GBC: Improved IO port behavior

Fixes unused_hwio-C test, and allows aevilia to run
SourMesen · Jul 3, 2020 · a223021 · a223021
1 parent a15b22a
commit a223021
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Showing 10 changed files with 92 additions and 19 deletions.
diff --git a/Core/Gameboy.cpp b/Core/Gameboy.cpp
@@ -31,7 +31,13 @@ Gameboy* Gameboy::Create(Console* console, VirtualFile &romFile, bool sgbEnabled
 	MessageManager::Log("File: " + romFile.GetFileName());
 	MessageManager::Log("Game: " + header.GetCartName());
 	MessageManager::Log("Cart Type: " + std::to_string(header.CartType));
+	switch(header.CgbFlag & 0xC0) {
+		case 0x00: MessageManager::Log("Supports: Game Boy"); break;
+		case 0x80: MessageManager::Log("Supports: Game Boy Color (compatible with GB)"); break;
+		case 0xC0: MessageManager::Log("Supports: Game Boy Color only"); break;
+	}
 	MessageManager::Log("File size: " + std::to_string(romData.size() / 1024) + " KB");
+
 	if(header.GetCartRamSize() > 0) {
 		string sizeString = header.GetCartRamSize() > 1024 ? std::to_string(header.GetCartRamSize() / 1024) + " KB" : std::to_string(header.GetCartRamSize()) + " bytes";
 		MessageManager::Log("Cart RAM size: " + sizeString + (header.HasBattery() ? " (with battery)" : ""));

diff --git a/Core/GbApu.cpp b/Core/GbApu.cpp
@@ -293,6 +293,17 @@ void GbApu::Write(uint16_t addr, uint8_t value)
 	}
 }
 
+uint8_t GbApu::ReadCgbRegister(uint16_t addr)
+{
+	switch(addr) {
+		case 0xFF76: return _square1->GetOutput() | (_square2->GetOutput() << 4);
+		case 0xFF77: return _noise->GetOutput() | (_wave->GetOutput() << 4);
+	}
+
+	//Should not be called
+	return 0;
+}
+
 template<typename T>
 void GbApu::ProcessLengthEnableFlag(uint8_t value, T &length, bool &lengthEnabled, bool &enabled)
 {

diff --git a/Core/GbApu.h b/Core/GbApu.h
@@ -57,6 +57,8 @@ class GbApu : public ISerializable
 	uint8_t Read(uint16_t addr);
 	void Write(uint16_t addr, uint8_t value);
 
+	uint8_t ReadCgbRegister(uint16_t addr);
+
 	template<typename T> void ProcessLengthEnableFlag(uint8_t value, T& length, bool& lengthEnabled, bool& enabled);
 
 	void Serialize(Serializer& s) override;

diff --git a/Core/GbDmaController.cpp b/Core/GbDmaController.cpp
@@ -60,10 +60,6 @@ void GbDmaController::Write(uint8_t value)
 uint8_t GbDmaController::ReadCgb(uint16_t addr)
 {
 	switch(addr) {
-		case 0xFF51: return _state.CgbDmaSource >> 8;
-		case 0xFF52: return _state.CgbDmaSource & 0xFF;
-		case 0xFF53: return _state.CgbDmaDest >> 8;
-		case 0xFF54: return _state.CgbDmaDest & 0xFF;
 		case 0xFF55: return _state.CgbDmaLength | (_state.CgbHdmaDone ? 0x80 : 0);
 	}
 

diff --git a/Core/GbMemoryManager.cpp b/Core/GbMemoryManager.cpp
@@ -248,18 +248,28 @@ uint8_t GbMemoryManager::ReadRegister(uint16_t addr)
 		} else if(addr >= 0xFF4C) {
 			if(_gameboy->IsCgb()) {
 				switch(addr) {
-					//FF4D - KEY1 - CGB Mode Only - Prepare Speed Switch
-					case 0xFF4D: return _state.CgbHighSpeed ? 0x80 : 0;
-
-					case 0xFF51: case 0xFF52: case 0xFF53: case 0xFF54: case 0xFF55: //CGB - DMA
-						return _dmaController->ReadCgb(addr);
+					case 0xFF55: //CGB - DMA
+						return _ppu->IsCgbEnabled() ? _dmaController->ReadCgb(addr) : 0xFF;
 
 					case 0xFF4F: //CGB - VRAM bank
 					case 0xFF68: case 0xFF69: case 0xFF6A: case 0xFF6B: //CGB - Palette
 						return _ppu->ReadCgbRegister(addr);
 
