quicknes: add "System Bus". note that this System Bus will not resolve any MMIO stuff at all

BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/LibQuickNES.cs

@@ -192,6 +192,22 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 		/// <returns></returns>
 		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
 		public static extern bool qn_get_memory_area(IntPtr e, int which, ref IntPtr data, ref int size, ref bool writable, ref IntPtr name);
+		/// <summary>
+		/// peek the system bus
+		/// </summary>
+		/// <param name="e">Context</param>
+		/// <param name="addr">0000:ffff, but non-ram/rom addresses won't work</param>
+		/// <returns></returns>
+		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
+		public static extern byte qn_peek_prgbus(IntPtr e, int addr);
+		/// <summary>
+		/// poke the system bus
+		/// </summary>
+		/// <param name="e">Context</param>
+		/// <param name="addr">0000:ffff, but non-ram/rom addresses won't work</param>
+		/// <param name="val"></param>
+		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
+		public static extern void qn_poke_prgbus(IntPtr e, int addr, byte val);
 
 		/// <summary>
 		/// handle "string error" as returned by some quicknes functions

BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs

@@ -308,9 +308,29 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 							if (addr < 0 || addr >= size)
 								throw new ArgumentOutOfRangeException();
 							p[addr] = val;
-					}));
+						}
+					));
 				}
 			}
+			// add system bus
+			mm.Add(new MemoryDomain
+			(
+				"System Bus",
+				0x10000,
+				MemoryDomain.Endian.Unknown,
+				delegate(int addr)
+				{
+					if (addr < 0 || addr >= 0x10000)
+						throw new ArgumentOutOfRangeException();
+					return LibQuickNES.qn_peek_prgbus(Context, addr);
+				},
+				delegate(int addr, byte val)
+				{
+					if (addr < 0 || addr >= 0x10000)
+						throw new ArgumentOutOfRangeException();
+					LibQuickNES.qn_poke_prgbus(Context, addr, val);
+				}
+			));
 			MemoryDomains = new MemoryDomainList(mm, 0);
 		}
 

quicknes/bizinterface.cpp

@@ -228,3 +228,13 @@ EXPORT int qn_get_memory_area(Nes_Emu *e, int which, const void **data, int *siz
 		return 1;
 	}
 }
+
+EXPORT unsigned char qn_peek_prgbus(Nes_Emu *e, int addr)
+{
+	return e->peek_prg(addr & 0xffff);
+}
+
+EXPORT void qn_poke_prgbus(Nes_Emu *e, int addr, unsigned char val)
+{
+	e->poke_prg(addr & 0xffff, val);
+}

quicknes/nes_emu/Nes_Emu.h

@@ -198,6 +198,11 @@ public:
 	enum { high_mem_size = 0x2000 };
 	byte* high_mem()            { return emu.impl->sram; }
 
+// Prg peek/poke for debuggin
+	byte peek_prg(nes_addr_t addr) const { return *static_cast<Nes_Cpu>(emu).get_code(addr); }
+	void poke_prg(nes_addr_t addr, byte value) { *static_cast<Nes_Cpu>(emu).get_code(addr) = value; }
+
+
 	// End of public interface
 public:
 	blargg_err_t set_sample_rate( long rate, class Nes_Buffer* );