diff -Nru openjdk.orig/hotspot/src/cpu/zero/vm/bytecodes_zero.hpp openjdk/hotspot/src/cpu/zero/vm/bytecodes_zero.hpp
--- openjdk.orig/hotspot/src/cpu/zero/vm/bytecodes_zero.hpp	2011-01-25 22:57:24.000000000 +0000
+++ openjdk/hotspot/src/cpu/zero/vm/bytecodes_zero.hpp	2011-01-28 01:46:18.769782690 +0000
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2009 Red Hat, Inc.
+ * Copyright 2009 Edward Nevill
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,6 +27,44 @@
 #ifndef CPU_ZERO_VM_BYTECODES_ZERO_HPP
 #define CPU_ZERO_VM_BYTECODES_ZERO_HPP
 
-// This file is intentionally empty
+#ifdef HOTSPOT_ASM
+#define _iaccess_0      ((Bytecodes::Code)0xdb)
+#define _iaccess_1      ((Bytecodes::Code)0xdc)
+#define _iaccess_2      ((Bytecodes::Code)0xdd)
+#define _iaccess_3      ((Bytecodes::Code)0xde)
+
+#define _invokeresolved         ((Bytecodes::Code)0xdf)
+#define _invokespecialresolved  ((Bytecodes::Code)0xe0)
+#define _invokestaticresolved   ((Bytecodes::Code)0xe1)
+
+#define _iload_iload    ((Bytecodes::Code)0xe3)
+#define _iload_iload_N  ((Bytecodes::Code)0xe4)
+
+#define _dmac           ((Bytecodes::Code)0xe6)
+
+        _iload_0_iconst_N       ,       // 231
+        _iload_1_iconst_N       ,       // 232
+        _iload_2_iconst_N       ,       // 233
+        _iload_3_iconst_N       ,       // 234
+        _iload_iconst_N         ,       // 235
+        _iadd_istore_N          ,       // 236
+        _isub_istore_N          ,       // 237
+        _iand_istore_N          ,       // 238
+        _ior_istore_N           ,       // 239
+        _ixor_istore_N          ,       // 240
+        _iadd_u4store           ,       // 241
+        _isub_u4store           ,       // 242
+        _iand_u4store           ,       // 243
+        _ior_u4store            ,       // 244
+        _ixor_u4store           ,       // 245
+        _iload_0_iload          ,       // 246
+        _iload_1_iload          ,       // 247
+        _iload_2_iload          ,       // 248
+        _iload_3_iload          ,       // 249
+        _iload_0_iload_N        ,       // 250
+        _iload_1_iload_N        ,       // 251
+        _iload_2_iload_N        ,       // 252
+        _iload_3_iload_N        ,       // 253
+#endif // HOTSPOT_ASM
 
 #endif // CPU_ZERO_VM_BYTECODES_ZERO_HPP
diff -Nru openjdk.orig/hotspot/make/linux/makefiles/zeroshark.make openjdk/hotspot/make/linux/makefiles/zeroshark.make
--- openjdk.orig/hotspot/make/linux/makefiles/zeroshark.make	2011-03-16 02:30:16.000000000 +0000
+++ openjdk/hotspot/make/linux/makefiles/zeroshark.make	2012-06-08 11:50:01.843317640 +0100
@@ -25,6 +25,43 @@
 
