support register reading on GB core. untested as i can't compile at the moment. flags are exported as part of register "F", as is usual for z80.

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

@@ -126,7 +126,20 @@ namespace BizHawk.Emulation.Consoles.GB
 
 		public List<KeyValuePair<string, int>> GetCpuFlagsAndRegisters()
 		{
-			throw new NotImplementedException();
+			List<KeyValuePair<string, int>> ret = new List<KeyValuePair<string, int>>();
+			int[] data = new int[10];
+			LibGambatte.gambatte_getregs(GambatteState, data);
+			ret.Add(new KeyValuePair<string, int>("PC", data[(int)LibGambatte.RegIndicies.PC] & 0xffff));
+			ret.Add(new KeyValuePair<string, int>("SP", data[(int)LibGambatte.RegIndicies.SP] & 0xffff));
+			ret.Add(new KeyValuePair<string, int>("A", data[(int)LibGambatte.RegIndicies.A] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("B", data[(int)LibGambatte.RegIndicies.B] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("C", data[(int)LibGambatte.RegIndicies.C] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("D", data[(int)LibGambatte.RegIndicies.D] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("E", data[(int)LibGambatte.RegIndicies.E] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("F", data[(int)LibGambatte.RegIndicies.F] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("H", data[(int)LibGambatte.RegIndicies.H] & 0xff));
+			ret.Add(new KeyValuePair<string, int>("L", data[(int)LibGambatte.RegIndicies.L] & 0xff));
+			return ret;
 		}
 
 		/// <summary>

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

@@ -402,5 +402,18 @@ namespace BizHawk.Emulation.Consoles.GB
 		/// <returns>todo</returns>
 		[DllImport("libgambatte.dll", CallingConvention = CallingConvention.Cdecl)]
 		public static extern int gambatte_linkstatus(IntPtr core, int which);
+
+		/// <summary>
+		/// get reg and flag values
+		/// </summary>
+		/// <param name="core">opaque state pointer</param>
+		/// <param name="dest">length of at least 10, please</param>
+		[DllImport("libgambatte.dll", CallingConvention = CallingConvention.Cdecl)]
+		public static extern void gambatte_getregs(IntPtr core, int[] dest);
+
+		public enum RegIndicies : int
+		{
+			PC, SP, A, B, C, D, E, F, H, L
+		}
 	}
 }

libgambatte/include/gambatte.h

@@ -162,6 +162,8 @@ public:
 
 	int LinkStatus(int which);
 
+	void GetRegs(int *dest);
+
 private:
 	struct Priv;
 	Priv *const p_;

libgambatte/src/cinterface.cpp

@@ -246,3 +246,9 @@ __declspec(dllexport) int gambatte_linkstatus(void *core, int which)
 	GB *g = (GB *) core;
 	return g->LinkStatus(which);
 }
+
+__declspec(dllexport) void gambatte_getregs(void *core, int *dest)
+{
+	GB *g = (GB *) core;
+	g->GetRegs(dest);
+}

libgambatte/src/cinterface.h

@@ -67,6 +67,8 @@ extern "C"
 
 	__declspec(dllexport) int gambatte_linkstatus(void *core, int which);
 
+	__declspec(dllexport) void gambatte_getregs(void *core, int *dest);
+
 }
 
 

libgambatte/src/cpu.cpp

@@ -2833,4 +2833,18 @@ void CPU::process(const unsigned long cycles) {
 	cycleCounter_ = cycleCounter;
 }
 
+void CPU::GetRegs(int *dest)
+{
+	dest[0] = PC_;
+	dest[1] = SP;
+	dest[2] = A_;
+	dest[3] = B;
+	dest[4] = C;
+	dest[5] = D;
+	dest[6] = E;
+	dest[7] = F();
+	dest[8] = H;
+	dest[9] = L;
+}
+
 }

libgambatte/src/cpu.h

@@ -127,6 +127,8 @@ public:
 	void ExternalWrite(unsigned short addr, unsigned char val) { memory.write(addr, val, cycleCounter_); }
 
 	int LinkStatus(int which) { return memory.LinkStatus(which); }
+
+	void GetRegs(int *dest);
 };
 
 }

libgambatte/src/gambatte.cpp

@@ -268,4 +268,8 @@ int GB::LinkStatus(int which) {
 	return p_->cpu.LinkStatus(which);
 }
 
+void GB::GetRegs(int *dest) {
+	p_->cpu.GetRegs(dest);
+}
+
 }