Add some structs for files that DSi_NAND reads (#1842)

* Add DSiFirmwareSystemSettings

* Replace DSiFirmwareSystemSettings::TouchCalibration fields with std::arrays

- So assignment can be done in one line

* Make DSiFirmwareSystemSettings a union

- So its bytes can be accessed

* Add a comment

* Use DSiFirmwareSystemSettings instead of raw byte offsets

* Add definitions for DSiSerialData and DSiHardwareInfoN

* Move DSiFirmwareSystemSettings's hash update logic into its own method

3 files changed, 145 insertions, 36 deletions

diff --git a/src/DSi.cpp b/src/DSi.cpp
index 64bc6d2..cdec819 100644
--- a/src/DSi.cpp
+++ b/src/DSi.cpp
@@ -530,20 +530,20 @@ void SetupDirectBoot()
 
         if (DSi_NAND::Init(&DSi::ARM7iBIOS[0x8308]))
         {
-            u8 userdata[0x1B0];
+            DSi_NAND::DSiFirmwareSystemSettings userdata {};
             DSi_NAND::ReadUserData(userdata);
             for (u32 i = 0; i < 0x128; i+=4)
-                ARM9Write32(0x02000400+i, *(u32*)&userdata[0x88+i]);
+                ARM9Write32(0x02000400+i, *(u32*)&userdata.Bytes[0x88+i]);
 
-            u8 hwinfoS[0xA4];
-            u8 hwinfoN[0x9C];
+            DSi_NAND::DSiSerialData hwinfoS {};
+            DSi_NAND::DSiHardwareInfoN hwinfoN;
             DSi_NAND::ReadHardwareInfo(hwinfoS, hwinfoN);
 
             for (u32 i = 0; i < 0x14; i+=4)
                 ARM9Write32(0x02000600+i, *(u32*)&hwinfoN[0x88+i]);
 
             for (u32 i = 0; i < 0x18; i+=4)
-                ARM9Write32(0x02FFFD68+i, *(u32*)&hwinfoS[0x88+i]);
+                ARM9Write32(0x02FFFD68+i, *(u32*)&hwinfoS.Bytes[0x88+i]);
 
             DSi_NAND::DeInit();
         }
diff --git a/src/DSi_NAND.cpp b/src/DSi_NAND.cpp
index b7ab620..7c3e745 100644
--- a/src/DSi_NAND.cpp
+++ b/src/DSi_NAND.cpp
@@ -486,7 +486,7 @@ bool ESDecrypt(u8* data, u32 len)
 }
 
 
-void ReadHardwareInfo(u8* dataS, u8* dataN)
+void ReadHardwareInfo(DSiSerialData& dataS, DSiHardwareInfoN& dataN)
 {
     FF_FIL file;
     FRESULT res;
@@ -495,20 +495,20 @@ void ReadHardwareInfo(u8* dataS, u8* dataN)
     res = f_open(&file, "0:/sys/HWINFO_S.dat", FA_OPEN_EXISTING | FA_READ);
     if (res == FR_OK)
     {
-        f_read(&file, dataS, 0xA4, &nread);
+        f_read(&file, &dataS, sizeof(DSiSerialData), &nread);
         f_close(&file);
     }
 
     res = f_open(&file, "0:/sys/HWINFO_N.dat", FA_OPEN_EXISTING | FA_READ);
     if (res == FR_OK)
     {
-        f_read(&file, dataN, 0x9C, &nread);
+        f_read(&file, dataN.data(), sizeof(dataN), &nread);
         f_close(&file);
     }
 }
 
 
-void ReadUserData(u8* data)
+void ReadUserData(DSiFirmwareSystemSettings& data)
 {
     FF_FIL file;
     FRESULT res;
@@ -553,7 +553,7 @@ void ReadUserData(u8* data)
     }
 
     f_lseek(&file, 0);
-    f_read(&file, data, 0x1B0, &nread);
+    f_read(&file, &data, sizeof(DSiFirmwareSystemSettings), &nread);
     f_close(&file);
 }
 
@@ -574,10 +574,10 @@ void PatchUserData()
             continue;
         }
 
-        u8 contents[0x1B0];
+        DSiFirmwareSystemSettings contents;
         u32 nres;
         f_lseek(&file, 0);
-        f_read(&file, contents, 0x1B0, &nres);
+        f_read(&file, &contents, sizeof(DSiFirmwareSystemSettings), &nres);
 
