From 0294bcb5f225846ca5b94ad023bb0f7598aba195 Mon Sep 17 00:00:00 2001
From: Arisotura <thetotalworm@gmail.com>
Date: Sun, 10 Apr 2022 14:54:40 +0200
Subject: [PATCH] add support for the mainRAM mirror at 0x0C000000 in DSi mode,
 makes SM64DSi work correctly

---
 src/ARMJIT_Memory.cpp |  6 +++-
 src/DSi.cpp           | 75 +++++++++++++++++++++++++++++++++++++++----
 2 files changed, 74 insertions(+), 7 deletions(-)

diff --git a/src/ARMJIT_Memory.cpp b/src/ARMJIT_Memory.cpp
index dbad9a7..d8a8c18 100644
--- a/src/ARMJIT_Memory.cpp
+++ b/src/ARMJIT_Memory.cpp
@@ -1107,6 +1107,8 @@ int ClassifyAddress9(u32 addr)
             return memregion_IO9;
         case 0x06000000:
             return memregion_VRAM;
+        case 0x0C000000:
+            return (NDS::ConsoleType==1) ? memregion_MainRAM : memregion_Other;
         default:
             return memregion_Other;
         }
@@ -1156,7 +1158,9 @@ int ClassifyAddress7(u32 addr)
         case 0x06000000:
         case 0x06800000:
             return memregion_VWRAM;
-
+        case 0x0C000000:
+        case 0x0C800000:
+            return (NDS::ConsoleType==1) ? memregion_MainRAM : memregion_Other;
         default:
             return memregion_Other;
         }
diff --git a/src/DSi.cpp b/src/DSi.cpp
index 5d382a1..638ecdc 100644
--- a/src/DSi.cpp
+++ b/src/DSi.cpp
@@ -1253,7 +1253,6 @@ u8 ARM9Read8(u32 addr)
     switch (addr & 0xFF000000)
     {
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1281,6 +1280,9 @@ u8 ARM9Read8(u32 addr)
     case 0x09000000:
     case 0x0A000000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0 : 0xFF;
+
+    case 0x0C000000:
+        return *(u8*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM9Read8(addr);
@@ -1299,7 +1301,6 @@ u16 ARM9Read16(u32 addr)
     switch (addr & 0xFF000000)
     {
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1327,6 +1328,9 @@ u16 ARM9Read16(u32 addr)
     case 0x09000000:
     case 0x0A000000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0 : 0xFFFF;
+
+    case 0x0C000000:
+        return *(u16*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM9Read16(addr);
@@ -1350,7 +1354,6 @@ u32 ARM9Read32(u32 addr)
         break;
 
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1378,6 +1381,9 @@ u32 ARM9Read32(u32 addr)
     case 0x09000000:
     case 0x0A000000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0 : 0xFFFFFFFF;
+
+    case 0x0C000000:
+        return *(u32*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM9Read32(addr);
@@ -1388,7 +1394,6 @@ void ARM9Write8(u32 addr, u8 val)
     switch (addr & 0xFF000000)
     {
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1476,6 +1481,13 @@ void ARM9Write8(u32 addr, u8 val)
     case 0x09000000:
     case 0x0A000000:
         return;
+
+    case 0x0C000000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<0, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u8*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM9Write8(addr, val);
@@ -1486,7 +1498,6 @@ void ARM9Write16(u32 addr, u16 val)
     switch (addr & 0xFF000000)
     {
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1560,6 +1571,13 @@ void ARM9Write16(u32 addr, u16 val)
     case 0x09000000:
     case 0x0A000000:
         return;
+
+    case 0x0C000000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<0, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u16*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM9Write16(addr, val);
@@ -1570,7 +1588,6 @@ void ARM9Write32(u32 addr, u32 val)
     switch (addr & 0xFF000000)
     {
     case 0x03000000:
-    case 0x03800000:
         if (SCFG_EXT[0] & (1 << 25))
         {
             if (addr >= NWRAMStart[0][0] && addr < NWRAMEnd[0][0])
@@ -1644,6 +1661,13 @@ void ARM9Write32(u32 addr, u32 val)
     case 0x09000000:
     case 0x0A000000:
         return;
+
+    case 0x0C000000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<0, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u32*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM9Write32(addr, val);
@@ -1654,6 +1678,7 @@ bool ARM9GetMemRegion(u32 addr, bool write, NDS::MemRegion* region)
     switch (addr & 0xFF000000)
     {
     case 0x02000000:
+    case 0x0C000000:
         region->Mem = NDS::MainRAM;
         region->Mask = NDS::MainRAMMask;
         return true;
@@ -1734,6 +1759,10 @@ u8 ARM7Read8(u32 addr)
     case 0x0A000000:
     case 0x0A800000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0xFF : 0;
+
+    case 0x0C000000:
+    case 0x0C800000:
+        return *(u8*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM7Read8(addr);
@@ -1787,6 +1816,10 @@ u16 ARM7Read16(u32 addr)
     case 0x0A000000:
     case 0x0A800000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0xFFFF : 0;
+
+    case 0x0C000000:
+    case 0x0C800000:
+        return *(u16*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM7Read16(addr);
@@ -1840,6 +1873,10 @@ u32 ARM7Read32(u32 addr)
     case 0x0A000000:
     case 0x0A800000:
         return (NDS::ExMemCnt[0] & (1<<7)) ? 0xFFFFFFFF : 0;
+
+    case 0x0C000000:
+    case 0x0C800000:
+        return *(u32*)&NDS::MainRAM[addr & NDS::MainRAMMask];
     }
 
     return NDS::ARM7Read32(addr);
@@ -1927,6 +1964,14 @@ void ARM7Write8(u32 addr, u8 val)
     case 0x0A000000:
     case 0x0A800000:
         return;
+
+    case 0x0C000000:
+    case 0x0C800000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<1, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u8*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM7Write8(addr, val);
@@ -2014,6 +2059,14 @@ void ARM7Write16(u32 addr, u16 val)
     case 0x0A000000:
     case 0x0A800000:
         return;
+
+    case 0x0C000000:
+    case 0x0C800000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<1, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u16*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM7Write16(addr, val);
@@ -2101,6 +2154,14 @@ void ARM7Write32(u32 addr, u32 val)
     case 0x0A000000:
     case 0x0A800000:
         return;
+
+    case 0x0C000000:
+    case 0x0C800000:
+#ifdef JIT_ENABLED
+        ARMJIT::CheckAndInvalidate<1, ARMJIT_Memory::memregion_MainRAM>(addr);
+#endif
+        *(u32*)&NDS::MainRAM[addr & NDS::MainRAMMask] = val;
+        return;
     }
 
     return NDS::ARM7Write32(addr, val);
@@ -2112,6 +2173,8 @@ bool ARM7GetMemRegion(u32 addr, bool write, NDS::MemRegion* region)
     {
     case 0x02000000:
     case 0x02800000:
+    case 0x0C000000:
+    case 0x0C800000:
         region->Mem = NDS::MainRAM;
         region->Mask = NDS::MainRAMMask;
         return true;