GBHawk: Add RockMan 8 mapper

BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj

@@ -641,6 +641,7 @@
     </Compile>
     <Compile Include="Consoles\Nintendo\GBA\VBARegisterHelper.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Audio.cs" />
+    <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_RockMan8.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_Sachen_MMC2.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_Sachen_MMC1.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\SerialPort.cs" />

BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBHawk.cs

@@ -367,6 +367,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 				mapper = new MapperMBC1Multi();
 			}
 
+			// special case for bootlegs
+			if ((_rom.HashMD5(0, _rom.Length) == "CAE0998A899DF2EE6ABA8E7695C2A096"))
+			{
+				Console.WriteLine("Using RockMan 8 (Unlicensed) Mapper");
+				mapper = new MapperRM8();
+			}
+
 			Console.Write("Mapper: ");
 			Console.WriteLine(mppr);
 
@@ -413,7 +420,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 
 			if (cart_RAM != null)
 			{
-
 				Console.Write("RAM: "); Console.WriteLine(cart_RAM.Length);
 
 				for (int i = 0; i < cart_RAM.Length; i++)
@@ -422,7 +428,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 				}
 			}
 			
-
 			// Extra RTC initialization for mbc3
 			if (mppr == "MBC3")
 			{

BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_RockMan8.cs

@@ -0,0 +1,69 @@
+using BizHawk.Common;
+using BizHawk.Common.NumberExtensions;
+using System;
+
+namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
+{
+	// RockMan 8, just some simple bankswitching 
+	public class MapperRM8 : MapperBase
+	{
+		public int ROM_bank;
+		public int ROM_mask;
+
+		public override void Initialize()
+		{
+			ROM_bank = 1;
+			ROM_mask = Core._rom.Length / 0x4000 - 1;
+
+			// some games have sizes that result in a degenerate ROM, account for it here
+			if (ROM_mask > 4) { ROM_mask |= 3; }
+	}
+
+		public override byte ReadMemory(ushort addr)
+		{
+			if (addr < 0x4000)
+			{
+				// lowest bank is fixed
+				return Core._rom[addr];
+			
+			}
+			else if (addr < 0x8000)
+			{
+				return Core._rom[(addr - 0x4000) + ROM_bank * 0x4000];
+			}
+			else
+			{
+				return 0xFF;
+			}
+		}
+
+		public override byte PeekMemory(ushort addr)
+		{
+			return ReadMemory(addr);
+		}
+
+		public override void WriteMemory(ushort addr, byte value)
+		{
+			if ((addr >= 0x2000) && (addr < 0x4000))
+			{
+				value &= 0x1F;
+
+				if (value == 0) { value = 1; }
+
+				// in hhugboy they just subtract 8, but to me looks like bits 4 and 5 are just swapped (and bit 4 is unused?)
+				ROM_bank = ((value & 0xF) | ((value & 0x10) >> 1)) & ROM_mask;
+			}
+		}
+
+		public override void PokeMemory(ushort addr, byte value)
+		{
+			WriteMemory(addr, value);
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			ser.Sync("ROM_Bank", ref ROM_bank);
+			ser.Sync("ROM_Mask", ref ROM_mask);
+		}
+	}
+}