GDB Stub: Initial commit

src/cpu/386.c

@@ -22,6 +22,7 @@
 #include <86box/fdd.h>
 #include <86box/fdc.h>
 #include <86box/machine.h>
+#include <86box/gdbstub.h>
 #include "386_common.h"
 #ifdef USE_NEW_DYNAREC
 #include "codegen.h"
@@ -256,6 +257,11 @@ exec386(int cycs)
 
 		if (TIMER_VAL_LESS_THAN_VAL(timer_target, (uint32_t) tsc))
 			timer_process_inline();
+
+#ifdef USE_GDBSTUB
+		if (gdbstub_singlestep)
+			return;
+#endif
 	}
     }
 }