GUIDS| map. |
| flags: GUID flags. |
| ab: If True, the partition is an A/B partition. |
| ab_expanded: If True, the A/B partitions have been generated. |
| ignore: If True, the partition should not be included in the final output. |
| position: The requested position of the partition or 0 if it doesn't matter. |
| """ |
| |
| def __init__(self): |
| """Initializer method.""" |
| self.label = '' |
| self.offset = None |
| self.size = None |
| self.grow = False |
| self.guid = None |
| self.type_guid = None |
| self.flags = 0 |
| self.ab = False |
| self.ab_expanded = False |
| self.ignore = False |
| self.position = 0 |
| |
| def add_info(self, pobj): |
| """Add information to partition. |
| |
| Arguments: |
| pobj: A JSON object with information about the partition. |
| """ |
| self.label = pobj[JSON_KEYWORD_PARTITIONS_LABEL] |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_OFFSET) |
| if value: |
| self.offset = ParseSize(value) |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_SIZE) |
| if value: |
| self.size = ParseSize(value) |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_GROW) |
| if value: |
| self.grow = True |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_AB) |
| if value: |
| self.ab = value |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_AB_EXPANDED) |
| if value: |
| self.ab_expanded = value |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_GUID) |
| if value: |
| self.guid = value |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_IGNORE) |
| if value: |
| self.ignore = value |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_TYPE_GUID) |
| if value: |
| self.type_guid = str.lower(str(value)) |
| if self.type_guid in KNOWN_TYPE_GUIDS: |
| self.type_guid = KNOWN_TYPE_GUIDS[self.type_guid] |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_FLAGS) |
| if value: |
| self.flags = ParseNumber(value) |
| value = pobj.get(JSON_KEYWORD_PARTITIONS_POSITION) |
| if value: |
| self.position = ParseNumber(value) |
| |
| def expand_guid(self, guid_generator, partition_number): |
| """Assign instance GUID and type GUID if required. |
| |
| Arguments: |
| guid_generator: A GuidGenerator object. |
| partition_number: The partition number, starting from 1. |
| """ |
| if not self.guid or self.guid == JSON_KEYWORD_AUTO: |
| self.guid = guid_generator.dispense_guid(partition_number) |
| if not self.type_guid: |
| self.type_guid = KNOWN_TYPE_GUIDS['brillo_vendor_specific'] |
| |
| def validate(self): |
| """Sanity checks data in object.""" |
| |
| try: |
| _ = uuid.UUID(str(self.guid)) |
| except ValueError: |
| raise ValueError('The string "{}" is not a valid GPT instance GUID on ' |
| 'partition with label "{}".'.format( |
| str(self.guid), self.label)) |
| |
| try: |
| _ = uuid.UUID(str(self.type_guid)) |
| except ValueError: |
| raise ValueError('The string "{}" is not a valid GPT type GUID on ' |
| 'partition with label "{}".'.format( |
| str(self.type_guid), self.label)) |
| |
| if not self.size: |
| if not self.grow: |
| raise ValueError('Size can only be unset if "grow" is True.') |
| |
| def cmp(self, other): |
| """Comparison method.""" |
| self_position = self.position |
| if self_position == 0: |
| self_position = GPT_MAX_PART_NUM |
| other_position = other.position |
| if other_position == 0: |
| other_position = GPT_MAX_PART_NUM |
| return cmp(self_position, other_position) |
| |
| |
| class Settings(object): |
| """An object for holding settings. |
| |
| Attributes: |
| ab_suffixes: A list of A/B suffixes to use. |
| disk_size: An integer with the disk size in bytes. |
| disk_alignment: The alignment to use for partitions. |
| disk_guid: The GUID to use for the disk or None or 'auto' if |
