5 files changed, 91 insertions, 2 deletions

diff --git a/src/core/hle/service/cfg/cfg.cpp b/src/core/hle/service/cfg/cfg.cpp
index 65655f45d..0bf59eb76 100644
--- a/src/core/hle/service/cfg/cfg.cpp
+++ b/src/core/hle/service/cfg/cfg.cpp
@@ -115,6 +115,8 @@ static const std::vector<u8> cfg_system_savedata_id = {
     0x00, 0x00, 0x00, 0x00, 0x17, 0x00, 0x01, 0x00,
 };
 
+static u32 preferred_region_code = 0;
+
 void GetCountryCodeString(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
     u32 country_code_id = cmd_buff[1];
@@ -160,11 +162,18 @@ void GetCountryCodeID(Service::Interface* self) {
     cmd_buff[2] = country_code_id;
 }
 
+static u32 GetRegionValue() {
+    if (Settings::values.region_value == Settings::REGION_VALUE_AUTO_SELECT)
+        return preferred_region_code;
+
+    return Settings::values.region_value;
+}
+
 void SecureInfoGetRegion(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
 
     cmd_buff[1] = RESULT_SUCCESS.raw;
-    cmd_buff[2] = Settings::values.region_value;
+    cmd_buff[2] = GetRegionValue();
 }
 
 void GenHashConsoleUnique(Service::Interface* self) {
@@ -184,7 +193,7 @@ void GetRegionCanadaUSA(Service::Interface* self) {
     cmd_buff[1] = RESULT_SUCCESS.raw;
 
     u8 canada_or_usa = 1;
-    if (canada_or_usa == Settings::values.region_value) {
+    if (canada_or_usa == GetRegionValue()) {
         cmd_buff[2] = 1;
     } else {
         cmd_buff[2] = 0;
@@ -314,10 +323,47 @@ static ResultVal<void*> GetConfigInfoBlockPointer(u32 block_id, u32 size, u32 fl
     return MakeResult<void*>(pointer);
 }
 
+/// Checks if the language is available in the chosen region, and returns a proper one
+static u8 AdjustLanguageInfoBlock(u32 region, u8 language) {
+    static const std::array<std::vector<u8>, 7> region_languages{{
+        // JPN
+        {LANGUAGE_JP},
+        // USA
+        {LANGUAGE_EN, LANGUAGE_FR, LANGUAGE_ES, LANGUAGE_PT},
+        // EUR
+        {LANGUAGE_EN, LANGUAGE_FR, LANGUAGE_DE, LANGUAGE_IT, LANGUAGE_ES, LANGUAGE_NL, LANGUAGE_PT,
+         LANGUAGE_RU},
+        // AUS
+        {LANGUAGE_EN, LANGUAGE_FR, LANGUAGE_DE, LANGUAGE_IT, LANGUAGE_ES, LANGUAGE_NL, LANGUAGE_PT,
+         LANGUAGE_RU},
+        // CHN
+        {LANGUAGE_ZH},
+        // KOR
+        {LANGUAGE_KO},
+        // TWN
+        {LANGUAGE_TW},
+    }};
+    const auto& available = region_languages[region];
+    if (std::find(available.begin(), available.end(), language) == available.end()) {
+        return available[0];
+    }
+    return language;
+}
+
 ResultCode GetConfigInfoBlock(u32 block_id, u32 size, u32 flag, void* output) {
     void* pointer;
     CASCADE_RESULT(pointer, GetConfigInfoBlockPointer(block_id, size, flag));
     memcpy(output, pointer, size);
+
+    // override the language setting if the region setting is auto
+    if (block_id == LanguageBlockID &&
+        Settings::values.region_value == Settings::REGION_VALUE_AUTO_SELECT) {
+        u8 language;
+        memcpy(&language, output, sizeof(u8));
+        language = AdjustLanguageInfoBlock(preferred_region_code, language);
+        memcpy(output, &language, sizeof(u8));
+    }
+
     return RESULT_SUCCESS;
 }
 
@@ -535,10 +581,17 @@ void Init() {
     AddService(new CFG_U);
 
