imma be real, i have no idea what is going on here

src/ARM.cpp

@@ -177,6 +177,8 @@ void ARM::Reset()
 
     ExceptionBase = Num ? 0x00000000 : 0xFFFF0000;
 
+    BuggyJump = 0;
+
     CodeMem.Mem = NULL;
 
 #ifdef JIT_ENABLED
@@ -284,6 +286,32 @@ void ARM::SetupCodeMem(u32 addr)
     }
 }
 
+void ARMv5::BuggedJumpTo32(const u32 addr)
+{
+    if (BuggyJump == 1)
+    {
+        BuggyJump = 2;
+        JumpTo(addr);
+    }
+    else
+    {
+        JumpTo(addr & ~0x1);
+    }
+}
+
+void ARMv5::BuggedJumpTo(const u32 addr)
+{
+    if ((BuggyJump == 0) && (addr & 0x3))
+    {
+        BuggyJump = 1;
+        PrefetchAbort(); // checkme
+    }
+    else
+    {
+        JumpTo(addr);
+    }
+}
+
 void ARMv5::JumpTo(u32 addr, bool restorecpsr)
 {
     if (restorecpsr)
@@ -352,6 +380,16 @@ void ARMv5::JumpTo(u32 addr, bool restorecpsr)
     NDS.MonitorARM9Jump(addr);
 }
 
+void ARMv4::BuggedJumpTo32(const u32 addr)
+{
+    JumpTo(addr); // todo
+}
+
+void ARMv4::BuggedJumpTo(const u32 addr)
+{
+    JumpTo(addr); // todo
+}
+
 void ARMv4::JumpTo(u32 addr, bool restorecpsr)
 {
     if (restorecpsr)

src/ARM.h

@@ -64,7 +64,9 @@ public:
     virtual void DoSavestate(Savestate* file);
 
     virtual void FillPipeline() = 0;
-
+    
+    virtual void BuggedJumpTo32(const u32 addr) = 0;
+    virtual void BuggedJumpTo(const u32 addr) = 0;
     virtual void JumpTo(u32 addr, bool restorecpsr = false) = 0;
     void RestoreCPSR();
 
@@ -173,6 +175,7 @@ public:
     u32 R_UND[3];
     u32 CurInstr;
     u32 NextInstr[2];
+    u32 BuggyJump;
 
     u32 ExceptionBase;
 
@@ -235,7 +238,9 @@ public:
     void UpdateRegionTimings(u32 addrstart, u32 addrend);
 
     void FillPipeline() override;
-
+    
+    void BuggedJumpTo32(const u32 addr) override;
+    void BuggedJumpTo(const u32 addr) override;
     void JumpTo(u32 addr, bool restorecpsr = false) override;
 
     void PrefetchAbort();
@@ -380,7 +385,9 @@ public:
     ARMv4(melonDS::NDS& nds, std::optional<GDBArgs> gdb, bool jit);
 
     void FillPipeline() override;
-
+    
+    void BuggedJumpTo32(const u32 addr) override;
+    void BuggedJumpTo(const u32 addr) override;
     void JumpTo(u32 addr, bool restorecpsr = false) override;
 
     void Execute() override;

src/ARMInterpreter_LoadStore.cpp

@@ -141,8 +141,8 @@ namespace melonDS::ARMInterpreter
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     if (cpu->CurInstr & (1<<21)) cpu->R[(cpu->CurInstr>>16) & 0xF] = offset; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->JumpTo(val); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
-    else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
+    else cpu->R[(cpu->CurInstr>>12) & 0xF] = val;
 
 // TODO: user mode (note: ldrbt w/ rd = 15 may be an undef instr)
 #define A_LDRB_POST \
@@ -151,8 +151,8 @@ namespace melonDS::ARMInterpreter
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     cpu->R[(cpu->CurInstr>>16) & 0xF] += offset; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->JumpTo(val); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
-    else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
+    else cpu->R[(cpu->CurInstr>>12) & 0xF] = val;
 
 
 
@@ -262,7 +262,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     if (r&1) { A_UNK(cpu); return; } /* checkme */ \
     if (!cpu->DataRead32 (offset  , &cpu->R[r  ])) {cpu->AddCycles_CDI(); return;} \
     u32 val; if (!cpu->DataRead32S(offset+4, &val)) {cpu->AddCycles_CDI(); return;} \
-    if (r == 14) A_UNK(cpu); /* checkme */ \
+    if (r == 14) cpu->BuggedJumpTo32(val); \
     else cpu->R[r+1] = val; \
     cpu->AddCycles_CDI(); \
     if (cpu->CurInstr & (1<<21)) cpu->R[(cpu->CurInstr>>16) & 0xF] = offset;
@@ -274,7 +274,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     if (r&1) { A_UNK(cpu); return; } /* checkme */ \
     if (!cpu->DataRead32 (addr  , &cpu->R[r  ])) {cpu->AddCycles_CDI(); return;} \
     u32 val; if (!cpu->DataRead32S(addr+4, &val)) {cpu->AddCycles_CDI(); return;} \
-    if (r == 14) A_UNK(cpu); /* checkme */ \
+    if (r == 14) cpu->BuggedJumpTo32(val); \
     else cpu->R[r+1] = val; \
     cpu->AddCycles_CDI(); \
     cpu->R[(cpu->CurInstr>>16) & 0xF] += offset;
@@ -308,7 +308,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     u32 val; bool dataabort = !cpu->DataRead16(offset, &val); \
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->JumpTo(val); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     if (cpu->CurInstr & (1<<21)) cpu->R[(cpu->CurInstr>>16) & 0xF] = offset;
 
@@ -317,7 +317,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     u32 val; bool dataabort = !cpu->DataRead16(addr, &val); \
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->JumpTo(val); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     cpu->R[(cpu->CurInstr>>16) & 0xF] += offset;
 
@@ -327,7 +327,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     val = (s32)(s8)val; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) A_UNK(cpu); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     if (cpu->CurInstr & (1<<21)) cpu->R[(cpu->CurInstr>>16) & 0xF] = offset;
 
@@ -337,7 +337,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     val = (s32)(s8)val; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) A_UNK(cpu); \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     cpu->R[(cpu->CurInstr>>16) & 0xF] += offset;
 
@@ -347,7 +347,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     val = (s32)(s16)val; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) A_UNK(cpu); /* checkme */ \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     if (cpu->CurInstr & (1<<21)) cpu->R[(cpu->CurInstr>>16) & 0xF] = offset;
 
@@ -357,7 +357,7 @@ A_IMPLEMENT_WB_LDRSTR(LDRB)
     cpu->AddCycles_CDI(); \
     if (dataabort) return; \
     val = (s32)(s16)val; \
-    if (((cpu->CurInstr>>12) & 0xF) == 15) A_UNK(cpu); /* checkme */ \
+    if (((cpu->CurInstr>>12) & 0xF) == 15) cpu->BuggedJumpTo(val); \
     else cpu->R[(cpu->CurInstr>>12) & 0xF] = val; \
     cpu->R[(cpu->CurInstr>>16) & 0xF] += offset;