Merge 9d92b8708a into 5e8beb3ab7

ty mgba discord

BUILD.md

@@ -47,7 +47,7 @@
      1. Install Qt: `pacman -S <prefix>-{qt6-base,qt6-svg,qt6-multimedia,qt6-svg,qt6-tools}`
      2. Set up the build directory with `cmake -B build`
    * Static builds (without DLLs, standalone executable)
-     1. Install Qt: `pacman -S <prefi>-qt5-static`  
+     1. Install Qt: `pacman -S <prefix>-qt5-static`  
         (Note: As of writing, the `qt6-static` package does not work.)
      2. Set up the build directory with `cmake -B build -DBUILD_STATIC=ON -DUSE_QT6=OFF -DCMAKE_PREFIX_PATH=$MSYSTEM_PREFIX/qt5-static`
 7. Compile: `cmake --build build`

src/ARM.cpp

@@ -222,7 +222,7 @@ void ARM::DoSavestate(Savestate* file)
     file->VarArray(R_ABT, 3*sizeof(u32));
     file->VarArray(R_IRQ, 3*sizeof(u32));
     file->VarArray(R_UND, 3*sizeof(u32));
-    file->Var32(&CurInstr);
+    file->Var64(&CurInstr);
 #ifdef JIT_ENABLED
     if (file->Saving && NDS.IsJITEnabled())
     {
@@ -232,7 +232,7 @@ void ARM::DoSavestate(Savestate* file)
         FillPipeline();
     }
 #endif
-    file->VarArray(NextInstr, 2*sizeof(u32));
+    file->VarArray(NextInstr, 2*sizeof(u64));
 
     file->Var32(&ExceptionBase);
 
@@ -344,12 +344,6 @@ void ARMv5::JumpTo(u32 addr, bool restorecpsr)
         CPSR &= ~0x20;
     }
 
-    if (!(PU_Map[addr>>12] & 0x04))
-    {
-        PrefetchAbort();
-        return;
-    }
-
     NDS.MonitorARM9Jump(addr);
 }
 
@@ -518,6 +512,7 @@ void ARM::UpdateMode(u32 oldmode, u32 newmode, bool phony)
     }
 }
 
+template <CPUExecuteMode mode>
 void ARM::TriggerIRQ()
 {
     if (CPSR & 0x80)
@@ -529,7 +524,12 @@ void ARM::TriggerIRQ()
     UpdateMode(oldcpsr, CPSR);
 
     R_IRQ[2] = oldcpsr;
-    R[14] = R[15] + (oldcpsr & 0x20 ? 2 : 0);
+#ifdef JIT_ENABLED
+    if constexpr (mode == CPUExecuteMode::JIT)
+        R[14] = R[15] + (oldcpsr & 0x20 ? 2 : 0);
+    else
+#endif
+        R[14] = R[15] - (oldcpsr & 0x20 ? 0 : 4);
     JumpTo(ExceptionBase + 0x18);
 
     // ARDS cheat support
@@ -540,6 +540,11 @@ void ARM::TriggerIRQ()
             NDS.AREngine.RunCheats();
     }
 }
+template void ARM::TriggerIRQ<CPUExecuteMode::Interpreter>();
+template void ARM::TriggerIRQ<CPUExecuteMode::InterpreterGDB>();
+#ifdef JIT_ENABLED
+template void ARM::TriggerIRQ<CPUExecuteMode::JIT>();
+#endif
 
 void ARMv5::PrefetchAbort()
 {
@@ -550,17 +555,8 @@ void ARMv5::PrefetchAbort()
     CPSR |= 0x97;
     UpdateMode(oldcpsr, CPSR);
 
-    // this shouldn't happen, but if it does, we're stuck in some nasty endless loop
-    // so better take care of it
-    if (!(PU_Map[ExceptionBase>>12] & 0x04))
-    {
-        Log(LogLevel::Error, "!!!!! EXCEPTION REGION NOT EXECUTABLE. THIS IS VERY BAD!!\n");
-        NDS.Stop(Platform::StopReason::BadExceptionRegion);
-        return;
-    }
-
     R_ABT[2] = oldcpsr;
-    R[14] = R[15] + (oldcpsr & 0x20 ? 2 : 0);
+    R[14] = R[15] - (oldcpsr & 0x20 ? 0 : 4);
     JumpTo(ExceptionBase + 0x0C);
 }
 
@@ -599,7 +595,13 @@ void ARMv5::Execute()
         {
             Halted = 0;
             if (NDS.IME[0] & 0x1)
-                TriggerIRQ();
+            {
+#ifdef JIT_ENABLED
+                if constexpr (mode == CPUExecuteMode::JIT) TriggerIRQ<mode>();
+                else
+#endif
+                    IRQ = 1;
+            }
         }
         else
         {
@@ -634,7 +636,7 @@ void ARMv5::Execute()
             {
                 // this order is crucial otherwise idle loops waiting for an IRQ won't function
                 if (IRQ)
-                    TriggerIRQ();
+                    TriggerIRQ<mode>();
 
                 if (Halted || IdleLoop)
                 {
@@ -662,10 +664,18 @@ void ARMv5::Execute()
                 NextInstr[0] = NextInstr[1];
                 if (R[15] & 0x2) { NextInstr[1] >>= 16; CodeCycles = 0; }
                 else             NextInstr[1] = CodeRead32(R[15], false);
-
-                // actually execute
-                u32 icode = (CurInstr >> 6) & 0x3FF;
-                ARMInterpreter::THUMBInstrTable[icode](this);
+                
+                
+                if (IRQ && !(CPSR & 0x80)) TriggerIRQ<mode>();
+                else if (CurInstr > 0xFFFFFFFF) [[unlikely]] // handle aborted instructions
+                {
+                    PrefetchAbort();
+                }
+                else [[likely]] // actually execute
+                {
+                    u32 icode = (CurInstr >> 6) & 0x3FF;
+                    ARMInterpreter::THUMBInstrTable[icode](this);
+                }
             }
             else
             {
@@ -677,9 +687,14 @@ void ARMv5::Execute()
                 CurInstr = NextInstr[0];
                 NextInstr[0] = NextInstr[1];
                 NextInstr[1] = CodeRead32(R[15], false);
+                
 
-                // actually execute
-                if (CheckCondition(CurInstr >> 28))
+                if (IRQ && !(CPSR & 0x80)) TriggerIRQ<mode>();
+                else if (CurInstr & ((u64)1<<63)) [[unlikely]] // handle aborted instructions
+                {
+                    PrefetchAbort();
+                }
+                else if (CheckCondition(CurInstr >> 28)) [[likely]] // actually execute
                 {
                     u32 icode = ((CurInstr >> 4) & 0xF) | ((CurInstr >> 16) & 0xFF0);
                     ARMInterpreter::ARMInstrTable[icode](this);
@@ -688,6 +703,10 @@ void ARMv5::Execute()
                 {
                     ARMInterpreter::A_BLX_IMM(this);
                 }
+                else if ((CurInstr & 0x0FF000F0) == 0x01200070)
+                {
+                    ARMInterpreter::A_BKPT(this); // always passes regardless of condition code
+                }
                 else
                     AddCycles_C();
             }
@@ -704,10 +723,8 @@ void ARMv5::Execute()
             /*if (NDS::IF[0] & NDS::IE[0])
             {
                 if (NDS::IME[0] & 0x1)
-                    TriggerIRQ();
+                    TriggerIRQ<mode>();
             }*/
-            if (IRQ) TriggerIRQ();
-
         }
 
