4 files changed, 38 insertions, 7 deletions

diff --git a/src/yuzu/bootmanager.cpp b/src/yuzu/bootmanager.cpp
index d62b0efc2..f0338cf7a 100644
--- a/src/yuzu/bootmanager.cpp
+++ b/src/yuzu/bootmanager.cpp
@@ -302,6 +302,12 @@ GRenderWindow::GRenderWindow(GMainWindow* parent, EmuThread* emu_thread_,
     this->setMouseTracking(true);
 
     connect(this, &GRenderWindow::FirstFrameDisplayed, parent, &GMainWindow::OnLoadComplete);
+    connect(this, &GRenderWindow::ExecuteProgramSignal, parent, &GMainWindow::OnExecuteProgram,
+            Qt::QueuedConnection);
+}
+
+void GRenderWindow::ExecuteProgram(std::size_t program_index) {
+    emit ExecuteProgramSignal(program_index);
 }
 
 GRenderWindow::~GRenderWindow() {
diff --git a/src/yuzu/bootmanager.h b/src/yuzu/bootmanager.h
index ca35cf831..503b4f89e 100644
--- a/src/yuzu/bootmanager.h
+++ b/src/yuzu/bootmanager.h
@@ -166,6 +166,12 @@ public:
 
     std::pair<u32, u32> ScaleTouch(const QPointF& pos) const;
 
+    /**
+     * Instructs the window to re-launch the application using the specified program_index.
+     * @param program_index Specifies the index within the application of the program to launch.
+     */
+    void ExecuteProgram(std::size_t program_index);
+
 public slots:
     void OnEmulationStarting(EmuThread* emu_thread);
     void OnEmulationStopping();
@@ -175,6 +181,7 @@ signals:
     /// Emitted when the window is closed
     void Closed();
     void FirstFrameDisplayed();
+    void ExecuteProgramSignal(std::size_t program_index);
 
 private:
     void TouchBeginEvent(const QTouchEvent* event);
diff --git a/src/yuzu/main.cpp b/src/yuzu/main.cpp
index e704cc656..805619ccf 100644
--- a/src/yuzu/main.cpp
+++ b/src/yuzu/main.cpp
@@ -978,7 +978,7 @@ void GMainWindow::AllowOSSleep() {
 #endif
 }
 
-bool GMainWindow::LoadROM(const QString& filename) {
+bool GMainWindow::LoadROM(const QString& filename, std::size_t program_index) {
     // Shutdown previous session if the emu thread is still active...
     if (emu_thread != nullptr)
         ShutdownGame();
@@ -1003,7 +1003,8 @@ bool GMainWindow::LoadROM(const QString& filename) {
 
     system.RegisterHostThread();
 
-    const Core::System::ResultStatus result{system.Load(*render_window, filename.toStdString())};
+    const Core::System::ResultStatus result{
+        system.Load(*render_window, filename.toStdString(), program_index)};
 
     const auto drd_callout =
         (UISettings::values.callout_flags & static_cast<u32>(CalloutFlag::DRDDeprecation)) == 0;
@@ -1085,14 +1086,18 @@ void GMainWindow::SelectAndSetCurrentUser() {
     Settings::values.current_user = dialog.GetIndex();
 }
 
-void GMainWindow::BootGame(const QString& filename) {
+void GMainWindow::BootGame(const QString& filename, std::size_t program_index) {
     LOG_INFO(Frontend, "yuzu starting...");
     StoreRecentFile(filename); // Put the filename on top of the list
 
     u64 title_id{0};
+
+    last_filename_booted = filename;
+
     auto& system = Core::System::GetInstance();
     const auto v_file = Core::GetGameFileFromPath(vfs, filename.toUtf8().constData());
-    const auto loader = Loader::GetLoader(system, v_file);
+    const auto loader = Loader::GetLoader(system, v_file, program_index);
+
     if (!(loader == nullptr || loader->ReadProgramId(title_id) != Loader::ResultStatus::Success)) {
         // Load per game settings
         Config per_game_config(fmt::format("{:016X}", title_id), Config::ConfigType::PerGameConfig);
@@ -1106,7 +1111,7 @@ void GMainWindow::BootGame(const QString& filename) {
         SelectAndSetCurrentUser();
     }
 
-    if (!LoadROM(filename))
+    if (!LoadROM(filename, program_index))
         return;
 
     // Create and start the emulation thread
@@ -1114,6 +1119,10 @@ void GMainWindow::BootGame(const QString& filename) {
     emit EmulationStarting(emu_thread.get());
     emu_thread->start();
 
+    // Register an ExecuteProgram callback such that Core can execute a sub-program
+    system.RegisterExecuteProgramCallback(
+        [this](std::size_t program_index) { render_window->ExecuteProgram(program_index); });
+
     connect(render_window, &GRenderWindow::Closed, this, &GMainWindow::OnStopGame);
     // BlockingQueuedConnection is important here, it makes sure we've finished refreshing our views
     // before the CPU continues
@@ -2136,6 +2145,11 @@ void GMainWindow::OnLoadComplete() {
     loading_screen->OnLoadComplete();
 }
 
+void GMainWindow::OnExecuteProgram(std::size_t program_index) {
+    ShutdownGame();
+    BootGame(last_filename_booted, program_index);
+}
+
 void GMainWindow::ErrorDisplayDisplayError(QString body) {
     QMessageBox::critical(this, tr("Error Display"), body);
     emit ErrorDisplayFinished();
diff --git a/src/yuzu/main.h b/src/yuzu/main.h
index b380a66f3..6242341d1 100644
--- a/src/yuzu/main.h
+++ b/src/yuzu/main.h
@@ -131,6 +131,7 @@ signals:
 
 public slots:
     void OnLoadComplete();
+    void OnExecuteProgram(std::size_t program_index);
     void ControllerSelectorReconfigureControllers(
         const Core::Frontend::ControllerParameters& parameters);
     void ErrorDisplayDisplayError(QString body);
@@ -154,8 +155,8 @@ private:
     void PreventOSSleep();
     void AllowOSSleep();
 
-    bool LoadROM(const QString& filename);
-    void BootGame(const QString& filename);
+    bool LoadROM(const QString& filename, std::size_t program_index);
+    void BootGame(const QString& filename, std::size_t program_index = 0);
     void ShutdownGame();
 
     void ShowTelemetryCallout();
@@ -317,6 +318,9 @@ private:
     // Install progress dialog
     QProgressDialog* install_progress;
 
+    // Last game booted, used for multi-process apps
+    QString last_filename_booted;
+
 protected:
     void dropEvent(QDropEvent* event) override;
     void dragEnterEvent(QDragEnterEvent* event) override;