Preserve cheats when OS_ResetSystem is used, move temporary save buffer to main memory

arm7/source/main.cpp

@@ -205,6 +205,14 @@ extern "C" void loaderMain()
         }
     }
 
+    if (gLoaderHeader.v3.cheats != nullptr && gLoaderHeader.v3.cheats->numberOfCheats != 0)
+    {
+        // Copy cheats to vram
+        auto cheats = (pload_cheats_t*)malloc(gLoaderHeader.v3.cheats->length);
+        memcpy(cheats, gLoaderHeader.v3.cheats, gLoaderHeader.v3.cheats->length);
+        sLoader.SetCheats(cheats);
+    }
+
     if (multiboot)
     {
         LOG_DEBUG("Multiboot\n");
@@ -219,19 +227,10 @@ extern "C" void loaderMain()
     }
     else
     {
-        pload_cheats_t* cheats = nullptr;
-        if (gLoaderHeader.v3.cheats != nullptr && gLoaderHeader.v3.cheats->numberOfCheats != 0)
-        {
-            // Copy cheats to vram
-            cheats = (pload_cheats_t*)malloc(gLoaderHeader.v3.cheats->length);
-            memcpy(cheats, gLoaderHeader.v3.cheats, gLoaderHeader.v3.cheats->length);
-        }
-
         sLoader.SetRomPath(gLoaderHeader.loadParams.romPath);
         handleSavePath();
         sLoader.SetArguments(gLoaderHeader.loadParams.arguments, gLoaderHeader.loadParams.argumentsLength);
         sLoader.SetLauncherPath(gLoaderHeader.v2.launcherPath);
-        sLoader.SetCheats(cheats);
         sLoader.Load(BootMode::Normal);
     }
 

arm9/source/Arm7Patcher.cpp

@@ -18,6 +18,18 @@
 #include "patches/arm7/cheats/CheatEnginePatch.h"
 #include "Arm7Patcher.h"
 
+static u32 correctAddress(u32 address, const nds_header_ntr_t* romHeader)
+{
+    if (gIsDsiMode && romHeader->unitCode == 0)
+    {
+        return address & ~0xC00000; // 0x023...
+    }
+    else
+    {
+        return address | 0x800000; // make sure it ends up in the right place while in 16MB mode
+    }
+}
+
 void* Arm7Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, u32 cheatsLength, void*& cheatsPtr) const
 {
     cheatsPtr = nullptr;
@@ -63,6 +75,37 @@ void* Arm7Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, u32 cheats
         auto arm7ArenaPatch = new OsGetInitArenaLoPatch();
         patchCollection.AddPatch(arm7ArenaPatch);
 
+        if (!arm7ArenaPatch->FindPatchTarget(patchContext))
+        {
+            ErrorDisplay().PrintError("Failed to apply arm7 patches.");
+        }
+
+        const u32 arm7PatchSpaceSize = 0x800;
+        void* privateWramHeapStart = arm7ArenaPatch->GetArm7PrivateWramArenaLo();
+        u32 mainMemoryArenaLo = (u32)arm7ArenaPatch->GetMainMemoryArenaLo();
+        if (0x0380F780 - (u32)privateWramHeapStart - 0x2100 >= arm7PatchSpaceSize)
+        {
+            patchSpaceStart = privateWramHeapStart;
+            arm7ArenaPatch->SetArm7PrivateWramArenaLo((u8*)patchSpaceStart + arm7PatchSpaceSize);
+        }
+        else
+        {
+            LOG_DEBUG("Arm 7 patches placed in main memory\n");
+            patchSpaceStart = (void*)correctAddress(mainMemoryArenaLo, romHeader);
+            mainMemoryArenaLo += arm7PatchSpaceSize;
+        }
+
+        patchContext.GetPatchHeap().AddFreeSpace(patchSpaceStart, arm7PatchSpaceSize);
+
+        if (cheatsLength > 0)
+        {
+            void* cheats = (void*)correctAddress(mainMemoryArenaLo, romHeader);
+            LOG_DEBUG("Cheats placed at 0x%p\n", cheats);
+            cheatsPtr = cheats;
+            patchCollection.AddPatch(new CheatEnginePatch(cheats));
+            mainMemoryArenaLo += cheatsLength;
+        }
+
         if (romHeader->unitCode == 0) // seems only present on NITRO, not on HYBRID or LIMITED
         {
             patchCollection.AddPatch(new DisableArm7WramClearPatch());
@@ -77,12 +120,16 @@ void* Arm7Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, u32 cheats
 