         NDS.ARM9Timestamp += Cycles;
@@ -739,7 +756,10 @@ void ARMv4::Execute()
         {
             Halted = 0;
             if (NDS.IME[1] & 0x1)
-                TriggerIRQ();
+            {
+                if constexpr (mode == CPUExecuteMode::JIT) TriggerIRQ<mode>();
+                else IRQ = 1;
+            }
         }
         else
         {
@@ -773,7 +793,7 @@ void ARMv4::Execute()
             if (StopExecution)
             {
                 if (IRQ)
-                    TriggerIRQ();
+                    TriggerIRQ<mode>();
 
                 if (Halted || IdleLoop)
                 {
@@ -801,9 +821,13 @@ void ARMv4::Execute()
                 NextInstr[0] = NextInstr[1];
                 NextInstr[1] = CodeRead16(R[15]);
 
-                // actually execute
-                u32 icode = (CurInstr >> 6);
-                ARMInterpreter::THUMBInstrTable[icode](this);
+                if (IRQ && !(CPSR & 0x80)) TriggerIRQ<mode>();
+                else
+                {
+                    // actually execute
+                    u32 icode = (CurInstr >> 6);
+                    ARMInterpreter::THUMBInstrTable[icode](this);
+                }
             }
             else
             {
@@ -816,8 +840,8 @@ void ARMv4::Execute()
                 NextInstr[0] = NextInstr[1];
                 NextInstr[1] = CodeRead32(R[15]);
 
-                // actually execute
-                if (CheckCondition(CurInstr >> 28))
+                if (IRQ && !(CPSR & 0x80)) TriggerIRQ<mode>();
+                else if (CheckCondition(CurInstr >> 28)) // actually execute
                 {
                     u32 icode = ((CurInstr >> 4) & 0xF) | ((CurInstr >> 16) & 0xFF0);
                     ARMInterpreter::ARMInstrTable[icode](this);
@@ -838,9 +862,8 @@ void ARMv4::Execute()
             /*if (NDS::IF[1] & NDS::IE[1])
             {
                 if (NDS::IME[1] & 0x1)
-                    TriggerIRQ();
+                    TriggerIRQ<mode>();
             }*/
-            if (IRQ) TriggerIRQ();
         }
 
         NDS.ARM7Timestamp += Cycles;
@@ -1113,70 +1136,78 @@ u32 ARMv5::ReadMem(u32 addr, int size)
 }
 #endif
 
-void ARMv4::DataRead8(u32 addr, u32* val)
+bool ARMv4::DataRead8(u32 addr, u32* val)
 {
     *val = BusRead8(addr);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][0];
+    return true;
 }
 
-void ARMv4::DataRead16(u32 addr, u32* val)
+bool ARMv4::DataRead16(u32 addr, u32* val)
 {
     addr &= ~1;
 
     *val = BusRead16(addr);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][0];
+    return true;
 }
 
-void ARMv4::DataRead32(u32 addr, u32* val)
+bool ARMv4::DataRead32(u32 addr, u32* val)
 {
     addr &= ~3;
 
     *val = BusRead32(addr);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][2];
+    return true;
 }
 
-void ARMv4::DataRead32S(u32 addr, u32* val)
+bool ARMv4::DataRead32S(u32 addr, u32* val)
 {
     addr &= ~3;
 
     *val = BusRead32(addr);
     DataCycles += NDS.ARM7MemTimings[addr >> 15][3];
+    return true;
 }
 
-void ARMv4::DataWrite8(u32 addr, u8 val)
+bool ARMv4::DataWrite8(u32 addr, u8 val)
 {
     BusWrite8(addr, val);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][0];
+    return true;
 }
 
-void ARMv4::DataWrite16(u32 addr, u16 val)
+bool ARMv4::DataWrite16(u32 addr, u16 val)
 {
     addr &= ~1;
 
     BusWrite16(addr, val);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][0];
+    return true;
 }
 
-void ARMv4::DataWrite32(u32 addr, u32 val)
+bool ARMv4::DataWrite32(u32 addr, u32 val)
 {
     addr &= ~3;
 
     BusWrite32(addr, val);
     DataRegion = addr;
     DataCycles = NDS.ARM7MemTimings[addr >> 15][2];
+    return true;
 }
 
-void ARMv4::DataWrite32S(u32 addr, u32 val)
+bool ARMv4::DataWrite32S(u32 addr, u32 val)
 {
     addr &= ~3;
 
     BusWrite32(addr, val);
     DataCycles += NDS.ARM7MemTimings[addr >> 15][3];
+    return true;
 }
 
 

src/ARM.h

@@ -128,19 +128,20 @@ public:
 
     void UpdateMode(u32 oldmode, u32 newmode, bool phony = false);
 
+    template <CPUExecuteMode mode>
     void TriggerIRQ();
 
     void SetupCodeMem(u32 addr);
 
 
-    virtual void DataRead8(u32 addr, u32* val) = 0;
-    virtual void DataRead16(u32 addr, u32* val) = 0;
-    virtual void DataRead32(u32 addr, u32* val) = 0;
-    virtual void DataRead32S(u32 addr, u32* val) = 0;
-    virtual void DataWrite8(u32 addr, u8 val) = 0;
-    virtual void DataWrite16(u32 addr, u16 val) = 0;
-    virtual void DataWrite32(u32 addr, u32 val) = 0;
-    virtual void DataWrite32S(u32 addr, u32 val) = 0;
+    virtual bool DataRead8(u32 addr, u32* val) = 0;
+    virtual bool DataRead16(u32 addr, u32* val) = 0;
+    virtual bool DataRead32(u32 addr, u32* val) = 0;
+    virtual bool DataRead32S(u32 addr, u32* val) = 0;
+    virtual bool DataWrite8(u32 addr, u8 val) = 0;
+    virtual bool DataWrite16(u32 addr, u16 val) = 0;
+    virtual bool DataWrite32(u32 addr, u32 val) = 0;
+    virtual bool DataWrite32S(u32 addr, u32 val) = 0;
 
     virtual void AddCycles_C() = 0;
     virtual void AddCycles_CI(s32 numI) = 0;
@@ -176,8 +177,8 @@ public:
     u32 R_ABT[3];
     u32 R_IRQ[3];
     u32 R_UND[3];
-    u32 CurInstr;
-    u32 NextInstr[2];
+    u64 CurInstr;
+    u64 NextInstr[2];
 
     u32 ExceptionBase;
 
@@ -250,16 +251,16 @@ public:
     void Execute();
 
     // all code accesses are forced nonseq 32bit
-    u32 CodeRead32(u32 addr, bool branch);
+    u64 CodeRead32(u32 addr, bool branch);
 
-    void DataRead8(u32 addr, u32* val) override;
-    void DataRead16(u32 addr, u32* val) override;
-    void DataRead32(u32 addr, u32* val) override;
-    void DataRead32S(u32 addr, u32* val) override;
-    void DataWrite8(u32 addr, u8 val) override;
-    void DataWrite16(u32 addr, u16 val) override;
-    void DataWrite32(u32 addr, u32 val) override;
-    void DataWrite32S(u32 addr, u32 val) override;
+    bool DataRead8(u32 addr, u32* val) override;
+    bool DataRead16(u32 addr, u32* val) override;
+    bool DataRead32(u32 addr, u32* val) override;
+    bool DataRead32S(u32 addr, u32* val) override;
+    bool DataWrite8(u32 addr, u8 val) override;
+    bool DataWrite16(u32 addr, u16 val) override;
+    bool DataWrite32(u32 addr, u32 val) override;
+    bool DataWrite32S(u32 addr, u32 val) override;
 
     void AddCycles_C() override
     {
@@ -399,18 +400,19 @@ public:
         return BusRead32(addr);
     }
 