 # Setup common to Zero (non-Shark) and Shark versions of VM
 
+ifeq ($(ZERO_LIBARCH),arm)
+
+Obj_Files += asm_helper.o
+Obj_Files += cppInterpreter_arm.o
+Obj_Files += thumb2.o
+
+#XXX disabled until it has the updated frame anchor code (PR icedteopenjdk.orig/hotspot/323)
+#XXX and the updated calling convention for deopt (PR icedteopenjdk.orig/hotspot/484)
+#CFLAGS += -DHOTSPOT_ASM
+
+%.o: %.S
+	@echo Assembling $<
+	$(QUIETLY) $(REMOVE_TARGET)
+	$(COMPILE.CC) -o $@ $< $(COMPILE_DONE)
+
+cppInterpreter_arm.o:	offsets_arm.s bytecodes_arm.s
+thumb2.o:		offsets_arm.s
+
+offsets_arm.s:	mkoffsets
+	@echo Generating assembler offsets
+	./mkoffsets > $@
+
+bytecodes_arm.s: bytecodes_arm.def mkbc
+	@echo Generatine ARM assembler bytecode sequences
+	$(CC_COMPILE) -E -x c++ - < $< | ./mkbc - $@ $(COMPILE_DONE)
+
+mkbc:	$(GAMMADIR)/tools/mkbc.c
+	@echo Compiling mkbc tool
+	$(CC_COMPILE) -o $@ $< $(COMPILE_DONE)
+
+mkoffsets:	asm_helper.cpp
+	@echo Compiling offset generator
+	$(QUIETLY) $(REMOVE_TARGET)
+	$(CC_COMPILE) -DSTATIC_OFFSETS -o $@ $< $(COMPILE_DONE)
+
+endif
+
 # The copied fdlibm routines in sharedRuntimeTrig.o must not be optimized
 OPT_CFLAGS/sharedRuntimeTrig.o = $(OPT_CFLAGS/NOOPT)
 # The copied fdlibm routines in sharedRuntimeTrans.o must not be optimized
diff -Nru openjdk.orig/hotspot/src/cpu/zero/vm/bytecodes_zero.cpp openjdk/hotspot/src/cpu/zero/vm/bytecodes_zero.cpp
--- openjdk.orig/hotspot/src/cpu/zero/vm/bytecodes_zero.cpp	2011-03-16 02:30:16.000000000 +0000
+++ openjdk/hotspot/src/cpu/zero/vm/bytecodes_zero.cpp	2012-06-08 11:50:01.851317769 +0100
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007 Red Hat, Inc.
+ * Copyright 2009 Edward Nevill
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,5 +28,54 @@
 #include "interpreter/bytecodes.hpp"
 
 void Bytecodes::pd_initialize() {
-  // No zero specific initialization
+#ifdef HOTSPOT_ASM
+  // Because iaccess_N can trap, we must say aload_N can trap, otherwise
+  // we get an assertion failure
+  def(_aload_1, "aload_1", "b", NULL, T_OBJECT ,  1, true);
+  def(_aload_2, "aload_2", "b", NULL, T_OBJECT ,  1, true);
+  def(_aload_3, "aload_3", "b", NULL, T_OBJECT ,  1, true);
+
+  def(_iaccess_0, "_iaccess_0", "b_jj", NULL, T_INT,  1, true, _aload_0);
+  def(_iaccess_1, "_iaccess_1", "b_jj", NULL, T_INT,  1, true, _aload_1);
+  def(_iaccess_2, "_iaccess_2", "b_jj", NULL, T_INT,  1, true, _aload_2);
+  def(_iaccess_3, "_iaccess_3", "b_jj", NULL, T_INT,  1, true, _aload_3);
+
+  def(_invokeresolved,   "invokeresolved",   "bjj", NULL, T_ILLEGAL, -1, true, _invokevirtual);
+  def(_invokespecialresolved, "invokespecialresolved", "bjj", NULL, T_ILLEGAL, -1, true, _invokespecial);
+  def(_invokestaticresolved,  "invokestaticresolved",  "bjj", NULL, T_ILLEGAL,  0, true, _invokestatic);
+
+  def(_dmac,            "dmac",      "b_",  NULL, T_DOUBLE, -16, false, _dmul);
+
+  def(_iload_iload,      "iload_iload",      "bi_i",NULL, T_INT, 2, false, _iload);
+  def(_iload_iload_N,    "ilaod_iload_N",    "bi_", NULL, T_INT, 2, false, _iload);
+
+  def(_iload_0_iconst_N, "iload_0_iconst_N", "b_",  NULL, T_INT, 2, false, _iload_0);
+  def(_iload_1_iconst_N, "iload_1_iconst_N", "b_",  NULL, T_INT, 2, false, _iload_1);
+  def(_iload_2_iconst_N, "iload_2_iconst_N", "b_",  NULL, T_INT, 2, false, _iload_2);
+  def(_iload_3_iconst_N, "iload_3_iconst_N", "b_",  NULL, T_INT, 2, false, _iload_3);
+  def(_iload_iconst_N,   "iload_iconst_N",   "bi_", NULL, T_INT, 2, false, _iload);
+
+  def(_iadd_istore_N,    "iadd_istore_N",    "b_",  NULL, T_VOID, -2, false, _iadd);
+  def(_isub_istore_N,    "isub_istore_N",    "b_",  NULL, T_VOID, -2, false, _isub);
+  def(_iand_istore_N,    "iand_istore_N",    "b_",  NULL, T_VOID, -2, false, _iand);
+  def(_ior_istore_N,     "ior_istore_N",     "b_",  NULL, T_VOID, -2, false, _ior);
+  def(_ixor_istore_N,    "ixor_istore_N",    "b_",  NULL, T_VOID, -2, false, _ixor);
+
+  def(_iadd_u4store,     "iadd_u4store",     "b_i", NULL, T_VOID, -2, false, _iadd);
+  def(_isub_u4store,     "isub_u4store",     "b_i", NULL, T_VOID, -2, false, _isub);
+  def(_iand_u4store,     "iand_u4store",     "b_i", NULL, T_VOID, -2, false, _iand);
+  def(_ior_u4store,      "ior_u4store",      "b_i", NULL, T_VOID, -2, false, _ior);
+  def(_ixor_u4store,     "ixor_u4store",     "b_i", NULL, T_VOID, -2, false, _ixor);
+
+  def(_iload_0_iload,    "iload_0_iload",    "b_i", NULL, T_INT, 2, false, _iload_0);
+  def(_iload_1_iload,    "iload_1_iload",    "b_i", NULL, T_INT, 2, false, _iload_1);
+  def(_iload_2_iload,    "iload_2_iload",    "b_i", NULL, T_INT, 2, false, _iload_2);
+  def(_iload_3_iload,    "iload_3_iload",    "b_i", NULL, T_INT, 2, false, _iload_3);
+
+  def(_iload_0_iload_N,  "iload_0_iload_N",  "b_",  NULL, T_INT, 2, false, _iload_0);
+  def(_iload_1_iload_N,  "iload_1_iload_N",  "b_",  NULL, T_INT, 2, false, _iload_1);
+  def(_iload_2_iload_N,  "iload_2_iload_N",  "b_",  NULL, T_INT, 2, false, _iload_2);
+  def(_iload_3_iload_N,  "iload_3_iload_N",  "b_",  NULL, T_INT, 2, false, _iload_3);
+
+#endif // HOTSPOT_ASM
 }
diff -Nru openjdk.orig/hotspot/src/cpu/zero/vm/cppInterpreter_zero.cpp openjdk/hotspot/src/cpu/zero/vm/cppInterpreter_zero.cpp
--- openjdk.orig/hotspot/src/cpu/zero/vm/cppInterpreter_zero.cpp	2011-03-16 02:30:16.000000000 +0000
+++ openjdk/hotspot/src/cpu/zero/vm/cppInterpreter_zero.cpp	2012-06-08 11:50:01.851317769 +0100
@@ -749,10 +749,21 @@
   return generate_entry((address) CppInterpreter::normal_entry);
 }
 
