Use Config Savegame to determine system language and change display title accordingly

src/core/CMakeLists.txt

@@ -12,6 +12,8 @@ add_library(core STATIC
   file_sys/certificate.cpp
   file_sys/certificate.h
   file_sys/cia_common.h
+  file_sys/config_savegame.cpp
+  file_sys/config_savegame.h
   file_sys/data/data_container.cpp
   file_sys/data/data_container.h
   file_sys/data/extdata.cpp

src/core/file_sys/config_savegame.cpp

@@ -0,0 +1,37 @@
+// Copyright 2021 Pengfei Zhu
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstring>
+#include "common/logging/log.h"
+#include "core/file_sys/config_savegame.h"
+
+namespace Core {
+
+ConfigSavegame::ConfigSavegame() = default;
+ConfigSavegame::~ConfigSavegame() = default;
+
+bool ConfigSavegame::Init(std::vector<u8> data) {
+    if (data.size() != ConfigSavegameSize) {
+        LOG_ERROR(Core, "Config savegame is of incorrect size");
+        return false;
+    }
+    std::memcpy(&header, data.data(), sizeof(header));
+    return true;
+}
+
+u8 ConfigSavegame::GetSystemLanguage() const {
+    static constexpr u32 LanguageBlockID = 0x000A0002;
+
+    const auto iter = std::find_if(
+        header.block_entries.begin(), header.block_entries.end(),
+        [](const ConfigSavegameBlockEntry& entry) { return entry.block_id == LanguageBlockID; });
+    if (iter == header.block_entries.end()) {
+        LOG_ERROR(Core, "Cannot find Language config block, returning default (English)");
+        return 1;
+    }
+    return static_cast<u8>(iter->offset_or_data);
+}
+
+} // namespace Core

src/core/file_sys/config_savegame.h

@@ -0,0 +1,48 @@
+// Copyright 2014 Citra Emulator Project / 2021 Pengfei Zhu
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include "common/swap.h"
+
+namespace Core {
+
+constexpr u32 ConfigSavegameSize = 0x8000;
+/// The maximum number of block entries that can exist in the config file
+constexpr u32 ConfigSavegameMaxEntries = 1479;
+
+/// Block header in the config savedata file
+struct ConfigSavegameBlockEntry {
+    u32_le block_id;       ///< The id of the current block
+    u32_le offset_or_data; ///< This is the absolute offset to the block data if the size is greater
+                           /// than 4 bytes, otherwise it contains the data itself
+    u16_le size;           ///< The size of the block
+    u16_le flags;          ///< The flags of the block, possibly used for access control
+};
+
+struct ConfigSavegameHeader {
+    u16_le total_entries;       ///< The total number of set entries in the config file
+    u16_le data_entries_offset; ///< The offset where the data for the blocks start
+    /// The block headers, the maximum possible value is 1479 as per hardware
+    std::array<ConfigSavegameBlockEntry, ConfigSavegameMaxEntries> block_entries;
+    u32_le unknown; ///< This field is unknown, possibly padding, 0 has been observed in hardware
+};
+static_assert(sizeof(ConfigSavegameHeader) == 0x455C,
+              "Config Savegame header must be exactly 0x455C bytes");
+
+// This is not the config savegame itself, but rather the `config` file inside.
+class ConfigSavegame {
+public:
+    explicit ConfigSavegame();
+    ~ConfigSavegame();
+
+    bool Init(std::vector<u8> data);
+    u8 GetSystemLanguage() const;
+
+private:
+    ConfigSavegameHeader header;
+};
+
+} // namespace Core

src/core/file_sys/data/savegame.h

@@ -25,6 +25,7 @@ private:
 
     friend class Archive<Savegame>;
     friend class InnerFAT<Savegame>;
+    friend class SDMCImporter; // Needed to read config savegame
 };
 
 } // namespace Core

src/core/importer.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <cstring>
 #include <map>
 #include <regex>
 #include <cryptopp/sha.h>
@@ -14,6 +15,7 @@
 #include "core/db/seed_db.h"
 #include "core/db/title_db.h"
 #include "core/file_sys/certificate.h"
+#include "core/file_sys/config_savegame.h"
 #include "core/file_sys/data/data_container.h"
 #include "core/file_sys/data/extdata.h"
 #include "core/file_sys/data/savegame.h"
@@ -76,6 +78,8 @@ bool SDMCImporter::Init() {
         }
     }
 
+    LoadSystemLanguage();
+
     // Create children
     sdmc_decryptor = std::make_unique<SDMCDecryptor>(config.sdmc_path);
     cia_builder = std::make_unique<CIABuilder>(config, ticket_db);
@@ -94,6 +98,41 @@ bool SDMCImporter::Init() {
     return true;
 }
 