| automatically generated. |
| """ |
| |
| def __init__(self): |
| """Initializer with defaults.""" |
| self.ab_suffixes = ['_a', '_b'] |
| self.disk_size = None |
| self.disk_alignment = 4096 |
| self.disk_guid = JSON_KEYWORD_AUTO |
| |
| |
| class BptError(Exception): |
| """Application-specific errors. |
| |
| These errors represent issues for which a stack-trace should not be |
| presented. |
| |
| Attributes: |
| message: Error message. |
| """ |
| |
| def __init__(self, message): |
| Exception.__init__(self, message) |
| |
| |
| class BptParsingError(BptError): |
| """Represents an error with an input file. |
| |
| Attributes: |
| message: Error message. |
| filename: Name of the file that caused an error. |
| """ |
| |
| def __init__(self, filename, message): |
| self.filename = filename |
| BptError.__init__(self, message) |
| |
| |
| class Bpt(object): |
| """Business logic for bpttool command-line tool.""" |
| |
| def _read_json(self, input_files, ab_collapse=True): |
| """Parses a stack of JSON files into suitable data structures. |
| |
| The order of files matters as later files can modify partitions |
| declared in earlier files. |
| |
| Arguments: |
| input_files: An ordered list of open files. |
| ab_collapse: If True, collapse A/B partitions. |
| |
| Returns: |
| A tuple where the first element is a list of Partition objects |
| and the second element is a Settings object. |
| |
| Raises: |
| BptParsingError: If an input file has an error. |
| """ |
| partitions = [] |
| settings = Settings() |
| |
| # Read all input file and merge partitions and settings. |
| for f in input_files: |
| try: |
| obj = json.loads(f.read()) |
| except ValueError as e: |
| # Unfortunately we can't easily get the line number where the |
| # error occurred. |
| raise BptParsingError(f.name, e.message) |
| |
| sobj = obj.get(JSON_KEYWORD_SETTINGS) |
| if sobj: |
| ab_suffixes = sobj.get(JSON_KEYWORD_SETTINGS_AB_SUFFIXES) |
| if ab_suffixes: |
| settings.ab_suffixes = ab_suffixes |
| disk_size = sobj.get(JSON_KEYWORD_SETTINGS_DISK_SIZE) |
| if disk_size: |
| settings.disk_size = ParseSize(disk_size) |
| disk_alignment = sobj.get(JSON_KEYWORD_SETTINGS_DISK_ALIGNMENT) |
| if disk_alignment: |
| settings.disk_alignment = ParseSize(disk_alignment) |
| disk_guid = sobj.get(JSON_KEYWORD_SETTINGS_DISK_GUID) |
| if disk_guid: |
| settings.disk_guid = disk_guid |
| |
| pobjs = obj.get(JSON_KEYWORD_PARTITIONS) |
| if pobjs: |
| for pobj in pobjs: |
| if ab_collapse and pobj.get(JSON_KEYWORD_PARTITIONS_AB_EXPANDED): |
| # If we encounter an expanded partition, unexpand it. This |
| # is to make it possible to use output-JSON (from this tool) |
| # and stack it with an input-JSON file that e.g. specifies |
| # size='256 GiB' for the 'system' partition. |
| label = pobj[JSON_KEYWORD_PARTITIONS_LABEL] |
| if label.endswith(settings.ab_suffixes[0]): |
| # Modify first A/B copy so it doesn't have the trailing suffix. |
| new_len = len(label) - len(settings.ab_suffixes[0]) |
| pobj[JSON_KEYWORD_PARTITIONS_LABEL] = label[0:new_len] |
| pobj[JSON_KEYWORD_PARTITIONS_AB_EXPANDED] = False |
| pobj[JSON_KEYWORD_PARTITIONS_GUID] = JSON_KEYWORD_AUTO |
| else: |
| # Skip other A/B copies. |
| continue |
| # Find or create a partition. |
| p = None |
| for candidate in partitions: |
| if candidate.label == pobj[JSON_KEYWORD_PARTITIONS_LABEL]: |
| p = candidate |
| break |
| if not p: |
| p = Partition() |
| partitions.append(p) |
| p.add_info(pobj) |
| |
| return partitions, settings |
| |
| def _generate_json(self, partitions, settings): |
| """Generate a string with JSON representing partitions and settings. |
| |
| Arguments: |
