Files
Aaru/DiscImageChef.Partitions/PC98.cs

178 lines
8.2 KiB
C#

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename : PC98.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Partitioning scheme plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Manages NEC PC-9800 partitions.
//
// --[ 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 © 2011-2018 Natalia Portillo
// ****************************************************************************/
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
using DiscImageChef.CommonTypes;
using DiscImageChef.Console;
using DiscImageChef.DiscImages;
using DiscImageChef.Helpers;
namespace DiscImageChef.Partitions
{
public class PC98 : PartitionPlugin
{
public PC98()
{
Name = "NEC PC-9800 partition table";
PluginUuid = new Guid("27333401-C7C2-447D-961C-22AD0641A09A");
}
public override bool GetInformation(ImagePlugin imagePlugin, out List<Partition> partitions, ulong sectorOffset)
{
partitions = new List<Partition>();
if(sectorOffset != 0) return false;
byte[] bootSector = imagePlugin.ReadSector(0);
byte[] sector = imagePlugin.ReadSector(1);
if(bootSector[bootSector.Length - 2] != 0x55 || bootSector[bootSector.Length - 1] != 0xAA) return false;
IntPtr tablePtr = Marshal.AllocHGlobal(256);
Marshal.Copy(sector, 0, tablePtr, 256);
PC98Table table = (PC98Table)Marshal.PtrToStructure(tablePtr, typeof(PC98Table));
Marshal.FreeHGlobal(tablePtr);
ulong counter = 0;
foreach(PC98Partition entry in table.entries)
{
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_mid = {0}", entry.dp_mid);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_sid = {0}", entry.dp_sid);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_dum1 = {0}", entry.dp_dum1);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_dum2 = {0}", entry.dp_dum2);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ipl_sct = {0}", entry.dp_ipl_sct);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ipl_head = {0}", entry.dp_ipl_head);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ipl_cyl = {0}", entry.dp_ipl_cyl);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ssect = {0}", entry.dp_ssect);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_shd = {0}", entry.dp_shd);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_scyl = {0}", entry.dp_scyl);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_esect = {0}", entry.dp_esect);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ehd = {0}", entry.dp_ehd);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_ecyl = {0}", entry.dp_ecyl);
DicConsole.DebugWriteLine("PC98 plugin", "entry.dp_name = \"{0}\"",
StringHandlers.CToString(entry.dp_name, Encoding.GetEncoding(932)));
if(entry.dp_scyl == entry.dp_ecyl || entry.dp_ecyl <= 0 ||
entry.dp_scyl > imagePlugin.ImageInfo.Cylinders || entry.dp_ecyl > imagePlugin.ImageInfo.Cylinders ||
entry.dp_shd > imagePlugin.ImageInfo.Heads || entry.dp_ehd > imagePlugin.ImageInfo.Heads ||
entry.dp_ssect > imagePlugin.ImageInfo.SectorsPerTrack ||
entry.dp_esect > imagePlugin.ImageInfo.SectorsPerTrack) continue;
Partition part = new Partition
{
Start = CHS.ToLBA(entry.dp_scyl, entry.dp_shd, (uint)(entry.dp_ssect + 1),
imagePlugin.ImageInfo.Heads, imagePlugin.ImageInfo.SectorsPerTrack),
Type = DecodePC98Sid(entry.dp_sid),
Name = StringHandlers.CToString(entry.dp_name, Encoding.GetEncoding(932)).Trim(),
Sequence = counter,
Scheme = Name
};
part.Offset = part.Start * imagePlugin.GetSectorSize();
part.Length = CHS.ToLBA(entry.dp_ecyl, entry.dp_ehd, (uint)(entry.dp_esect + 1),
imagePlugin.ImageInfo.Heads,
imagePlugin.ImageInfo.SectorsPerTrack) - part.Start;
part.Size = part.Length * imagePlugin.GetSectorSize();
DicConsole.DebugWriteLine("PC98 plugin", "part.Start = {0}", part.Start);
DicConsole.DebugWriteLine("PC98 plugin", "part.Type = {0}", part.Type);
DicConsole.DebugWriteLine("PC98 plugin", "part.Name = {0}", part.Name);
DicConsole.DebugWriteLine("PC98 plugin", "part.Sequence = {0}", part.Sequence);
DicConsole.DebugWriteLine("PC98 plugin", "part.Offset = {0}", part.Offset);
DicConsole.DebugWriteLine("PC98 plugin", "part.Length = {0}", part.Length);
DicConsole.DebugWriteLine("PC98 plugin", "part.Size = {0}", part.Size);
if(((entry.dp_mid & 0x20) != 0x20 && (entry.dp_mid & 0x44) != 0x44) ||
part.Start >= imagePlugin.ImageInfo.Sectors ||
part.End > imagePlugin.ImageInfo.Sectors) continue;
partitions.Add(part);
counter++;
}
return partitions.Count > 0;
}
static string DecodePC98Sid(byte sid)
{
switch(sid & 0x7F)
{
case 0x01: return "FAT12";
case 0x04: return "PC-UX";
case 0x06: return "N88-BASIC(86)";
// Supposedly for FAT16 < 32 MiB, seen in bigger partitions
case 0x11:
case 0x21: return "FAT16";
case 0x28:
case 0x41:
case 0x48: return "Windows Volume Set";
case 0x44: return "FreeBSD";
case 0x61: return "FAT32";
case 0x62: return "Linux";
default: return "Unknown";
}
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct PC98Table
{
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)] public PC98Partition[] entries;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct PC98Partition
{
/// <summary>
/// Some ID, if 0x80 bit is set, it is bootable
/// </summary>
public byte dp_mid;
/// <summary>
/// Some ID, if 0x80 bit is set, it is active
/// </summary>
public byte dp_sid;
public byte dp_dum1;
public byte dp_dum2;
public byte dp_ipl_sct;
public byte dp_ipl_head;
public ushort dp_ipl_cyl;
public byte dp_ssect;
public byte dp_shd;
public ushort dp_scyl;
public byte dp_esect;
public byte dp_ehd;
public ushort dp_ecyl;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)] public byte[] dp_name;
}
}
}