+void SDMCImporter::LoadSystemLanguage() {
+    FileUtil::IOFile file(nand_config.data_path + "sysdata/00010017/00000000", "rb");
+    if (!file) {
+        LOG_ERROR(Core, "Could not open config savegame");
+        return;
+    }
+
+    DataContainer container(file.GetData());
+    std::vector<std::vector<u8>> raw_data;
+    if (!container.IsGood() || !container.GetIVFCLevel4Data(raw_data)) {
+        return;
+    }
+
+    Savegame save(raw_data);
+    // Find index of the 'config' file
+    for (std::size_t i = 0; i < save.file_entry_table.size(); ++i) {
+        if (std::strncmp(save.file_entry_table[i].name.data(), "config", 16) != 0) {
+            continue;
+        }
+
+        // Load 'config' file
+        std::vector<u8> data;
+        if (!save.GetFileData(data, i)) {
+            return;
+        }
+
+        ConfigSavegame config;
+        if (!config.Init(std::move(data))) {
+            return;
+        }
+        system_language = static_cast<SMDH::TitleLanguage>(config.GetSystemLanguage());
+        break;
+    }
+}
+
 bool SDMCImporter::IsGood() const {
     return is_good;
 }
@@ -438,7 +477,7 @@ struct TitleData {
     u64 extdata_id;
     std::vector<u16> icon;
 };
-static TitleData LoadTitleData(NCCHContainer& ncch) {
+static TitleData LoadTitleData(NCCHContainer& ncch, SMDH::TitleLanguage language) {
     static const std::unordered_map<u64, const char*> NamedTitles{{
         // System Applications (to avoid confusion)
         {0x00040010'2002c800, "New 3DS HOME Menu manual (JPN)"},
@@ -501,7 +540,11 @@ static TitleData LoadTitleData(NCCHContainer& ncch) {
     SMDH smdh;
     std::memcpy(&smdh, smdh_buffer.data(), smdh_buffer.size());
     if (!NamedTitles.count(program_id)) { // Name was not overridden
-        title_name = Common::UTF16BufferToUTF8(smdh.GetShortTitle(SMDH::TitleLanguage::English));
+        title_name = Common::UTF16BufferToUTF8(smdh.GetShortTitle(language));
+        if (title_name.empty()) { // No title in the language for some reason
+            title_name =
+                Common::UTF16BufferToUTF8(smdh.GetShortTitle(SMDH::TitleLanguage::English));
+        }
     }
     return TitleData{std::move(title_name), extdata_id, smdh.GetIcon(false)};
 }
@@ -803,7 +846,7 @@ void SDMCImporter::ListTitle(std::vector<ContentSpecifier>& out) const {
                             break;
                         }
 
-                        const auto& [name, extdata_id, icon] = LoadTitleData(ncch);
+                        const auto& [name, extdata_id, icon] = LoadTitleData(ncch, system_language);
                         const auto size =
                             FileUtil::GetDirectoryTreeSize(directory + virtual_name + "/content/") +
                             TitleSizeAllowance;
@@ -879,7 +922,7 @@ void SDMCImporter::ListNandTitle(std::vector<ContentSpecifier>& out) const {
                             break;
                         }
 
-                        const auto& [name, extdata_id, icon] = LoadTitleData(ncch);
+                        const auto& [name, extdata_id, icon] = LoadTitleData(ncch, system_language);
                         const auto size =
                             FileUtil::GetDirectoryTreeSize(directory + virtual_name + "/content/") +
                             TitleSizeAllowance;

src/core/importer.h

@@ -13,6 +13,7 @@
 #include "common/progress_callback.h"
 #include "core/file_decryptor.h"
 #include "core/file_sys/cia_common.h"
+#include "core/file_sys/smdh.h"
 
 namespace Core {
 
@@ -196,8 +197,13 @@ public:
         return ticket_db;
     }
 
+    SMDH::TitleLanguage GetSystemLanguage() const {
+        return system_language;
+    }
+
 private:
     bool Init();
+    void LoadSystemLanguage();
 
     // Impl of ImportContent without deleting mechanism.
     bool ImportContentImpl(
@@ -230,6 +236,9 @@ private:
     bool is_good{};
     Config config;
     Config::NandConfig nand_config; // Main NAND config
+    // System language, determined from config savegame. Used to return the title's names.
+    SMDH::TitleLanguage system_language{SMDH::TitleLanguage::English};
+
     std::unique_ptr<SDMCDecryptor> sdmc_decryptor;
     FileDecryptor file_decryptor;
 

src/frontend/title_info_dialog.cpp

@@ -145,7 +145,7 @@ void TitleInfoDialog::InitializeLanguageComboBox() {
         }
 
         ui->languageComboBox->addItem(tr(LanguageNames.at(i)), static_cast<int>(i));
-        if (i == 1) { // English
+        if (i == static_cast<u8>(importer.GetSystemLanguage())) {
             ui->languageComboBox->setCurrentIndex(ui->languageComboBox->count() - 1);
         }
     }