| partitions: A list of Partition objects. |
| settings: A Settings object. |
| |
| Returns: |
| A JSON string. |
| """ |
| suffixes_str = '[' |
| for n in range(0, len(settings.ab_suffixes)): |
| if n != 0: |
| suffixes_str += ', ' |
| suffixes_str += '"{}"'.format(settings.ab_suffixes[n]) |
| suffixes_str += ']' |
| |
| ret = ('{{\n' |
| ' "' + JSON_KEYWORD_SETTINGS + '": {{\n' |
| ' "' + JSON_KEYWORD_SETTINGS_AB_SUFFIXES + '": {},\n' |
| ' "' + JSON_KEYWORD_SETTINGS_DISK_SIZE + '": {},\n' |
| ' "' + JSON_KEYWORD_SETTINGS_DISK_ALIGNMENT + '": {},\n' |
| ' "' + JSON_KEYWORD_SETTINGS_DISK_GUID + '": "{}"\n' |
| ' }},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS + '": [\n').format( |
| suffixes_str, |
| settings.disk_size, |
| settings.disk_alignment, |
| settings.disk_guid) |
| |
| for n in range(0, len(partitions)): |
| p = partitions[n] |
| ret += (' {{\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_LABEL + '": "{}",\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_OFFSET + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_SIZE + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_GROW + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_GUID + '": "{}",\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_TYPE_GUID + '": "{}",\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_FLAGS + '": "{:#018x}",\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_IGNORE + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_AB + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_AB_EXPANDED + '": {},\n' |
| ' "' + JSON_KEYWORD_PARTITIONS_POSITION + '": {}\n' |
| ' }}{}\n').format(p.label, |
| p.offset, |
| p.size, |
| 'true' if p.grow else 'false', |
| p.guid, |
| p.type_guid, |
| p.flags, |
| 'true' if p.ignore else 'false', |
| 'true' if p.ab else 'false', |
| 'true' if p.ab_expanded else 'false', |
| p.position, |
| '' if n == len(partitions) - 1 else ',') |
| ret += (' ]\n' |
| '}\n') |
| return ret |
| |
| def _lba_to_chs(self, lba): |
| """Converts LBA to CHS. |
| |
| Arguments: |
| lba: The sector number to convert. |
| |
| Returns: |
| An array containing the CHS encoded the way it's expected in a |
| MBR partition table. |
| """ |
| # See https://en.wikipedia.org/wiki/Cylinder-head-sector |
| num_heads = 255 |
| num_sectors = 63 |
| # If LBA isn't going to fit in CHS, return maximum CHS values. |
| max_lba = 255*num_heads*num_sectors |
| if lba > max_lba: |
| return [255, 255, 255] |
| c = lba / (num_heads*num_sectors) |
| h = (lba / num_sectors) % num_heads |
| s = lba % num_sectors |
| return [h, (((c>>8) & 0x03)<<6) | (s & 0x3f), c & 0xff] |
| |
| def _generate_protective_mbr(self, settings): |
| """Generate Protective MBR. |
| |
| Arguments: |
| settings: A Settings object. |
| |
| Returns: |
| A string with the binary protective MBR (512 bytes). |
| """ |
| # See https://en.wikipedia.org/wiki/Master_boot_record for MBR layout. |
| # |
| # The first partition starts at offset 446 (0x1be). |
| lba_start = 1 |
| lba_end = settings.disk_size/DISK_SECTOR_SIZE - 1 |
| start_chs = self._lba_to_chs(lba_start) |
| end_chs = self._lba_to_chs(lba_end) |
| pmbr = struct.pack('<446s' # Bootloader code |
| 'B' # Status. |
| 'BBB' # CHS start. |
| 'B' # Partition type. |
| 'BBB' # CHS end. |
| 'I' # LBA of partition start. |
| 'I' # Number of sectors in partition. |
| '48x' # Padding to get to offset 510 (0x1fe). |
| 'BB', # Boot signature. |
| '\xfa\xeb\xfe', # cli ; jmp $ (x86) |
| 0x00, |
| start_chs[0], start_chs[1], start_chs[2], |
| 0xee, # MBR Partition Type: GPT protective MBR. |
| end_chs[0], end_chs[1], end_chs[2], |
| 1, # LBA start |
| lba_end, |
| 0x55, 0xaa) |
| return pmbr |
| |