+#ifdef HOTSPOT_ASM
+extern "C" address asm_generate_method_entry(
+  AbstractInterpreter::MethodKind kind);
+#endif // HOTSPOT_ASM
+
 address AbstractInterpreterGenerator::generate_method_entry(
     AbstractInterpreter::MethodKind kind) {
   address entry_point = NULL;
 
+#ifdef HOTSPOT_ASM
+    address asm_entry = asm_generate_method_entry(kind);
+    if (asm_entry)
+      return ((InterpreterGenerator*) this)->generate_entry(asm_entry);
+#endif // HOTSPOT_ASM
+
   switch (kind) {
   case Interpreter::zerolocals:
   case Interpreter::zerolocals_synchronized:
diff -Nru openjdk.orig/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp openjdk/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp
--- openjdk.orig/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp	2011-03-16 02:30:16.000000000 +0000
+++ openjdk/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.cpp	2012-06-08 11:50:01.851317769 +0100
@@ -116,6 +116,10 @@
   ShouldNotCallThis();
 }
 
+#ifdef HOTSPOT_ASM
+extern "C" int asm_check_null_ptr(ucontext_t *uc);
+#endif // HOTSPOT_ASM
+
 extern "C" int
 JVM_handle_linux_signal(int sig,
                         siginfo_t* info,
@@ -123,6 +127,12 @@
                         int abort_if_unrecognized) {
   ucontext_t* uc = (ucontext_t*) ucVoid;
 
+#ifdef HOTSPOT_ASM
+  if (sig == SIGSEGV) {
+        if (asm_check_null_ptr(uc)) return 1;
+  }
+#endif // HOTSPOT_ASM
+
   Thread* t = ThreadLocalStorage::get_thread_slow();
 
   SignalHandlerMark shm(t);