From 0214f234a839e3ca3a6f3627fee784f885ae5541 Mon Sep 17 00:00:00 2001
From: SuuperW <SuuperW@gmail.com>
Date: Mon, 23 Dec 2019 10:02:51 -0600
Subject: [PATCH] MelonDS: Re-work sync settings a bit.

---
 .../Consoles/Nintendo/NDS/MelonDS.cs          | 49 ++++++++++++-------
 .../Consoles/Nintendo/NDS/MelonDS_Settable.cs |  9 ++--
 2 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.cs
index b787161eba..e425773a91 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS.cs
@@ -71,7 +71,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 		private static extern void FrameAdvance(short buttons, byte touchX, byte touchY);
 
 		[CoreConstructor("NDS")]
-		public MelonDS(byte[] file, CoreComm comm)
+		public MelonDS(byte[] file, CoreComm comm, object settings, object syncsettings)
 		{
 			_serviceProvider = new BasicServiceProvider(this);
 			ControllerDefinition = new ControllerDefinition();
@@ -100,23 +100,8 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 			CoreComm = comm;
 			CoreComm.NominalWidth = 256;
 			CoreComm.NominalHeight = 192;
-			// MelonDS will look for bios + firmware files at specific locations
-			byte[] fwBytes;
-			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "bios7", false);
-			if (fwBytes != null)
-				File.WriteAllBytes("melon/bios7.bin", fwBytes);
-			else
-				File.Delete("melon/bios7.bin");
-			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "bios9", false);
-			if (fwBytes != null)
-				File.WriteAllBytes("melon/bios9.bin", fwBytes);
-			else
-				File.Delete("melon/bios9.bin");
-			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "firmware", false);
-			if (fwBytes != null)
-				File.WriteAllBytes("melon/firmware.bin", fwBytes);
-			else
-				File.Delete("melon/firmware.bin");
+
+			SetUpFiles(syncsettings as MelonSyncSettings);
 
 			if (!Init())
 				throw new Exception("Failed to init NDS.");
@@ -126,5 +111,33 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 				LoadROM(f, file.Length);
 			}
 		}
+
+		/// <summary>
+		/// MelonDS expects bios and firmware files at a specific location.
+		/// </summary>
+		private void SetUpFiles(MelonSyncSettings ss)
+		{
+			byte[] fwBytes;
+			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "bios7", false);
+			if (fwBytes != null)
+				File.WriteAllBytes("melon/bios7.bin", fwBytes);
+			else
+				File.Delete("melon/bios7.bin");
+
+			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "bios9", false);
+			if (fwBytes != null)
+				File.WriteAllBytes("melon/bios9.bin", fwBytes);
+			else
+				File.Delete("melon/bios9.bin");
+
+			fwBytes = CoreComm.CoreFileProvider.GetFirmware("NDS", "firmware", false);
+			if (fwBytes != null)
+			{
+				ss.data.CopyTo(fwBytes, fwBytes.Length - 0x200); // NDS user settings are included in the firmware file.
+				File.WriteAllBytes("melon/firmware.bin", fwBytes);
+			}
+			else
+				File.Delete("melon/firmware.bin");
+		}
 	}
 }
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs
index 939ba7a035..acf3f7081e 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs
@@ -31,17 +31,14 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 
 		public bool PutSyncSettings(MelonSyncSettings o)
 		{
-			fixed (byte* ptr = o.data)
-				SetUserSettings(ptr);
-
+			// At present, no sync settings can be modified without requiring a reboot.
+			// Also all sync settings are in the firmware file, which is modified upon core construction.
+			// So there's nothing to actually do here.
 			return true;
 		}
 
 		[DllImport(dllPath)]
 		private static extern bool GetUserSettings(byte* dst);
-		[DllImport(dllPath)]
-		private static extern bool SetUserSettings(byte* src);
-
 		[DllImport(dllPath)]
 		private static extern int getUserSettingsLength();
 		static int userSettingsLength = getUserSettingsLength();