-    void DataRead8(u32 addr, u32* val) override;
-    void DataRead16(u32 addr, u32* val) override;
-    void DataRead32(u32 addr, u32* val) override;
-    void DataRead32S(u32 addr, u32* val) override;
-    void DataWrite8(u32 addr, u8 val) override;
-    void DataWrite16(u32 addr, u16 val) override;
-    void DataWrite32(u32 addr, u32 val) override;
-    void DataWrite32S(u32 addr, u32 val) override;
+    bool DataRead8(u32 addr, u32* val) override;
+    bool DataRead16(u32 addr, u32* val) override;
+    bool DataRead32(u32 addr, u32* val) override;
+    bool DataRead32S(u32 addr, u32* val) override;
+    bool DataWrite8(u32 addr, u8 val) override;
+    bool DataWrite16(u32 addr, u16 val) override;
+    bool DataWrite32(u32 addr, u32 val) override;
+    bool DataWrite32S(u32 addr, u32 val) override;
     void AddCycles_C() override;
     void AddCycles_CI(s32 num) override;
     void AddCycles_CDI() override;
     void AddCycles_CD() override;
+
 protected:
     u8 BusRead8(u32 addr) override;
     u16 BusRead16(u32 addr) override;

src/ARMInterpreter.cpp

@@ -69,6 +69,14 @@ void T_UNK(ARM* cpu)
     cpu->JumpTo(cpu->ExceptionBase + 0x04);
 }
 
+void A_BKPT(ARM* cpu)
+{
+    if (cpu->Num == 1) A_UNK(cpu); // checkme
+    
+    Log(LogLevel::Warn, "BKPT: "); // combine with the prefetch abort warning message
+    ((ARMv5*)cpu)->PrefetchAbort();
+}
+
 
 
 void A_MSR_IMM(ARM* cpu)
@@ -90,7 +98,8 @@ void A_MSR_IMM(ARM* cpu)
             case 0x1A:
             case 0x1B: psr = &cpu->R_UND[2]; break;
             default:
-                cpu->AddCycles_C();
+                if (cpu->Num != 1) cpu->AddCycles_C(); // arm 7
+                else cpu->AddCycles_CI(2); // arm 9
                 return;
         }
     }
@@ -101,12 +110,9 @@ void A_MSR_IMM(ARM* cpu)
 
     u32 mask = 0;
     if (cpu->CurInstr & (1<<16)) mask |= 0x000000FF;
-    if (cpu->CurInstr & (1<<17)) mask |= 0x0000FF00;
-    if (cpu->CurInstr & (1<<18)) mask |= 0x00FF0000;
-    if (cpu->CurInstr & (1<<19)) mask |= 0xFF000000;
-
-    if (!(cpu->CurInstr & (1<<22)))
-        mask &= 0xFFFFFFDF;
+    //if (cpu->CurInstr & (1<<17)) mask |= 0x0000FF00; // unused by arm 7 & 9
+    //if (cpu->CurInstr & (1<<18)) mask |= 0x00FF0000; // unused by arm 7 & 9
+    if (cpu->CurInstr & (1<<19)) mask |= ((cpu->Num==1) ? 0xF0000000 : 0xF8000000);
 
     if ((cpu->CPSR & 0x1F) == 0x10) mask &= 0xFFFFFF00;
 
@@ -121,7 +127,26 @@ void A_MSR_IMM(ARM* cpu)
     if (!(cpu->CurInstr & (1<<22)))
         cpu->UpdateMode(oldpsr, cpu->CPSR);
 
-    cpu->AddCycles_C();
+    if (cpu->CPSR & 0x20) [[unlikely]]
+    {
+        if (cpu->Num == 0) cpu->R[15] += 2; // pc should actually increment by 4 one more time after switching to thumb mode without a pipeline flush, this gets the same effect.
+        else
+        {
+            Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: MSR REG T bit change on ARM7\n");
+            cpu->CPSR &= ~0x20; // keep it from crashing the emulator at least
+        }
+    }
+    
+    if (cpu->Num != 1)
+    {
+        if (cpu->CurInstr & (1<<22))
+        {
+            cpu->AddCycles_CI(2); // spsr
+        }
+        else if (cpu->CurInstr & (0x7<<16)) cpu->AddCycles_CI(2); // cpsr_sxc
+        else cpu->AddCycles_C();
+    }
+    else cpu->AddCycles_C();
 }
 
 void A_MSR_REG(ARM* cpu)
@@ -143,7 +168,8 @@ void A_MSR_REG(ARM* cpu)
             case 0x1A:
             case 0x1B: psr = &cpu->R_UND[2]; break;
             default:
-                cpu->AddCycles_C();
+                if (cpu->Num != 1) cpu->AddCycles_C(); // arm 7
+                else cpu->AddCycles_CI(2); // arm 9
                 return;
         }
     }
@@ -154,12 +180,9 @@ void A_MSR_REG(ARM* cpu)
 
     u32 mask = 0;
     if (cpu->CurInstr & (1<<16)) mask |= 0x000000FF;
-    if (cpu->CurInstr & (1<<17)) mask |= 0x0000FF00;
-    if (cpu->CurInstr & (1<<18)) mask |= 0x00FF0000;
-    if (cpu->CurInstr & (1<<19)) mask |= 0xFF000000;
-
-    if (!(cpu->CurInstr & (1<<22)))
-        mask &= 0xFFFFFFDF;
+    //if (cpu->CurInstr & (1<<17)) mask |= 0x0000FF00; // unused by arm 7 & 9
+    //if (cpu->CurInstr & (1<<18)) mask |= 0x00FF0000; // unused by arm 7 & 9
+    if (cpu->CurInstr & (1<<19)) mask |= ((cpu->Num==1) ? 0xF0000000 : 0xF8000000);
 
     if ((cpu->CPSR & 0x1F) == 0x10) mask &= 0xFFFFFF00;
 
@@ -174,7 +197,26 @@ void A_MSR_REG(ARM* cpu)
     if (!(cpu->CurInstr & (1<<22)))
         cpu->UpdateMode(oldpsr, cpu->CPSR);
 
-    cpu->AddCycles_C();
+    if (cpu->CPSR & 0x20) [[unlikely]]
+    {
+        if (cpu->Num == 0) cpu->R[15] += 2; // pc should actually increment by 4 one more time after switching to thumb mode without a pipeline flush, this gets the same effect.
+        else
+        {
+            Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: MSR REG T bit change on ARM7\n");
+            cpu->CPSR &= ~0x20; // keep it from crashing the emulator at least
+        }
+    }
+    
+    if (cpu->Num != 1)
+    {
+        if (cpu->CurInstr & (1<<22))
+        {
+            cpu->AddCycles_CI(2); // spsr
+        }
+        else if (cpu->CurInstr & (0x7<<16)) cpu->AddCycles_CI(2); // cpsr_sxc
+        else cpu->AddCycles_C();
+    }
+    else cpu->AddCycles_C();
 }
 
 void A_MRS(ARM* cpu)
@@ -201,8 +243,15 @@ void A_MRS(ARM* cpu)
     else
         psr = cpu->CPSR;
 
-    cpu->R[(cpu->CurInstr>>12) & 0xF] = psr;
-    cpu->AddCycles_C();
+    if (((cpu->CurInstr>>12) & 0xF) == 15)
+    {
+        if (cpu->Num == 1) // doesn't seem to jump on the arm9? checkme
+            cpu->JumpTo(psr & ~0x1); // checkme: this shouldn't be able to switch to thumb?
+    }
+    else cpu->R[(cpu->CurInstr>>12) & 0xF] = psr;
+
+    if (cpu->Num != 1) cpu->AddCycles_CI(1); // arm9
+    else cpu->AddCycles_C(); // arm7
 }
 