| def _generate_gpt(self, partitions, settings, primary=True): |
| """Generate GUID Partition Table. |
| |
| Arguments: |
| partitions: A list of Partition objects. |
| settings: A Settings object. |
| primary: True to generate primary GPT, False to generate secondary. |
| |
| Returns: |
| A string with the binary GUID Partition Table (33*512 bytes). |
| """ |
| # See https://en.wikipedia.org/wiki/Master_boot_record for MBR layout. |
| # |
| # The first partition starts at offset 446 (0x1be). |
| |
| disk_num_lbas = settings.disk_size/DISK_SECTOR_SIZE |
| if primary: |
| current_lba = 1 |
| other_lba = disk_num_lbas - 1 |
| partitions_lba = 2 |
| else: |
| current_lba = disk_num_lbas - 1 |
| other_lba = 1 |
| partitions_lba = disk_num_lbas - GPT_NUM_LBAS |
| first_usable_lba = GPT_NUM_LBAS + 1 |
| last_usable_lba = disk_num_lbas - GPT_NUM_LBAS - 1 |
| |
| part_array = [] |
| for p in partitions: |
| part_array.append(struct.pack( |
| '<16s' # Partition type GUID. |
| '16s' # Partition instance GUID. |
| 'QQ' # First and last LBA. |
| 'Q' # Flags. |
| '72s', # Name (36 UTF-16LE code units). |
| uuid.UUID(p.type_guid).get_bytes_le(), |
| uuid.UUID(p.guid).get_bytes_le(), |
| p.offset/DISK_SECTOR_SIZE, |
| (p.offset + p.size)/DISK_SECTOR_SIZE - 1, |
| p.flags, |
| p.label.encode(encoding='utf-16le'))) |
| |
| part_array.append(((128 - len(partitions))*128) * '\0') |
| part_array_str = ''.join(part_array) |
| |
| partitions_crc32 = zlib.crc32(part_array_str) % (1<<32) |
| |
| header_crc32 = 0 |
| while True: |
| header = struct.pack( |
| '<8s' # Signature. |
| '4B' # Version. |
| 'I' # Header size. |
| 'I' # CRC32 (must be zero during calculation). |
| 'I' # Reserved (must be zero). |
| 'QQ' # Current and Other LBA. |
| 'QQ' # First and last usable LBA. |
| '16s' # Disk GUID. |
| 'Q' # Starting LBA of array of partitions. |
| 'I' # Number of partitions. |
| 'I' # Partition entry size, in bytes. |
| 'I' # CRC32 of partition array |
| '420x', # Padding to get to 512 bytes. |
| 'EFI PART', |
| 0x00, 0x00, 0x01, 0x00, |
| 92, |
| header_crc32, |
| 0x00000000, |
| current_lba, other_lba, |
| first_usable_lba, last_usable_lba, |
| uuid.UUID(settings.disk_guid).get_bytes_le(), |
| partitions_lba, |
| 128, |
| 128, |
| partitions_crc32) |
| if header_crc32 != 0: |
| break |
| header_crc32 = zlib.crc32(header[0:92]) % (1<<32) |
| |
| if primary: |
| return header + part_array_str |
| else: |
| return part_array_str + header |
| |
| def _generate_gpt_bin(self, partitions, settings): |
| """Generate a bytearray representing partitions and settings. |
| |
| The blob will have three partition tables, laid out one after |
| another: 1) Protective MBR (512 bytes); 2) Primary GPT (33*512 |
| bytes); and 3) Secondary GPT (33*512 bytes). |
| |
| The total size will be 34,304 bytes. |
| |
| Arguments: |
| partitions: A list of Partition objects. |
| settings: A Settings object. |
| |
| Returns: |
| A bytearray() object. |
| """ |
| protective_mbr = self._generate_protective_mbr(settings) |
| primary_gpt = self._generate_gpt(partitions, settings) |
| secondary_gpt = self._generate_gpt(partitions, settings, primary=False) |
| ret = protective_mbr + primary_gpt + secondary_gpt |
| return ret |
| |
| def _validate_disk_partitions(self, partitions, disk_size): |
| """Check that a list of partitions have assigned offsets and fits on a |
| disk of a given size. |
| |
| This function checks partition offsets and sizes to see if they may fit on |
| a disk image. |
| |
| Arguments: |
| partitions: A list of Partition objects. |
| settings: Integer size of disk image. |
| |
| Raises: |
| BptError: If checked condition is not satisfied. |
| """ |
| for p in partitions: |