             if (!twlRomHeader->IsDsiWare())
             {
-                patchCollection.AddPatch(new CardiDoTaskFromArm9Patch());
+                void* saveTmpBuffer = (void*)correctAddress(mainMemoryArenaLo, romHeader);
+                mainMemoryArenaLo += 512;
+                patchCollection.AddPatch(new CardiDoTaskFromArm9Patch(saveTmpBuffer));
             }
         }
         else
         {
-            patchCollection.AddPatch(new CardiTaskThreadPatch());
+            void* saveTmpBuffer = (void*)correctAddress(mainMemoryArenaLo, romHeader);
+            mainMemoryArenaLo += 512;
+            patchCollection.AddPatch(new CardiTaskThreadPatch(saveTmpBuffer));
         }
 
         if (*(vu32*)0x02FFF00C == GAMECODE("ADAJ") &&
@@ -93,54 +140,7 @@ void* Arm7Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, u32 cheats
             patchCollection.AddPatch(new PokemonDownloaderArm7Patch());
         }
 
-        CheatEnginePatch* cheatEnginePatch = nullptr;
-        if (cheatsLength > 0)
-        {
-            cheatEnginePatch = new CheatEnginePatch();
-            patchCollection.AddPatch(cheatEnginePatch);
-        }
-
-        if (arm7ArenaPatch->FindPatchTarget(patchContext))
-        {
-            const u32 arm7PatchSpaceSize = 0x800;
-            void* privateWramHeapStart = arm7ArenaPatch->GetArm7PrivateWramArenaLo();
-            u32 mainMemoryArenaLo = (u32)arm7ArenaPatch->GetMainMemoryArenaLo();
-            if (0x0380F780 - (u32)privateWramHeapStart - 0x2100 >= arm7PatchSpaceSize)
-            {
-                patchSpaceStart = privateWramHeapStart;
-                arm7ArenaPatch->SetArm7PrivateWramArenaLo((u8*)patchSpaceStart + arm7PatchSpaceSize);
-            }
-            else
-            {
-                LOG_DEBUG("Arm 7 patches placed in main memory\n");
-                if (gIsDsiMode && romHeader->unitCode == 0)
-                {
-                    patchSpaceStart = (void*)(mainMemoryArenaLo & ~0xC00000); // 0x023...
-                }
-                else
-                {
-                    patchSpaceStart = (void*)(mainMemoryArenaLo | 0x800000); // make sure it ends up in the right place while in 16MB mode
-                }
-                mainMemoryArenaLo += arm7PatchSpaceSize;
-            }
-            if (cheatsLength > 0)
-            {
-                void* cheats;
-                if (gIsDsiMode && romHeader->unitCode == 0)
-                {
-                    cheats = (void*)(mainMemoryArenaLo & ~0xC00000); // 0x023...
-                }
-                else
-                {
-                    cheats = (void*)(mainMemoryArenaLo | 0x800000); // make sure it ends up in the right place while in 16MB mode
-                }
-                cheatsPtr = cheats;
-                cheatEnginePatch->SetCheats(cheats);
-                mainMemoryArenaLo += cheatsLength;
-            }
         arm7ArenaPatch->SetMainMemoryArenaLo((void*)mainMemoryArenaLo);
-            patchContext.GetPatchHeap().AddFreeSpace(patchSpaceStart, arm7PatchSpaceSize);
-        }
 
         // The arm7 patcher uses the fact that the ntr wram is mirrored over the entire 03 region.
         // Since the reserved patch space is smaller than the ntr wram, it will never overlap.

arm9/source/Arm9Patcher.cpp

@@ -47,7 +47,7 @@ static const u32 sMiiUncompressBackwardPatternOld2[] = { 0xE3500000, 0x0A00002B,
 static const u32 sMiiUncompressBackwardPattern[] = { 0xE3500000, 0x0A000027, 0xE92D00F0, 0xE9100006 };
 static const u32 sMiiUncompressBackwardPatternHybrid[] = { 0xE3500000, 0x0A000029, 0xE92D01F0, 0xE9100006 };
 