 
@@ -216,10 +265,12 @@ void A_MCR(ARM* cpu)
     u32 cn = (cpu->CurInstr >> 16) & 0xF;
     u32 cm = cpu->CurInstr & 0xF;
     u32 cpinfo = (cpu->CurInstr >> 5) & 0x7;
+    u32 val = cpu->R[(cpu->CurInstr>>12)&0xF];
+    if (((cpu->CurInstr>>12) & 0xF) == 15) val += 4;
 
     if (cpu->Num==0 && cp==15)
     {
-        ((ARMv5*)cpu)->CP15Write((cn<<8)|(cm<<4)|cpinfo, cpu->R[(cpu->CurInstr>>12)&0xF]);
+        ((ARMv5*)cpu)->CP15Write((cn<<8)|(cm<<4)|cpinfo, val);
     }
     else if (cpu->Num==1 && cp==14)
     {
@@ -244,10 +295,17 @@ void A_MRC(ARM* cpu)
     u32 cn = (cpu->CurInstr >> 16) & 0xF;
     u32 cm = cpu->CurInstr & 0xF;
     u32 cpinfo = (cpu->CurInstr >> 5) & 0x7;
+    u32 rd = (cpu->CurInstr>>12) & 0xF;
 
     if (cpu->Num==0 && cp==15)
     {
-        cpu->R[(cpu->CurInstr>>12)&0xF] = ((ARMv5*)cpu)->CP15Read((cn<<8)|(cm<<4)|cpinfo);
+        if (rd != 15) cpu->R[rd] = ((ARMv5*)cpu)->CP15Read((cn<<8)|(cm<<4)|cpinfo);
+        else
+        {
+            // r15 updates the top 4 bits of the cpsr, done to "allow for conditional branching based on coprocessor status"
+            u32 flags = ((ARMv5*)cpu)->CP15Read((cn<<8)|(cm<<4)|cpinfo) & 0xF0000000;
+            cpu->CPSR = (cpu->CPSR & ~0xF0000000) | flags;
+        }
     }
     else if (cpu->Num==1 && cp==14)
     {
@@ -259,12 +317,13 @@ void A_MRC(ARM* cpu)
         return A_UNK(cpu); // TODO: check what kind of exception it really is
     }
 
-    cpu->AddCycles_CI(2 + 1); // TODO: checkme
+    if (cpu->Num != 1) cpu->AddCycles_CI(1); // checkme
+    else cpu->AddCycles_CI(2 + 1); // TODO: checkme
 }
 
 
 
-void A_SVC(ARM* cpu)
+void A_SVC(ARM* cpu) // A_SWI
 {
     u32 oldcpsr = cpu->CPSR;
     cpu->CPSR &= ~0xBF;
@@ -276,7 +335,7 @@ void A_SVC(ARM* cpu)
     cpu->JumpTo(cpu->ExceptionBase + 0x08);
 }
 
-void T_SVC(ARM* cpu)
+void T_SVC(ARM* cpu) // T_SWI
 {
     u32 oldcpsr = cpu->CPSR;
     cpu->CPSR &= ~0xBF;

src/ARMInterpreter.h

@@ -36,6 +36,7 @@ void A_MRS(ARM* cpu);
 void A_MCR(ARM* cpu);
 void A_MRC(ARM* cpu);
 void A_SVC(ARM* cpu);
+void A_BKPT(ARM* cpu);
 
 void T_SVC(ARM* cpu);
 

src/ARMInterpreter_ALU.cpp

@@ -19,6 +19,7 @@
 #include <stdio.h>
 #include "ARM.h"
 #include "NDS.h"
+#include "ARMInterpreter_MultiplySuperLLE.h"
 
 namespace melonDS::ARMInterpreter
 {
@@ -581,8 +582,27 @@ A_IMPLEMENT_ALU_OP(RSC,)
 #define A_TST(c) \
     u32 a = cpu->R[(cpu->CurInstr>>16) & 0xF]; \
     u32 res = a & b; \
-    cpu->SetNZ(res & 0x80000000, \
-               !res); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) [[unlikely]] /* this seems to trigger alu rd==15 behavior for arm7 and legacy instruction behavior for arm9 */ \
+    { \
+        if (cpu->Num == 1) \
+        { \
+            cpu->SetNZ(res & 0x80000000, \
+                       !res); \
+            u32 oldpsr = cpu->CPSR; \
+            cpu->RestoreCPSR(); /* ARM7TDMI restores cpsr and does ___not___ flush the pipeline. */ \
+            if (cpu->CPSR & 0x20) \
+            { \
+                Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: TST T bit change on ARM7\n"); \
+                cpu->CPSR &= ~0x20; /* keep it from crashing the emulator at least */ \
+            } \
+        } \
+        else cpu->JumpTo(res & ~1, true); /* TSTP dna, doesn't update flags */ \
+    } \
+    else \
+    { \
+        cpu->SetNZ(res & 0x80000000, \
+                   !res); \
+    } \
     if (c) cpu->AddCycles_CI(c); else cpu->AddCycles_C();
 
 A_IMPLEMENT_ALU_TEST(TST,_S)
@@ -591,8 +611,27 @@ A_IMPLEMENT_ALU_TEST(TST,_S)
 #define A_TEQ(c) \
     u32 a = cpu->R[(cpu->CurInstr>>16) & 0xF]; \
     u32 res = a ^ b; \
-    cpu->SetNZ(res & 0x80000000, \
-               !res); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) [[unlikely]] /* this seems to trigger alu rd==15 behavior for arm7 and legacy instruction behavior for arm9 */ \
+    { \
+        if (cpu->Num == 1) \
+        { \
+            cpu->SetNZ(res & 0x80000000, \
+                       !res); \
+            u32 oldpsr = cpu->CPSR; \
+            cpu->RestoreCPSR(); /* ARM7TDMI restores cpsr and does ___not___ flush the pipeline. */ \
+            if (cpu->CPSR & 0x20) \
+            { \
+                Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: TEQ T bit change on ARM7\n"); \
+                cpu->CPSR &= ~0x20; /* keep it from crashing the emulator at least */ \
+            } \
+        } \
+        else cpu->JumpTo(res & ~1, true); /* TEQP dna, doesn't update flags */ \
+    } \
+    else \
+    { \
+        cpu->SetNZ(res & 0x80000000, \
+                   !res); \
+    } \
     if (c) cpu->AddCycles_CI(c); else cpu->AddCycles_C();
 
 A_IMPLEMENT_ALU_TEST(TEQ,_S)
@@ -601,10 +640,31 @@ A_IMPLEMENT_ALU_TEST(TEQ,_S)
 #define A_CMP(c) \
     u32 a = cpu->R[(cpu->CurInstr>>16) & 0xF]; \
     u32 res = a - b; \
-    cpu->SetNZCV(res & 0x80000000, \
-                 !res, \
-                 CarrySub(a, b), \
-                 OverflowSub(a, b)); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) [[unlikely]] /* this seems to trigger alu rd==15 behavior for arm7 and legacy instruction behavior for arm9 */ \
+    { \
+        if (cpu->Num == 1) \
+        { \
+            cpu->SetNZCV(res & 0x80000000, \
+                         !res, \
+                         CarrySub(a, b), \
+                         OverflowSub(a, b)); \
+            u32 oldpsr = cpu->CPSR; \
+            cpu->RestoreCPSR(); /* ARM7TDMI restores cpsr and does ___not___ flush the pipeline. */ \
+            if (cpu->CPSR & 0x20) \
+            { \
+                Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: CMP T bit change on ARM7\n"); \
+                cpu->CPSR &= ~0x20; /* keep it from crashing the emulator at least */ \
+            } \
+        } \
+        else cpu->JumpTo(res & ~1, true); /* CMPP dna, doesn't update flags */ \
+    } \
+    else \
+    { \
+        cpu->SetNZCV(res & 0x80000000, \
+                     !res, \
+                     CarrySub(a, b), \
+                     OverflowSub(a, b)); \
+    } \
     if (c) cpu->AddCycles_CI(c); else cpu->AddCycles_C();
 
