Initial work on homebrew return to loader

* DATEL: Make read sector function vram safe

The platform code was performing reads in single byte units, breaking in case the destination buffer was in vram.
This caused issues with some games (e.g. Castelvania Order of Ecclesia), and also broke soft resetting.

* Halve wait timeout on sector read since we read 2 bytes at the time

.github/workflows/nightly.yml

@@ -2,7 +2,6 @@ name: Build Pico Loader
 
 on:
   push:
-    branches: ["develop"]
     paths-ignore:
       - 'README.md'
   pull_request:

README.md

@@ -45,7 +45,7 @@ Note that there are still SDK versions and variants for which Pico Loader does n
 We recommend using WSL (Windows Subsystem for Linux), or MSYS2 to compile this repository.
 The steps provided will assume you already have one of those environments set up.
 
-1. Install [BlocksDS](https://blocksds.skylyrac.net/docs/setup/options/)
+1. Install [BlocksDS](https://blocksds.skylyrac.net/docs/setup/)
 2. Install [.NET 9.0](https://learn.microsoft.com/en-us/dotnet/core/install/linux-ubuntu-install?tabs=dotnet9&pivots=os-linux-ubuntu-2404) for your system (note: this link points to the instructions for Ubuntu, but links for most OS'es are available on the same page)
 
 ## Compiling

arm7/source/core/Environment.cpp

@@ -2,6 +2,9 @@
 #include "picoAgbAdapter.h"
 #include "Environment.h"
 
+#define NOCASH_ID         0x67246F6E
+#define NOCASH_ID_MELONDS 0x6F6C656D
+
 u32 Environment::_flags;
 
 static bool detectIsNitroEmulator()
@@ -15,10 +18,10 @@ static bool detectIsNitroEmulator()
     return true;
 }
 
-static bool detectNocashPrintSuppport()
+static bool detectNocashPrintSupport()
 {
     u32 nocashIdentifier = *(vu32*)0x04FFFA00;
-    return nocashIdentifier == 0x67246F6E; //no$g
+    return nocashIdentifier == NOCASH_ID || nocashIdentifier == NOCASH_ID_MELONDS;
 }
 
 static bool detectPicoAgbAdapter()
@@ -55,7 +58,7 @@ void Environment::Initialize(bool dsiMode)
     }
     if (!(_flags & ENVIRONMENT_FLAGS_IS_NITRO_EMULATOR))
     {
-        if (detectNocashPrintSuppport())
+        if (detectNocashPrintSupport())
             _flags |= ENVIRONMENT_FLAGS_NOCASH_PRINT;
     }
-}
+}

arm7/source/fat/dldi.cpp

@@ -95,3 +95,8 @@ bool dldi_patchTo(dldi_header_t* stub)
 {
     return sDldiDriver.PatchTo(stub);
 }
+
+void dldi_copyTo(void* target)
+{
+    memcpy(target, sDldiBuffer, sizeof(sDldiBuffer));
+}

arm7/source/fat/dldi.h

@@ -3,6 +3,7 @@
 
 bool dldi_init();
 bool dldi_patchTo(dldi_header_t* stub);
+void dldi_copyTo(void* target);
 
 #ifdef __cplusplus
 extern "C" {

arm7/source/header.cpp

@@ -10,5 +10,6 @@ extern u8 __bss_size[];
 pload_header7_t gLoaderHeader
 {
     .entryPoint = (void*)&_start,
-    .apiVersion = PICO_LOADER_API_VERSION
+    .apiVersion = PICO_LOADER_API_VERSION,
+    .launcherPath = "/_picoboot.nds"
 };

arm7/source/loader/NdsLoader.cpp

@@ -344,6 +344,7 @@ void NdsLoader::Load(BootMode bootMode)
     if (isHomebrew)
     {
         InsertArgv();
+        HandleHomebrewPatching();
     }
 
     HandleDldiPatching();
@@ -429,6 +430,22 @@ void NdsLoader::InsertArgv()
     HOMEBREW_ARGV->length = argSize;
 }
 
