Files
Aaru/Aaru.Images/CopyQM/Read.cs

217 lines
10 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Read.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Reads Sydex CopyQM disk images.
//
// --[ License ] --------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2021 Natalia Portillo
// ****************************************************************************/
using System;
using System.IO;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Console;
using Aaru.Helpers;
namespace Aaru.DiscImages
{
public sealed partial class CopyQm
{
public bool Open(IFilter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
byte[] hdr = new byte[133];
stream.Read(hdr, 0, 133);
_header = Marshal.ByteArrayToStructureLittleEndian<Header>(hdr);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.magic = 0x{0:X4}", _header.magic);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.mark = 0x{0:X2}", _header.mark);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectorSize = {0}", _header.sectorSize);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectorPerCluster = {0}", _header.sectorPerCluster);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.reservedSectors = {0}", _header.reservedSectors);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.fatCopy = {0}", _header.fatCopy);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.rootEntries = {0}", _header.rootEntries);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectors = {0}", _header.sectors);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.mediaType = 0x{0:X2}", _header.mediaType);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectorsPerFat = {0}", _header.sectorsPerFat);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectorsPerTrack = {0}", _header.sectorsPerTrack);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.heads = {0}", _header.heads);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.hidden = {0}", _header.hidden);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.sectorsBig = {0}", _header.sectorsBig);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.description = {0}", _header.description);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.blind = {0}", _header.blind);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.density = {0}", _header.density);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.imageCylinders = {0}", _header.imageCylinders);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.totalCylinders = {0}", _header.totalCylinders);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.crc = 0x{0:X8}", _header.crc);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.volumeLabel = {0}", _header.volumeLabel);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.time = 0x{0:X4}", _header.time);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.date = 0x{0:X4}", _header.date);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.commentLength = {0}", _header.commentLength);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.secbs = {0}", _header.secbs);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.unknown = 0x{0:X4}", _header.unknown);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.interleave = {0}", _header.interleave);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.skew = {0}", _header.skew);
AaruConsole.DebugWriteLine("CopyQM plugin", "header.drive = {0}", _header.drive);
byte[] cmt = new byte[_header.commentLength];
stream.Read(cmt, 0, _header.commentLength);
_imageInfo.Comments = StringHandlers.CToString(cmt);
_decodedImage = new MemoryStream();
_calculatedDataCrc = 0;
while(stream.Position + 2 < stream.Length)
{
byte[] runLengthBytes = new byte[2];
if(stream.Read(runLengthBytes, 0, 2) != 2)
break;
short runLength = BitConverter.ToInt16(runLengthBytes, 0);
if(runLength < 0)
{
byte repeatedByte = (byte)stream.ReadByte();
byte[] repeatedArray = new byte[runLength * -1];
ArrayHelpers.ArrayFill(repeatedArray, repeatedByte);
for(int i = 0; i < runLength * -1; i++)
{
_decodedImage.WriteByte(repeatedByte);
_calculatedDataCrc = _copyQmCrcTable[(repeatedByte ^ _calculatedDataCrc) & 0x3F] ^
(_calculatedDataCrc >> 8);
}
}
else if(runLength > 0)
{
byte[] nonRepeated = new byte[runLength];
stream.Read(nonRepeated, 0, runLength);
_decodedImage.Write(nonRepeated, 0, runLength);
foreach(byte c in nonRepeated)
_calculatedDataCrc =
_copyQmCrcTable[(c ^ _calculatedDataCrc) & 0x3F] ^ (_calculatedDataCrc >> 8);
}
}
// In case there is omitted data
long sectors = _header.sectorsPerTrack * _header.heads * _header.totalCylinders;
long fillingLen = (sectors * _header.sectorSize) - _decodedImage.Length;
if(fillingLen > 0)
{
byte[] filling = new byte[fillingLen];
ArrayHelpers.ArrayFill(filling, (byte)0xF6);
_decodedImage.Write(filling, 0, filling.Length);
}
int sum = 0;
for(int i = 0; i < hdr.Length - 1; i++)
sum += hdr[i];
_headerChecksumOk = ((-1 * sum) & 0xFF) == _header.headerChecksum;
AaruConsole.DebugWriteLine("CopyQM plugin", "Calculated header checksum = 0x{0:X2}, {1}", (-1 * sum) & 0xFF,
_headerChecksumOk);
AaruConsole.DebugWriteLine("CopyQM plugin", "Calculated data CRC = 0x{0:X8}, {1}", _calculatedDataCrc,
_calculatedDataCrc == _header.crc);
_imageInfo.Application = "CopyQM";
_imageInfo.CreationTime = DateHandlers.DosToDateTime(_header.date, _header.time);
_imageInfo.LastModificationTime = _imageInfo.CreationTime;
_imageInfo.MediaTitle = _header.volumeLabel;
_imageInfo.ImageSize = (ulong)(stream.Length - 133 - _header.commentLength);
_imageInfo.Sectors = (ulong)sectors;
_imageInfo.SectorSize = _header.sectorSize;
_imageInfo.MediaType = Geometry.GetMediaType(((ushort)_header.totalCylinders, (byte)_header.heads,
_header.sectorsPerTrack, (uint)_header.sectorSize,
MediaEncoding.MFM, false));
switch(_imageInfo.MediaType)
{
case MediaType.NEC_525_HD when _header.drive == COPYQM_35_HD || _header.drive == COPYQM_35_ED:
_imageInfo.MediaType = MediaType.NEC_35_HD_8;
break;
case MediaType.DOS_525_HD when _header.drive == COPYQM_35_HD || _header.drive == COPYQM_35_ED:
_imageInfo.MediaType = MediaType.NEC_35_HD_15;
break;
case MediaType.RX50 when _header.drive == COPYQM_525_DD || _header.drive == COPYQM_525_HD:
_imageInfo.MediaType = MediaType.ATARI_35_SS_DD;
break;
}
_imageInfo.XmlMediaType = XmlMediaType.BlockMedia;
_decodedDisk = _decodedImage.ToArray();
_decodedImage.Close();
AaruConsole.VerboseWriteLine("CopyQM image contains a disk of type {0}", _imageInfo.MediaType);
if(!string.IsNullOrEmpty(_imageInfo.Comments))
AaruConsole.VerboseWriteLine("CopyQM comments: {0}", _imageInfo.Comments);
_imageInfo.Heads = _header.heads;
_imageInfo.Cylinders = _header.totalCylinders;
_imageInfo.SectorsPerTrack = _header.sectorsPerTrack;
return true;
}
public byte[] ReadSector(ulong sectorAddress) => ReadSectors(sectorAddress, 1);
public byte[] ReadSectors(ulong sectorAddress, uint length)
{
if(sectorAddress > _imageInfo.Sectors - 1)
throw new ArgumentOutOfRangeException(nameof(sectorAddress), "Sector address not found");
if(sectorAddress + length > _imageInfo.Sectors)
throw new ArgumentOutOfRangeException(nameof(length), "Requested more sectors than available");
byte[] buffer = new byte[length * _imageInfo.SectorSize];
Array.Copy(_decodedDisk, (int)sectorAddress * _imageInfo.SectorSize, buffer, 0,
length * _imageInfo.SectorSize);
return buffer;
}
public bool? VerifyMediaImage() => _calculatedDataCrc == _header.crc && _headerChecksumOk;
}
}