patch_manager: Add support for dumping decompressed NSOs

When enabled in settings, PatchNSO will dump the unmodified NSO that it was passed to a file named <build id>.nso in the dump root for the current title ID.

src/core/file_sys/patch_manager.cpp

@@ -19,6 +19,7 @@
 #include "core/file_sys/vfs_vector.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/loader/loader.h"
+#include "core/settings.h"
 
 namespace FileSys {
 
@@ -119,6 +120,18 @@ std::vector<u8> PatchManager::PatchNSO(const std::vector<u8>& nso) const {
     const auto build_id_raw = Common::HexArrayToString(header.build_id);
     const auto build_id = build_id_raw.substr(0, build_id_raw.find_last_not_of('0') + 1);
 
+    if (Settings::values.dump_nso) {
+        LOG_INFO(Loader, "Dumping NSO for build_id={}, title_id={:016X}", build_id, title_id);
+        const auto dump_dir = Service::FileSystem::GetModificationDumpRoot(title_id);
+        if (dump_dir != nullptr) {
+            const auto nso_dir = GetOrCreateDirectoryRelative(dump_dir, "/nso");
+            const auto file = nso_dir->CreateFile(fmt::format("{}.nso", build_id));
+
+            file->Resize(nso.size());
+            file->WriteBytes(nso);
+        }
+    }
+
     LOG_INFO(Loader, "Patching NSO for build_id={}", build_id);
 
     const auto load_dir = Service::FileSystem::GetModificationLoadRoot(title_id);

src/core/loader/nso.cpp

@@ -154,7 +154,7 @@ std::optional<VAddr> AppLoader_NSO::LoadModule(const FileSys::VfsFile& file, VAd
     program_image.resize(image_size);
 
     // Apply patches if necessary
-    if (pm && pm->HasNSOPatch(nso_header.build_id)) {
+    if (pm && (pm->HasNSOPatch(nso_header.build_id) || Settings::values.dump_nso)) {
         std::vector<u8> pi_header(program_image.size() + 0x100);
         std::memcpy(pi_header.data(), &nso_header, sizeof(NsoHeader));
         std::memcpy(pi_header.data() + 0x100, program_image.data(), program_image.size());