+void NdsLoader::HandleHomebrewPatching()
+{
+    sendToArm9(IPC_COMMAND_ARM9_APPLY_HOMEBREW_PATCHES);
+    sendToArm9(16 * 1024); // required dldi space
+    void* dldiSpace = (void*)receiveFromArm9();
+    char* launcherPath = (char*)receiveFromArm9();
+    if (dldiSpace != nullptr)
+    {
+        dldi_copyTo(dldiSpace);
+    }
+    if (launcherPath != nullptr)
+    {
+        strncpy(launcherPath, _launcherPath, 256);
+    }
+}
+
 void NdsLoader::ApplyArm7Patches()
 {
     sendToArm9(IPC_COMMAND_ARM9_APPLY_ARM7_PATCHES);

arm7/source/loader/NdsLoader.h

@@ -26,6 +26,13 @@ public:
         _savePath = savePath;
     }
 
+    /// @brief Sets the \p launcherPath to use.
+    /// @param launcherPath The launcher path to use.
+    void SetLauncherPath(const TCHAR* launcherPath)
+    {
+        _launcherPath = launcherPath;
+    }
+
     /// @brief Sets the argv arguments to pass to the rom.
     /// @param arguments The argv arguments.
     /// @param argumentsLength The length of the argv arguments.
@@ -41,8 +48,9 @@ public:
 
 private:
     FIL _romFile;
-    const TCHAR* _romPath;
-    const TCHAR* _savePath;
+    const TCHAR* _romPath = nullptr;
+    const TCHAR* _savePath = nullptr;
+    const TCHAR* _launcherPath = nullptr;
     u32 _argumentsLength = 0;
     const char* _arguments = nullptr;
     nds_header_twl_t _romHeader;
@@ -71,6 +79,7 @@ private:
         char driveLetter, const char* deviceName, const char* path, u8 flags, u8 accessRights);
     void SetupDsiDeviceList();
     void InsertArgv();
+    void HandleHomebrewPatching();
     bool TrySetupDsiWareSave();
     bool TryDecryptSecureArea();
     ConsoleRegion GetRomRegion(u32 gameCode);

arm7/source/loader/dldiHeader.h

@@ -1,5 +1,4 @@
 #pragma once
-#include "common.h"
 
 #define DLDI_MAGIC              0xBF8DA5ED
 #define DLDI_DRIVER_MAGIC_NONE  0x49444C44

arm7/source/main.cpp

@@ -222,6 +222,7 @@ extern "C" void loaderMain()
         sLoader.SetRomPath(gLoaderHeader.loadParams.romPath);
         handleSavePath();
         sLoader.SetArguments(gLoaderHeader.loadParams.arguments, gLoaderHeader.loadParams.argumentsLength);
+        sLoader.SetLauncherPath(gLoaderHeader.launcherPath);
         sLoader.Load(BootMode::Normal);
     }
 

arm9/source/Arm9Patcher.cpp

@@ -21,6 +21,8 @@
 #include "patches/arm9/OverlayPatches/DSProtectPatches/DSProtectOverlayPatch.h"
 #include "patches/arm9/OverlayPatches/DSProtectPatches/DSProtectPuyoPuyo7Patch.h"
 #include "patches/arm9/OverlayPatches/PokemonIr/PokemonIrApPatch.h"
+#include "patches/arm9/OverlayPatches/KirbySuperStarUltra/KirbySuperStarUltraPatch.h"
+#include "patches/arm9/OverlayPatches/RabbidsGoHome/RabbidsGoHomePatch.h"
 #include "patches/arm9/OverlayPatches/GoldenSunDarkDawn/GoldenSunDarkDawnOverlayHookPatch.h"
 #include "SecureSysCallsUnusedSpaceLocator.h"
 #include "fastSearch.h"
@@ -404,6 +406,22 @@ void Arm9Patcher::AddGameSpecificPatches(
             patchCollection.AddPatch(new NintendoDSGuideNandSavePatch());
             break;
         }
+        // Rabbids Go Home
+        case GAMECODE("VRGE"):
+        case GAMECODE("VRGV"):
+        {
+            overlayHookPatch->AddOverlayPatch(new RabbidsGoHomePatch());
+            break;
+        }
+        // Kirby Super Star Ultra
+        case GAMECODE("YKWE"):
+        case GAMECODE("YKWJ"):
+        case GAMECODE("YKWK"):
+        case GAMECODE("YKWP"):
+        {
+            overlayHookPatch->AddOverlayPatch(new KirbySuperStarUltraPatch());
+            break;
+        }
     }
 }
 

arm9/source/main.cpp

@@ -27,6 +27,8 @@
 #include "errorDisplay/ErrorDisplay.h"
 #include "LoaderInfo.h"
 #include "jumpToArm9EntryPoint.h"
+#include "patches/homebrew/BootstubPatchCode.h"
+#include "HomebrewBootstub.h"
 