 					//FF70 - SVBK - CGB Mode Only - WRAM Bank
-					case 0xFF70: return _state.CgbWorkRamBank;
+					case 0xFF70: return _ppu->IsCgbEnabled() ? (_state.CgbWorkRamBank | 0xF8) : 0xFF;
+					case 0xFF72: return _state.CgbRegFF72;
+					case 0xFF73: return _state.CgbRegFF73;
+
+					case 0xFF74: 
+						if(_ppu->IsCgbEnabled()) {
+							return _state.CgbRegFF74;
+						}
+						return 0xFF;
+
+					case 0xFF75: return _state.CgbRegFF75 | 0x8F;
+
+					case 0xFF76: case 0xFF77:
+						return _apu->ReadCgbRegister(addr);
 				}
 			}
 			LogDebug("[Debug] GB - Missing read handler: $" + HexUtilities::ToHex(addr));
@@ -274,7 +284,7 @@ uint8_t GbMemoryManager::ReadRegister(uint16_t addr)
 				case 0xFF00: return ReadInputPort(); break;
 
 				case 0xFF01: return _state.SerialData; //SB - Serial transfer data (R/W)
-				case 0xFF02: return _state.SerialControl | ~(_gameboy->IsCgb() ? 0x83 : 0x81); //SC - Serial Transfer Control (R/W)
+				case 0xFF02: return _state.SerialControl | 0x7E; //SC - Serial Transfer Control (R/W)
 
 				case 0xFF04: case 0xFF05: case 0xFF06: case 0xFF07:
 					return _timer->Read(addr);
@@ -313,11 +323,15 @@ void GbMemoryManager::WriteRegister(uint16_t addr, uint8_t value)
 				switch(addr) {
 					case 0xFF4D:
 						//FF4D - KEY1 - CGB Mode Only - Prepare Speed Switch
-						_state.CgbSwitchSpeedRequest = (value & 0x01) != 0;
+						if(_ppu->IsCgbEnabled()) {
+							_state.CgbSwitchSpeedRequest = (value & 0x01) != 0;
+						}
 						break;
 
 					case 0xFF51: case 0xFF52: case 0xFF53: case 0xFF54: case 0xFF55: //CGB - DMA
-						_dmaController->WriteCgb(addr, value);
+						if(_ppu->IsCgbEnabled()) {
+							_dmaController->WriteCgb(addr, value);
+						}
 						break;
 
 					case 0xFF4C: //CGB - "LCDMODE", set by boot rom to turn off CGB features for the LCD for DMG games
@@ -333,10 +347,22 @@ void GbMemoryManager::WriteRegister(uint16_t addr, uint8_t value)
 
 					case 0xFF70:
 						//FF70 - SVBK - CGB Mode Only - WRAM Bank
-						_state.CgbWorkRamBank = std::max(1, value & 0x07);
-						RefreshMappings();
+						if(_ppu->IsCgbEnabled()) {
+							_state.CgbWorkRamBank = std::max(1, value & 0x07);
+							RefreshMappings();
+						}
+						break;
+
+					case 0xFF72: _state.CgbRegFF72 = value; break;
+					case 0xFF73: _state.CgbRegFF73 = value; break;
+					case 0xFF74:
+						if(_ppu->IsCgbEnabled()) {
+							_state.CgbRegFF74 = value;
+						}
 						break;
 
+					case 0xFF75: _state.CgbRegFF75 = value; break;
+
 					default:
 						LogDebug("[Debug] GBC - Missing write handler: $" + HexUtilities::ToHex(addr));
 						break;
@@ -417,6 +443,11 @@ bool GbMemoryManager::IsHighSpeed()
 	return _state.CgbHighSpeed;
 }
 
+bool GbMemoryManager::IsBootRomDisabled()
+{
+	return _state.DisableBootRom;
+}
+
 uint64_t GbMemoryManager::GetCycleCount()
 {
 	return _state.CycleCount;
@@ -485,7 +516,8 @@ void GbMemoryManager::Serialize(Serializer& s)
 	s.Stream(
 		_state.DisableBootRom, _state.IrqEnabled, _state.IrqRequests, _state.InputSelect,
 		_state.ApuCycleCount, _state.CgbHighSpeed, _state.CgbSwitchSpeedRequest, _state.CgbWorkRamBank,
-		_state.SerialData, _state.SerialControl, _state.SerialBitCount, _state.CycleCount
+		_state.SerialData, _state.SerialControl, _state.SerialBitCount, _state.CycleCount,
+		_state.CgbRegFF72, _state.CgbRegFF73, _state.CgbRegFF74, _state.CgbRegFF75
 	);
 	s.StreamArray(_state.MemoryType, 0x100);
 	s.StreamArray(_state.MemoryOffset, 0x100);

