Class: VirtDisk::PartitionType::GptPartition

Inherits:
VirtDisk::Partition show all
Includes:
LogDecorator::Logging, ExportMethods
Defined in:
lib/virt_disk/partition_type/gpt_partition.rb

Constant Summary collapse

GPT_HEADER = 
BinaryStruct.new([
  'a8',    :signature,    # 00-07: Signature "EFI PART"
  'a4',    :version,      # 08-11: Revision
  'L',     :header_size,  # 12-15: Header size
  'L',     :crc32_header, # 16-19:
  'L',     :reserved,     # 20-23:
  'Q',     :cur_lba,      # 24-31:
  'Q',     :bak_lba,      # 32-39:
  'Q',     :first_lba,    # 40-47:
  'Q',     :last_lba,     # 48-55:
  'a16',   :guid,         # 56-71:
  'Q',     :startLBA,     # 72-79:
  'L',     :part_num,     # 80-83:
  'L',     :part_size,    # 84-87:
  'L',     :part_array,   # 88-91:
  'a420',  :reserved2,    # 92-511:
])
GPT_PARTITION_ENTRY = 
BinaryStruct.new([
  'a16',   :ptype,      # 00-15: partition type
  'a16',   :pguid,      # 16-31: partition GUID
  'Q',     :first_lba,  # 32-39: first LBA
  'Q',     :last_lba,   # 40-47: last LBA
  'a8',    :attr_flag,  # 48-55: attribute flag
  'a72',   :pname,      # 56-127: partition name
])

Constants inherited from VirtDisk::Partition

VirtDisk::Partition::DOS_PARTITION_ENTRY, VirtDisk::Partition::DOS_PT_START, VirtDisk::Partition::DOS_SIG, VirtDisk::Partition::GPT_SIG, VirtDisk::Partition::MBR_SIZE, VirtDisk::Partition::PTE_LEN

Instance Attribute Summary

Attributes inherited from VirtDisk::Partition

#end_lba, #pnum, #ptype, #start_lba

Attributes inherited from ClientHead

#end_byte_addr, #seek_pos, #size, #start_byte_addr

Class Method Summary collapse

Methods included from ExportMethods

#delegate, #delegate=, #exported?, included, #method_missing, #respond_to_missing?

Methods inherited from VirtDisk::Partition

#initialize

Methods inherited from ClientHead

#close, #initialize, #mod_read, #mod_write, #read, #seek, #write

Constructor Details

This class inherits a constructor from VirtDisk::Partition

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class VirtDisk::ExportMethods

Class Method Details

.discover_gpt_partitions(disk) ⇒ Object

rubocop:disable AbcSize



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# File 'lib/virt_disk/partition_type/gpt_partition.rb', line 52

def self.discover_gpt_partitions(disk) # rubocop:disable AbcSize
  _log.info "Parsing GPT disk ..."
  gpt_header = disk.mod_read(MBR_SIZE, GPT_HEADER.size)
  header = GPT_HEADER.decode(gpt_header)

  partitions = []
  pte = GPT_HEADER.size + MBR_SIZE
  (1..header[:part_num]).each do |n|
    gpt = disk.mod_read(pte, GPT_PARTITION_ENTRY.size)
    pt_entry = GPT_PARTITION_ENTRY.decode(gpt)
    ptype = UUIDTools::UUID.parse_raw(pt_entry[:ptype]).to_s

    partitions.push(new(disk, ptype, n, pt_entry[:first_lba], pt_entry[:last_lba])) if pt_entry[:first_lba] != 0
    pte += header[:part_size]
  end
  partitions
end

.discover_partitions(disk) ⇒ Object

rubocop:disable AbcSize



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# File 'lib/virt_disk/partition_type/gpt_partition.rb', line 36

def self.discover_partitions(disk) # rubocop:disable AbcSize
  mbr = disk.mod_read(0, MBR_SIZE)
  if mbr.length < MBR_SIZE
    _log.info "<#{disk.object_id}> disk does not contain a master boot record"
    return []
  end

  sig = mbr[510..511].unpack('H4')

  pt_entry = DOS_PARTITION_ENTRY.decode(mbr[DOS_PT_START, PTE_LEN])
  ptype = pt_entry[:ptype]

  return [] if sig[0] != DOS_SIG || ptype != GPT_SIG
  discover_gpt_partitions(disk)
end