         // override user settings, if needed
         if (Platform::GetConfigBool(Platform::Firm_OverrideSettings))
@@ -586,46 +586,39 @@ void PatchUserData()
             std::string orig_username = Platform::GetConfigString(Platform::Firm_Username);
             std::u16string username = std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t>{}.from_bytes(orig_username);
             size_t usernameLength = std::min(username.length(), (size_t) 10);
-            memset(contents + 0xD0, 0, 11 * sizeof(char16_t));
-            memcpy(contents + 0xD0, username.data(), usernameLength * sizeof(char16_t));
+            memset(&contents.Nickname, 0, sizeof(contents.Nickname));
+            memcpy(&contents.Nickname, username.data(), usernameLength * sizeof(char16_t));
 
             // setting language
-            contents[0x8E] = Platform::GetConfigInt(Platform::Firm_Language);
+            contents.Language = static_cast<SPI_Firmware::Language>(Platform::GetConfigInt(Platform::Firm_Language));
 
             // setting up color
-            contents[0xCC] = Platform::GetConfigInt(Platform::Firm_Color);
+            contents.FavoriteColor = Platform::GetConfigInt(Platform::Firm_Color);
 
             // setting up birthday
-            contents[0xCE] = Platform::GetConfigInt(Platform::Firm_BirthdayMonth);
-            contents[0xCF] = Platform::GetConfigInt(Platform::Firm_BirthdayDay);
+            contents.BirthdayMonth = Platform::GetConfigInt(Platform::Firm_BirthdayMonth);
+            contents.BirthdayDay = Platform::GetConfigInt(Platform::Firm_BirthdayDay);
 
             // setup message
             std::string orig_message = Platform::GetConfigString(Platform::Firm_Message);
             std::u16string message = std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t>{}.from_bytes(orig_message);
             size_t messageLength = std::min(message.length(), (size_t) 26);
-            memset(contents + 0xE6, 0, 27 * sizeof(char16_t));
-            memcpy(contents + 0xE6, message.data(), messageLength * sizeof(char16_t));
+            memset(&contents.Message, 0, sizeof(contents.Message));
+            memcpy(&contents.Message, message.data(), messageLength * sizeof(char16_t));
 
             // TODO: make other items configurable?
         }
 
         // fix touchscreen coords
-        *(u16*)&contents[0xB8] = 0;
-        *(u16*)&contents[0xBA] = 0;
-        contents[0xBC] = 0;
-        contents[0xBD] = 0;
-        *(u16*)&contents[0xBE] = 255<<4;
-        *(u16*)&contents[0xC0] = 191<<4;
-        contents[0xC2] = 255;
-        contents[0xC3] = 191;
-
-        SHA1_CTX sha;
-        SHA1Init(&sha);
-        SHA1Update(&sha, &contents[0x88], 0x128);
-        SHA1Final(&contents[0], &sha);
+        contents.TouchCalibrationADC1 = {0, 0};
+        contents.TouchCalibrationPixel1 = {0, 0};
+        contents.TouchCalibrationADC2 = {255 << 4, 191 << 4};
+        contents.TouchCalibrationPixel2 = {255, 191};
+
+        contents.UpdateHash();
 
         f_lseek(&file, 0);
-        f_write(&file, contents, 0x1B0, &nres);
+        f_write(&file, &contents, sizeof(DSiFirmwareSystemSettings), &nres);
 
         f_close(&file);
     }
@@ -1318,4 +1311,12 @@ bool ExportTitleData(u32 category, u32 titleid, int type, const char* file)
     return ExportFile(fname, file);
 }
 
+void DSiFirmwareSystemSettings::UpdateHash()
+{
+    SHA1_CTX sha;
+    SHA1Init(&sha);
+    SHA1Update(&sha, &Bytes[0x88], 0x128);
+    SHA1Final(Hash.data(), &sha);
+}
+
 }
diff --git a/src/DSi_NAND.h b/src/DSi_NAND.h
index 14599b2..9bff8f2 100644
--- a/src/DSi_NAND.h
+++ b/src/DSi_NAND.h
@@ -22,6 +22,8 @@
 #include "types.h"
 #include "NDS_Header.h"
 #include "DSi_TMD.h"
+#include "SPI_Firmware.h"
+#include <array>
 #include <vector>
 #include <string>
 
@@ -35,6 +37,10 @@ enum
     TitleData_BannerSav,
 };
 
+union DSiFirmwareSystemSettings;
+union DSiSerialData;
+using DSiHardwareInfoN = std::array<u8, 0x9C>;
+
 bool Init(u8* es_keyY);
 void DeInit();
 
