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34c324cc3a
This change removes /usr/sbin/write_gpt.sh from images which we have no use for. This allows us to drop the indirection of writing partition tables by first writing out a script to call. Now cgpt.py can call cgpt directly to initialize the partition layout. This opens the way for further improvements to how disk images are created.
562 lines
17 KiB
Python
Executable File
562 lines
17 KiB
Python
Executable File
#!/usr/bin/python
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# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
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# Use of this source code is governed by a BSD-style license that can be
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# found in the LICENSE file.
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import json
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import os
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import re
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import subprocess
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import sys
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import uuid
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from optparse import OptionParser
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# First sector we can use.
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START_SECTOR = 64
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class ConfigNotFound(Exception):
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pass
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class PartitionNotFound(Exception):
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pass
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class InvalidLayout(Exception):
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pass
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class InvalidAdjustment(Exception):
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pass
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def LoadPartitionConfig(filename):
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"""Loads a partition tables configuration file into a Python object.
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Args:
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filename: Filename to load into object
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Returns:
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Object containing disk layout configuration
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"""
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valid_keys = set(('_comment', 'metadata', 'layouts'))
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valid_layout_keys = set((
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'_comment', 'type', 'num', 'label', 'blocks', 'block_size', 'fs_blocks',
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'fs_block_size', 'features', 'uuid'))
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if not os.path.exists(filename):
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raise ConfigNotFound('Partition config %s was not found!' % filename)
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with open(filename) as f:
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config = json.load(f)
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try:
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metadata = config['metadata']
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for key in ('block_size', 'fs_block_size'):
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metadata[key] = int(metadata[key])
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unknown_keys = set(config.keys()) - valid_keys
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if unknown_keys:
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raise InvalidLayout('Unknown items: %r' % unknown_keys)
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if len(config['layouts']) <= 0:
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raise InvalidLayout('Missing "layouts" entries')
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for layout_name, layout in config['layouts'].items():
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for part in layout:
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unknown_keys = set(part.keys()) - valid_layout_keys
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if unknown_keys:
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raise InvalidLayout('Unknown items in layout %s: %r' %
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(layout_name, unknown_keys))
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if part['type'] != 'blank':
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for s in ('num', 'label'):
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if not s in part:
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raise InvalidLayout('Layout "%s" missing "%s"' % (layout_name, s))
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part['blocks'] = int(part['blocks'])
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part['bytes'] = part['blocks'] * metadata['block_size']
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if 'fs_blocks' in part:
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part['fs_blocks'] = int(part['fs_blocks'])
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part['fs_bytes'] = part['fs_blocks'] * metadata['fs_block_size']
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if part['fs_bytes'] > part['bytes']:
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raise InvalidLayout(
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'Filesystem may not be larger than partition: %s %s: %d > %d' %
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(layout_name, part['label'], part['fs_bytes'], part['bytes']))
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if 'uuid' in part:
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try:
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# double check the string formatting
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part['uuid'] = str(uuid.UUID(part['uuid']))
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except ValueError as e:
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raise InvalidLayout('Invalid uuid %r: %s' % (part['uuid'], e))
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else:
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part['uuid'] = str(uuid.uuid4())
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except KeyError as e:
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raise InvalidLayout('Layout is missing required entries: %s' % e)
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return config
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def GetPartitionTable(options, config, image_type):
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"""Generates requested image_type layout from a layout configuration.
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This loads the base table and then overlays the requested layout over
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the base layout.