 A_IMPLEMENT_ALU_TEST(CMP,)
@@ -613,10 +673,31 @@ A_IMPLEMENT_ALU_TEST(CMP,)
 #define A_CMN(c) \
     u32 a = cpu->R[(cpu->CurInstr>>16) & 0xF]; \
     u32 res = a + b; \
-    cpu->SetNZCV(res & 0x80000000, \
-                 !res, \
-                 CarryAdd(a, b), \
-                 OverflowAdd(a, b)); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) [[unlikely]] /* this seems to trigger alu rd==15 behavior for arm7 and legacy instruction behavior for arm9 */ \
+    { \
+        if (cpu->Num == 1) \
+        { \
+            cpu->SetNZCV(res & 0x80000000, \
+                         !res, \
+                         CarryAdd(a, b), \
+                         OverflowAdd(a, b)); \
+            u32 oldpsr = cpu->CPSR; \
+            cpu->RestoreCPSR(); /* ARM7TDMI restores cpsr and does ___not___ flush the pipeline. */ \
+            if (cpu->CPSR & 0x20) \
+            { \
+                Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: CMN T bit change on ARM7\n"); \
+                cpu->CPSR &= ~0x20; /* keep it from crashing the emulator at least */ \
+            } \
+        } \
+        else cpu->JumpTo(res & ~1, true); /* CMNP dna, doesn't update flags */ \
+    } \
+    else \
+    { \
+        cpu->SetNZCV(res & 0x80000000, \
+                     !res, \
+                     CarryAdd(a, b), \
+                     OverflowAdd(a, b)); \
+    } \
     if (c) cpu->AddCycles_CI(c); else cpu->AddCycles_C();
 
 A_IMPLEMENT_ALU_TEST(CMN,)
@@ -766,12 +847,14 @@ void A_MUL(ARM* cpu)
 
     u32 res = rm * rs;
 
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
+    // all multiply instructions fail writes to r15 on arm7/9
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
+
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ(res & 0x80000000,
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
@@ -783,6 +866,7 @@ void A_MUL(ARM* cpu)
         else if ((rs & 0xFFFF0000) == 0x00000000 || (rs & 0xFFFF0000) == 0xFFFF0000) cycles = 2;
         else if ((rs & 0xFF000000) == 0x00000000 || (rs & 0xFF000000) == 0xFF000000) cycles = 3;
         else cycles = 4;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(MULSCarry(rm, rs, 0, cycles==4));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -795,13 +879,14 @@ void A_MLA(ARM* cpu)
     u32 rn = cpu->R[(cpu->CurInstr >> 12) & 0xF];
 
     u32 res = (rm * rs) + rn;
+    
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
 
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ(res & 0x80000000,
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
@@ -813,6 +898,7 @@ void A_MLA(ARM* cpu)
         else if ((rs & 0xFFFF0000) == 0x00000000 || (rs & 0xFFFF0000) == 0xFFFF0000) cycles = 3;
         else if ((rs & 0xFF000000) == 0x00000000 || (rs & 0xFF000000) == 0xFF000000) cycles = 4;
         else cycles = 5;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(MULSCarry(rm, rs, rn, cycles==5));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -825,24 +911,27 @@ void A_UMULL(ARM* cpu)
 
     u64 res = (u64)rm * (u64)rs;
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
+
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ((u32)(res >> 63ULL),
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
     if (cpu->Num == 0)
-        cycles = (cpu->CurInstr & (1<<20)) ? 3 : 1;
+        cycles = (cpu->CurInstr & (1<<20)) ? 4 : 2;
     else
     {
         if      ((rs & 0xFFFFFF00) == 0x00000000) cycles = 2;
         else if ((rs & 0xFFFF0000) == 0x00000000) cycles = 3;
         else if ((rs & 0xFF000000) == 0x00000000) cycles = 4;
         else cycles = 5;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(UMULLSCarry(0, rm, rs, cycles==5));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -857,25 +946,28 @@ void A_UMLAL(ARM* cpu)
 
     u64 rd = (u64)cpu->R[(cpu->CurInstr >> 12) & 0xF] | ((u64)cpu->R[(cpu->CurInstr >> 16) & 0xF] << 32ULL);
     res += rd;
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ((u32)(res >> 63ULL),
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
     if (cpu->Num == 0)
-        cycles = (cpu->CurInstr & (1<<20)) ? 3 : 1;
+        cycles = (cpu->CurInstr & (1<<20)) ? 4 : 2;
     else
     {
         if      ((rs & 0xFFFFFF00) == 0x00000000) cycles = 2;
         else if ((rs & 0xFFFF0000) == 0x00000000) cycles = 3;
         else if ((rs & 0xFF000000) == 0x00000000) cycles = 4;
         else cycles = 5;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(UMULLSCarry(rd, rm, rs, cycles==5));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -887,25 +979,28 @@ void A_SMULL(ARM* cpu)
     u32 rs = cpu->R[(cpu->CurInstr >> 8) & 0xF];
 
     s64 res = (s64)(s32)rm * (s64)(s32)rs;
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ((u32)(res >> 63ULL),
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
     if (cpu->Num == 0)
-        cycles = (cpu->CurInstr & (1<<20)) ? 3 : 1;
+        cycles = (cpu->CurInstr & (1<<20)) ? 4 : 2;
     else
     {
         if      ((rs & 0xFFFFFF00) == 0x00000000 || (rs & 0xFFFFFF00) == 0xFFFFFF00) cycles = 2;
         else if ((rs & 0xFFFF0000) == 0x00000000 || (rs & 0xFFFF0000) == 0xFFFF0000) cycles = 3;
         else if ((rs & 0xFF000000) == 0x00000000 || (rs & 0xFF000000) == 0xFF000000) cycles = 4;
         else cycles = 5;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(SMULLSCarry(0, rm, rs, cycles==5));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -920,25 +1015,28 @@ void A_SMLAL(ARM* cpu)
 
     s64 rd = (s64)((u64)cpu->R[(cpu->CurInstr >> 12) & 0xF] | ((u64)cpu->R[(cpu->CurInstr >> 16) & 0xF] << 32ULL));
     res += rd;
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
     if (cpu->CurInstr & (1<<20))
     {
         cpu->SetNZ((u32)(res >> 63ULL),
                    !res);
-        if (cpu->Num==1) cpu->SetC(0);
     }
 
     u32 cycles;
     if (cpu->Num == 0)
-        cycles = (cpu->CurInstr & (1<<20)) ? 3 : 1;
+        cycles = (cpu->CurInstr & (1<<20)) ? 4 : 2;
     else
     {
         if      ((rs & 0xFFFFFF00) == 0x00000000 || (rs & 0xFFFFFF00) == 0xFFFFFF00) cycles = 2;
         else if ((rs & 0xFFFF0000) == 0x00000000 || (rs & 0xFFFF0000) == 0xFFFF0000) cycles = 3;
         else if ((rs & 0xFF000000) == 0x00000000 || (rs & 0xFF000000) == 0xFF000000) cycles = 4;
         else cycles = 5;
+        if (cpu->CurInstr & (1<<20)) cpu->SetC(SMULLSCarry(rd, rm, rs, cycles==5));
     }
 
     cpu->AddCycles_CI(cycles);
@@ -959,8 +1057,10 @@ void A_SMLAxy(ARM* cpu)
 
     u32 res_mul = ((s16)rm * (s16)rs);
     u32 res = res_mul + rn;
+    
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
 
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
     if (OverflowAdd(res_mul, rn))
         cpu->CPSR |= 0x08000000;
 
@@ -980,8 +1080,9 @@ void A_SMLAWy(ARM* cpu)
 
     u32 res_mul = ((s64)(s32)rm * (s16)rs) >> 16;
     u32 res = res_mul + rn;
-
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
+    
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
     if (OverflowAdd(res_mul, rn))
         cpu->CPSR |= 0x08000000;
 
