generic-poky/scripts/lib/wic/utils/partitionedfs.py

302 lines
13 KiB
Python

#!/usr/bin/env python -tt
#
# Copyright (c) 2009, 2010, 2011 Intel, Inc.
# Copyright (c) 2007, 2008 Red Hat, Inc.
# Copyright (c) 2008 Daniel P. Berrange
# Copyright (c) 2008 David P. Huff
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; version 2 of the License
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc., 59
# Temple Place - Suite 330, Boston, MA 02111-1307, USA.
import os
from wic import msger
from wic.utils.errors import ImageError
from wic.utils.misc import exec_native_cmd
from wic.filemap import sparse_copy
# Overhead of the MBR partitioning scheme (just one sector)
MBR_OVERHEAD = 1
# Overhead of the GPT partitioning scheme
GPT_OVERHEAD = 34
# Size of a sector in bytes
SECTOR_SIZE = 512
class PartitionedImage():
"""
Partitioned image in a file.
"""
def __init__(self, path, ptable_format, native_sysroot=None):
self.path = path # Path to the image file
self.numpart = 0 # Number of allocated partitions
self.realpart = 0 # Number of partitions in the partition table
self.offset = 0 # Offset of next partition (in sectors)
self.min_size = 0 # Minimum required disk size to fit
# all partitions (in bytes)
self.ptable_format = ptable_format # Partition table format
# Disk system identifier
self.identifier = int.from_bytes(os.urandom(4), 'little')
self.partitions = []
self.partimages = []
# Size of a sector used in calculations
self.sector_size = SECTOR_SIZE
self.native_sysroot = native_sysroot
def add_partition(self, part):
"""
Add the next partition. Partitions have to be added in the
first-to-last order.
"""
part.ks_pnum = len(self.partitions)
# Converting kB to sectors for parted
part.size_sec = part.disk_size * 1024 // self.sector_size
self.partitions.append(part)
def layout_partitions(self):
""" Layout the partitions, meaning calculate the position of every
partition on the disk. The 'ptable_format' parameter defines the
partition table format and may be "msdos". """
msger.debug("Assigning %s partitions to disks" % self.ptable_format)
# Go through partitions in the order they are added in .ks file
for num in range(len(self.partitions)):
part = self.partitions[num]
if self.ptable_format == 'msdos' and part.part_type:
# The --part-type can also be implemented for MBR partitions,
# in which case it would map to the 1-byte "partition type"
# filed at offset 3 of the partition entry.
raise ImageError("setting custom partition type is not " \
"implemented for msdos partitions")
# Get the disk where the partition is located
self.numpart += 1
if not part.no_table:
self.realpart += 1
if self.numpart == 1:
if self.ptable_format == "msdos":
overhead = MBR_OVERHEAD
elif self.ptable_format == "gpt":
overhead = GPT_OVERHEAD
# Skip one sector required for the partitioning scheme overhead
self.offset += overhead
if self.realpart > 3:
# Reserve a sector for EBR for every logical partition
# before alignment is performed.
if self.ptable_format == "msdos":
self.offset += 1
if part.align:
# If not first partition and we do have alignment set we need
# to align the partition.
# FIXME: This leaves a empty spaces to the disk. To fill the
# gaps we could enlargea the previous partition?
# Calc how much the alignment is off.
align_sectors = self.offset % (part.align * 1024 // self.sector_size)
if align_sectors:
# If partition is not aligned as required, we need
# to move forward to the next alignment point
align_sectors = (part.align * 1024 // self.sector_size) - align_sectors
msger.debug("Realignment for %s%s with %s sectors, original"
" offset %s, target alignment is %sK." %
(part.disk, self.numpart, align_sectors,
self.offset, part.align))
# increase the offset so we actually start the partition on right alignment
self.offset += align_sectors
part.start = self.offset
self.offset += part.size_sec
part.type = 'primary'
if not part.no_table:
part.num = self.realpart
else:
part.num = 0
if self.ptable_format == "msdos":
# only count the partitions that are in partition table
if len([p for p in self.partitions if not p.no_table]) > 4:
if self.realpart > 3:
part.type = 'logical'
part.num = self.realpart + 1
msger.debug("Assigned %s to %s%d, sectors range %d-%d size %d "
"sectors (%d bytes)." \
% (part.mountpoint, part.disk, part.num,
part.start, self.offset - 1,
part.size_sec, part.size_sec * self.sector_size))
# Once all the partitions have been layed out, we can calculate the
# minumim disk size
self.min_size = self.offset
if self.ptable_format == "gpt":
self.min_size += GPT_OVERHEAD
self.min_size *= self.sector_size
def _create_partition(self, device, parttype, fstype, start, size):
""" Create a partition on an image described by the 'device' object. """