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Args:
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options: Flags passed to the script
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config: Partition configuration file object
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image_type: Type of image eg base/test/dev/factory_install
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Returns:
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Object representing a selected partition table
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"""
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partitions = config['layouts']['base']
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metadata = config['metadata']
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if image_type != 'base':
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for partition_t in config['layouts'][image_type]:
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for partition in partitions:
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if partition['type'] == 'blank' or partition_t['type'] == 'blank':
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continue
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if partition_t['num'] == partition['num']:
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for k, v in partition_t.items():
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partition[k] = v
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for adjustment_str in options.adjust_part.split():
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adjustment = adjustment_str.split(':')
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if len(adjustment) < 2:
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raise InvalidAdjustment('Adjustment specified was incomplete')
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label = adjustment[0]
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operator = adjustment[1][0]
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operand = adjustment[1][1:]
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ApplyPartitionAdjustment(partitions, metadata, label, operator, operand)
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return partitions
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def ApplyPartitionAdjustment(partitions, metadata, label, operator, operand):
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"""Applies an adjustment to a partition specified by label
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Args:
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partitions: Partition table to modify
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metadata: Partition table metadata
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label: The label of the partition to adjust
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operator: Type of adjustment (+/-/=)
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operand: How much to adjust by
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"""
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partition = GetPartitionByLabel(partitions, label)
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operand_digits = re.sub('\D', '', operand)
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size_factor = block_factor = 1
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suffix = operand[len(operand_digits):]
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if suffix:
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size_factors = { 'B': 0, 'K': 1, 'M': 2, 'G': 3, 'T': 4, }
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try:
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size_factor = size_factors[suffix[0].upper()]
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except KeyError:
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raise InvalidAdjustment('Unknown size type %s' % suffix)
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if size_factor == 0 and len(suffix) > 1:
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raise InvalidAdjustment('Unknown size type %s' % suffix)
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block_factors = { '': 1024, 'B': 1000, 'IB': 1024, }
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try:
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block_factor = block_factors[suffix[1:].upper()]
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except KeyError:
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raise InvalidAdjustment('Unknown size type %s' % suffix)
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operand_bytes = int(operand_digits) * pow(block_factor, size_factor)
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if operand_bytes % metadata['block_size'] == 0:
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operand_blocks = operand_bytes / metadata['block_size']
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else:
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raise InvalidAdjustment('Adjustment size not divisible by block size')
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if operator == '+':
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partition['blocks'] += operand_blocks
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partition['bytes'] += operand_bytes
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elif operator == '-':
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partition['blocks'] -= operand_blocks
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partition['bytes'] -= operand_bytes
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elif operator == '=':
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partition['blocks'] = operand_blocks
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partition['bytes'] = operand_bytes
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else:
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raise ValueError('unknown operator %s' % operator)
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if partition['type'] == 'rootfs':
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# If we're adjusting a rootFS partition, we assume the full partition size
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# specified is being used for the filesytem, minus the space reserved for
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# the hashpad.
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partition['fs_bytes'] = partition['bytes']
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partition['fs_blocks'] = partition['fs_bytes'] / metadata['fs_block_size']
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partition['blocks'] = int(partition['blocks'] * 1.15)
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partition['bytes'] = partition['blocks'] * metadata['block_size']
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def GetPartitionTableFromConfig(options, layout_filename, image_type):
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"""Loads a partition table and returns a given partition table type
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Args:
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options: Flags passed to the script
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layout_filename: The filename to load tables from
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image_type: The type of partition table to return
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"""
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config = LoadPartitionConfig(layout_filename)
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partitions = GetPartitionTable(options, config, image_type)
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return partitions
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def WritePartitionTable(options, image_type, layout_filename, disk_filename):
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"""Writes the given partition table to a disk image or device.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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disk_filename: Path to disk image or device file
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"""
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def Cgpt(*args):
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subprocess.check_call(['cgpt'] + [str(a) for a in args])
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config = LoadPartitionConfig(layout_filename)
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partitions = GetPartitionTable(options, config, image_type)
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disk_block_count = START_SECTOR * config['metadata']['block_size']
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for partition in partitions:
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disk_block_count += partition['blocks']
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sector = START_SECTOR
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Cgpt('create', '-c', '-s', disk_block_count, disk_filename)
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for partition in partitions:
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if partition['type'] != 'blank':
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Cgpt('add', '-i', partition['num'],
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'-b', sector,
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'-s', partition['blocks'],
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'-t', partition['type'],
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'-l', partition['label'],
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'-u', partition['uuid'],
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disk_filename)
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sector += partition['blocks']
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Cgpt('show', disk_filename)
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def WriteMbrBoot(options, image_type, layout_filename,
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disk_filename, mbr_filename):
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"""Writes the protective MBR with the given boot code.