@@ -1001,8 +1102,9 @@ void A_SMULxy(ARM* cpu)
     else                        rs &= 0xFFFF;
 
     u32 res = ((s16)rm * (s16)rs);
-
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
+    
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1017,8 +1119,9 @@ void A_SMULWy(ARM* cpu)
     else                        rs &= 0xFFFF;
 
     u32 res = ((s64)(s32)rm * (s16)rs) >> 16;
-
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
+    
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = res;
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1039,8 +1142,11 @@ void A_SMLALxy(ARM* cpu)
     s64 rd = (s64)((u64)cpu->R[(cpu->CurInstr >> 12) & 0xF] | ((u64)cpu->R[(cpu->CurInstr >> 16) & 0xF] << 32ULL));
     res += rd;
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
-    cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = (u32)res;
+
+    if (((cpu->CurInstr >> 16) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 16) & 0xF] = (u32)(res >> 32ULL);
 
     cpu->AddCycles_CI(1); // TODO: interlock??
 }
@@ -1067,7 +1173,8 @@ void A_CLZ(ARM* cpu)
         val |= 0x1;
     }
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
+    if (((cpu->CurInstr >> 12) & 0xF) == 15) cpu->JumpTo(res & ~1);
+    else cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
     cpu->AddCycles_C();
 }
 
@@ -1085,7 +1192,10 @@ void A_QADD(ARM* cpu)
         cpu->CPSR |= 0x08000000;
     }
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
+    // all saturated math instructions fail writes to r15
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
+
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1102,8 +1212,10 @@ void A_QSUB(ARM* cpu)
         res = (res & 0x80000000) ? 0x7FFFFFFF : 0x80000000;
         cpu->CPSR |= 0x08000000;
     }
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1128,8 +1240,10 @@ void A_QDADD(ARM* cpu)
         res = (res & 0x80000000) ? 0x7FFFFFFF : 0x80000000;
         cpu->CPSR |= 0x08000000;
     }
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1154,8 +1268,10 @@ void A_QDSUB(ARM* cpu)
         res = (res & 0x80000000) ? 0x7FFFFFFF : 0x80000000;
         cpu->CPSR |= 0x08000000;
     }
+    
+    if (((cpu->CurInstr >> 12) & 0xF) != 15)
+        cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
 
-    cpu->R[(cpu->CurInstr >> 12) & 0xF] = res;
     cpu->AddCycles_C(); // TODO: interlock??
 }
 
@@ -1460,18 +1576,18 @@ void T_MUL_REG(ARM* cpu)
     cpu->SetNZ(res & 0x80000000,
                !res);
 
-    s32 cycles = 0;
+    s32 cycles;
     if (cpu->Num == 0)
     {
-        cycles += 3;
+        cycles = 3;
     }
     else
     {
-        cpu->SetC(0); // carry flag destroyed, they say. whatever that means...
-        if      (a & 0xFF000000) cycles += 4;
-        else if (a & 0x00FF0000) cycles += 3;
-        else if (a & 0x0000FF00) cycles += 2;
-        else                     cycles += 1;
+        if      ((a & 0xFFFFFF00) == 0x00000000 || (a & 0xFFFFFF00) == 0xFFFFFF00) cycles = 1;
+        else if ((a & 0xFFFF0000) == 0x00000000 || (a & 0xFFFF0000) == 0xFFFF0000) cycles = 2;
+        else if ((a & 0xFF000000) == 0x00000000 || (a & 0xFF000000) == 0xFF000000) cycles = 3;
+        else cycles = 4;
+        cpu->SetC(MULSCarry(b, a, 0, cycles==4)); // carry flag destroyed, they say. whatever that means...
     }
     cpu->AddCycles_CI(cycles);
 }
@@ -1534,6 +1650,18 @@ void T_CMP_HIREG(ARM* cpu)
                  !res,
                  CarrySub(a, b),
                  OverflowSub(a, b));
+
+    if ((cpu->Num == 1) && (rd == 15))
+    {
+        u32 oldpsr = cpu->CPSR;
+        cpu->RestoreCPSR(); // ARM7TDMI restores cpsr and does ___not___ flush the pipeline.
+        if (!(cpu->CPSR & 0x20))
+        {
+            Platform::Log(Platform::LogLevel::Warn, "UNIMPLEMENTED: MSR REG T bit change on ARM7\n");
+            cpu->CPSR |= 0x20; // keep it from crashing the emulator at least
+        }
+    }
+
     cpu->AddCycles_C();
 }
 

src/ARMInterpreter_Branch.cpp

@@ -104,6 +104,9 @@ void T_BL_LONG_1(ARM* cpu)
 
 void T_BL_LONG_2(ARM* cpu)
 {
+    if ((cpu->CurInstr & 0x1801) == 0x0801) // "BLX" with bit 0 set is an undefined instruction.
+        return T_UNK(cpu); // TODO: Check ARM7 for exceptions
+    
     s32 offset = (cpu->CurInstr & 0x7FF) << 1;
     u32 pc = cpu->R[14] + offset;
     cpu->R[14] = (cpu->R[15] - 2) | 1;

src/ARMInterpreter_MultiplySuperLLE.h

@@ -0,0 +1,136 @@
+#ifndef ARMINTERPRETER_MULTIPLYSUPERLLE_H
+#define ARMINTERPRETER_MULTIPLYSUPERLLE_H
+
+#include "types.h"
+
+using namespace melonDS;
+
+/*
+    Copyright (c) 2024 zaydlang
+
+    This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.
+
+    Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
+
+        1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software.
+           If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+        2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+        3. This notice may not be removed or altered from any source distribution.
+*/
+
+
+
+
+// code taken from: (also features a few alternative implementations that could maybe be worth looking at?)
+// https://github.com/calc84maniac/multiplication-algorithm/blob/master/impl_opt.h
+// based on research that can be found here: https://bmchtech.github.io/post/multiply/
+
+// the code in this file is dedicated to handling the calculation of the carry flag for multiplication (S variant) instructions on the ARM7TDMI.
+
+
+// Takes a multiplier between -0x01000000 and 0x00FFFFFF, cycles between 0 and 2
+static inline bool booths_multiplication32_opt(u32 multiplicand, u32 multiplier, u32 accumulator) {
+    // Set the low bit of the multiplicand to cause negation to invert the upper bits, this bit can't propagate to bit 31
+    multiplicand |= 1;
+
+    // Optimized first iteration
+    u32 booth = (s32)(multiplier << 31) >> 31;
+    u32 carry = booth * multiplicand;
+    // Pre-populate accumulator for output
+    u32 output = accumulator;
+
+    u32 sum = output + carry;
+    int shift = 29;
+    do {
+        for (int i = 0; i < 4; i++, shift -= 2) {
+            // Get next booth factor (-2 to 2, shifted left by 30-shift)
+            u32 next_booth = (s32)(multiplier << shift) >> shift;
+            u32 factor = next_booth - booth;
+            booth = next_booth;
+            // Get scaled value of booth addend
+            u32 addend = multiplicand * factor;
+            // Combine the addend with the CSA
+            // Not performing any masking seems to work because the lower carries can't propagate to bit 31
+            output ^= carry ^ addend;
+            sum += addend;
+            carry = sum - output;
+        }
+    } while (booth != multiplier);
+
+    return carry >> 31;
+}
+
+// Takes a multiplicand shifted right by 6 and a multiplier shifted right by 26 (zero or sign extended)
+static inline bool booths_multiplication64_opt(u32 multiplicand, u32 multiplier, u32 accum_hi) {
+    // Skipping the first 14 iterations seems to work because the lower carries can't propagate to bit 63
+    // This means only magic bits 62-61 are needed (which requires decoding 3 booth chunks),
+    // and only the last two booth iterations are needed
+
+    // Set the low bit of the multiplicand to cause negation to invert the upper bits
+    multiplicand |= 1;
+
+    // Pre-populate magic bit 61 for carry
+    u32 carry = ~accum_hi & UINT32_C(0x20000000);
+    // Pre-populate magic bits 63-60 for output (with carry magic pre-added in)
+    u32 output = accum_hi - UINT32_C(0x08000000);
+
+    // Get factors from the top 3 booth chunks
+    u32 booth0 = (s32)(multiplier << 27) >> 27;
+    u32 booth1 = (s32)(multiplier << 29) >> 29;
+    u32 booth2 = (s32)(multiplier << 31) >> 31;
+    u32 factor0 = multiplier - booth0;
+    u32 factor1 = booth0 - booth1;
+    u32 factor2 = booth1 - booth2;
+
+    // Get scaled value of the 3rd top booth addend
+    u32 addend = multiplicand * factor2;
+    // Finalize bits 61-60 of output magic using its sign
+    output -= addend & UINT32_C(0x10000000);
+    // Get scaled value of the 2nd top booth addend
+    addend = multiplicand * factor1;
+    // Finalize bits 63-62 of output magic using its sign
+    output -= addend & UINT32_C(0x40000000);
+
+    // Get the carry from the CSA in bit 61 and propagate it to bit 62, which is not processed in this iteration
+    u32 sum = output + (addend & UINT32_C(0x20000000));
+    // Subtract out the carry magic to get the actual output magic
+    output -= carry;
+
+    // Get scaled value of the 1st top booth addend
+    addend = multiplicand * factor0;
+    // Add to bit 62 and propagate the carry
+    sum += addend & UINT32_C(0x40000000);
+
+    // Cancel out the output magic bit 63 to get the carry bit 63
+    return (sum ^ output) >> 31;
+}
+
+
+// also for MLAS and MUL (thumb ver.)
+inline bool MULSCarry(s32 rm, s32 rs, u32 rn, bool lastcycle)
+{
+    if (lastcycle)
+        return (rs >> 30) == -2;
+    else
+        return booths_multiplication32_opt(rm, rs, rn);
+}
+
+// also for UMLALS
+inline bool UMULLSCarry(u64 rd, u32 rm, u32 rs, bool lastcycle)
+{
+    if (lastcycle)
+        return booths_multiplication64_opt(rm >> 6, rs >> 26, rd >> 32);
+    else
+        return booths_multiplication32_opt(rm, rs, rd & 0xFFFFFFFF);
+}
+
+// also for SMLALS
+inline bool SMULLSCarry(u64 rd, s32 rm, s32 rs, bool lastcycle)
+{
+    if (lastcycle)
+        return booths_multiplication64_opt(rm >> 6, rs >> 26, rd >> 32);
+    else
+        return booths_multiplication32_opt(rm, rs, rd & 0xFFFFFFFF);
+}
+
+#endif

