Add interrupt controller emulation

src/common/bitfield.h

@@ -80,6 +80,18 @@ struct BitField
     return *this;
   }
 
+  BitField& operator&=(DataType rhs)
+  {
+    SetValue(GetValue() & rhs);
+    return *this;
+  }
+
+  BitField& operator|=(DataType rhs)
+  {
+    SetValue(GetValue() & rhs);
+    return *this;
+  }
+
   BitField& operator^=(DataType rhs)
   {
     SetValue(GetValue() ^ rhs);

src/pse/bus.cpp

@@ -3,22 +3,34 @@
 #include "YBaseLib/Log.h"
 #include "YBaseLib/String.h"
 #include "common/state_wrapper.h"
+#include "cpu_core.h"
 #include "cpu_disasm.h"
 #include "dma.h"
 #include "gpu.h"
+#include "interrupt_controller.h"
 #include <cstdio>
 Log_SetChannel(Bus);
 
+// Offset and value remapping for (w32) registers from nocash docs.
+void FixupUnalignedWordAccessW32(u32& offset, u32& value)
+{
+  const u32 byte_offset = offset & u32(3);
+  offset &= ~u32(3);
+  value <<= byte_offset * 8;
+}
+
 Bus::Bus() = default;
 
 Bus::~Bus() = default;
 
-bool Bus::Initialize(System* system, DMA* dma, GPU* gpu)
+bool Bus::Initialize(CPU::Core* cpu, DMA* dma, InterruptController* interrupt_controller, GPU* gpu)
 {
   if (!LoadBIOS())
     return false;
 
+  m_cpu = cpu;
   m_dma = dma;
+  m_interrupt_controller = interrupt_controller;
   m_gpu = gpu;
   return true;
 }
@@ -216,6 +228,20 @@ bool Bus::DoWriteGPU(MemoryAccessSize size, u32 offset, u32 value)
   return true;
 }
 
+bool Bus::DoReadInterruptController(MemoryAccessSize size, u32 offset, u32& value)
+{
+  FixupUnalignedWordAccessW32(offset, value);
+  value = m_interrupt_controller->ReadRegister(offset);
+  return true;
+}
+
+bool Bus::DoWriteInterruptController(MemoryAccessSize size, u32 offset, u32 value)
+{
+  FixupUnalignedWordAccessW32(offset, value);
+  m_interrupt_controller->WriteRegister(offset, value);
+  return true;
+}
+
 bool Bus::ReadSPU(MemoryAccessSize size, u32 offset, u32& value)
 {
   if (offset == 0x1AE)

src/pse/bus.h

@@ -5,8 +5,15 @@
 #include <array>
 
 class StateWrapper;
+
+namespace CPU
+{
+class Core;
+}
+
 class DMA;
 class GPU;
+class InterruptController;
 class System;
 
 class Bus
@@ -15,7 +22,7 @@ public:
   Bus();
   ~Bus();
 
-  bool Initialize(System* system, DMA* dma, GPU* gpu);
+  bool Initialize(CPU::Core* cpu, DMA* dma, InterruptController* interrupt_controller, GPU* gpu);
   void Reset();
   bool DoState(StateWrapper& sw);
 
@@ -32,12 +39,15 @@ public:
   void PatchBIOS(u32 address, u32 value, u32 mask = UINT32_C(0xFFFFFFFF));
 
 private:
-  static constexpr u32 DMA_BASE = 0x1F801080;
-  static constexpr u32 DMA_SIZE = 0x80;
-  static constexpr u32 DMA_MASK = DMA_SIZE - 1;
   static constexpr u32 GPU_BASE = 0x1F801810;
   static constexpr u32 GPU_SIZE = 0x10;
   static constexpr u32 GPU_MASK = GPU_SIZE - 1;
+  static constexpr u32 INTERRUPT_CONTROLLER_BASE = 0x1F801070;
+  static constexpr u32 INTERRUPT_CONTROLLER_SIZE = 0x08;
+  static constexpr u32 INTERRUPT_CONTROLLER_MASK = INTERRUPT_CONTROLLER_SIZE - 1;
+  static constexpr u32 DMA_BASE = 0x1F801080;
+  static constexpr u32 DMA_SIZE = 0x80;
+  static constexpr u32 DMA_MASK = DMA_SIZE - 1;
   static constexpr u32 SPU_BASE = 0x1F801C00;
   static constexpr u32 SPU_SIZE = 0x300;
   static constexpr u32 SPU_MASK = 0x3FF;
@@ -64,13 +74,18 @@ private:
   bool DoReadGPU(MemoryAccessSize size, u32 offset, u32& value);
   bool DoWriteGPU(MemoryAccessSize size, u32 offset, u32 value);
 