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The EFI System Partition will be marked as the 'boot' partition.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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disk_filename: Path to disk image or device file
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mbr_filename: Path to boot code, usually gptmbr.bin from syslinux.
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"""
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config = LoadPartitionConfig(layout_filename)
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partitions = GetPartitionTable(options, config, image_type)
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esp_number = None
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for partition in partitions:
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if partition['type'] == 'efi':
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esp_number = partition['num']
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break
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if esp_number is None:
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raise InvalidLayout('Table does not include an EFI partition.')
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subprocess.check_call(['cgpt', 'boot', '-p', '-b', mbr_filename,
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'-i', str(partition['num']), disk_filename])
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def GetPartitionByNumber(partitions, num):
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"""Given a partition table and number returns the partition object.
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Args:
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partitions: List of partitions to search in
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num: Number of partition to find
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Returns:
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An object for the selected partition
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"""
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for partition in partitions:
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if partition['type'] == 'blank':
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continue
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if partition['num'] == int(num):
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return partition
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raise PartitionNotFound('Partition not found')
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def GetPartitionByLabel(partitions, label):
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"""Given a partition table and label returns the partition object.
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Args:
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partitions: List of partitions to search in
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label: Label of partition to find
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Returns:
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An object for the selected partition
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"""
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for partition in partitions:
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if 'label' not in partition:
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continue
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if partition['label'] == label:
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return partition
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raise PartitionNotFound('Partition not found')
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def GetBlockSize(options, layout_filename):
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"""Returns the partition table block size.
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Args:
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options: Flags passed to the script
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layout_filename: Path to partition configuration file
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Returns:
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Block size of all partitions in the layout
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"""
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config = LoadPartitionConfig(layout_filename)
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return config['metadata']['block_size']
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def GetFilesystemBlockSize(options, layout_filename):
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"""Returns the filesystem block size.
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Args:
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options: Flags passed to the script
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This is used for all partitions in the table that have filesystems.
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Args:
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layout_filename: Path to partition configuration file
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Returns:
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Block size of all filesystems in the layout
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"""
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config = LoadPartitionConfig(layout_filename)
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return config['metadata']['fs_block_size']
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def GetPartitionSize(options, image_type, layout_filename, num):
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"""Returns the partition size of a given partition for a given layout type.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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num: Number of the partition you want to read from
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Returns:
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Size of selected partition in bytes
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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partition = GetPartitionByNumber(partitions, num)
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return partition['bytes']
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def GetFilesystemSize(options, image_type, layout_filename, num):
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"""Returns the filesystem size of a given partition for a given layout type.
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If no filesystem size is specified, returns the partition size.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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num: Number of the partition you want to read from
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Returns:
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Size of selected partition filesystem in bytes
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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partition = GetPartitionByNumber(partitions, num)
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if 'fs_bytes' in partition:
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return partition['fs_bytes']
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else:
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return partition['bytes']
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def GetLabel(options, image_type, layout_filename, num):
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"""Returns the label for a given partition.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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num: Number of the partition you want to read from
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Returns:
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Label of selected partition, or 'UNTITLED' if none specified
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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partition = GetPartitionByNumber(partitions, num)
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if 'label' in partition:
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return partition['label']
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else:
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return 'UNTITLED'
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def GetNum(options, image_type, layout_filename, label):
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"""Returns the number for a given label.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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label: Label of the partition you want to read from
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Returns:
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Number of selected partition, or '-1' if there is no number
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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partition = GetPartitionByLabel(partitions, label)
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if 'num' in partition:
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return partition['num']
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else:
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return '-1'
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def GetUuid(options, image_type, layout_filename, label):
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"""Returns the unique partition UUID for a given label.