-void Arm9Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, const ApListEntry* apListEntry,
+Arm9Patcher::PatchResult Arm9Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, const ApListEntry* apListEntry,
     bool isCloneBootRom, const loader_info_t* loaderInfo) const
 {
     auto romHeader = (const nds_header_ntr_t*)TWL_SHARED_MEMORY->ntrSharedMem.romHeader;
@@ -165,6 +165,7 @@ void Arm9Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, const ApLis
         loaderPlatform
     };
     PatchCollection patchCollection;
+    OSResetSystemPatch* osResetSystemPatch = nullptr;
     if (sdkVersion != 0)
     {
         if (*(vu32*)0x02FFF00C == GAMECODE("ADAJ") &&
@@ -217,7 +218,8 @@ void Arm9Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, const ApLis
         }
 
         patchCollection.AddPatch(new CardiReadRomIdCorePatch());
-        patchCollection.AddPatch(new OSResetSystemPatch(loaderInfo));
+        osResetSystemPatch = new OSResetSystemPatch(loaderInfo);
+        patchCollection.AddPatch(osResetSystemPatch);
         AddGamePatches(patchCollection, romHeader->gameCode, apListEntry);
 
         if (moduleParams && compressedEnd != 0)
@@ -236,6 +238,17 @@ void Arm9Patcher::ApplyPatches(const LoaderPlatform* loaderPlatform, const ApLis
     dc_flushAll();
     dc_drainWriteBuffer();
     ic_invalidateAll();
+
+    void** softResetCheatsPointer = nullptr;
+    if (osResetSystemPatch != nullptr)
+    {
+        softResetCheatsPointer = osResetSystemPatch->GetCheatsPointerAtTarget();
+    }
+
+    return PatchResult
+    {
+        .softResetCheatsPointer = softResetCheatsPointer
+    };
 }
 
 const u32* Arm9Patcher::FindMIiUncompressBackward(u32 arm9LoadAddress, SdkVersion sdkVersion) const

arm9/source/Arm9Patcher.h

@@ -12,12 +12,20 @@ class OverlayHookPatch;
 class Arm9Patcher
 {
 public:
+    struct PatchResult
+    {
+        /// @brief Pointer to the cheats pointer used for soft reset.
+        ///        This pointer must be set to keep cheats over soft resets.
+        void** softResetCheatsPointer;
+    };
+
     /// @brief Applies arm9 patches using the given \p loaderPlatform.
     /// @param loaderPlatform The loader platform to use.
     /// @param apListEntry The AP list entry for the rom being loaded, or \c nullptr if there is none.
     /// @param isCloneBootRom \c true if the rom being loaded is a clone boot rom, or \c false otherwise.
     /// @param loaderInfo The loader info to use.
-    void ApplyPatches(const LoaderPlatform* loaderPlatform, const ApListEntry* apListEntry,
+    /// @return Some information resulting from the patching.
+    PatchResult ApplyPatches(const LoaderPlatform* loaderPlatform, const ApListEntry* apListEntry,
         bool isCloneBootRom, const loader_info_t* loaderInfo) const;
 
 private:

arm9/source/main.cpp

@@ -47,6 +47,7 @@ static u32 sRomDirSector;
 static u32 sRomDirSectorOffset;
 static u16 sIsCloneBootRom;
 static loader_info_t sLoaderInfo;
+static void** sSoftResetCheatsPointer = nullptr;
 
 u16 gIsDsiMode;
 
@@ -147,11 +148,12 @@ static void handleClearMainMemCommand()
 
 static void handleApplyArm9PatchesCommand()
 {
-    Arm9Patcher().ApplyPatches(
+    auto result = Arm9Patcher().ApplyPatches(
         sLoaderPlatform,
         sApListEntry.GetGameCode() == 0 ? nullptr : &sApListEntry,
         sIsCloneBootRom,
         &sLoaderInfo);
+    sSoftResetCheatsPointer = result.softResetCheatsPointer;
     ipc_sendWordDirect(1);
 }
 
@@ -159,6 +161,10 @@ static void handleApplyArm7PatchesCommand(u32 cheatsLength)
 {
     void* cheats = nullptr;
     void* patchSpaceStart = Arm7Patcher().ApplyPatches(sLoaderPlatform, cheatsLength, cheats);
+    if (sSoftResetCheatsPointer != nullptr)
+    {
+        *sSoftResetCheatsPointer = cheats;
+    }
     ipc_sendWordDirect((u32)patchSpaceStart);
     ipc_sendWordDirect((u32)cheats);
 }

arm9/source/patches/arm7/cheats/CheatEnginePatch.h

@@ -5,16 +5,14 @@
 class CheatEnginePatch : public Patch
 {
 public:
+    explicit CheatEnginePatch(const void* cheats)
+        : _cheats(cheats) { }
+
     bool FindPatchTarget(PatchContext& patchContext) override;
     void ApplyPatch(PatchContext& patchContext) override;
 