+  bool DoReadInterruptController(MemoryAccessSize size, u32 offset, u32& value);
+  bool DoWriteInterruptController(MemoryAccessSize size, u32 offset, u32 value);
+
   bool DoReadDMA(MemoryAccessSize size, u32 offset, u32& value);
   bool DoWriteDMA(MemoryAccessSize size, u32 offset, u32 value);
 
   bool ReadSPU(MemoryAccessSize size, u32 offset, u32& value);
   bool WriteSPU(MemoryAccessSize size, u32 offset, u32 value);
 
+  CPU::Core* m_cpu = nullptr;
   DMA* m_dma = nullptr;
+  InterruptController* m_interrupt_controller = nullptr;
   GPU* m_gpu = nullptr;
 
   std::array<u8, 2097152> m_ram{}; // 2MB RAM

src/pse/bus.inl

@@ -80,6 +80,16 @@ bool Bus::DispatchAccess(PhysicalMemoryAddress cpu_address, PhysicalMemoryAddres
   {
     return DoRAMAccess<type, size>(bus_address, value);
   }
+  else if (bus_address < INTERRUPT_CONTROLLER_BASE)
+  {
+    return DoInvalidAccess(type, size, cpu_address, bus_address, value);
+  }
+  else if (bus_address < (INTERRUPT_CONTROLLER_BASE + INTERRUPT_CONTROLLER_SIZE))
+  {
+    return (type == MemoryAccessType::Read) ?
+             DoReadInterruptController(size, bus_address & INTERRUPT_CONTROLLER_MASK, value) :
+             DoWriteInterruptController(size, bus_address & INTERRUPT_CONTROLLER_MASK, value);
+  }
   else if (bus_address < DMA_BASE)
   {
     return DoInvalidAccess(type, size, cpu_address, bus_address, value);

src/pse/cdrom.cpp

@@ -0,0 +1 @@
+#include "interrupt_controller.h"

src/pse/cpu_core.cpp

@@ -36,6 +36,7 @@ void Core::Reset()
   m_cop0_regs.BPCM = 0;
   m_cop0_regs.EPC = 0;
   m_cop0_regs.sr.bits = 0;
+  m_cop0_regs.cause.bits = 0;
 
   SetPC(RESET_VECTOR);
 }
@@ -60,10 +61,13 @@ bool Core::DoState(StateWrapper& sw)
   sw.Do(&m_cop0_regs.cause.bits);
   sw.Do(&m_cop0_regs.dcic.bits);
   sw.Do(&m_next_instruction.bits);
-  sw.Do(&m_in_branch_delay_slot);
-  sw.Do(&m_branched);
+  sw.Do(&m_current_instruction_pc);
   sw.Do(&m_load_delay_reg);
   sw.Do(&m_load_delay_old_value);
+  sw.Do(&m_next_load_delay_reg);
+  sw.Do(&m_next_load_delay_old_value);
+  sw.Do(&m_in_branch_delay_slot);
+  sw.Do(&m_branched);
   sw.Do(&m_cache_control);
   sw.DoBytes(m_dcache.data(), m_dcache.size());
   return !sw.HasError();
@@ -197,6 +201,28 @@ void Core::RaiseException(Exception excode, u8 coprocessor /* = 0 */)
   FlushPipeline();
 }
 