src/ARMJIT.cpp

@@ -588,7 +588,7 @@ void ARMJIT::CompileBlock(ARM* cpu) noexcept
     u32 numWriteAddrs = 0, writeAddrsTranslated = 0;
 
     cpu->FillPipeline();
-    u32 nextInstr[2] = {cpu->NextInstr[0], cpu->NextInstr[1]};
+    u32 nextInstr[2] = {(u32)cpu->NextInstr[0], (u32)cpu->NextInstr[1]};
     u32 nextInstrAddr[2] = {blockAddr, r15};
 
     JIT_DEBUGPRINT("start block %x %08x (%x)\n", blockAddr, cpu->CPSR, localAddr);

src/ARM_InstrInfo.cpp

@@ -194,6 +194,7 @@ const u32 A_BX = A_BranchAlways | A_Read0 | ak(ak_BX);
 const u32 A_BLX_REG = A_BranchAlways | A_Link | A_Read0 | ak(ak_BLX_REG);
 
 const u32 A_UNK = A_BranchAlways | A_Link | ak(ak_UNK);
+const u32 A_BKPT = A_BranchAlways | A_Link | ak(ak_UNK);
 const u32 A_MSR_IMM = ak(ak_MSR_IMM);
 const u32 A_MSR_REG = A_Read0 | ak(ak_MSR_REG);
 const u32 A_MRS = A_Write12 | ak(ak_MRS);

src/ARM_InstrTable.h

@@ -130,7 +130,7 @@ INSTRFUNC_PROTO(ARMInstrTable[4096]) =
 
     // 0001 0010 0000
     A_MSR_REG, A_BX, A_UNK, A_BLX_REG,
-    A_UNK, A_QSUB, A_UNK, A_UNK,
+    A_UNK, A_QSUB, A_UNK, A_BKPT,
     A_SMLAWy, A_UNK, A_SMULWy, A_STRH_REG,
     A_SMLAWy, A_LDRD_REG, A_SMULWy, A_STRD_REG,
 

src/CP15.cpp

@@ -266,8 +266,6 @@ void ARMv5::UpdatePURegions(bool update_all)
         // PU disabled
 
         u8 mask = 0x07;
-        if (CP15Control & (1<<2))  mask |= 0x30;
-        if (CP15Control & (1<<12)) mask |= 0x40;
 
         memset(PU_UserMap, mask, 0x100000);
         memset(PU_PrivMap, mask, 0x100000);
@@ -579,7 +577,7 @@ void ARMv5::CP15Write(u32 id, u32 val)
     case 0x670:
     case 0x671:
         char log_output[1024];
-        PU_Region[(id >> 4) & 0xF] = val;
+        PU_Region[(id >> 4) & 0xF] = val & ~(0x3F<<6);
 
         std::snprintf(log_output,
                  sizeof(log_output),
@@ -773,16 +771,15 @@ u32 ARMv5::CP15Read(u32 id) const
 // TCM are handled here.
 // TODO: later on, handle PU, and maybe caches
 
-u32 ARMv5::CodeRead32(u32 addr, bool branch)
+u64 ARMv5::CodeRead32(u32 addr, bool branch)
 {
-    /*if (branch || (!(addr & 0xFFF)))
+    // prefetch abort
+    // the actual exception is not raised until the aborted instruction is executed
+    if (!(PU_Map[addr>>12] & 0x04)) [[unlikely]]
     {
-        if (!(PU_Map[addr>>12] & 0x04))
-        {
-            PrefetchAbort();
-            return 0;
-        }
-    }*/
+        CodeCycles = 1;
+        return ((u64)1<<63);
+    }
 
     if (addr < ITCMSize)
     {
@@ -807,150 +804,163 @@ u32 ARMv5::CodeRead32(u32 addr, bool branch)
 }
 
 
-void ARMv5::DataRead8(u32 addr, u32* val)
+bool ARMv5::DataRead8(u32 addr, u32* val)
 {
-    if (!(PU_Map[addr>>12] & 0x01))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x01)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     if (addr < ITCMSize)
     {
         DataCycles = 1;
         *val = *(u8*)&ITCM[addr & (ITCMPhysicalSize - 1)];
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *val = *(u8*)&DTCM[addr & (DTCMPhysicalSize - 1)];
-        return;
+        return true;
     }
-
+    
     *val = BusRead8(addr);
     DataCycles = MemTimings[addr >> 12][1];
+    return true;
 }
 
-void ARMv5::DataRead16(u32 addr, u32* val)
+bool ARMv5::DataRead16(u32 addr, u32* val)
 {
-    if (!(PU_Map[addr>>12] & 0x01))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x01)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     addr &= ~1;
 
     if (addr < ITCMSize)
     {
         DataCycles = 1;
         *val = *(u16*)&ITCM[addr & (ITCMPhysicalSize - 1)];
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *val = *(u16*)&DTCM[addr & (DTCMPhysicalSize - 1)];
-        return;
+        return true;
     }
-
+    
     *val = BusRead16(addr);
     DataCycles = MemTimings[addr >> 12][1];
+    return true;
 }
 
-void ARMv5::DataRead32(u32 addr, u32* val)
+bool ARMv5::DataRead32(u32 addr, u32* val)
 {
-    if (!(PU_Map[addr>>12] & 0x01))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x01)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     addr &= ~3;
 
     if (addr < ITCMSize)
     {
         DataCycles = 1;
         *val = *(u32*)&ITCM[addr & (ITCMPhysicalSize - 1)];
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *val = *(u32*)&DTCM[addr & (DTCMPhysicalSize - 1)];
-        return;
+        return true;
     }
 
     *val = BusRead32(addr);
     DataCycles = MemTimings[addr >> 12][2];
+    return true;
 }
 