 #define HANDSHAKE_PART0     0xA
 #define HANDSHAKE_PART1     0xB
@@ -192,8 +194,8 @@ static void handleGetSdFunctionsCommand()
     {
         auto sdReadPatchCode = sLoaderPlatform->CreateSdReadPatchCode(patchCodeCollection, patchHeap);
         auto sdWritePatchCode = sLoaderPlatform->CreateSdWritePatchCode(patchCodeCollection, patchHeap);
-        *(vu32*)0x037F8000 = (u32)sdReadPatchCode->GetSdReadFunction();
-        *(vu32*)0x037F8004 = (u32)sdWritePatchCode->GetSdWriteFunction();
+        *(vu32*)0x037F8000 = (u32)sdReadPatchCode->GetReadSectorsFunction();
+        *(vu32*)0x037F8004 = (u32)sdWritePatchCode->GetWriteSectorFunction();
         patchCodeCollection.CopyAllToTarget();
     }
     dc_flushAll();
@@ -231,6 +233,37 @@ static void handleBootCommand()
     bootArm9();
 }
 
+static void handleApplyHomebrewPatches(u32 dldiRequiredSpace)
+{
+    // Insert bootstub
+    PatchHeap patchHeap;
+    PatchCodeCollection patchCodeCollection;
+    void* patchSpace = (void*)&HOMEBREW_BOOTSTUB[1];
+    auto romHeader = (const nds_header_ntr_t*)TWL_SHARED_MEMORY->ntrSharedMem.romHeader;
+    if (!romHeader->IsTwlRom())
+    {
+        patchSpace = (u8*)patchSpace - 0x2F00000 + 0x2300000;
+    }
+    patchHeap.AddFreeSpace(patchSpace, 32 * 1024 - sizeof(homebrew_bootstub_t));
+
+    void* dldi = patchHeap.Alloc(dldiRequiredSpace);
+    char* launcherPath = (char*)patchHeap.Alloc(256);
+
+    auto bootstubPatchCode = patchCodeCollection.AddUniquePatchCode<BootstubPatchCode>(
+        patchHeap, dldi, launcherPath, &sLoaderInfo,
+        sLoaderPlatform->CreateSdReadPatchCode(patchCodeCollection, patchHeap));
+
+    HOMEBREW_BOOTSTUB->bootSig = HOMEBREW_BOOTSTUB_BOOTSIG;
+    HOMEBREW_BOOTSTUB->arm9Reboot = (void*)bootstubPatchCode->GetArm9RebootFunction();
+    HOMEBREW_BOOTSTUB->arm7Reboot = (void*)bootstubPatchCode->GetArm7RebootFunction();
+    HOMEBREW_BOOTSTUB->bootSize = 32 * 1024 - sizeof(homebrew_bootstub_t);
+
+    patchCodeCollection.CopyAllToTarget();
+
+    ipc_sendWordDirect((u32)dldi);
+    ipc_sendWordDirect((u32)launcherPath);
+}
+
 static void handleArm7Command(u32 command)
 {
     switch (command)
@@ -295,6 +328,12 @@ static void handleArm7Command(u32 command)
             handleBootCommand();
             break;
         }
+        case IPC_COMMAND_ARM9_APPLY_HOMEBREW_PATCHES:
+        {
+            u32 dldiRequiredSpace = receiveFromArm7();
+            handleApplyHomebrewPatches(dldiRequiredSpace);
+            break;
+        }
     }
 }
 

arm9/source/patches/ISectorRemapPatchCode.h

@@ -0,0 +1,13 @@
+#pragma once
+
+/// @brief Interface for sector remapping patch code.
+class ISectorRemapPatchCode
+{
+protected:
+    ISectorRemapPatchCode() { }
+
+public:
+    /// @brief Gets a pointer to the sector remap function in the patch code.
+    /// @return The pointer to the sector remap function.
+    virtual const void* GetRemapFunction() const = 0;
+};

arm9/source/patches/OffsetToSectorRemapPatchCode.h

@@ -1,17 +1,17 @@
 #pragma once
 #include "sections.h"
-#include "SectorRemapPatchCode.h"
+#include "PatchCode.h"
+#include "ISectorRemapPatchCode.h"
 
 DEFINE_SECTION_SYMBOLS(offsettosectorremap);
 
 extern "C" u32 offset_to_sector_remap(u32 romOffset);
 