| if not p.offset or p.offset < (GPT_NUM_LBAS + 1)*DISK_SECTOR_SIZE: |
| raise BptError('Partition with label "{}" has no offset.' |
| .format(p.label)) |
| if not p.size or p.size < 0: |
| raise BptError('Partition with label "{}" has no size.' |
| .format(p.label)) |
| if (p.offset + p.size) > (disk_size - GPT_NUM_LBAS*DISK_SECTOR_SIZE): |
| raise BptError('Partition with label "{}" exceeds the disk ' |
| 'image size.'.format(p.label)) |
| |
| def make_table(self, |
| inputs, |
| ab_suffixes=None, |
| disk_size=None, |
| disk_alignment=None, |
| disk_guid=None, |
| guid_generator=None): |
| """Implementation of the 'make_table' command. |
| |
| This function takes a list of input partition definition files, |
| flattens them, expands A/B partitions, grows partitions, and lays |
| out partitions according to alignment constraints. |
| |
| Arguments: |
| inputs: List of JSON files to parse. |
| ab_suffixes: List of the A/B suffixes (as a comma-separated string) |
| to use or None to not override. |
| disk_size: Size of disk or None to not override. |
| disk_alignment: Disk alignment or None to not override. |
| disk_guid: Disk GUID as a string or None to not override. |
| guid_generator: A GuidGenerator or None to use the default. |
| |
| Returns: |
| A tuple where the first argument is a JSON string for the resulting |
| partitions and the second argument is the binary partition tables. |
| |
| Raises: |
| BptParsingError: If an input file has an error. |
| BptError: If another application-specific error occurs |
| """ |
| partitions, settings = self._read_json(inputs) |
| |
| # Command-line arguments override anything specified in input |
| # files. |
| if disk_size: |
| settings.disk_size = int(math.ceil(disk_size)) |
| if disk_alignment: |
| settings.disk_alignment = int(disk_alignment) |
| if ab_suffixes: |
| settings.ab_suffixes = ab_suffixes.split(',') |
| if disk_guid: |
| settings.disk_guid = disk_guid |
| |
| if not guid_generator: |
| guid_generator = GuidGenerator() |
| |
| # We need to know the disk size. Also round it down to ensure it's |
| # a multiple of the sector size. |
| if not settings.disk_size: |
| raise BptError('Disk size not specified. Use --disk_size option ' |
| 'or specify it in an input file.\n') |
| settings.disk_size = RoundToMultiple(settings.disk_size, |
| DISK_SECTOR_SIZE, |
| round_down=True) |
| |
| # Alignment must be divisible by disk sector size. |
| if settings.disk_alignment % DISK_SECTOR_SIZE != 0: |
| raise BptError( |
| 'Disk alignment size of {} is not divisible by {}.\n'.format( |
| settings.disk_alignment, DISK_SECTOR_SIZE)) |
| |
| # Expand A/B partitions and skip ignored partitions. |
| expanded_partitions = [] |
| for p in partitions: |
| if p.ignore: |
| continue |
| if p.ab and not p.ab_expanded: |
| p.ab_expanded = True |
| for suffix in settings.ab_suffixes: |
| new_p = copy.deepcopy(p) |
| new_p.label += suffix |
| expanded_partitions.append(new_p) |
| else: |
| expanded_partitions.append(p) |
| partitions = expanded_partitions |
| |
| # Expand Disk GUID if needed. |
| if not settings.disk_guid or settings.disk_guid == JSON_KEYWORD_AUTO: |
| settings.disk_guid = guid_generator.dispense_guid(0) |
| |
| # Sort according to 'position' attribute. |
| partitions = sorted(partitions, cmp=lambda x, y: x.cmp(y)) |
| |
| # Automatically generate GUIDs if the GUID is unset or set to |
| # 'auto'. Also validate the rest of the fields. |
| part_no = 1 |
| for p in partitions: |
| p.expand_guid(guid_generator, part_no) |
| p.validate() |
| part_no += 1 |
| |
| # Idenfify partition to grow and lay out partitions, ignoring the |
| # one to grow. This way we can figure out how much space is left. |
