From fb49fbb6c9336dbe0c1d725bbca6cc232090c2fa Mon Sep 17 00:00:00 2001
From: Souryo <mesenemu@gmail.com>
Date: Sat, 25 Jul 2015 17:39:19 -0400
Subject: [PATCH] Mapper 71 (BF909x) support - Fixes firehawk

---
 Core/BF909x.h             | 36 ++++++++++++++++++++++++++++++++++++
 Core/Core.vcxproj         |  1 +
 Core/Core.vcxproj.filters |  3 +++
 Core/MapperFactory.cpp    |  3 ++-
 4 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 Core/BF909x.h

diff --git a/Core/BF909x.h b/Core/BF909x.h
new file mode 100644
index 00000000..934bcf05
--- /dev/null
+++ b/Core/BF909x.h
@@ -0,0 +1,36 @@
+#pragma once
+#include "stdafx.h"
+#include "BaseMapper.h"
+
+class BF909x : public BaseMapper
+{
+private:
+	bool _bf9097Mode = false;  //Auto-detect for firehawk
+
+protected:
+	virtual uint32_t GetPRGPageSize() { return 0x4000; }
+	virtual uint32_t GetCHRPageSize() {	return 0x2000; }
+
+	void InitMapper() 
+	{
+		//First and last PRG page
+		SelectPRGPage(0, 0);
+		SelectPRGPage(1, -1);
+
+		SelectCHRPage(0, 0);
+	}
+
+	void WriteRegister(uint16_t addr, uint8_t value)
+	{
+		if(addr == 0x9000) {
+			//Firehawk uses $9000 to change mirroring
+			_bf9097Mode = true;
+		}
+
+		if(addr >= 0xC000 || !_bf9097Mode) {
+			SelectPRGPage(0, value);
+		} else if(addr < 0xC000) {
+			_mirroringType = (value & 0x10) ? MirroringType::ScreenAOnly : MirroringType::ScreenBOnly;
+		}
+	}
+};
\ No newline at end of file
diff --git a/Core/Core.vcxproj b/Core/Core.vcxproj
index b6206bf1..be0bd35c 100644
--- a/Core/Core.vcxproj
+++ b/Core/Core.vcxproj
@@ -266,6 +266,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClInclude Include="APU.h" />
+    <ClInclude Include="BF909x.h" />
     <ClInclude Include="DeltaModulationChannel.h" />
     <ClInclude Include="ApuEnvelope.h" />
     <ClInclude Include="ApuFrameCounter.h" />
diff --git a/Core/Core.vcxproj.filters b/Core/Core.vcxproj.filters
index 4a2bfa94..eb12fe65 100644
--- a/Core/Core.vcxproj.filters
+++ b/Core/Core.vcxproj.filters
@@ -224,6 +224,9 @@
     <ClInclude Include="VideoDecoder.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="BF909x.h">
+      <Filter>Header Files\Mappers</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="CPU.cpp">
diff --git a/Core/MapperFactory.cpp b/Core/MapperFactory.cpp
index 8a1d4aef..86e43398 100644
--- a/Core/MapperFactory.cpp
+++ b/Core/MapperFactory.cpp
@@ -14,6 +14,7 @@
 #include "NROM.h"
 #include "UNROM.h"
 #include "VRC2_4.h"
+#include "BF909x.h"
 
 BaseMapper* MapperFactory::GetMapperFromID(uint8_t mapperID)
 {
@@ -34,7 +35,7 @@ BaseMapper* MapperFactory::GetMapperFromID(uint8_t mapperID)
 		case 23: return new VRC2_4(VRCVariant::VRC2b);  //Conflicts: VRC4e
 		case 25: return new VRC2_4(VRCVariant::VRC4b);  //Conflicts: VRC2c, VRC4d
 		case 27: return new VRC2_4(VRCVariant::VRC4_27);  //Untested
-		case 71: return new UNROM(); //TODO: "It's largely a clone of UNROM, and Camerica games were initially emulated under iNES Mapper 002 before 071 was assigned."
+		case 71: return new BF909x();
 		case 163: return new Nanjing();
 		case 189: return new MMC3_189();
 		default: MessageManager::DisplayMessage("Error", "Unsupported mapper, cannot load game.");