-    void SetCheats(const void* cheats)
-    {
-        _cheats = cheats;
-    }
-
 private:
-    const void* _cheats = nullptr;
+    const void* _cheats;
     u32* _vblankIrqHandler = nullptr;
     const u32* _foundPattern = nullptr;
 };

arm9/source/patches/arm7/sdk2to4/CardiTaskThreadPatch.cpp

@@ -103,13 +103,12 @@ void CardiTaskThreadPatch::ApplyPatch(PatchContext& patchContext)
         patchContext.GetPatchHeap(),
         (const save_file_info_t*)((u32)SHARED_SAVE_FILE_INFO - 0x02F00000 + 0x02700000)
     );
-    void* tmpBuffer = patchContext.GetPatchHeap().Alloc(512);
     auto readSavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<ReadSavePatchCode>
     (
         patchContext.GetPatchHeap(),
         sectorRemapPatchCode,
         readPatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
     auto writeSavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<WriteSavePatchCode>
     (
@@ -117,13 +116,13 @@ void CardiTaskThreadPatch::ApplyPatch(PatchContext& patchContext)
         sectorRemapPatchCode,
         readPatchCode,
         writePatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
     auto verifySavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<VerifySavePatchCode>(
         patchContext.GetPatchHeap(),
         sectorRemapPatchCode,
         readPatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
 
     __patch_carditaskthread_readsave_asm_address = (u32)readSavePatchCode->GetReadSaveFunction();

arm9/source/patches/arm7/sdk2to4/CardiTaskThreadPatch.h

@@ -22,11 +22,15 @@ public:
         ThumbF
     };
 
+    explicit CardiTaskThreadPatch(void* saveTmpBuffer)
+        : _saveTmpBuffer(saveTmpBuffer) { }
+
     bool FindPatchTarget(PatchContext& patchContext) override;
     void ApplyPatch(PatchContext& patchContext) override;
 
 private:
     u32* _cardiTaskThread = nullptr;
+    void* _saveTmpBuffer;
     PatchVariant _patchVariant = PatchVariant::None;
 
     void ApplyArmPatch(void* patch1Address) const;

arm9/source/patches/arm7/sdk5/CardiDoTaskFromArm9Patch.cpp

@@ -68,25 +68,24 @@ void CardiDoTaskFromArm9Patch::ApplyPatch(PatchContext& patchContext)
         patchContext.GetPatchCodeCollection(), patchContext.GetPatchHeap());
     auto sectorRemapPatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<SaveOffsetToSdSectorPatchCode>(
         patchContext.GetPatchHeap(), SHARED_SAVE_FILE_INFO);
-    void* tmpBuffer = patchContext.GetPatchHeap().Alloc(512);
     auto readSavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<ReadSavePatchCode>(
         patchContext.GetPatchHeap(),
         sectorRemapPatchCode,
         readPatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
     auto writeSavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<WriteSavePatchCode>(
         patchContext.GetPatchHeap(),
         sectorRemapPatchCode,
         readPatchCode,
         writePatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
     auto verifySavePatchCode = patchContext.GetPatchCodeCollection().AddUniquePatchCode<VerifySavePatchCode>(
         patchContext.GetPatchHeap(),
         sectorRemapPatchCode,
         readPatchCode,
-        tmpBuffer
+        _saveTmpBuffer
     );
 
     __patch_carditaskthread_readsave_asm_address = (u32)readSavePatchCode->GetReadSaveFunction();

arm9/source/patches/arm7/sdk5/CardiDoTaskFromArm9Patch.h

@@ -5,12 +5,16 @@
 class CardiDoTaskFromArm9Patch : public Patch
 {
 public:
+    explicit CardiDoTaskFromArm9Patch(void* saveTmpBuffer)
+        : _saveTmpBuffer(saveTmpBuffer) { }
+
     bool FindPatchTarget(PatchContext& patchContext) override;
     void ApplyPatch(PatchContext& patchContext) override;
 
 private:
     u32* _cardiDoTaskFromArm9 = nullptr;
     const u32* _foundPattern = nullptr;
+    void* _saveTmpBuffer;
     u16 _thumb = false;
 
     void TryPattern(PatchContext& patchContext, const u32* pattern);

arm9/source/patches/arm9/OSResetSystemPatch.cpp

@@ -126,5 +126,7 @@ void OSResetSystemPatch::ApplyPatch(PatchContext& patchContext)
 
