From c1fbe684ef7981e5b3c48ce9027b6ea81092eec0 Mon Sep 17 00:00:00 2001
From: Takoroka <137927095+Takoroka@users.noreply.github.com>
Date: Thu, 29 Oct 2026 03:22:44 -0400
Subject: core: use the 12 GiB layout and auto-stub IPC for Switch 2 titles

Switch 2 titles size their heap from the total memory and stop at the
first unimplemented command, so they only booted with the 12 GiB layout
and EDEN_NX2_AUTO_STUB set by hand. Detect them from main.npdm before the
kernel starts and apply the layout as a per-game value (the configured
layout comes back once the game is closed), and auto-stub unknown
commands from Switch 2 processes.
---
 src/core/core.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'src/core/core.cpp')

diff --git a/src/core/core.cpp b/src/core/core.cpp
index eee91ef4fc..f3d224b1ce 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -24,6 +24,7 @@
 #include "core/device_memory.h"
 #include "core/file_sys/fs_filesystem.h"
 #include "core/file_sys/patch_manager.h"
+#include "core/file_sys/program_metadata.h"
 #include "core/file_sys/registered_cache.h"
 #include "core/file_sys/romfs_factory.h"
 #include "core/file_sys/savedata_factory.h"
@@ -109,6 +110,19 @@ FileSys::VirtualFile GetGameFileFromPath(const FileSys::VirtualFilesystem& vfs,
     return vfs->OpenFile(path, FileSys::OpenMode::Read);
 }
 
+namespace {
+
+// Switch 2 titles boot as a loose ExeFS, with main.npdm next to main.
+bool IsSwitch2Program(const FileSys::VirtualFile& file) {
+    const auto dir = file != nullptr ? file->GetContainingDirectory() : nullptr;
+    const auto npdm = dir != nullptr ? dir->GetFile("main.npdm") : nullptr;
+    FileSys::ProgramMetadata metadata;
+    return npdm != nullptr && metadata.Load(npdm) == Loader::ResultStatus::Success &&
+           metadata.IsSwitch2();
+}
+
+} // namespace
+
 struct System::Impl {
     explicit Impl(System& system)
         : kernel{system}, fs_controller{system}, hid_core{kernel}, cpu_manager{system},
@@ -299,6 +313,16 @@ struct System::Impl {
             fs_controller.InitTempStorage();
         }
 
+        // Switch 2 titles size their heap from the total memory and need the 12 GiB layout. Set it
+        // as a per-game value, so RestoreGlobalState brings back the configured layout afterwards.
+        if (virtual_filesystem != nullptr &&
+            Settings::values.memory_layout_mode.GetValue() != Settings::MemoryLayout::Memory_12Gb &&
+            IsSwitch2Program(GetGameFileFromPath(virtual_filesystem, filepath))) {
+            LOG_INFO(Core, "Switch 2 program: using the 12 GiB memory layout");
+            Settings::values.memory_layout_mode.SetGlobal(false);
+            Settings::values.memory_layout_mode.SetValue(Settings::MemoryLayout::Memory_12Gb);
+        }
+
         InitializeKernel(system);
 
         if (params.applet_type == Service::AM::AppletType::Application) {
-- 
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