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Note: Only useful if the UUID is specified in the config file, otherwise
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the value returned unlikely to be what is actually used in the image.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/prod
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layout_filename: Path to partition configuration file
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label: Label of the partition you want to read from
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Returns:
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String containing the requested UUID
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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partition = GetPartitionByLabel(partitions, label)
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return partition['uuid']
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def DoDebugOutput(options, image_type, layout_filename):
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"""Prints out a human readable disk layout in on-disk order.
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This will round values larger than 1MB, it's exists to quickly
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visually verify a layout looks correct.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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for partition in partitions:
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if partition['bytes'] < 1024 * 1024:
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size = '%d bytes' % partition['bytes']
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else:
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size = '%d MB' % (partition['bytes'] / 1024 / 1024)
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if 'label' in partition:
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if 'fs_bytes' in partition:
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if partition['fs_bytes'] < 1024 * 1024:
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fs_size = '%d bytes' % partition['fs_bytes']
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else:
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fs_size = '%d MB' % (partition['fs_bytes'] / 1024 / 1024)
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print '%s - %s/%s' % (partition['label'], fs_size, size)
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else:
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print '%s - %s' % (partition['label'], size)
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else:
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print 'blank - %s' % size
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def DoParseOnly(options, image_type, layout_filename):
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"""Parses a layout file only, used before reading sizes to check for errors.
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Args:
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options: Flags passed to the script
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image_type: Type of image eg base/test/dev/factory_install
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layout_filename: Path to partition configuration file
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"""
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partitions = GetPartitionTableFromConfig(options, layout_filename, image_type)
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def main(argv):
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action_map = {
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'write_gpt': {
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'usage': ['<image_type>', '<partition_config_file>', '<disk_image>'],
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'func': WritePartitionTable,
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},
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'write_mbr': {
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'usage': ['<image_type>', '<partition_config_file>', '<disk_image>',
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'<mbr_boot_code>'],
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'func': WriteMbrBoot,
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},
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'readblocksize': {
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'usage': ['<partition_config_file>'],
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'func': GetBlockSize,
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},
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'readfsblocksize': {
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'usage': ['<partition_config_file>'],
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'func': GetFilesystemBlockSize,
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},
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'readpartsize': {
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'usage': ['<image_type>', '<partition_config_file>', '<partition_num>'],
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'func': GetPartitionSize,
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},
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'readfssize': {
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'usage': ['<image_type>', '<partition_config_file>', '<partition_num>'],
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'func': GetFilesystemSize,
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},
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'readlabel': {
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'usage': ['<image_type>', '<partition_config_file>', '<partition_num>'],
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'func': GetLabel,
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},
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'readnum': {
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'usage': ['<image_type>', '<partition_config_file>', '<label>'],
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'func': GetNum,
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},
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'readuuid': {
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'usage': ['<image_type>', '<partition_config_file>', '<label>'],
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'func': GetUuid,
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},
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'debug': {
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'usage': ['<image_type>', '<partition_config_file>'],
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'func': DoDebugOutput,
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},
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'parseonly': {
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'usage': ['<image_type>', '<partition_config_file>'],
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'func': DoParseOnly,
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}
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}
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parser = OptionParser()
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parser.add_option("--adjust_part", dest="adjust_part",
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help="adjust partition sizes", default="")
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(options, args) = parser.parse_args()
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|
|
if len(args) < 1 or args[0] not in action_map:
|
|
print 'Usage: %s <action>\n' % sys.argv[0]
|
|
print 'Valid actions are:'
|
|
for action in action_map:
|
|
print ' %s %s' % (action, ' '.join(action_map[action]['usage']))
|
|
sys.exit(1)
|
|
else:
|
|
action_name = args[0]
|
|
action = action_map[action_name]
|
|
if len(action['usage']) == len(args) - 1:
|
|
print action['func'](options, *args[1:])
|
|
else:
|
|
sys.exit('Usage: %s %s %s' % (sys.argv[0], args[0],
|
|
' '.join(action['usage'])))
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main(sys.argv)
|