am: Switch 2 appletOE/IApplicationProxy entry points

- appletOE command 10 opens the application proxy (same arguments as 0).
- IApplicationProxy commands 40/50/.../90 are new getters; return an
  INx2StubInterface (nx2_stub_interface.h). Interfaces whose name starts
  with nx2: answer every call with an empty success and log it.

6 files changed, 73 insertions, 1 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 1b578f67ba..0c37a561cf 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -1033,6 +1033,7 @@ add_library(core STATIC
     hle/service/server_manager.h
     hle/service/service.cpp
     hle/service/service.h
+    hle/service/nx2_stub_interface.h
     hle/service/services.cpp
     hle/service/services.h
     hle/service/set/factory_settings_server.cpp
diff --git a/src/core/hle/service/am/service/application_proxy.cpp b/src/core/hle/service/am/service/application_proxy.cpp
index df438e1e17..80a21c0d05 100644
--- a/src/core/hle/service/am/service/application_proxy.cpp
+++ b/src/core/hle/service/am/service/application_proxy.cpp
@@ -16,6 +16,7 @@
 #include "core/hle/service/am/service/self_controller.h"
 #include "core/hle/service/am/service/window_controller.h"
 #include "core/hle/service/cmif_serialization.h"
+#include "core/hle/service/nx2_stub_interface.h"
 
 namespace Service::AM {
 
@@ -33,6 +34,13 @@ IApplicationProxy::IApplicationProxy(Core::System& system_, std::shared_ptr<Appl
         {10, D<&IApplicationProxy::GetProcessWindingController>, "GetProcessWindingController"},
         {11, D<&IApplicationProxy::GetLibraryAppletCreator>, "GetLibraryAppletCreator"},
         {20, D<&IApplicationProxy::GetApplicationFunctions>, "GetApplicationFunctions"},
+        // Switch 2-only getters; see nx2_stub_interface.h.
+        {40, &IApplicationProxy::GetNx2Interface, "Nx2Getter40"},
+        {50, &IApplicationProxy::GetNx2Interface, "Nx2Getter50"},
+        {60, &IApplicationProxy::GetNx2Interface, "Nx2Getter60"},
+        {70, &IApplicationProxy::GetNx2Interface, "Nx2Getter70"},
+        {80, &IApplicationProxy::GetNx2Interface, "Nx2Getter80"},
+        {90, &IApplicationProxy::GetNx2Interface, "Nx2Getter90"},
         {1000, D<&IApplicationProxy::GetDebugFunctions>, "GetDebugFunctions"},
     };
     // clang-format on
@@ -42,6 +50,10 @@ IApplicationProxy::IApplicationProxy(Core::System& system_, std::shared_ptr<Appl
 
 IApplicationProxy::~IApplicationProxy() = default;
 
+void IApplicationProxy::GetNx2Interface(HLERequestContext& ctx) {
+    ReturnNx2StubInterface(system, ctx, "IApplicationProxy");
+}
+
 Result IApplicationProxy::GetAudioController(
     Out<SharedPointer<IAudioController>> out_audio_controller) {
     LOG_DEBUG(Service_AM, "called");
diff --git a/src/core/hle/service/am/service/application_proxy.h b/src/core/hle/service/am/service/application_proxy.h
index b56f597605..04f4b4e175 100644
--- a/src/core/hle/service/am/service/application_proxy.h
+++ b/src/core/hle/service/am/service/application_proxy.h
@@ -30,6 +30,7 @@ public:
     ~IApplicationProxy();
 
