Miscellaneous DSi NAND fixes (#1852)

* Replace some standard I/O calls with Platform equivalents

- I missed a spot when I submitted that PR a few months ago

* Include <memory> in DSi_NAND.h

- Because it uses unique_ptr

* Split DSi_NAND::ReadHardwareInfo into ReadSerialData and ReadHardwareInfoN

* Add a RegionMask enum

* Move DSi NAND patching to the frontend

* Add DSiSupportedLanguageMask

- Not currently used by the frontend, but I use it in melonDS DS

* Remove some Platform::ConfigEntry values

- The core no longer needs to know about them
- The corresponding Config values are unchanged

* Mark NANDMount's destructor as noexcept

src/DSi_NAND.h

@@ -25,6 +25,7 @@
 #include "DSi_TMD.h"
 #include "SPI_Firmware.h"
 #include <array>
+#include <memory>
 #include <vector>
 #include <string>
 
@@ -84,7 +85,7 @@ class NANDMount
 {
 public:
     explicit NANDMount(NANDImage& nand) noexcept;
-    ~NANDMount();
+    ~NANDMount() noexcept;
     NANDMount(const NANDMount&) = delete;
     NANDMount& operator=(const NANDMount&) = delete;
 
@@ -92,10 +93,15 @@ public:
     NANDMount(NANDMount&&) = delete;
     NANDMount& operator=(NANDMount&&) = delete;
 
+    bool ReadSerialData(DSiSerialData& dataS);
+    bool ReadHardwareInfoN(DSiHardwareInfoN& dataN);
     void ReadHardwareInfo(DSiSerialData& dataS, DSiHardwareInfoN& dataN);
 
-    void ReadUserData(DSiFirmwareSystemSettings& data);
-    void PatchUserData();
+    bool ReadUserData(DSiFirmwareSystemSettings& data);
+
+    /// Saves the given system settings to the DSi NAND,
+    /// to both TWLCFG0.dat and TWLCFG1.dat.
+    bool ApplyUserData(const DSiFirmwareSystemSettings& data);
 
     void ListTitles(u32 category, std::vector<u32>& titlelist);
     bool TitleExists(u32 category, u32 titleid);
@@ -211,6 +217,29 @@ enum class ConsoleRegion : u8
     Korea,
 };
 
+/// Languages that the given NAND image supports.
+/// @see https://problemkaputt.de/gbatek.htm#dsiregions
+enum DSiSupportedLanguageMask : u32 {
+    NoLanguagesSet = 0,
+    JapaneseSupported = 1 << 0,
+    EnglishSupported = 1 << 1,
+    FrenchSupported = 1 << 2,
+    GermanSupported = 1 << 3,
+    ItalianSupported = 1 << 4,
+    SpanishSupported = 1 << 5,
+    ChineseSupported = 1 << 6,
+    KoreanSupported = 1 << 7,
+
+    JapanLanguages = JapaneseSupported,
+    AmericaLanguages = EnglishSupported | FrenchSupported | SpanishSupported,
+    EuropeLanguages = EnglishSupported | FrenchSupported | GermanSupported | ItalianSupported | SpanishSupported,
+    AustraliaLanguages = EnglishSupported,
+
+    // "Unknown (supposedly Chinese/Mandarin?, and maybe English or so)"
+    ChinaLanguages = ChineseSupported | EnglishSupported,
+    KoreaLanguages = KoreanSupported,
+};
+
 /// Data file saved to 0:/sys/HWINFO_S.dat.
 /// @note The file is normally 16KiB, but only the first 164 bytes are used;
 /// the rest is FF-padded.
@@ -223,7 +252,7 @@ union DSiSerialData
         u8 RsaSha1HMAC[0x80];
         u32 Version;
         u32 EntrySize;
-        u32 SupportedLanguages;
+        DSiSupportedLanguageMask SupportedLanguages;
         u8 Unknown0[4];
         ConsoleRegion Region;
         char Serial[12];