# Start is included to the size so we need to substract one from the end.
end = start + size - 1
msger.debug("Added '%s' partition, sectors %d-%d, size %d sectors" %
(parttype, start, end, size))
cmd = "parted -s %s unit s mkpart %s" % (device, parttype)
if fstype:
cmd += " %s" % fstype
cmd += " %d %d" % (start, end)
return exec_native_cmd(cmd, self.native_sysroot)
def create(self):
msger.debug("Creating sparse file %s" % self.path)
with open(self.path, 'w') as sparse:
os.ftruncate(sparse.fileno(), self.min_size)
msger.debug("Initializing partition table for %s" % self.path)
exec_native_cmd("parted -s %s mklabel %s" %
(self.path, self.ptable_format), self.native_sysroot)
msger.debug("Set disk identifier %x" % self.identifier)
with open(self.path, 'r+b') as img:
img.seek(0x1B8)
img.write(self.identifier.to_bytes(4, 'little'))
msger.debug("Creating partitions")
for part in self.partitions:
if part.num == 0:
continue
if self.ptable_format == "msdos" and part.num == 5:
# Create an extended partition (note: extended
# partition is described in MBR and contains all
# logical partitions). The logical partitions save a
# sector for an EBR just before the start of a
# partition. The extended partition must start one
# sector before the start of the first logical
# partition. This way the first EBR is inside of the
# extended partition. Since the extended partitions
# starts a sector before the first logical partition,
# add a sector at the back, so that there is enough
# room for all logical partitions.
self._create_partition(self.path, "extended",
None, part.start - 1,
self.offset - part.start + 1)
if part.fstype == "swap":
parted_fs_type = "linux-swap"
elif part.fstype == "vfat":
parted_fs_type = "fat32"
elif part.fstype == "msdos":
parted_fs_type = "fat16"
elif part.fstype == "ontrackdm6aux3":
parted_fs_type = "ontrackdm6aux3"
else:
# Type for ext2/ext3/ext4/btrfs
parted_fs_type = "ext2"
# Boot ROM of OMAP boards require vfat boot partition to have an
# even number of sectors.
if part.mountpoint == "/boot" and part.fstype in ["vfat", "msdos"] \
and part.size_sec % 2:
msger.debug("Subtracting one sector from '%s' partition to " \
"get even number of sectors for the partition" % \
part.mountpoint)
part.size_sec -= 1
self._create_partition(self.path, part.type,
parted_fs_type, part.start, part.size_sec)
if part.part_type:
msger.debug("partition %d: set type UID to %s" % \
(part.num, part.part_type))
exec_native_cmd("sgdisk --typecode=%d:%s %s" % \
(part.num, part.part_type,
self.path), self.native_sysroot)
if part.uuid and self.ptable_format == "gpt":
msger.debug("partition %d: set UUID to %s" % \
(part.num, part.uuid))
exec_native_cmd("sgdisk --partition-guid=%d:%s %s" % \
(part.num, part.uuid, self.path),
self.native_sysroot)
if part.label and self.ptable_format == "gpt":
msger.debug("partition %d: set name to %s" % \
(part.num, part.label))
exec_native_cmd("parted -s %s name %d %s" % \
(self.path, part.num, part.label),
self.native_sysroot)
if part.active:
flag_name = "legacy_boot" if self.ptable_format == 'gpt' else "boot"
msger.debug("Set '%s' flag for partition '%s' on disk '%s'" % \
(flag_name, part.num, self.path))
exec_native_cmd("parted -s %s set %d %s on" % \
(self.path, part.num, flag_name),
self.native_sysroot)
if part.system_id:
exec_native_cmd("sfdisk --part-type %s %s %s" % \
(self.path, part.num, part.system_id),
self.native_sysroot)
# Parted defaults to enabling the lba flag for fat16 partitions,
# which causes compatibility issues with some firmware (and really
# isn't necessary).
if parted_fs_type == "fat16":
if self.ptable_format == 'msdos':
msger.debug("Disable 'lba' flag for partition '%s' on disk '%s'" % \
(part.num, self.path))
exec_native_cmd("parted -s %s set %d lba off" % \
(self.path, part.num),
self.native_sysroot)
def cleanup(self):
# remove partition images
for image in self.partimages:
os.remove(image)
def assemble(self):
msger.debug("Installing partitions")
for part in self.partitions:
source = part.source_file
if source:
# install source_file contents into a partition
sparse_copy(source, self.path, part.start * self.sector_size)
msger.debug("Installed %s in partition %d, sectors %d-%d, "
"size %d sectors" % \
(source, part.num, part.start,
part.start + part.size_sec - 1, part.size_sec))
partimage = self.path + '.p%d' % part.num
os.rename(source, partimage)
self.partimages.append(partimage)