fix on_bus_read issue for genplus-gx core

- related to issue TASEmulators#3813
- update signatures, create new value variable in each of the memory read core functions, pass it to the callback and return it instead of the inline calculations. Also, pass val to write and exec callbacks in IDebuggable since they all use the same mem_cb signature and it would break otherwise. I want to update write and exec callbacks in next commit though to ensure nothing unexpected happens.

Author: VelpaChallenger

Assets/dll/gpgx.wbx.zst

@@ -59,23 +59,23 @@ public void SetCpuRegister(string register, int value)
 
 		private void InitMemCallbacks()
 		{
-			ExecCallback = new LibGPGX.mem_cb(a =>
+			ExecCallback = new LibGPGX.mem_cb((a, val) =>
 			{
 				if (MemoryCallbacks.HasExecutes)
 				{
 					uint flags = (uint)MemoryCallbackFlags.AccessExecute;
 					MemoryCallbacks.CallMemoryCallbacks(a, 0, flags, "M68K BUS");
 				}
 			});
-			ReadCallback = new LibGPGX.mem_cb(a =>
+			ReadCallback = new LibGPGX.mem_cb((a, val) =>
 			{
 				if (MemoryCallbacks.HasReads)
 				{
 					uint flags = (uint)MemoryCallbackFlags.AccessRead;
-					MemoryCallbacks.CallMemoryCallbacks(a, 0, flags, "M68K BUS");
+					MemoryCallbacks.CallMemoryCallbacks(a, val, flags, "M68K BUS");
 				}
 			});
-			WriteCallback = new LibGPGX.mem_cb(a =>
+			WriteCallback = new LibGPGX.mem_cb((a, val) =>
 			{
 				if (MemoryCallbacks.HasWrites)
 				{

src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IDebuggable.cs

@@ -148,7 +148,7 @@ public enum CDLog_Flags
 		public abstract void gpgx_set_input_callback(input_cb cb);
 
 		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-		public delegate void mem_cb(uint addr);
+		public delegate void mem_cb(uint addr, uint value); //value MUST be uint, since the value will be trimmed if the type is byte (8-bit) or ushort (16-bit) and the value read/written/executed is bigger than that (i.e 32 bits).
 
 		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
 		public delegate void CDCallback(int addr, CDLog_AddrType addrtype, CDLog_Flags flags);

src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/LibGPGX.cs

@@ -8,7 +8,7 @@
 typedef ECL_ENTRY void (*CDCallback)(int32 addr, int32 addrtype, int32 flags);
 
 extern ECL_ENTRY void (*biz_execcb)(unsigned addr);
-extern ECL_ENTRY void (*biz_readcb)(unsigned addr);
+extern ECL_ENTRY void (*biz_readcb)(unsigned addr, unsigned int value);
 extern ECL_ENTRY void (*biz_writecb)(unsigned addr);
 extern CDCallback biz_cdcallback;
 extern unsigned biz_lastpc;

waterbox/gpgx/cinterface/callbacks.h

@@ -56,7 +56,7 @@ static uint8_t brm_format[0x40] =
 };
 
 ECL_ENTRY void (*biz_execcb)(unsigned addr);
-ECL_ENTRY void (*biz_readcb)(unsigned addr);
+ECL_ENTRY void (*biz_readcb)(unsigned addr, unsigned int value);
 ECL_ENTRY void (*biz_writecb)(unsigned addr);
 CDCallback biz_cdcallback = NULL;
 unsigned biz_lastpc = 0;

waterbox/gpgx/cinterface/cinterface.c

@@ -870,24 +870,25 @@ INLINE uint m68ki_read_imm_32(void)
 INLINE uint m68ki_read_8_fc(uint address, uint fc)
 {
   cpu_memory_map *temp = &m68ki_cpu.memory_map[((address)>>16)&0xff];;
-	if (biz_readcb)
-		biz_readcb(address);
 
 	if(biz_cdcallback)
 		CDLog68k(address,eCDLog_Flags_Data68k);
 
   m68ki_set_fc(fc) /* auto-disable (see m68kcpu.h) */
 
-  if (temp->read8) return (*temp->read8)(ADDRESS_68K(address));
-  else return READ_BYTE(temp->base, (address) & 0xffff);
+  uint value;	  
+  if (temp->read8)
+    value = (*temp->read8)(ADDRESS_68K(address));
+  else
+    value = READ_BYTE(temp->base, (address) & 0xffff);  
+  if (biz_readcb)
+    biz_readcb(address, value);
+  return value;
 }
 
 INLINE uint m68ki_read_16_fc(uint address, uint fc)
 {
   cpu_memory_map *temp;
-	if (biz_readcb)
-		biz_readcb(address);
-
 	if(biz_cdcallback)
 	{
 		CDLog68k(address,eCDLog_Flags_Data68k);
@@ -898,16 +899,19 @@ INLINE uint m68ki_read_16_fc(uint address, uint fc)
   m68ki_check_address_error(address, MODE_READ, fc) /* auto-disable (see m68kcpu.h) */
 
   temp = &m68ki_cpu.memory_map[((address)>>16)&0xff];
-  if (temp->read16) return (*temp->read16)(ADDRESS_68K(address));
-  else return *(uint16 *)(temp->base + ((address) & 0xffff));
+  uint value;
+  if (temp->read16)
+	  value = (*temp->read16)(ADDRESS_68K(address));
+  else
+	  value = *(uint16 *)(temp->base + ((address) & 0xffff));
+  if (biz_readcb)
+	  biz_readcb(address, value);
+  return value;
 }
 
 INLINE uint m68ki_read_32_fc(uint address, uint fc)
 {
   cpu_memory_map *temp;
-	if (biz_readcb)
-		biz_readcb(address);
-
 	if(biz_cdcallback)
 	{
 		CDLog68k(address,eCDLog_Flags_Data68k);
@@ -920,8 +924,14 @@ INLINE uint m68ki_read_32_fc(uint address, uint fc)
   m68ki_check_address_error(address, MODE_READ, fc) /* auto-disable (see m68kcpu.h) */
 
   temp = &m68ki_cpu.memory_map[((address)>>16)&0xff];
-  if (temp->read16) return ((*temp->read16)(ADDRESS_68K(address)) << 16) | ((*temp->read16)(ADDRESS_68K(address + 2)));
-  else return m68k_read_immediate_32(address);
+  uint value;
+  if (temp->read16)
+	  value = ((*temp->read16)(ADDRESS_68K(address)) << 16) | ((*temp->read16)(ADDRESS_68K(address + 2)));
+  else
+	  value = m68k_read_immediate_32(address);
+  if (biz_readcb)
+	  biz_readcb(address, value);
+  return value;
 }
 
 INLINE void m68ki_write_8_fc(uint address, uint fc, uint value)