BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/iNES.cs

using System;
using System.Linq;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Collections.Generic;
using BizHawk.Emulation.CPUs.M6502;

namespace BizHawk.Emulation.Consoles.Nintendo
{
	partial class NES
	{
		//public class RomHeaderInfo
		//{
		//    public int MapperNo, Mirroring, Num_PRG_Banks, Num_CHR_Banks, Num_PRAM_Banks;
		//    public bool Battery;
		//    public byte[] ROM, VROM;
		//}


		unsafe struct iNES_HEADER
		{
			public fixed byte ID[4]; /*NES^Z*/
			public byte ROM_size;
			public byte VROM_size;
			public byte ROM_type;
			public byte ROM_type2;
			public fixed byte reserve[8];

			public bool CheckID()
			{
				fixed (iNES_HEADER* self = &this)
					return 0 == Util.memcmp(self, "NES\x1A", 4);
			}

			//some cleanup code recommended by fceux
			public void Cleanup()
			{
				fixed (iNES_HEADER* self = &this)
				{
					if (0 == Util.memcmp((char*)(self) + 0x7, "DiskDude", 8))
					{
						Util.memset((char*)(self) + 0x7, 0, 0x9);
					}

					if (0 == Util.memcmp((char*)(self) + 0x7, "demiforce", 9))
					{
						Util.memset((char*)(self) + 0x7, 0, 0x9);
					}

					if (0 == Util.memcmp((char*)(self) + 0xA, "Ni03", 4))
					{
						if (0 == Util.memcmp((char*)(self) + 0x7, "Dis", 3))
							Util.memset((char*)(self) + 0x7, 0, 0x9);
						else
							Util.memset((char*)(self) + 0xA, 0, 0x6);
					}
				}
			}

			//public RomInfo Analyze()
			//{
			//    var ret = new RomInfo();
			//    ret.MapperNumber = (ROM_type >> 4);
			//    ret.MapperNumber |= (ROM_type2 & 0xF0);
			//    int mirroring = (ROM_type & 1);
			//    if ((ROM_type & 8) != 0) mirroring = 2;
			//    if (mirroring == 0) ret.MirrorType = EMirrorType.Horizontal;
			//    else if (mirroring == 1) ret.MirrorType = EMirrorType.Vertical;
			//    else ret.MirrorType = EMirrorType.External;
			//    ret.PRG_Size = ROM_size;
			//    if (ret.PRG_Size == 0)
			//        ret.PRG_Size = 256;
			//    ret.CHR_Size = VROM_size;
			//    ret.Battery = (ROM_type & 2) != 0;

			//    fixed (iNES_HEADER* self = &this) ret.PRAM_Size = self->reserve[0] * 8;
			//    //0 is supposed to mean 1 (for compatibility, as this is an extension to original iNES format)
			//    if (ret.PRAM_Size == 0) ret.PRAM_Size = 8;

			//    Console.WriteLine("iNES header: map:{0}, mirror:{1}, PRG:{2}, CHR:{3}, CRAM:{4}, PRAM:{5}, bat:{6}", ret.MapperNumber, ret.MirrorType, ret.PRG_Size, ret.CHR_Size, ret.CRAM_Size, ret.PRAM_Size, ret.Battery ? 1 : 0);

			//    //fceux calls uppow2(PRG_Banks) here, and also ups the chr size as well
			//    //then it does something complicated that i don't understand with making sure it doesnt read too much data
			//    //fceux only allows this condition for mappers in the list "not_power2" which is only 228

			//    return ret;
			//}
		}

	}
}