APM (Apple Partition Map) partition table: JavaScript parsing library

This page hosts a formal specification of APM (Apple Partition Map) partition table using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.

The JavaScript runtime library is available at npm:

npm install kaitai-struct

Code

See the usage examples in the JavaScript notes.

Parse structure from an ArrayBuffer:

var arrayBuffer = ...;
var data = new ApmPartitionTable(new KaitaiStream(arrayBuffer));

After that, one can get various attributes from the structure by accessing fields or properties like:

data.sectorSize // => 0x200 (512) bytes for disks, 0x1000 (4096) bytes is not supported by APM
0x800 (2048) bytes for CDROM

JavaScript source code to parse APM (Apple Partition Map) partition table

ApmPartitionTable.js

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define(['kaitai-struct/KaitaiStream'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(require('kaitai-struct/KaitaiStream'));
  } else {
    root.ApmPartitionTable = factory(root.KaitaiStream);
  }
}(this, function (KaitaiStream) {
/**
 * @see {@link https://en.wikipedia.org/wiki/Apple_Partition_Map|Source}
 */

var ApmPartitionTable = (function() {
  function ApmPartitionTable(_io, _parent, _root) {
    this._io = _io;
    this._parent = _parent;
    this._root = _root || this;

    this._read();
  }
  ApmPartitionTable.prototype._read = function() {
  }

  var PartitionEntry = ApmPartitionTable.PartitionEntry = (function() {
    function PartitionEntry(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    PartitionEntry.prototype._read = function() {
      this.magic = this._io.readBytes(2);
      if (!((KaitaiStream.byteArrayCompare(this.magic, [80, 77]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([80, 77], this.magic, this._io, "/types/partition_entry/seq/0");
      }
      this.reserved1 = this._io.readBytes(2);
      this.numberOfPartitions = this._io.readU4be();
      this.partitionStart = this._io.readU4be();
      this.partitionSize = this._io.readU4be();
      this.partitionName = KaitaiStream.bytesToStr(KaitaiStream.bytesTerminate(this._io.readBytes(32), 0, false), "ascii");
      this.partitionType = KaitaiStream.bytesToStr(KaitaiStream.bytesTerminate(this._io.readBytes(32), 0, false), "ascii");
      this.dataStart = this._io.readU4be();
      this.dataSize = this._io.readU4be();
      this.partitionStatus = this._io.readU4be();
      this.bootCodeStart = this._io.readU4be();
      this.bootCodeSize = this._io.readU4be();
      this.bootLoaderAddress = this._io.readU4be();
      this.reserved2 = this._io.readBytes(4);
      this.bootCodeEntry = this._io.readU4be();
      this.reserved3 = this._io.readBytes(4);
      this.bootCodeCksum = this._io.readU4be();
      this.processorType = KaitaiStream.bytesToStr(KaitaiStream.bytesTerminate(this._io.readBytes(16), 0, false), "ascii");
    }
    Object.defineProperty(PartitionEntry.prototype, 'partition', {
      get: function() {
        if (this._m_partition !== undefined)
          return this._m_partition;
        if ((this.partitionStatus & 1) != 0) {
          var io = this._root._io;
          var _pos = io.pos;
          io.seek((this.partitionStart * this._root.sectorSize));
          this._m_partition = io.readBytes((this.partitionSize * this._root.sectorSize));
          io.seek(_pos);
        }
        return this._m_partition;
      }
    });
    Object.defineProperty(PartitionEntry.prototype, 'data', {
      get: function() {
        if (this._m_data !== undefined)
          return this._m_data;
        var io = this._root._io;
        var _pos = io.pos;
        io.seek((this.dataStart * this._root.sectorSize));
        this._m_data = io.readBytes((this.dataSize * this._root.sectorSize));
        io.seek(_pos);
        return this._m_data;
      }
    });
    Object.defineProperty(PartitionEntry.prototype, 'bootCode', {
      get: function() {
        if (this._m_bootCode !== undefined)
          return this._m_bootCode;
        var io = this._root._io;
        var _pos = io.pos;
        io.seek((this.bootCodeStart * this._root.sectorSize));
        this._m_bootCode = io.readBytes(this.bootCodeSize);
        io.seek(_pos);
        return this._m_bootCode;
      }
    });

    /**
     * First sector
     */

    /**
     * Number of sectors
     */

    /**
     * First sector
     */

    /**
     * Number of sectors
     */

    /**
     * First sector
     */

    /**
     * Number of bytes
     */

    /**
     * Address of bootloader code
     */

    /**
     * Boot code entry point
     */

    /**
     * Boot code checksum
     */

    return PartitionEntry;
  })();

  /**
   * 0x200 (512) bytes for disks, 0x1000 (4096) bytes is not supported by APM
   * 0x800 (2048) bytes for CDROM
   */
  Object.defineProperty(ApmPartitionTable.prototype, 'sectorSize', {
    get: function() {
      if (this._m_sectorSize !== undefined)
        return this._m_sectorSize;
      this._m_sectorSize = 512;
      return this._m_sectorSize;
    }
  });

  /**
   * Every partition entry contains the number of partition entries.
   * We parse the first entry, to know how many to parse, including the first one.
   * No logic is given what to do if other entries have a different number.
   */
  Object.defineProperty(ApmPartitionTable.prototype, 'partitionLookup', {
    get: function() {
      if (this._m_partitionLookup !== undefined)
        return this._m_partitionLookup;
      var io = this._root._io;
      var _pos = io.pos;
      io.seek(this._root.sectorSize);
      this._raw__m_partitionLookup = io.readBytes(this.sectorSize);
      var _io__raw__m_partitionLookup = new KaitaiStream(this._raw__m_partitionLookup);
      this._m_partitionLookup = new PartitionEntry(_io__raw__m_partitionLookup, this, this._root);
      io.seek(_pos);
      return this._m_partitionLookup;
    }
  });
  Object.defineProperty(ApmPartitionTable.prototype, 'partitionEntries', {
    get: function() {
      if (this._m_partitionEntries !== undefined)
        return this._m_partitionEntries;
      var io = this._root._io;
      var _pos = io.pos;
      io.seek(this._root.sectorSize);
      this._raw__m_partitionEntries = new Array(this._root.partitionLookup.numberOfPartitions);
      this._m_partitionEntries = new Array(this._root.partitionLookup.numberOfPartitions);
      for (var i = 0; i < this._root.partitionLookup.numberOfPartitions; i++) {
        this._raw__m_partitionEntries[i] = io.readBytes(this.sectorSize);
        var _io__raw__m_partitionEntries = new KaitaiStream(this._raw__m_partitionEntries[i]);
        this._m_partitionEntries[i] = new PartitionEntry(_io__raw__m_partitionEntries, this, this._root);
      }
      io.seek(_pos);
      return this._m_partitionEntries;
    }
  });

  return ApmPartitionTable;
})();
return ApmPartitionTable;
}));