-void ARMv5::DataRead32S(u32 addr, u32* val)
+bool ARMv5::DataRead32S(u32 addr, u32* val)
 {
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x01)) [[unlikely]]
+    {
+        DataCycles += 1;
+        return false;
+    }
+
     addr &= ~3;
 
     if (addr < ITCMSize)
     {
         DataCycles += 1;
         *val = *(u32*)&ITCM[addr & (ITCMPhysicalSize - 1)];
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles += 1;
         *val = *(u32*)&DTCM[addr & (DTCMPhysicalSize - 1)];
-        return;
+        return true;
     }
 
     *val = BusRead32(addr);
     DataCycles += MemTimings[addr >> 12][3];
+    return true;
 }
 
-void ARMv5::DataWrite8(u32 addr, u8 val)
+bool ARMv5::DataWrite8(u32 addr, u8 val)
 {
-    if (!(PU_Map[addr>>12] & 0x02))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x02)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     if (addr < ITCMSize)
     {
         DataCycles = 1;
         *(u8*)&ITCM[addr & (ITCMPhysicalSize - 1)] = val;
         NDS.JIT.CheckAndInvalidate<0, ARMJIT_Memory::memregion_ITCM>(addr);
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *(u8*)&DTCM[addr & (DTCMPhysicalSize - 1)] = val;
-        return;
+        return true;
     }
 
     BusWrite8(addr, val);
     DataCycles = MemTimings[addr >> 12][1];
+    return true;
 }
 
-void ARMv5::DataWrite16(u32 addr, u16 val)
+bool ARMv5::DataWrite16(u32 addr, u16 val)
 {
-    if (!(PU_Map[addr>>12] & 0x02))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x02)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     addr &= ~1;
 
     if (addr < ITCMSize)
@@ -958,29 +968,30 @@ void ARMv5::DataWrite16(u32 addr, u16 val)
         DataCycles = 1;
         *(u16*)&ITCM[addr & (ITCMPhysicalSize - 1)] = val;
         NDS.JIT.CheckAndInvalidate<0, ARMJIT_Memory::memregion_ITCM>(addr);
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *(u16*)&DTCM[addr & (DTCMPhysicalSize - 1)] = val;
-        return;
+        return true;
     }
 
     BusWrite16(addr, val);
     DataCycles = MemTimings[addr >> 12][1];
+    return true;
 }
 
-void ARMv5::DataWrite32(u32 addr, u32 val)
+bool ARMv5::DataWrite32(u32 addr, u32 val)
 {
-    if (!(PU_Map[addr>>12] & 0x02))
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x02)) [[unlikely]]
     {
-        DataAbort();
-        return;
+        DataCycles = 1;
+        return false;
     }
 
-    DataRegion = addr;
-
     addr &= ~3;
 
     if (addr < ITCMSize)
@@ -988,21 +999,30 @@ void ARMv5::DataWrite32(u32 addr, u32 val)
         DataCycles = 1;
         *(u32*)&ITCM[addr & (ITCMPhysicalSize - 1)] = val;
         NDS.JIT.CheckAndInvalidate<0, ARMJIT_Memory::memregion_ITCM>(addr);
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles = 1;
         *(u32*)&DTCM[addr & (DTCMPhysicalSize - 1)] = val;
-        return;
+        return true;
     }
 
     BusWrite32(addr, val);
     DataCycles = MemTimings[addr >> 12][2];
+    return true;
 }
 
-void ARMv5::DataWrite32S(u32 addr, u32 val)
+bool ARMv5::DataWrite32S(u32 addr, u32 val)
 {
+    // Data Aborts
+    // Exception is handled in the actual instruction implementation
+    if (!(PU_Map[addr>>12] & 0x02)) [[unlikely]]
+    {
+        DataCycles += 1;
+        return false;
+    }
+
     addr &= ~3;
 
     if (addr < ITCMSize)
@@ -1012,17 +1032,18 @@ void ARMv5::DataWrite32S(u32 addr, u32 val)
 #ifdef JIT_ENABLED
         NDS.JIT.CheckAndInvalidate<0, ARMJIT_Memory::memregion_ITCM>(addr);
 #endif
-        return;
+        return true;
     }
     if ((addr & DTCMMask) == DTCMBase)
     {
         DataCycles += 1;
         *(u32*)&DTCM[addr & (DTCMPhysicalSize - 1)] = val;
-        return;
+        return true;
     }
 
     BusWrite32(addr, val);
     DataCycles += MemTimings[addr >> 12][3];
+    return true;
 }
 
 void ARMv5::GetCodeMemRegion(u32 addr, MemRegion* region)

src/DSi.cpp

@@ -162,6 +162,7 @@ void DSi::Reset()
     SCFG_Clock9 = 0x0187; // CHECKME
     SCFG_Clock7 = 0x0187;
     SCFG_EXT[0] = 0x8307F100;
+    SetVRAMTimings(true);
     SCFG_EXT[1] = 0x93FFFB06;
     SCFG_MC = 0x0010 | (~((u32)(NDSCartSlot.GetCart() != nullptr))&1);//0x0011;
     SCFG_RST = 0;
@@ -235,6 +236,7 @@ void DSi::DoSavestateExtra(Savestate* file)
         Set_SCFG_Clock9(SCFG_Clock9);
         Set_SCFG_MC(SCFG_MC);
         DSP.SetRstLine(SCFG_RST & 0x0001);
+        SetVRAMTimings(SCFG_EXT[0] & (1<<13));
 
         MBK[0][8] = 0;
         MBK[1][8] = 0;
@@ -713,6 +715,7 @@ void DSi::SoftReset()
     SCFG_Clock9 = 0x0187; // CHECKME
     SCFG_Clock7 = 0x0187;
     SCFG_EXT[0] = 0x8307F100;
+    SetVRAMTimings(true);
     SCFG_EXT[1] = 0x93FFFB06;
     SCFG_MC = 0x0010;//0x0011;
     // TODO: is this actually reset?
@@ -1303,6 +1306,14 @@ void DSi::Set_SCFG_MC(u32 val)
     }
 }
 
+void DSi::SetVRAMTimings(bool extrabuswidth)
+{
+    if (extrabuswidth)
+        SetARM9RegionTimings(0x06000, 0x07000, Mem9_VRAM, 32, 1, 1); // dsi vram
+    else
+        SetARM9RegionTimings(0x06000, 0x07000, Mem9_VRAM, 16, 1, 1); // ds vram
+}
+
 
 u8 DSi::ARM9Read8(u32 addr)
 {
@@ -2541,11 +2552,18 @@ void DSi::ARM9IOWrite32(u32 addr, u32 val)
             u32 oldram = (SCFG_EXT[0] >> 14) & 0x3;
             u32 newram = (val >> 14) & 0x3;
 
+            u32 oldvram = (SCFG_EXT[0] & (1<<13));
+            u32 newvram = (val & (1<<13));
+
             SCFG_EXT[0] &= ~0x8007F19F;
             SCFG_EXT[0] |= (val & 0x8007F19F);
             SCFG_EXT[1] &= ~0x0000F080;
             SCFG_EXT[1] |= (val & 0x0000F080);
             Log(LogLevel::Debug, "SCFG_EXT = %08X / %08X (val9 %08X)\n", SCFG_EXT[0], SCFG_EXT[1], val);
+
+            if (oldvram != newvram)
+                SetVRAMTimings(newvram);
+
             /*switch ((SCFG_EXT[0] >> 14) & 0x3)
             {
             case 0:

src/DSi.h

@@ -96,6 +96,7 @@ public:
     void MapNWRAM_B(u32 num, u8 val);
     void MapNWRAM_C(u32 num, u8 val);
     void MapNWRAMRange(u32 cpu, u32 num, u32 val);
+    void SetVRAMTimings(bool extrabuswidth);
 
     u8 ARM9Read8(u32 addr) override;
     u16 ARM9Read16(u32 addr) override;