     LoadConfigNANDSaveFile();
+
+    preferred_region_code = 0;
 }
 
 void Shutdown() {}
 
+void SetPreferredRegionCode(u32 region_code) {
+    preferred_region_code = region_code;
+    LOG_INFO(Service_CFG, "Preferred region code set to %u", preferred_region_code);
+}
+
 void SetUsername(const std::u16string& name) {
     ASSERT(name.size() <= 10);
     UsernameBlock block{};
diff --git a/src/core/hle/service/cfg/cfg.h b/src/core/hle/service/cfg/cfg.h
index fb47c2aa5..618c9647e 100644
--- a/src/core/hle/service/cfg/cfg.h
+++ b/src/core/hle/service/cfg/cfg.h
@@ -282,6 +282,13 @@ void Init();
 /// Shutdown the config service
 void Shutdown();
 
+/**
+ * Set the region code preferred by the game so that CFG will adjust to it when the region setting
+ * is auto.
+ * @param region_code the preferred region code to set
+ */
+void SetPreferredRegionCode(u32 region_code);
+
 // Utilities for frontend to set config data.
 // Note: before calling these functions, LoadConfigNANDSaveFile should be called,
 // and UpdateConfigNANDSavegame should be called after making changes to config data.
diff --git a/src/core/loader/ncch.cpp b/src/core/loader/ncch.cpp
index 6f2164428..a204dc336 100644
--- a/src/core/loader/ncch.cpp
+++ b/src/core/loader/ncch.cpp
@@ -11,8 +11,10 @@
 #include "core/file_sys/archive_romfs.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
+#include "core/hle/service/cfg/cfg.h"
 #include "core/hle/service/fs/archive.h"
 #include "core/loader/ncch.h"
+#include "core/loader/smdh.h"
 #include "core/memory.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -309,6 +311,23 @@ ResultStatus AppLoader_NCCH::LoadExeFS() {
     return ResultStatus::Success;
 }
 
+void AppLoader_NCCH::ParseRegionLockoutInfo() {
+    std::vector<u8> smdh_buffer;
+    if (ReadIcon(smdh_buffer) == ResultStatus::Success && smdh_buffer.size() >= sizeof(SMDH)) {
+        SMDH smdh;
+        memcpy(&smdh, smdh_buffer.data(), sizeof(SMDH));
+        u32 region_lockout = smdh.region_lockout;
+        constexpr u32 REGION_COUNT = 7;
+        for (u32 region = 0; region < REGION_COUNT; ++region) {
+            if (region_lockout & 1) {
+                Service::CFG::SetPreferredRegionCode(region);
+                break;
+            }
+            region_lockout >>= 1;
+        }
+    }
+}
+
 ResultStatus AppLoader_NCCH::Load() {
     if (is_loaded)
         return ResultStatus::ErrorAlreadyLoaded;
@@ -325,6 +344,9 @@ ResultStatus AppLoader_NCCH::Load() {
 
     Service::FS::RegisterArchiveType(std::make_unique<FileSys::ArchiveFactory_RomFS>(*this),
                                      Service::FS::ArchiveIdCode::RomFS);
+
+    ParseRegionLockoutInfo();
+
     return ResultStatus::Success;
 }
 
diff --git a/src/core/loader/ncch.h b/src/core/loader/ncch.h
index 6afc171a5..fe08f5b45 100644
--- a/src/core/loader/ncch.h
+++ b/src/core/loader/ncch.h
@@ -229,6 +229,9 @@ private:
      */
     ResultStatus LoadExeFS();
 
+    /// Reads the region lockout info in the SMDH and send it to CFG service
+    void ParseRegionLockoutInfo();
+
     bool is_exefs_loaded = false;
     bool is_compressed = false;
 
diff --git a/src/core/settings.h b/src/core/settings.h
index db4c8fada..4e7a4b1be 100644
--- a/src/core/settings.h
+++ b/src/core/settings.h
@@ -110,5 +110,9 @@ struct Values {
     u16 gdbstub_port;
 } extern values;
 
+// a special value for Values::region_value indicating that citra will automatically select a region
+// value to fit the region lockout info of the game
+static constexpr int REGION_VALUE_AUTO_SELECT = -1;
+
 void Apply();
 }