Add a check for O3DS extended-memory ROMs in applet_manager.cpp to ensure reboot if necessary.

src/core/hle/service/apt/applet_manager.cpp

@@ -1349,6 +1349,19 @@ Result AppletManager::StartApplication(const std::vector<u8>& parameter,
     // PM::LaunchTitle. We should research more about that.
     ASSERT_MSG(app_start_parameters, "Trying to start an application without preparing it first.");
 
+    // Determine if the target title is an O3DS extended-memory title.
+    bool needs_extended_memory_reboot = NS::RequiresExtendedMemoryOld3DS(
+        app_start_parameters->next_media_type, app_start_parameters->next_title_id);
+
+    if (needs_extended_memory_reboot) {
+        // For O3DS extended-memory titles, reboot to ensure a clean low-memory state to prevent
+        // hang/crash.
+        NS::RebootToTitle(system, app_start_parameters->next_media_type,
+                          app_start_parameters->next_title_id);
+        app_start_parameters.reset();
+        return ResultSuccess;
+    }
+
     active_slot = AppletSlot::Application;
 
     // Launch the title directly.

src/core/hle/service/apt/ns.cpp

@@ -1,4 +1,4 @@
-// Copyright 2017 Citra Emulator Project
+// Copyright Citra Emulator Project / Azahar Emulator Project
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
@@ -54,4 +54,17 @@ void RebootToTitle(Core::System& system, FS::MediaType media_type, u64 title_id)
     system.RequestReset(new_path);
 }
 
+bool RequiresExtendedMemoryOld3DS(FS::MediaType media_type, u64 title_id) {
+    const std::string path = AM::GetTitleContentPath(media_type, title_id);
+    auto loader = Loader::GetLoader(path);
+    if (!loader)
+        return false;
+
+    auto [mem_mode_opt, status] = loader->LoadKernelMemoryMode();
+    if (status != Loader::ResultStatus::Success || !mem_mode_opt.has_value())
+        return false;
+
+    return (*mem_mode_opt != Kernel::MemoryMode::Prod);
+}
+
 } // namespace Service::NS

src/core/hle/service/apt/ns.h

@@ -1,4 +1,4 @@
-// Copyright 2017 Citra Emulator Project
+// Copyright Citra Emulator Project / Azahar Emulator Project
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
@@ -22,4 +22,8 @@ std::shared_ptr<Kernel::Process> LaunchTitle(Core::System& system, FS::MediaType
 /// Reboots the system to the specified title.
 void RebootToTitle(Core::System& system, FS::MediaType media_type, u64 title_id);
 
+/// Returns true if the specified title requires extended memory on Old 3DS
+/// (i.e., its ExHeader system mode is not Prod/64MB).
+bool RequiresExtendedMemoryOld3DS(FS::MediaType media_type, u64 title_id);
+
 } // namespace Service::NS