Added a specific breakpoint for the M68K Unimplemented instruction, and Exception...

[clinton/Virtual-Jaguar-Rx.git] / src / jaguar.cpp

diff --git a/src/jaguar.cpp b/src/jaguar.cpp
index 638cfe3..6e4b04a 100644 (file)
--- a/src/jaguar.cpp
+++ b/src/jaguar.cpp
@@ -15,6 +15,7 @@
 // JLH  11/25/2009  Major rewrite of memory subsystem and handlers
 // JPM  09/04/2018  Added the new Models and BIOS handler
 // JPM  10/13/2018  Added breakpoints features
+// JPM   Aug./2019  Fix specific breakpoint for ROM cartridge or unknown memory location writing; added a specific breakpoint for the M68K illegal & unimplemented instruction, unknown exceptions and address error exceptions
 //
 
 
@@ -1418,6 +1419,26 @@ unsigned int m68k_read_memory_16(unsigned int address)
 }
 
 
+// Alert message in case of exception vector request
+bool m68k_read_exception_vector(unsigned int address, char *text)
+{
+       QString msg;
+       QMessageBox msgBox;
+
+#if 0
+       msg.sprintf("68000 exception\n%s at $%06x", text, pcQueue[pcQPtr ? (pcQPtr - 1) : 0x3FF]);
+#else
+       msg.sprintf("68000 exception\n$%06x: %s", pcQueue[pcQPtr ? (pcQPtr - 1) : 0x3FF], text);
+#endif
+       msgBox.setText(msg);
+       msgBox.setStandardButtons(QMessageBox::Abort);
+       msgBox.setDefaultButton(QMessageBox::Abort);
+       msgBox.exec();
+       return M68KDebugHalt();
+}
+
+
+// Read 4 bytes from memory
 unsigned int m68k_read_memory_32(unsigned int address)
 {
 #ifdef ALPINE_FUNCTIONS
@@ -1436,23 +1457,48 @@ unsigned int m68k_read_memory_32(unsigned int address)
 
 //WriteLog("--> [RM32]\n");
 #ifndef USE_NEW_MMU
-       uint32_t retVal = 0;
+       //uint32_t retVal = 0;
 
-       if ((address >= 0x800000) && (address <= 0xDFFEFE))
+       // check exception vectors access
+       if ((address >= 0x8) && (address <= 0x7c))
        {
-               // Memory Track reading...
-               if (((TOMGetMEMCON1() & 0x0006) == (2 << 1)) && (jaguarMainROMCRC32 == 0xFDF37F47))
+               switch (address)
                {
-                       retVal = MTReadLong(address);
+               case 0x0c:
+                       m68k_read_exception_vector(address, "Address error");
+                       break;
+
+               case 0x10:
+                       m68k_read_exception_vector(address, "Illegal instruction");
+                       break;
+
+               case 0x2c:
+                       m68k_read_exception_vector(address, "Unimplemented instruction");
+                       break;
+
+               default:
+                       m68k_read_exception_vector(address, "Exception not referenced");
+                       break;
                }
-               else
+       }
+       else
+       {
+               // check ROM or Memory Track access
+               if ((address >= 0x800000) && (address <= 0xDFFEFE))
                {
-                       retVal = GET32(jaguarMainROM, address - 0x800000);
+                       // Memory Track reading...
+                       if (((TOMGetMEMCON1() & 0x0006) == (2 << 1)) && (jaguarMainROMCRC32 == 0xFDF37F47))
+                       {
+                               return MTReadLong(address);
+                       }
+                       else
+                       {
+                               return GET32(jaguarMainROM, address - 0x800000);
+                       }
                }
-
-               return retVal;
        }
 
+       // return value from memory
        return (m68k_read_memory_16(address) << 16) | m68k_read_memory_16(address + 2);
 #else
        return MMURead32(address, M68K);