diff --git a/makefile b/makefile
index 7ce70e22e2..676ecfdf6e 100644
--- a/makefile
+++ b/makefile
@@ -449,7 +449,7 @@ $(bootimage-bin): $(bootimage-generator)
 $(bootimage-object): $(bootimage-bin) $(binaryToMacho)
 	@echo "creating $(@)"
 ifeq ($(platform),darwin)
-	$(binaryToMacho) $(<) __BOOT __boot \
+	$(binaryToMacho) $(asm) $(<) __BOOT __boot \
 		__binary_bootimage_bin_start __binary_bootimage_bin_end > $(@)
 else
 	(wd=$$(pwd); \
diff --git a/src/assembler.h b/src/assembler.h
index 6aa6242072..8fda163ca3 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -277,6 +277,9 @@ class Assembler {
     virtual void updateCall(UnaryOperation op, bool assertAlignment,
                             void* returnAddress, void* newTarget) = 0;
 
+    virtual uintptr_t getConstant(const void* src) = 0;
+    virtual void setConstant(void* dst, uintptr_t constant) = 0;
+
     virtual unsigned alignFrameSize(unsigned sizeInWords) = 0;
 
     virtual void* frameIp(void* stack) = 0;
diff --git a/src/compile.cpp b/src/compile.cpp
index bd1b3367b5..df17107cbd 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -27,7 +27,7 @@ vmCall();
 
 namespace {
 
-const bool DebugCompile = true;
+const bool DebugCompile = false;
 const bool DebugNatives = false;
 const bool DebugCallTable = false;
 const bool DebugMethodTree = false;
@@ -5627,28 +5627,33 @@ fixupHeap(MyThread* t UNUSED, uintptr_t* map, unsigned size, uintptr_t* heap)
 }
 
 void
-fixupCode(Thread*, uintptr_t* map, unsigned size, uint8_t* code,
+fixupCode(Thread* t, uintptr_t* map, unsigned size, uint8_t* code,
           uintptr_t* heap)
 {
+  Assembler::Architecture* arch = makeArchitecture(t->m->system);
+  arch->acquire();
+
   for (unsigned word = 0; word < size; ++word) {
     uintptr_t w = map[word];
     if (w) {
       for (unsigned bit = 0; bit < BitsPerWord; ++bit) {
         if (w & (static_cast<uintptr_t>(1) << bit)) {
           unsigned index = indexOf(word, bit);
-          uintptr_t v; memcpy(&v, code + index, BytesPerWord);
+          uintptr_t v = arch->getConstant(code + index);
           uintptr_t mark = v >> BootShift;
           if (mark) {
-            v = reinterpret_cast<uintptr_t>(code + (v & BootMask));
-            memcpy(code + index, &v, BytesPerWord);
+            arch->setConstant(code + index, reinterpret_cast<uintptr_t>
+                              (code + (v & BootMask)));
           } else {
-            v = reinterpret_cast<uintptr_t>(heap + v - 1);
-            memcpy(code + index, &v, BytesPerWord);
+            arch->setConstant(code + index, reinterpret_cast<uintptr_t>
+                              (heap + v - 1));
           }
         }
       }
     }
   }
+
+  arch->release();
 }
 
 void
diff --git a/src/powerpc.cpp b/src/powerpc.cpp
index 9ad08e11b1..99e06601cb 100644
--- a/src/powerpc.cpp
+++ b/src/powerpc.cpp
@@ -1690,10 +1690,25 @@ class MyArchitecture: public Assembler::Architecture {
                    reinterpret_cast<intptr_t>(newTarget));
     } break;
 
+    case LongCall:
+    case LongJump: {
+      updateImmediate(c.s, static_cast<uint8_t*>(returnAddress) - 12,
+                      reinterpret_cast<intptr_t>(newTarget), BytesPerWord);
+    } break;
+
     default: abort(&c);
     }
   }
 
+  virtual uintptr_t getConstant(const void* src) {
+    const int32_t* p = static_cast<const int32_t*>(src);
+    return (p[0] << 16) | (p[1] & 0xFFFF);    
+  }
+
+  virtual void setConstant(void* dst, uintptr_t constant) {
+    updateImmediate(c.s, dst, constant, BytesPerWord);
+  }
+
   virtual unsigned alignFrameSize(unsigned sizeInWords) {
     const unsigned alignment = 16 / BytesPerWord;
     return (ceiling(sizeInWords + FrameFooterSize, alignment) * alignment);
diff --git a/src/x86.cpp b/src/x86.cpp
index c63ba57365..a5c01de2e3 100644
--- a/src/x86.cpp
+++ b/src/x86.cpp
@@ -2085,6 +2085,16 @@ class MyArchitecture: public Assembler::Architecture {
     }
   }
 
+  virtual uintptr_t getConstant(const void* src) {
+    uintptr_t v;
+    memcpy(&v, src, BytesPerWord);
+    return v;
+  }
+
+  virtual void setConstant(void* dst, uintptr_t constant) {
+    memcpy(dst, &constant, BytesPerWord);
+  }
+
   virtual unsigned alignFrameSize(unsigned sizeInWords) {
     const unsigned alignment = 16 / BytesPerWord;
     return (ceiling(sizeInWords + FrameHeaderSize, alignment) * alignment)