CartridgeDevice.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using BizHawk.Common;
using BizHawk.Emulation.Common;

namespace BizHawk.Emulation.Cores.Computers.Commodore64.Cartridge
{
	public abstract partial class CartridgeDevice : IDriveLight
	{
	    public Func<int> ReadOpenBus; 

		public static CartridgeDevice Load(byte[] crtFile)
		{
		    using (var mem = new MemoryStream(crtFile))
		    {
                var reader = new BinaryReader(mem);

                if (new string(reader.ReadChars(16)) != "C64 CARTRIDGE   ")
                {
                    return null;
                }

                var chipAddress = new List<int>();
                var chipBank = new List<int>();
                var chipData = new List<int[]>();
                var chipType = new List<int>();

                var headerLength = ReadCRTInt(reader);
                var version = ReadCRTShort(reader);
                var mapper = ReadCRTShort(reader);
                var exrom = reader.ReadByte() != 0;
                var game = reader.ReadByte() != 0;

                // reserved
                reader.ReadBytes(6);

                // cartridge name
                reader.ReadBytes(0x20);

                // skip extra header bytes
                if (headerLength > 0x40)
                {
                    reader.ReadBytes(headerLength - 0x40);
                }

                // read chips
                while (reader.PeekChar() >= 0)
                {
                    if (new string(reader.ReadChars(4)) != "CHIP")
                    {
                        break;
                    }

                    var chipLength = ReadCRTInt(reader);
                    chipType.Add(ReadCRTShort(reader));
                    chipBank.Add(ReadCRTShort(reader));
                    chipAddress.Add(ReadCRTShort(reader));
                    var chipDataLength = ReadCRTShort(reader);
                    chipData.Add(reader.ReadBytes(chipDataLength).Select(x => (int)x).ToArray());
                    chipLength -= chipDataLength + 0x10;
                    if (chipLength > 0)
                        reader.ReadBytes(chipLength);
                }

                if (chipData.Count <= 0)
                {
                    return null;
                }

                CartridgeDevice result;
                switch (mapper)
                {
                    case 0x0000:    // Standard Cartridge
                        result = new Mapper0000(chipAddress, chipData, game, exrom);
                        break;
                    case 0x0001:    // Action Replay (4.2 and up)
                        result = new Mapper0001(chipAddress, chipBank, chipData);
                        break;
                    case 0x0005:    // Ocean
                        result = new Mapper0005(chipAddress, chipBank, chipData);
                        break;
                    case 0x000A:    // Epyx FastLoad
                        result = new Mapper000A(chipData);
                        break;
                    case 0x000B:    // Westermann Learning
                        result = new Mapper000B(chipAddress, chipData);
                        break;
                    case 0x000F:    // C64 Game System / System 3
                        result = new Mapper000F(chipAddress, chipBank, chipData);
                        break;
                    case 0x0011:    // Dinamic
                        result = new Mapper0011(chipAddress, chipBank, chipData);
                        break;
                    case 0x0012:    // Zaxxon / Super Zaxxon
                        result = new Mapper0012(chipAddress, chipBank, chipData);
                        break;
                    case 0x0013:    // Domark
                        result = new Mapper0013(chipAddress, chipBank, chipData);
                        break;
                    case 0x0020:    // EasyFlash
                        result = new Mapper0020(chipAddress, chipBank, chipData);
                        break;
                    case 0x002B:    // Prophet 64
                        result = new Mapper002B(chipAddress, chipBank, chipData);
                        break;
                    default:
                        throw new Exception("This cartridge file uses an unrecognized mapper: " + mapper);
                }
                result.HardReset();

                return result;
            }
        }

		private static int ReadCRTShort(BinaryReader reader)
		{
		    return (reader.ReadByte() << 8) |
                reader.ReadByte();
		}

		private static int ReadCRTInt(BinaryReader reader)
		{
			return (reader.ReadByte() << 24) |
                (reader.ReadByte() << 16) |
                (reader.ReadByte() << 8) |
                reader.ReadByte();
		}

        [SaveState.SaveWithName("ExRom")]
		protected bool pinExRom;
        [SaveState.SaveWithName("Game")]
        protected bool pinGame;
        [SaveState.SaveWithName("IRQ")]
        protected bool pinIRQ;
        [SaveState.SaveWithName("NMI")]
        protected bool pinNMI;
        [SaveState.SaveWithName("Reset")]
        protected bool pinReset;
        [SaveState.DoNotSave]
        protected bool validCartridge;

		public virtual void ExecutePhase()
		{
		}

        [SaveState.DoNotSave]
		public bool ExRom
		{
			get
			{
				return pinExRom;
			}
		}

        [SaveState.DoNotSave]
        public bool Game
		{
			get
			{
				return pinGame;
			}
		}

		public virtual void HardReset()
		{
			pinIRQ = true;
			pinNMI = true;
			pinReset = true;
		}

        [SaveState.DoNotSave]
        public bool IRQ
		{
			get
			{
				return pinIRQ;
			}
		}

        [SaveState.DoNotSave]
        public bool NMI
		{
			get
			{
				return pinNMI;
			}
		}

		public virtual int Peek8000(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int PeekA000(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int PeekDE00(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int PeekDF00(int addr)
		{
			return ReadOpenBus();
		}

		public virtual void Poke8000(int addr, int val)
		{
		}

		public virtual void PokeA000(int addr, int val)
		{
		}

		public virtual void PokeDE00(int addr, int val)
		{
		}

		public virtual void PokeDF00(int addr, int val)
		{
		}

		public virtual int Read8000(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int ReadA000(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int ReadDE00(int addr)
		{
			return ReadOpenBus();
		}

		public virtual int ReadDF00(int addr)
		{
			return ReadOpenBus();
		}

        [SaveState.DoNotSave]
        public bool Reset
		{
			get
			{
				return pinReset;
			}
		}

		public virtual void SyncState(Serializer ser)
		{
			SaveState.SyncObject(ser, this);
		}

        [SaveState.DoNotSave]
        public bool Valid
		{
			get
			{
				return validCartridge;
			}
		}

		public virtual void Write8000(int addr, int val)
		{
		}

		public virtual void WriteA000(int addr, int val)
		{
		}

		public virtual void WriteDE00(int addr, int val)
		{
		}

		public virtual void WriteDF00(int addr, int val)
		{
		}

	    public bool DriveLightEnabled { get; protected set; }
	    public bool DriveLightOn { get; protected set; }
	}
}