4 files changed, 46 insertions, 18 deletions

diff --git a/src/core/file_sys/patch_manager.cpp b/src/core/file_sys/patch_manager.cpp
index 53b8b7ca0..7c0950bb0 100644
--- a/src/core/file_sys/patch_manager.cpp
+++ b/src/core/file_sys/patch_manager.cpp
@@ -345,8 +345,10 @@ std::vector<Core::Memory::CheatEntry> PatchManager::CreateCheatList(
 static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType type,
                            const Service::FileSystem::FileSystemController& fs_controller) {
     const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
+    const auto sdmc_load_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
     if ((type != ContentRecordType::Program && type != ContentRecordType::Data) ||
-        load_dir == nullptr || load_dir->GetSize() <= 0) {
+        ((load_dir == nullptr || load_dir->GetSize() <= 0) &&
+         (sdmc_load_dir == nullptr || sdmc_load_dir->GetSize() <= 0))) {
         return;
     }
 
@@ -356,7 +358,10 @@ static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType t
     }
 
     const auto& disabled = Settings::values.disabled_addons[title_id];
-    auto patch_dirs = load_dir->GetSubdirectories();
+    std::vector<VirtualDir> patch_dirs = load_dir->GetSubdirectories();
+    if (std::find(disabled.cbegin(), disabled.cend(), "SDMC") == disabled.cend()) {
+        patch_dirs.push_back(sdmc_load_dir);
+    }
     std::sort(patch_dirs.begin(), patch_dirs.end(),
               [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });
 
@@ -402,7 +407,7 @@ static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType t
 }
 
 VirtualFile PatchManager::PatchRomFS(VirtualFile romfs, u64 ivfc_offset, ContentRecordType type,
-                                     VirtualFile update_raw) const {
+                                     VirtualFile update_raw, bool apply_layeredfs) const {
     const auto log_string = fmt::format("Patching RomFS for title_id={:016X}, type={:02X}",
                                         title_id, static_cast<u8>(type));
 
@@ -442,7 +447,9 @@ VirtualFile PatchManager::PatchRomFS(VirtualFile romfs, u64 ivfc_offset, Content
     }
 
     // LayeredFS
-    ApplyLayeredFS(romfs, title_id, type, fs_controller);
+    if (apply_layeredfs) {
+        ApplyLayeredFS(romfs, title_id, type, fs_controller);
+    }
 
     return romfs;
 }
@@ -524,6 +531,15 @@ PatchManager::PatchVersionNames PatchManager::GetPatchVersionNames(VirtualFile u
         }
     }
 
+    // SDMC mod directory (RomFS LayeredFS)
+    const auto sdmc_mod_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
+    if (sdmc_mod_dir != nullptr && sdmc_mod_dir->GetSize() > 0 &&
+        IsDirValidAndNonEmpty(FindSubdirectoryCaseless(sdmc_mod_dir, "romfs"))) {
+        const auto mod_disabled =
+            std::find(disabled.begin(), disabled.end(), "SDMC") != disabled.end();
+        out.insert_or_assign(mod_disabled ? "[D] SDMC" : "SDMC", "LayeredFS");
+    }
+
     // DLC
     const auto dlc_entries =
         content_provider.ListEntriesFilter(TitleType::AOC, ContentRecordType::Data);
diff --git a/src/core/file_sys/patch_manager.h b/src/core/file_sys/patch_manager.h
index fb1853035..3be871f35 100644
--- a/src/core/file_sys/patch_manager.h
+++ b/src/core/file_sys/patch_manager.h
@@ -64,7 +64,8 @@ public:
     // - LayeredFS
     [[nodiscard]] VirtualFile PatchRomFS(VirtualFile base, u64 ivfc_offset,
                                          ContentRecordType type = ContentRecordType::Program,
-                                         VirtualFile update_raw = nullptr) const;
+                                         VirtualFile update_raw = nullptr,
+                                         bool apply_layeredfs = true) const;
 