+void Core::SetExternalInterrupt(u8 bit)
+{
+  m_cop0_regs.cause.Ip |= static_cast<u8>(1u << bit);
+}
+
+void Core::ClearExternalInterrupt(u8 bit)
+{
+  m_cop0_regs.cause.Ip &= static_cast<u8>(~(1u << bit));
+}
+
+bool Core::DispatchInterrupts()
+{
+  // const bool do_interrupt = m_cop0_regs.sr.IEc && ((m_cop0_regs.cause.Ip & m_cop0_regs.sr.Im) != 0);
+  const bool do_interrupt =
+    m_cop0_regs.sr.IEc && (((m_cop0_regs.cause.bits & m_cop0_regs.sr.bits) & (UINT32_C(0xFF) << 8)) != 0);
+  if (!do_interrupt)
+    return false;
+
+  RaiseException(Exception::INT);
+  return true;
+}
+
 void Core::FlushLoadDelay()
 {
   m_load_delay_reg = Reg::count;
@@ -284,7 +310,7 @@ TickCount Core::Execute()
     m_current_instruction_pc = m_regs.pc;
 
     // fetch the next instruction
-    if (!FetchInstruction())
+    if (DispatchInterrupts() || !FetchInstruction())
       continue;
 
     // handle branch delays - we are now in a delay slot if we just branched

src/pse/cpu_core.h

@@ -28,14 +28,11 @@ public:
 
   TickCount Execute();
 
-  void SetSliceTicks(TickCount downcount)
-  {
-    m_slice_ticks = (downcount < m_slice_ticks ? downcount : m_slice_ticks);
-  }
-
   const Registers& GetRegs() const { return m_regs; }
   Registers& GetRegs() { return m_regs; }
 
+  void SetSliceTicks(TickCount downcount) { m_slice_ticks = (downcount < m_slice_ticks ? downcount : m_slice_ticks); }
+
   // Sets the PC and flushes the pipeline.
   void SetPC(u32 new_pc);
 
@@ -46,6 +43,10 @@ public:
   bool SafeWriteMemoryHalfWord(VirtualMemoryAddress addr, u16 value);
   bool SafeWriteMemoryWord(VirtualMemoryAddress addr, u32 value);
 
+  // External IRQs
+  void SetExternalInterrupt(u8 bit);
+  void ClearExternalInterrupt(u8 bit);
+
 private:
   template<MemoryAccessType type, MemoryAccessSize size, bool is_instruction_fetch, bool raise_exceptions>
   bool DoMemoryAccess(VirtualMemoryAddress address, u32& value);
@@ -78,6 +79,7 @@ private:
   // exceptions
   u32 GetExceptionVector(Exception excode) const;
   void RaiseException(Exception excode, u8 coprocessor = 0);
+  bool DispatchInterrupts();
 
   // flushes any load delays if present
   void FlushLoadDelay();
@@ -101,9 +103,8 @@ private:
   TickCount m_slice_ticks = 0;
 
   Registers m_regs = {};
+  Cop0Registers m_cop0_regs = {};
   Instruction m_next_instruction = {};
-  bool m_in_branch_delay_slot = false;
-  bool m_branched = false;
 
   // address of the instruction currently being executed
   u32 m_current_instruction_pc = 0;
@@ -113,11 +114,11 @@ private:
   u32 m_load_delay_old_value = 0;
   Reg m_next_load_delay_reg = Reg::count;
   u32 m_next_load_delay_old_value = 0;
+  bool m_in_branch_delay_slot = false;
+  bool m_branched = false;
 
   u32 m_cache_control = 0;
 
-  Cop0Registers m_cop0_regs = {};
-
   // data cache (used as scratchpad)
   std::array<u8, DCACHE_SIZE> m_dcache = {};
 };