-class OffsetToSectorRemapPatchCode : public SectorRemapPatchCode
+class OffsetToSectorRemapPatchCode : public PatchCode, public ISectorRemapPatchCode
 {
 public:
     explicit OffsetToSectorRemapPatchCode(PatchHeap& patchHeap)
-        : SectorRemapPatchCode(SECTION_START(offsettosectorremap), SECTION_SIZE(offsettosectorremap), patchHeap)
-    { }
+        : PatchCode(SECTION_START(offsettosectorremap), SECTION_SIZE(offsettosectorremap), patchHeap) { }
 
     const void* GetRemapFunction() const override
     {

arm9/source/patches/PatchCode.h

@@ -20,15 +20,6 @@ public:
         while (1);
     }
 
-    /// @brief Converts a pointer inside the original code block
-    ///        to a pointer at the target location in the patch heap.
-    /// @param ptr The pointer to convert.
-    /// @return The converted pointer.
-    const void* GetAddressAtTarget(const void* ptr) const
-    {
-        return (const void*)((u32)ptr - (u32)_code + (u32)_targetAddress);
-    }
-
     /// @brief Copies the patch code to the target address.
     void CopyToTarget() const
     {
@@ -44,4 +35,13 @@ protected:
 
     /// @brief The target address for the code block in the patch heap.
     void* const _targetAddress;
+
+    /// @brief Converts a pointer inside the original code block
+    ///        to a pointer at the target location in the patch heap.
+    /// @param ptr The pointer to convert.
+    /// @return The converted pointer.
+    const void* GetAddressAtTarget(const void* ptr) const
+    {
+        return (const void*)((u32)ptr - (u32)_code + (u32)_targetAddress);
+    }
 };

arm9/source/patches/SaveOffsetToSdSectorPatchCode.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "sections.h"
-#include "SectorRemapPatchCode.h"
+#include "PatchCode.h"
+#include "ISectorRemapPatchCode.h"
 #include "fileInfo.h"
 
 DEFINE_SECTION_SYMBOLS(saveoffsettosdsector);
@@ -9,11 +10,11 @@ extern "C" u32 save_offset_to_sd_sector_asm(u32 saveOffset);
 
 extern u32 saveoffsettosdsector_fatDataPtr;
 
-class SaveOffsetToSdSectorPatchCode : public SectorRemapPatchCode
+class SaveOffsetToSdSectorPatchCode : public PatchCode, public ISectorRemapPatchCode
 {
 public:
     SaveOffsetToSdSectorPatchCode(PatchHeap& patchHeap, const save_file_info_t* fatDataPtr)
-        : SectorRemapPatchCode(SECTION_START(saveoffsettosdsector), SECTION_SIZE(saveoffsettosdsector), patchHeap)
+        : PatchCode(SECTION_START(saveoffsettosdsector), SECTION_SIZE(saveoffsettosdsector), patchHeap)
     {
         saveoffsettosdsector_fatDataPtr = (u32)fatDataPtr;
     }

arm9/source/patches/SectorRemapPatchCode.h

@@ -1,11 +0,0 @@
-#pragma once
-#include "PatchCode.h"
-
-class SectorRemapPatchCode : public PatchCode
-{
-public:
-    SectorRemapPatchCode(const void* code, u32 size, PatchHeap& patchHeap)
-        : PatchCode(code, size, patchHeap) { }
-
-    virtual const void* GetRemapFunction() const = 0;
-};

arm9/source/patches/arm7/ReadSavePatchCode.h

@@ -1,8 +1,8 @@
 #pragma once
 #include "sections.h"
-#include "../PatchCode.h"
-#include "../SectorRemapPatchCode.h"
-#include "../platform/SdReadPatchCode.h"
+#include "patches/PatchCode.h"
+#include "patches/ISectorRemapPatchCode.h"
+#include "patches/platform/IReadSectorsPatchCode.h"
 
 DEFINE_SECTION_SYMBOLS(readsave);
 
@@ -15,12 +15,12 @@ extern u32 readsave_sdread_asm_address;
 class ReadSavePatchCode : public PatchCode
 {
 public:
-    ReadSavePatchCode(PatchHeap& patchHeap, const SectorRemapPatchCode* sectorRemapPatchCode,
-        const SdReadPatchCode* sdReadPatchCode, void* tmpBuffer)
+    ReadSavePatchCode(PatchHeap& patchHeap, const ISectorRemapPatchCode* sectorRemapPatchCode,
+        const IReadSectorsPatchCode* readSectorsPatchCode, void* tmpBuffer)
         : PatchCode(SECTION_START(readsave), SECTION_SIZE(readsave), patchHeap)
     {
         readsave_save_offset_to_sd_sector_asm_address = (u32)sectorRemapPatchCode->GetRemapFunction();
-        readsave_sdread_asm_address = (u32)sdReadPatchCode->GetSdReadFunction();
+        readsave_sdread_asm_address = (u32)readSectorsPatchCode->GetReadSectorsFunction();
         readsave_tmpBufferPtr = (u32)tmpBuffer;
     }