successfully generates a "return 0xffff" instruction on 68k and testable on mac

system6/CMakeLists.txt

@@ -17,3 +17,8 @@ add_application(Emulator
     lcd_mac.c
     resources.r
 )
+
+add_application(CompilerTest
+    compiler68k.c
+    CONSOLE
+)

system6/compiler68k.c

@@ -2,8 +2,11 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+
+#ifdef USE_MPROTECT
 #include <sys/mman.h> // mprotect
 #include <unistd.h> // getpagesize
+#endif
 
 // A -> D0
 // BC -> D1
@@ -64,13 +67,12 @@ struct basic_block *compile_block(uint16_t src_address, uint8_t *gb_code)
         }
     }
 
-    bblock->length = 6;
-    bblock->code[0] = 0xb8; // mov eax, 1234h
-    bblock->code[1] = 0x34;
-    bblock->code[2] = 0x12;
-    bblock->code[3] = 0x00;
-    bblock->code[4] = 0x00;
-    bblock->code[5] = 0xc3; // ret
+    bblock->length = 4;
+    // bblock->code[0] = 0xc3;
+    bblock->code[0] = 0x70; // moveq #$ff, d0
+    bblock->code[1] = 0xff;
+    bblock->code[2] = 0x4e; // rts
+    bblock->code[3] = 0x75;
 
     return bblock;
 }
@@ -114,6 +116,7 @@ void run_all(uint8_t *gb_code)
         }
 
         // for testing...
+#ifdef USE_MPROTECT
         page_size = getpagesize();
         ret = mprotect(
             (void *) ((uint64_t) bblock & ~(page_size - 1)),
@@ -124,7 +127,13 @@ void run_all(uint8_t *gb_code)
             perror("mprotect");
             exit(0);
         }
+#endif
+        // __builtin___clear_cache(bblock, bblock + sizeof *bblock);
+        asm("":::"memory");
         jump_target = ((uint16_t (*)()) bblock->code)();
+        if (jump_target == 0xffff) {
+            break;
+        }
     }
 }
 
@@ -152,5 +161,7 @@ int main(int argc, char *argv[])
         free(data);
     }
 
+    while(1);
+
     return 0;
 }

system6/emulator.c

@@ -85,13 +85,13 @@ void Render(void)
   SetPort(g_wp);
   // CopyBits(&offscreenBmp, &g_wp->portBits, &offscreenRect, &offscreenRect, srcCopy, NULL);
 
-  EraseRect(&g_wp->portRect);
-  MoveTo(10, 180);
-  char debug[128];
-  double ms = execTime / 600.0;
-  sprintf(debug, "10000 in %d ticks, %.2f ms per instruction", execTime, ms);
-  C2PStr(debug);
-  DrawString(debug);
+  // EraseRect(&g_wp->portRect);
+  // MoveTo(10, 180);
+  // char debug[128];
+  // double ms = execTime / 600.0;
+  // sprintf(debug, "10000 in %d ticks, %.2f ms per instruction", execTime, ms);
+  // C2PStr(debug);
+  // DrawString(debug);
 }
 
 // 417 ticks
@@ -121,7 +121,7 @@ void StartEmulation(void)
   emulationOn = 1;
 }
 
-bool LoadRom(StrFileName fileName, short vRefNum)
+bool LoadRom(Str255 fileName, short vRefNum)
 {
   int err;
   short fileNo;

system6/emulator.h

@@ -37,8 +37,4 @@
 #define EMULATION_PREFERENCES 4
 #define EMULATION_KEY_MAPPINGS 5
 
-typedef unsigned char bool;
-#define true 1
-#define false 0
-
 #endif

test-compiler.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+cc -DUSE_MPROTECT -o compiler system6/compiler68k.c