     // Returns a vector of pairs between patch names and patch versions.
     // i.e. Update 3.2.2 will return {"Update", "3.2.2"}
diff --git a/src/core/file_sys/sdmc_factory.cpp b/src/core/file_sys/sdmc_factory.cpp
index cb56d8f2d..e5c72cd4d 100644
--- a/src/core/file_sys/sdmc_factory.cpp
+++ b/src/core/file_sys/sdmc_factory.cpp
@@ -12,23 +12,32 @@ namespace FileSys {
 
 constexpr u64 SDMC_TOTAL_SIZE = 0x10000000000; // 1 TiB
 
-SDMCFactory::SDMCFactory(VirtualDir dir_)
-    : dir(std::move(dir_)), contents(std::make_unique<RegisteredCache>(
-                                GetOrCreateDirectoryRelative(dir, "/Nintendo/Contents/registered"),
-                                [](const VirtualFile& file, const NcaID& id) {
-                                    return NAX{file, id}.GetDecrypted();
-                                })),
+SDMCFactory::SDMCFactory(VirtualDir sd_dir_, VirtualDir sd_mod_dir_)
+    : sd_dir(std::move(sd_dir_)), sd_mod_dir(std::move(sd_mod_dir_)),
+      contents(std::make_unique<RegisteredCache>(
+          GetOrCreateDirectoryRelative(sd_dir, "/Nintendo/Contents/registered"),
+          [](const VirtualFile& file, const NcaID& id) {
+              return NAX{file, id}.GetDecrypted();
+          })),
       placeholder(std::make_unique<PlaceholderCache>(
-          GetOrCreateDirectoryRelative(dir, "/Nintendo/Contents/placehld"))) {}
+          GetOrCreateDirectoryRelative(sd_dir, "/Nintendo/Contents/placehld"))) {}
 
 SDMCFactory::~SDMCFactory() = default;
 
 ResultVal<VirtualDir> SDMCFactory::Open() const {
-    return MakeResult<VirtualDir>(dir);
+    return MakeResult<VirtualDir>(sd_dir);
+}
+
+VirtualDir SDMCFactory::GetSDMCModificationLoadRoot(u64 title_id) const {
+    // LayeredFS doesn't work on updates and title id-less homebrew
+    if (title_id == 0 || (title_id & 0xFFF) == 0x800) {
+        return nullptr;
+    }
+    return GetOrCreateDirectoryRelative(sd_mod_dir, fmt::format("/{:016X}", title_id));
 }
 
 VirtualDir SDMCFactory::GetSDMCContentDirectory() const {
-    return GetOrCreateDirectoryRelative(dir, "/Nintendo/Contents");
+    return GetOrCreateDirectoryRelative(sd_dir, "/Nintendo/Contents");
 }
 
 RegisteredCache* SDMCFactory::GetSDMCContents() const {
@@ -40,11 +49,11 @@ PlaceholderCache* SDMCFactory::GetSDMCPlaceholder() const {
 }
 
 VirtualDir SDMCFactory::GetImageDirectory() const {
-    return GetOrCreateDirectoryRelative(dir, "/Nintendo/Album");
+    return GetOrCreateDirectoryRelative(sd_dir, "/Nintendo/Album");
 }
 
 u64 SDMCFactory::GetSDMCFreeSpace() const {
-    return GetSDMCTotalSpace() - dir->GetSize();
+    return GetSDMCTotalSpace() - sd_dir->GetSize();
 }
 
 u64 SDMCFactory::GetSDMCTotalSpace() const {
diff --git a/src/core/file_sys/sdmc_factory.h b/src/core/file_sys/sdmc_factory.h
index 2bb92ba93..3a3d11f3a 100644
--- a/src/core/file_sys/sdmc_factory.h
+++ b/src/core/file_sys/sdmc_factory.h
@@ -16,11 +16,12 @@ class PlaceholderCache;
 /// File system interface to the SDCard archive
 class SDMCFactory {
 public:
-    explicit SDMCFactory(VirtualDir dir);
+    explicit SDMCFactory(VirtualDir sd_dir_, VirtualDir sd_mod_dir_);
     ~SDMCFactory();
 
     ResultVal<VirtualDir> Open() const;
 
+    VirtualDir GetSDMCModificationLoadRoot(u64 title_id) const;
     VirtualDir GetSDMCContentDirectory() const;
 
     RegisteredCache* GetSDMCContents() const;
@@ -32,7 +33,8 @@ public:
     u64 GetSDMCTotalSpace() const;
 
 private:
-    VirtualDir dir;
+    VirtualDir sd_dir;
+    VirtualDir sd_mod_dir;
 
     std::unique_ptr<RegisteredCache> contents;
     std::unique_ptr<PlaceholderCache> placeholder;