Rework system title handling with up-to-date title list and region detection support. (#6356)

src/core/CMakeLists.txt

@@ -458,6 +458,8 @@ add_library(core STATIC
     rpc/udp_server.h
     savestate.cpp
     savestate.h
+    system_titles.cpp
+    system_titles.h
     telemetry_session.cpp
     telemetry_session.h
     tracer/citrace.h

src/core/loader/ncch.cpp

@@ -25,6 +25,7 @@
 #include "core/loader/ncch.h"
 #include "core/loader/smdh.h"
 #include "core/memory.h"
+#include "core/system_titles.h"
 #include "network/network.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -162,7 +163,10 @@ ResultStatus AppLoader_NCCH::LoadExec(std::shared_ptr<Kernel::Process>& process)
     return ResultStatus::Error;
 }
 
-void AppLoader_NCCH::ParseRegionLockoutInfo() {
+void AppLoader_NCCH::ParseRegionLockoutInfo(u64 program_id) {
+    auto cfg = Service::CFG::GetModule(Core::System::GetInstance());
+    ASSERT_MSG(cfg, "CFG Module missing!");
+
     std::vector<u8> smdh_buffer;
     if (ReadIcon(smdh_buffer) == ResultStatus::Success && smdh_buffer.size() >= sizeof(SMDH)) {
         SMDH smdh;
@@ -176,9 +180,12 @@ void AppLoader_NCCH::ParseRegionLockoutInfo() {
             }
             region_lockout >>= 1;
         }
-        auto cfg = Service::CFG::GetModule(Core::System::GetInstance());
-        ASSERT_MSG(cfg, "CFG Module missing!");
         cfg->SetPreferredRegionCodes(regions);
+    } else {
+        const auto region = Core::GetSystemTitleRegion(program_id);
+        if (region.has_value()) {
+            cfg->SetPreferredRegionCodes({region.value()});
+        }
     }
 }
 
@@ -229,7 +236,7 @@ ResultStatus AppLoader_NCCH::Load(std::shared_ptr<Kernel::Process>& process) {
 
     system.ArchiveManager().RegisterSelfNCCH(*this);
 
-    ParseRegionLockoutInfo();
+    ParseRegionLockoutInfo(ncch_program_id);
 
     return ResultStatus::Success;
 }

src/core/loader/ncch.h

@@ -76,7 +76,9 @@ private:
     ResultStatus LoadExec(std::shared_ptr<Kernel::Process>& process);
 
     /// Reads the region lockout info in the SMDH and send it to CFG service
-    void ParseRegionLockoutInfo();
+    /// If an SMDH is not present, the program ID is compared against a list
+    /// of known system titles to determine the region.
+    void ParseRegionLockoutInfo(u64 program_id);
 
     /// Detects whether the NCCH contains GBA Virtual Console.
     bool IsGbaVirtualConsole(const std::vector<u8>& code);

src/core/system_titles.h

@@ -0,0 +1,28 @@
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <vector>
+#include "common/common_types.h"
+
+namespace Core {
+
+constexpr u32 NUM_SYSTEM_TITLE_REGIONS = 7;
+
+enum SystemTitleSet : u32 { Minimal = 1 << 0, Old3ds = 1 << 1, New3ds = 1 << 2 };
+
+/// Returns a list of firmware title IDs for a specific set and region.
+std::vector<u64> GetSystemTitleIds(SystemTitleSet set, u32 region);
+
+/// Gets the home menu title ID for a specific region.
+u64 GetHomeMenuTitleId(u32 region);
+
+/// Gets the home menu NCCH path for a specific region.
+std::string GetHomeMenuNcchPath(u32 region);
+
+/// Returns the region of a system title, if it can be determined.
+std::optional<u32> GetSystemTitleRegion(u64 title_id);
+
+} // namespace Core