[Gambatte] Open Bus Emulation (#2798)

* [Gambatte] Open Bus Emulation

* Fix regressions

* a

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.ISettable.cs

@@ -118,6 +118,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 			[DefaultValue(false)]
 			public bool MulticartCompat { get; set; }
 
+			[DisplayName("Cart Bus Pull-Up Time")]
+			[Description("Time it takes for the cart bus to pull-up to 0xFF in CPU cycles. Used to account for differences in pull-up times between carts/consoles.")]
+			[DefaultValue(8)]
+			public uint CartBusPullUpTime { get; set; }
+
 			[DisplayName("Realtime RTC")]
 			[Description("If true, the real time clock in MBC3 and HuC3 games will reflect real time, instead of emulated time.  Ignored (treated as false) when a movie is recording.")]
 			[DefaultValue(false)]

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/Gambatte.cs

@@ -180,6 +180,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 
 				LibGambatte.gambatte_setrtcdivisoroffset(GambatteState, _syncSettings.RTCDivisorOffset);
 
+				LibGambatte.gambatte_setcartbuspulluptime(GambatteState, _syncSettings.CartBusPullUpTime);
+
 				_cdCallback = new LibGambatte.CDCallback(CDCallbackProc);
 
 				NewSaveCoreSetBuff();

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/LibGambatte.cs

@@ -279,6 +279,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 		[DllImport("libgambatte.dll", CallingConvention = CallingConvention.Cdecl)]
 		public static extern void gambatte_setrtcdivisoroffset(IntPtr core, int rtcDivisorOffset);
 
+		/// <summary>
+		/// Sets how long until the cart bus pulls up in CPU cycles.
+		/// This is used to account for differences in pull-up times between carts/consoles.
+		/// </summary>
+		/// <param name="core">opaque state pointer</param>
+		/// <param name="cartBusPullUpTime">Pull-Up Time</param>
+		[DllImport("libgambatte.dll", CallingConvention = CallingConvention.Cdecl)]
+		public static extern void gambatte_setcartbuspulluptime(IntPtr core, uint cartBusPullUpTime);
+
 		/// <summary>
 		/// Returns true if the currently loaded ROM image is treated as having CGB support.
 		/// </summary>

submodules/gambatte

@@ -1 +1 @@
-Subproject commit 7054db26504566649882688244be59cd75c29a19
+Subproject commit 97c6008635508bda05e198af393805af49a38563