| # |
| # Right now we only support a single 'grow' partition but we could |
| # support more in the future by splitting up the available bytes |
| # between them. |
| grow_part = None |
| offset = DISK_SECTOR_SIZE*(1 + GPT_NUM_LBAS) |
| for p in partitions: |
| if p.grow: |
| if grow_part: |
| raise BptError('Only a single partition can be automatically ' |
| 'grown.\n') |
| grow_part = p |
| else: |
| # Ensure size is a multiple of DISK_SECTOR_SIZE by rounding up |
| # (user may specify it as e.g. "1.5 GB" which is not divisible |
| # by 512). |
| p.size = RoundToMultiple(p.size, DISK_SECTOR_SIZE) |
| # Align offset to disk alignment. |
| offset = RoundToMultiple(offset, settings.disk_alignment) |
| offset += p.size |
| |
| # After laying out (respecting alignment) all non-grow |
| # partitions, check that the given disk size is big enough. |
| if offset > settings.disk_size - DISK_SECTOR_SIZE*GPT_NUM_LBAS: |
| raise BptError('Disk size of {} bytes is too small for partitions ' |
| 'totaling {} bytes.\n'.format( |
| settings.disk_size, offset)) |
| |
| # If we have a grow partition, it'll starts at the next |
| # available alignment offset and we can calculate its size as |
| # follows. |
| if grow_part: |
| offset = RoundToMultiple(offset, settings.disk_alignment) |
| grow_part.size = RoundToMultiple( |
| settings.disk_size - DISK_SECTOR_SIZE*GPT_NUM_LBAS - offset, |
| settings.disk_alignment, |
| round_down=True) |
| if grow_part.size < DISK_SECTOR_SIZE: |
| raise BptError('Not enough space for partition "{}" to be ' |
| 'automatically grown.\n'.format(grow_part.label)) |
| |
| # Now we can assign partition start offsets for all partitions, |
| # including the grow partition. |
| offset = DISK_SECTOR_SIZE*(1 + GPT_NUM_LBAS) |
| for p in partitions: |
| # Align offset. |
| offset = RoundToMultiple(offset, settings.disk_alignment) |
| p.offset = offset |
| offset += p.size |
| assert offset <= settings.disk_size - DISK_SECTOR_SIZE*GPT_NUM_LBAS |
| |
| json_str = self._generate_json(partitions, settings) |
| |
| gpt_bin = self._generate_gpt_bin(partitions, settings) |
| |
| return json_str, gpt_bin |
| |
| def make_disk_image(self, output, bpt, images, allow_empty_partitions=False): |
| """Implementation of the 'make_disk_image' command. |
| |
| This function takes in a list of partitions images and a bpt file |
| for the purpose of creating a raw disk image with a protective MBR, |
| primary and secondary GPT, and content for each partition as specified. |
| |
| Arguments: |
| output: Output file where disk image is to be written to. |
| bpt: BPT JSON file to parse. |
| images: List of partition image paths to be combined (as specified by |
| bpt). Each element is of the form. |
| 'PARTITION_NAME:/PATH/TO/PARTITION_IMAGE' |
| allow_empty_partitions: If True, partitions defined in |bpt| need not to |
| be present in |images|. Otherwise an exception is |
| thrown if a partition is referenced in |bpt| but |
| not in |images|. |
| |
| Raises: |
| BptParsingError: If an image file has an error. |
| BptError: If another application-specific error occurs. |
| """ |
| # Generate partition list and settings. |
| partitions, settings = self._read_json([bpt], ab_collapse=False) |
| |
| # Validated partition sizes and offsets. |
| self._validate_disk_partitions(partitions, settings.disk_size) |
| |
| # Sort according to 'offset' attribute. |
| partitions = sorted(partitions, cmp=lambda x, y: cmp(x.offset, y.offset)) |
| |
| # Create necessary tables. |
| protective_mbr = self._generate_protective_mbr(settings) |
| primary_gpt = self._generate_gpt(partitions, settings) |
| secondary_gpt = self._generate_gpt(partitions, settings, primary=False) |