src/pse/interrupt_controller.cpp

@@ -0,0 +1,86 @@
+#include "interrupt_controller.h"
+#include "YBaseLib/Log.h"
+#include "common/state_wrapper.h"
+#include "cpu_core.h"
+Log_SetChannel(InterruptController);
+
+InterruptController::InterruptController() = default;
+
+InterruptController::~InterruptController() = default;
+
+bool InterruptController::Initialize(CPU::Core* cpu)
+{
+  m_cpu = cpu;
+  return true;
+}
+
+void InterruptController::Reset()
+{
+  m_interrupt_status_register = 0;
+  m_interrupt_mask_register = DEFAULT_INTERRUPT_MASK;
+}
+
+bool InterruptController::DoState(StateWrapper& sw)
+{
+  sw.Do(&m_interrupt_status_register);
+  sw.Do(&m_interrupt_mask_register);
+
+  return !sw.HasError();
+}
+
+void InterruptController::InterruptRequest(IRQ irq)
+{
+  const u32 bit = (u32(1) << static_cast<u32>(irq));
+  m_interrupt_status_register |= (bit & m_interrupt_mask_register);
+  UpdateCPUInterruptRequest();
+}
+
+u32 InterruptController::ReadRegister(u32 offset)
+{
+  switch (offset)
+  {
+    case 0x00: // I_STATUS
+      return m_interrupt_status_register;
+
+    case 0x04: // I_MASK
+      return m_interrupt_mask_register;
+
+    default:
+      Log_ErrorPrintf("Invalid read at offset 0x%08X", offset);
+      return UINT32_C(0xFFFFFFFF);
+  }
+}
+
+void InterruptController::WriteRegister(u32 offset, u32 value)
+{
+  switch (offset)
+  {
+    case 0x00: // I_STATUS
+    {
+      Log_DebugPrintf("Clearing bits 0x%08X", value);
+      m_interrupt_status_register = m_interrupt_status_register & (~(value & REGISTER_WRITE_MASK));
+      UpdateCPUInterruptRequest();
+    }
+    break;
+
+    case 0x04: // I_MASK
+    {
+      Log_DebugPrintf("Interrupt mask <- 0x%08X", value);
+      m_interrupt_mask_register = value & REGISTER_WRITE_MASK;
+    }
+    break;
+
+    default:
+      Log_ErrorPrintf("Invalid write at offset 0x%08X", offset);
+      break;
+  }
+}
+
+void InterruptController::UpdateCPUInterruptRequest()
+{
+  // external interrupts set bit 10 only?
+  if (m_interrupt_status_register != 0)
+    m_cpu->SetExternalInterrupt(3);
+  else
+    m_cpu->ClearExternalInterrupt(3);
+}

src/pse/interrupt_controller.h

@@ -0,0 +1,60 @@
+#pragma once
+#include "types.h"
+
+class StateWrapper;
+
+namespace CPU
+{
+class Core;
+}
+
+class InterruptController
+{
+public:
+  static constexpr u32 NUM_IRQS = 11;
+
+  enum class IRQ : u32
+  {
+    VBLANK = 0, // IRQ0 - VBLANK
+    GPU = 1,    // IRQ1 - GPU via GP0(1Fh)
+    CDROM = 2,  // IRQ2 - CDROM
+    DMA = 3,    // IRQ3 - DMA
+    TMR0 = 4,   // IRQ4 - TMR0 - Sysclk or Dotclk
+    TMR1 = 5,   // IRQ5 - TMR1 - Sysclk Hblank
+    TMR2 = 6,   // IRQ6 - TMR2 - Sysclk or Sysclk / 8
+    IRQ7 = 7,   // IRQ7 - Controller and Memory Card Byte Received
+    SIO = 8,    // IRQ8 - SIO
+    SPU = 9,    // IRQ9 - SPU
+    IRQ10 = 10  // IRQ10 - Lightpen interrupt, PIO
+  };
+
+
+  InterruptController();
+  ~InterruptController();
+
+  bool Initialize(CPU::Core* cpu);
+  void Reset();
+  bool DoState(StateWrapper& sw);
+
+  // Should mirror CPU state.
+  bool GetIRQLineState() const { return (m_interrupt_status_register != 0); }
+
+  // Interupts are edge-triggered, so if it is masked when TriggerInterrupt() is called, it will be lost.
+  void InterruptRequest(IRQ irq);
+
+  // I/O
+  u32 ReadRegister(u32 offset);
+  void WriteRegister(u32 offset, u32 value);
+
+private:
+  static constexpr u32 REGISTER_WRITE_MASK = (u32(1) << NUM_IRQS) - 1;
+  static constexpr u32 DEFAULT_INTERRUPT_MASK = (u32(1) << NUM_IRQS) - 1;
+
+  void UpdateCPUInterruptRequest();
+
+  CPU::Core* m_cpu;
+
+  u32 m_interrupt_status_register = 0;
+  u32 m_interrupt_mask_register = DEFAULT_INTERRUPT_MASK;
+};
+