 private:
+    void GetNx2Interface(HLERequestContext& ctx);
     Result GetAudioController(Out<SharedPointer<IAudioController>> out_audio_controller);
     Result GetDisplayController(Out<SharedPointer<IDisplayController>> out_display_controller);
     Result GetProcessWindingController(
diff --git a/src/core/hle/service/am/service/application_proxy_service.cpp b/src/core/hle/service/am/service/application_proxy_service.cpp
index 7727951d8c..67306aadc0 100644
--- a/src/core/hle/service/am/service/application_proxy_service.cpp
+++ b/src/core/hle/service/am/service/application_proxy_service.cpp
@@ -19,6 +19,8 @@ IApplicationProxyService::IApplicationProxyService(Core::System& system_,
     : ServiceFramework{system_, "appletOE"}, m_window_system{window_system} {
     static const FunctionInfo functions[] = {
         {0, D<&IApplicationProxyService::OpenApplicationProxy>, "OpenApplicationProxy"},
+        // Switch 2 SDKs open the proxy with command 10, same arguments.
+        {10, D<&IApplicationProxyService::OpenApplicationProxy>, "OpenApplicationProxy (Switch 2)"},
     };
     RegisterHandlers(functions);
 }
diff --git a/src/core/hle/service/nx2_stub_interface.h b/src/core/hle/service/nx2_stub_interface.h
new file mode 100644
index 0000000000..6890298d1b
--- /dev/null
+++ b/src/core/hle/service/nx2_stub_interface.h
@@ -0,0 +1,55 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <deque>
+#include <mutex>
+#include <string>
+#include <string_view>
+
+#include <fmt/format.h>
+
+#include "core/hle/service/ipc_helpers.h"
+#include "core/hle/service/service.h"
+
+namespace Service {
+
+// Prefix of placeholder interfaces for Switch 2-only IPC. ReportUnimplementedFunction answers
+// every call on such an interface with an empty success, so boot can go on while the log shows
+// which commands are used.
+inline constexpr std::string_view Nx2StubPrefix = "nx2:";
+
+class INx2StubInterface final : public ServiceFramework<INx2StubInterface> {
+public:
+    explicit INx2StubInterface(Core::System& system_, const char* name)
+        : ServiceFramework{system_, name} {}
+
+    // Names must outlive the interface, so they are interned here.
+    static const char* InternName(std::string name) {
+        static std::mutex mutex;
+        static std::deque<std::string> names;
+        std::scoped_lock lk{mutex};
+        for (const auto& n : names) {
+            if (n == name) {
+                return n.c_str();
+            }
+        }
+        return names.emplace_back(std::move(name)).c_str();
+    }
+};
+
+// Handler for an unknown Switch 2 command that returns an interface: hands back a stub named
+// after the owning service and the command id.
+inline void ReturnNx2StubInterface(Core::System& system, HLERequestContext& ctx,
+                                   std::string_view owner) {
+    const char* name =
+        INx2StubInterface::InternName(fmt::format("{}{}::{}", Nx2StubPrefix, owner, ctx.GetCommand()));
+    LOG_WARNING(Service, "(STUBBED) Switch 2 {}::{} -> stub interface {}", owner, ctx.GetCommand(),
+                name);
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(ResultSuccess);
+    rb.PushIpcInterface<INx2StubInterface>(ctx, system, name);
+}
+
+} // namespace Service
diff --git a/src/core/hle/service/service.cpp b/src/core/hle/service/service.cpp
index b4fe2b3ed5..373b8a2545 100644
--- a/src/core/hle/service/service.cpp
+++ b/src/core/hle/service/service.cpp
@@ -13,6 +13,7 @@
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/service/ipc_helpers.h"
 #include "core/hle/service/service.h"
+#include "core/hle/service/nx2_stub_interface.h"
 #include "core/hle/service/sm/sm.h"
 #include "core/reporter.h"
 
@@ -69,7 +70,7 @@ void ServiceFrameworkBase::ReportUnimplementedFunction(HLERequestContext& ctx,
 
     system.GetReporter().SaveUnimplementedFunctionReport(ctx, ctx.GetCommand(), function_name, service_name);
     UNIMPLEMENTED_MSG("Unknown / unimplemented {}", fmt::to_string(buf));
-    if (Settings::values.use_auto_stub) {
+    if (Settings::values.use_auto_stub || std::string_view{service_name}.starts_with(Nx2StubPrefix)) {
         LOG_WARNING(Service, "Using auto stub fallback!");
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(ResultSuccess);