diff --git a/Core/GbMemoryManager.h b/Core/GbMemoryManager.h
@@ -70,6 +70,8 @@ class GbMemoryManager : public ISerializable
 
 	void ToggleSpeed();
 	bool IsHighSpeed();
+	bool IsBootRomDisabled();
+
 	uint64_t GetCycleCount();
 	uint64_t GetApuCycleCount();
 

diff --git a/Core/GbPpu.cpp b/Core/GbPpu.cpp
@@ -609,6 +609,11 @@ bool GbPpu::IsLcdEnabled()
 	return _state.LcdEnabled;
 }
 
+bool GbPpu::IsCgbEnabled()
+{
+	return _state.CgbEnabled;
+}
+
 PpuMode GbPpu::GetMode()
 {
 	return _state.Mode;
@@ -892,11 +897,15 @@ void GbPpu::WriteOam(uint8_t addr, uint8_t value, bool forDma)
 
 uint8_t GbPpu::ReadCgbRegister(uint16_t addr)
 {
+	if(!_state.CgbEnabled) {
+		return 0xFF;
+	}
+
 	switch(addr) {
-		case 0xFF4F: return _state.CgbVramBank;
-		case 0xFF68: return _state.CgbBgPalPosition | (_state.CgbBgPalAutoInc ? 0x80 : 0);
+		case 0xFF4F: return _state.CgbVramBank | 0xFE;
+		case 0xFF68: return _state.CgbBgPalPosition | (_state.CgbBgPalAutoInc ? 0x80 : 0) | 0x40;
 		case 0xFF69: return (_state.CgbBgPalettes[_state.CgbBgPalPosition >> 1] >> ((_state.CgbBgPalPosition & 0x01) ? 8 : 0) & 0xFF);
-		case 0xFF6A: return _state.CgbObjPalPosition | (_state.CgbObjPalAutoInc ? 0x80 : 0);
+		case 0xFF6A: return _state.CgbObjPalPosition | (_state.CgbObjPalAutoInc ? 0x80 : 0) | 0x40;
 		case 0xFF6B: return (_state.CgbObjPalettes[_state.CgbObjPalPosition >> 1] >> ((_state.CgbObjPalPosition & 0x01) ? 8 : 0) & 0xFF);
 	}
 	LogDebug("[Debug] GBC - Missing read handler: $" + HexUtilities::ToHex(addr));
@@ -905,6 +914,10 @@ uint8_t GbPpu::ReadCgbRegister(uint16_t addr)
 
 void GbPpu::WriteCgbRegister(uint16_t addr, uint8_t value)
 {
+	if(!_state.CgbEnabled && _memoryManager->IsBootRomDisabled()) {
+		return;
+	}
+
 	switch(addr) {
 		case 0xFF4C: _state.CgbEnabled = (value & 0x0C) == 0; break;
 		case 0xFF4F: _state.CgbVramBank = value & 0x01; break;

diff --git a/Core/GbPpu.h b/Core/GbPpu.h
@@ -87,6 +87,7 @@ class GbPpu : public ISerializable
 	uint8_t GetScanline();
 	uint16_t GetCycle();
 	bool IsLcdEnabled();
+	bool IsCgbEnabled();
 	PpuMode GetMode();
 
 	void Exec();

diff --git a/Core/GbTypes.h b/Core/GbTypes.h
@@ -353,6 +353,11 @@ struct GbMemoryManagerState
 	bool CgbSwitchSpeedRequest;
 	bool CgbHighSpeed;
 
+	uint8_t CgbRegFF72;
+	uint8_t CgbRegFF73;
+	uint8_t CgbRegFF74;
+	uint8_t CgbRegFF75;
+
 	bool DisableBootRom;
 	uint8_t IrqRequests;
 	uint8_t IrqEnabled;

diff --git a/UI/Interop/DebugState.cs b/UI/Interop/DebugState.cs
@@ -632,6 +632,11 @@ public struct GbMemoryManagerState
 		[MarshalAs(UnmanagedType.I1)] public bool CgbSwitchSpeedRequest;
 		[MarshalAs(UnmanagedType.I1)] public bool CgbHighSpeed;
 
+		public byte CgbRegFF72;
+		public byte CgbRegFF73;
+		public byte CgbRegFF74;
+		public byte CgbRegFF75;
+
 		[MarshalAs(UnmanagedType.I1)] public bool DisableBootRom;
 		public byte IrqRequests;
 		public byte IrqEnabled;