@@ -42,9 +48,9 @@ Platform::FileHandle* GetFile();
 
 void GetIDs(u8* emmc_cid, u64& consoleid);
 
-void ReadHardwareInfo(u8* dataS, u8* dataN);
+void ReadHardwareInfo(DSiSerialData& dataS, DSiHardwareInfoN& dataN);
 
-void ReadUserData(u8* data);
+void ReadUserData(DSiFirmwareSystemSettings& data);
 void PatchUserData();
 
 void ListTitles(u32 category, std::vector<u32>& titlelist);
@@ -58,6 +64,108 @@ u32 GetTitleDataMask(u32 category, u32 titleid);
 bool ImportTitleData(u32 category, u32 titleid, int type, const char* file);
 bool ExportTitleData(u32 category, u32 titleid, int type, const char* file);
 
+typedef std::array<u8, 20> SHA1Hash;
+typedef std::array<u8, 8> TitleID;
+
+/// Firmware settings for the DSi, saved to the NAND as TWLCFG0.dat or TWLCFG1.dat.
+/// The DSi mirrors this information to its own firmware for compatibility with NDS games.
+/// @note The file is normally 16KiB, but only the first 432 bytes are used;
+/// the rest is FF-padded.
+/// This struct excludes the padding.
+/// @see https://problemkaputt.de/gbatek.htm#dsisdmmcfirmwaresystemsettingsdatafiles
+union DSiFirmwareSystemSettings
+{
+    struct
+    {
+        SHA1Hash Hash;
+        u8 Zero00[108];
+        u8 Version;
+        u8 UpdateCounter;
+        u8 Zero01[2];
+        u32 BelowRAMAreaSize;
+        u32 ConfigFlags;
+        u8 Zero02;
+        u8 CountryCode;
+        SPI_Firmware::Language Language;
+        u8 RTCYear;
+        u32 RTCOffset;
+        u8 Zero3[4];
+        u8 EULAVersion;
+        u8 Zero04[9];
+        u8 AlarmHour;
+        u8 AlarmMinute;
+        u8 Zero05[2];
+        bool AlarmEnable;
+        u8 Zero06[2];
+        u8 SystemMenuUsedTitleSlots;
+        u8 SystemMenuFreeTitleSlots;
+        u8 Unknown0;
+        u8 Unknown1;
+        u8 Zero07[3];
+        TitleID SystemMenuMostRecentTitleID;
+        std::array<u16, 2> TouchCalibrationADC1;
+        std::array<u8, 2> TouchCalibrationPixel1;
+        std::array<u16, 2> TouchCalibrationADC2;
+        std::array<u8, 2> TouchCalibrationPixel2;
+        u8 Unknown2[4];
+        u8 Zero08[4];
+        u8 FavoriteColor;
+        u8 Zero09;
+        u8 BirthdayMonth;
+        u8 BirthdayDay;
+        char16_t Nickname[11];
+        char16_t Message[27];
+        u8 ParentalControlsFlags;
+        u8 Zero10[6];
+        u8 ParentalControlsRegion;
+        u8 ParentalControlsYearsOfAgeRating;
+        u8 ParentalControlsSecretQuestion;
+        u8 Unknown3;
+        u8 Zero11[2];
+        char ParentalControlsPIN[5];
+        char16_t ParentalControlsSecretAnswer[65];
+    };
+    u8 Bytes[432];
+
+    void UpdateHash();
+};
+
+static_assert(sizeof(DSiFirmwareSystemSettings) == 432, "DSiFirmwareSystemSettings must be exactly 432 bytes");
+
+enum class ConsoleRegion : u8
+{
+    Japan,
+    USA,
+    Europe,
+    Australia,
+    China,
+    Korea,
+};
+
+/// 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.
+/// This struct excludes the padding.
+/// @see https://problemkaputt.de/gbatek.htm#dsisdmmcfirmwaremiscfiles
+union DSiSerialData
+{
+    struct
+    {
+        u8 RsaSha1HMAC[0x80];
+        u32 Version;
+        u32 EntrySize;
+        u32 SupportedLanguages;
+        u8 Unknown0[4];
+        ConsoleRegion Region;
+        char Serial[12];
+        u8 Unknown1[3];
+        u8 TitleIDLSBs[4];
+    };
+    u8 Bytes[164];
+};
+
+static_assert(sizeof(DSiSerialData) == 164, "DSiSerialData must be exactly 164 bytes");
+
 }
 
 #endif // DSI_NAND_H