src/pse/pse.vcxproj

@@ -43,6 +43,7 @@
     <ClCompile Include="gpu_hw.cpp" />
     <ClCompile Include="gpu_hw_opengl.cpp" />
     <ClCompile Include="host_interface.cpp" />
+    <ClCompile Include="interrupt_controller.cpp" />
     <ClCompile Include="system.cpp" />
   </ItemGroup>
   <ItemGroup>
@@ -55,6 +56,7 @@
     <ClInclude Include="gpu_hw.h" />
     <ClInclude Include="gpu_hw_opengl.h" />
     <ClInclude Include="host_interface.h" />
+    <ClInclude Include="interrupt_controller.h" />
     <ClInclude Include="save_state_version.h" />
     <ClInclude Include="system.h" />
     <ClInclude Include="types.h" />

src/pse/pse.vcxproj.filters

@@ -10,6 +10,7 @@
     <ClCompile Include="gpu_hw_opengl.cpp" />
     <ClCompile Include="gpu_hw.cpp" />
     <ClCompile Include="host_interface.cpp" />
+    <ClCompile Include="interrupt_controller.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="types.h" />
@@ -24,6 +25,7 @@
     <ClInclude Include="gpu_hw_opengl.h" />
     <ClInclude Include="gpu_hw.h" />
     <ClInclude Include="host_interface.h" />
+    <ClInclude Include="interrupt_controller.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="cpu_core.inl" />

src/pse/system.cpp

@@ -5,12 +5,14 @@
 #include "cpu_core.h"
 #include "dma.h"
 #include "gpu.h"
+#include "interrupt_controller.h"
 
 System::System(HostInterface* host_interface) : m_host_interface(host_interface)
 {
   m_cpu = std::make_unique<CPU::Core>();
   m_bus = std::make_unique<Bus>();
   m_dma = std::make_unique<DMA>();
+  m_interrupt_controller = std::make_unique<InterruptController>();
   // m_gpu = std::make_unique<GPU>();
   m_gpu = GPU::CreateHardwareOpenGLRenderer();
 }
@@ -22,12 +24,15 @@ bool System::Initialize()
   if (!m_cpu->Initialize(m_bus.get()))
     return false;
 
-  if (!m_bus->Initialize(this, m_dma.get(), m_gpu.get()))
+  if (!m_bus->Initialize(m_cpu.get(), m_dma.get(), m_interrupt_controller.get(), m_gpu.get()))
     return false;
 
   if (!m_dma->Initialize(m_bus.get(), m_gpu.get()))
     return false;
 
+  if (!m_interrupt_controller->Initialize(m_cpu.get()))
+    return false;
+
   if (!m_gpu->Initialize(this, m_bus.get(), m_dma.get()))
     return false;
 
@@ -45,6 +50,9 @@ bool System::DoState(StateWrapper& sw)
   if (!sw.DoMarker("DMA") || !m_dma->DoState(sw))
     return false;
 
+  if (!sw.DoMarker("InterruptController") || !m_interrupt_controller->DoState(sw))
+    return false;
+
   if (!sw.DoMarker("GPU") || !m_gpu->DoState(sw))
     return false;
 
@@ -58,6 +66,7 @@ void System::Reset()
   m_cpu->Reset();
   m_bus->Reset();
   m_dma->Reset();
+  m_interrupt_controller->Reset();
   m_gpu->Reset();
   m_frame_number = 1;
 }

src/pse/system.h

@@ -13,6 +13,7 @@ class Core;
 
 class Bus;
 class DMA;
+class InterruptController;
 class GPU;
 
 class System
@@ -45,6 +46,7 @@ private:
   std::unique_ptr<CPU::Core> m_cpu;
   std::unique_ptr<Bus> m_bus;
   std::unique_ptr<DMA> m_dma;
+  std::unique_ptr<InterruptController> m_interrupt_controller;
   std::unique_ptr<GPU> m_gpu;
   u32 m_frame_number = 1;
 };