| |
| # Start at 0 offset for mbr and primary gpt. |
| output.seek(0) |
| output.write(protective_mbr) |
| output.write(primary_gpt) |
| |
| # Create mapping of partition name to partition image file. |
| image_file_names = {} |
| try: |
| for name_path in images: |
| name, path = name_path.split(":") |
| image_file_names[name] = path |
| except ValueError as e: |
| raise BptParsingError(name_path, 'Bad image argument {}.'.format( |
| images[i])) |
| |
| # Read image and insert in correct offset. |
| for p in partitions: |
| if p.label not in image_file_names: |
| if allow_empty_partitions: |
| continue |
| else: |
| raise BptParsingError(bpt.name, 'No content specified for partition' |
| ' with label {}'.format(p.label)) |
| |
| with open(image_file_names[p.label], 'rb') as partition_image: |
| output.seek(p.offset) |
| partition_blob = partition_image.read() |
| if len(partition_blob) > p.size: |
| raise BptError('Partition image content with label "{}" exceeds the ' |
| 'partition size.'.format(p.label)) |
| output.write(partition_blob) |
| |
| # Put secondary GPT and end of disk. |
| output.seek(settings.disk_size - len(secondary_gpt)) |
| output.write(secondary_gpt) |
| |
| def query_partition(self, input_file, part_label, query_type, ab_collapse): |
| """Implementation of the 'query_partition' command. |
| |
| This reads the partition definition file given by |input_file| and |
| returns information of type |query_type| for the partition with |
| label |part_label|. |
| |
| Arguments: |
| input_file: A JSON file to parse. |
| part_label: Label of partition to query information about. |
| query_type: The information to query, see |QUERY_PARTITION_TYPES|. |
| ab_collapse: If True, collapse A/B partitions. |
| |
| Returns: |
| The requested information as a string or None if there is no |
| partition with the given label. |
| |
| Raises: |
| BptParsingError: If an input file has an error. |
| BptError: If another application-specific error occurs |
| """ |
| |
| partitions, _ = self._read_json([input_file], ab_collapse) |
| |
| part = None |
| for p in partitions: |
| if p.label == part_label: |
| part = p |
| break |
| |
| if not part: |
| return None |
| |
| value = part.__dict__.get(query_type) |
| # Print out flags as a hex-value. |
| if query_type == 'flags': |
| return '{:#018x}'.format(value) |
| return str(value) |
| |
| |
| class BptTool(object): |
| """Object for bpttool command-line tool.""" |
| |
| def __init__(self): |
| """Initializer method.""" |
| self.bpt = Bpt() |
| |
| def run(self, argv): |
| """Command-line processor. |
| |
| Arguments: |
| argv: Pass sys.argv from main. |
| """ |
| parser = argparse.ArgumentParser() |
| subparsers = parser.add_subparsers(title='subcommands') |
| |
| sub_parser = subparsers.add_parser( |
| 'version', |
| help='Prints version of bpttool.') |
| sub_parser.set_defaults(func=self.version) |
| |
| sub_parser = subparsers.add_parser( |
| 'make_table', |
| help='Lays out partitions and creates partition table.') |
| sub_parser.add_argument('--input', |
| help='Path to partition definition file.', |
| type=argparse.FileType('r'), |
| action='append') |
| sub_parser.add_argument('--ab_suffixes', |
| help='Set or override A/B suffixes.') |
| sub_parser.add_argument('--disk_size', |
| help='Set or override disk size.', |
| type=ParseSize) |
| sub_parser.add_argument('--disk_alignment', |
| help='Set or override disk alignment.', |
| type=ParseSize) |
| sub_parser.add_argument('--disk_guid', |
| help='Set or override disk GUID.', |
| type=ParseGuid) |
| sub_parser.add_argument('--output_json', |
| help='JSON output file name.', |
| type=argparse.FileType('w')) |