     *(u32*)((u8*)_osResetSystem + offset) = 0xE51FF004;
     *(u32*)((u8*)_osResetSystem + offset + 4) = (u32)patchCode->GetOSResetSystemFunction();
+
+    _cheatsPointer = patchCodePart2->GetCheatsPointerAtTarget();
 }
 

arm9/source/patches/arm9/OSResetSystemPatch.h

@@ -12,8 +12,14 @@ public:
     bool FindPatchTarget(PatchContext& patchContext) override;
     void ApplyPatch(PatchContext& patchContext) override;
 
+    void** GetCheatsPointerAtTarget() const
+    {
+        return _cheatsPointer;
+    }
+
 private:
     u32* _osResetSystem = nullptr;
     u32 _hybrid = false;
     const loader_info_t* _loaderInfo;
+    void** _cheatsPointer = nullptr;
 };

arm9/source/patches/arm9/OSResetSystemPatchCode.h

@@ -15,6 +15,7 @@ extern u32 patch_osresetsystem_readSdSectors_address;
 extern u32 patch_osresetsystem_bootPicoLoader_address;
 extern u16 patch_osresetsystem_entry_jump_to_twl_arm7_sync;
 extern u32 patch_osresetsystem_arm7Entry_address;
+extern u32 patch_osresetsystem_cheats_address;
 
 class OSResetSystemPart2PatchCode : public PatchCode
 {
@@ -28,6 +29,11 @@ public:
     {
         return GetAddressAtTarget((void*)patch_osresetsystem_bootPicoLoader);
     }
+
+    void** GetCheatsPointerAtTarget() const
+    {
+        return (void**)GetAddressAtTarget(&patch_osresetsystem_cheats_address);
+    }
 };
 
 class OSResetSystemPatchCode : public PatchCode

arm9/source/patches/arm9/OSResetSystemPatchCode.s

@@ -108,16 +108,24 @@ patch_osresetsystem_bootPicoLoader:
     ldmia r5, {r3, r5}
     ldrh r0, [r3, #2] // loader_info_t::picoLoaderBootDrive
     strh r0, [r5, #8] // pload_header7_t::bootDrive
-    ldr r0, [r5] // pload_header7_t::entryPoint
+
+    adr r0, regVramCntA
+    ldmia r0, {r0, r4, r6, r7}
+    // r0 = regVramCntA
+    // r4 = patch_osresetsystem_arm7Entry_address
+    // r6 = vramCDSettings
+    // r7 = patch_osresetsystem_cheats_address
+
+    movs r2, #0x41
+    lsls r2, r2, #4 // 0x410
+    str r7, [r5, r2] // pload_header7_t::v3.cheats
+    ldr r1, [r5] // pload_header7_t::entryPoint
 
     // set NTR_SHARED_MEMORY->romHeader.arm7EntryAddress
-    ldr r4, patch_osresetsystem_arm7Entry_address
+    str r1, [r4]
-    str r0, [r4]
 
     // map vram CD to arm7
-    ldr r0,= 0x04000240
+    strh r6, [r0, #2]
-    ldr r7,= 0x8A82
-    strh r7, [r0, #2]
 
     adds r0, #(0x04000180 - 0x04000240) // REG_IPC_SYNC
     movs r1, #1
@@ -139,21 +147,17 @@ twl_arm7_sync:
     ldr r7,= 0x02FFFC24
     movs r1, #1
     strh r1, [r7, #4]
-
+    mov r11, pc
-    ldrh r6, [r7, #2]
+    b do_sync
-    ldrh r1, [r7]
-1:
-    adds r1, #1
-    strh r1, [r7]
-    ldrh r4, [r7, #2]
-    cmp r6, r4
-    beq 1b
-    adds r1, #1
-    strh r1, [r7]
 
     movs r1, #3
     strh r1, [r7, #4]
+    mov r11, pc
+    b do_sync
 
+    mov pc, lr
+
+do_sync:
     ldrh r6, [r7, #2]
     ldrh r1, [r7]
 1:
@@ -164,14 +168,23 @@ twl_arm7_sync:
     beq 1b
     adds r1, #1
     strh r1, [r7]
-
+    mov pc, r11
-    mov pc, lr
 
 .balign 4
 
+regVramCntA:
+    .word 0x04000240
+
 .global patch_osresetsystem_arm7Entry_address
 patch_osresetsystem_arm7Entry_address:
     .word 0x027FFE34
 
+vramCDSettings:
+    .word 0x8A82
+
+.global patch_osresetsystem_cheats_address
+patch_osresetsystem_cheats_address:
+    .word 0
+
 .pool
 .end