| sub_parser.add_argument('--output_gpt', |
| help='Output file name for MBR/GPT/GPT file.', |
| type=argparse.FileType('w')) |
| sub_parser.set_defaults(func=self.make_table) |
| |
| sub_parser = subparsers.add_parser( |
| 'make_disk_image', |
| help='Creates disk image for loaded with partitions.') |
| sub_parser.add_argument('--output', |
| help='Path to image output.', |
| type=argparse.FileType('w'), |
| required=True) |
| sub_parser.add_argument('--input', |
| help='Path to bpt file input.', |
| type=argparse.FileType('r'), |
| required=True) |
| sub_parser.add_argument('--image', |
| help='Partition name and path to image file.', |
| metavar='PARTITION_NAME:PATH', |
| action='append') |
| sub_parser.add_argument('--allow_empty_partitions', |
| help='Allow skipping partitions in bpt file.', |
| action='store_true') |
| sub_parser.set_defaults(func=self.make_disk_image) |
| |
| sub_parser = subparsers.add_parser( |
| 'query_partition', |
| help='Looks up informtion about a partition.') |
| sub_parser.add_argument('--input', |
| help='Path to partition definition file.', |
| type=argparse.FileType('r'), |
| required=True) |
| sub_parser.add_argument('--label', |
| help='Label of partition to look up.', |
| required=True) |
| sub_parser.add_argument('--ab_collapse', |
| help='Collapse A/B partitions.', |
| action='store_true') |
| sub_parser.add_argument('--type', |
| help='Type of information to look up.', |
| choices=QUERY_PARTITION_TYPES, |
| required=True) |
| sub_parser.set_defaults(func=self.query_partition) |
| |
| args = parser.parse_args(argv[1:]) |
| args.func(args) |
| |
| def version(self, _): |
| """Implements the 'version' sub-command.""" |
| print '{}.{}'.format(BPT_VERSION_MAJOR, BPT_VERSION_MINOR) |
| |
| def query_partition(self, args): |
| """Implements the 'query_partition' sub-command.""" |
| try: |
| result = self.bpt.query_partition(args.input, |
| args.label, |
| args.type, |
| args.ab_collapse) |
| except BptParsingError as e: |
| sys.stderr.write('{}: Error parsing: {}\n'.format(e.filename, e.message)) |
| sys.exit(1) |
| except BptError as e: |
| sys.stderr.write('{}\n'.format(e.message)) |
| sys.exit(1) |
| |
| if not result: |
| sys.stderr.write('No partition with label "{}".\n'.format(args.label)) |
| sys.exit(1) |
| |
| print result |
| |
| def make_table(self, args): |
| """Implements the 'make_table' sub-command.""" |
| if not args.input: |
| sys.stderr.write('Option --input is required one or more times.\n') |
| sys.exit(1) |
| |
| try: |
| (json_str, gpt_bin) = self.bpt.make_table(args.input, args.ab_suffixes, |
| args.disk_size, |
| args.disk_alignment, |
| args.disk_guid) |
| except BptParsingError as e: |
| sys.stderr.write('{}: Error parsing: {}\n'.format(e.filename, e.message)) |
| sys.exit(1) |
| except BptError as e: |
| sys.stderr.write('{}\n'.format(e.message)) |
| sys.exit(1) |
| |
| if args.output_json: |
| args.output_json.write(json_str) |
| if args.output_gpt: |
| args.output_gpt.write(gpt_bin) |
| |
| def make_disk_image(self, args): |
| """Implements the 'make_disk_image' sub-command.""" |
| if not args.input: |
| sys.stderr.write('Option --input is required.\n') |
| sys.exit(1) |
| if not args.output: |
| sys.stderr.write('Option --ouptut is required.\n') |
| sys.exit(1) |
| |
| try: |
| self.bpt.make_disk_image(args.output, |
| args.input, |
| args.image, |
| args.allow_empty_partitions) |
| except BptParsingError as e: |
| sys.stderr.write('{}: Error parsing: {}\n'.format(e.filename, e.message)) |
| sys.exit(1) |
| except 'BptError' as e: |
| sys.stderr.write('{}\n'.format(e.message)) |
| sys.exit(1) |
| |
| if __name__ == '__main__': |
| tool = BptTool() |
| tool.run(sys.argv) |
