diff --git a/src/class_loader.h b/src/class_loader.h
index 3309a8a..ff62d12 100644
--- a/src/class_loader.h
+++ b/src/class_loader.h
@@ -16,7 +16,7 @@
   static const std::vector<const DexFile*>& GetClassPath(const ClassLoader* class_loader);
 
   void SetClassPath(std::vector<const DexFile*>& class_path) {
-    DCHECK_EQ(0U, class_path_.size());
+    DCHECK_EQ(class_path_.size(), 0U);
     // TODO: use setter
     class_path_ = class_path;
   }
diff --git a/src/common_test.h b/src/common_test.h
index 4689b28..4ed61f2 100644
--- a/src/common_test.h
+++ b/src/common_test.h
@@ -98,8 +98,10 @@
       setenv("ANDROID_ROOT", root.c_str(), 1);
     }
 
-    android_data_ = (is_host_ ? "/tmp/art-data-XXXXXX" : "/sdcard/art-data-XXXXXX");
-    ASSERT_TRUE(mkdtemp(&android_data_[0]) != NULL);
+    android_data_ = (is_host_ ? "/tmp/art-data-XXXXXX" : "/mnt/sdcard/art-data-XXXXXX");
+    if (mkdtemp(&android_data_[0]) == NULL) {
+      PLOG(FATAL) << "mkdtemp(\"" << &android_data_[0] << "\") failed";
+    }
     setenv("ANDROID_DATA", android_data_.c_str(), 1);
     art_cache_.append(android_data_.c_str());
     art_cache_.append("/art-cache");
@@ -257,7 +259,8 @@
     Class* klass = class_linker_->FindClass(class_descriptor, class_loader);
     CHECK(klass != NULL) << "Class not found " << class_name;
     Method* method = klass->FindDirectMethod(method_name, signature);
-    CHECK(method != NULL) << "Method not found " << method_name;
+    CHECK(method != NULL) << "Direct method not found: "
+                          << class_name << "." << method_name << signature;
     CompileMethod(method);
   }
 
@@ -269,7 +272,8 @@
     Class* klass = class_linker_->FindClass(class_descriptor, class_loader);
     CHECK(klass != NULL) << "Class not found " << class_name;
     Method* method = klass->FindVirtualMethod(method_name, signature);
-    CHECK(method != NULL) << "Method not found " << method_name;
+    CHECK(method != NULL) << "Virtual method not found: "
+                          << class_name << "." << method_name << signature;
     CompileMethod(method);
   }
 
diff --git a/src/compiler/Frontend.cc b/src/compiler/Frontend.cc
index e9f8a3a..64d701e 100644
--- a/src/compiler/Frontend.cc
+++ b/src/compiler/Frontend.cc
@@ -699,40 +699,7 @@
  */
 bool oatCompileMethod(Method* method, art::InstructionSet insnSet)
 {
-    bool compiling = true;
-    if (!method->IsStatic()) {
-        compiling = false;  // assume skip
-        if (PrettyMethod(method).find("virtualCall") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("tryThing") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("getFoo") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("setFoo") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("IntMath.<init>") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("IntMathBase.<init>") != std::string::npos) {
-            compiling = true;
-        }
-        if (PrettyMethod(method).find("java.lang.Object.<init>") != std::string::npos) {
-            compiling = true;
-        }
-    } else if (method->GetName()->ToModifiedUtf8().find("foo") != std::string::npos) {
-        compiling = false;
-    }
-
-    if (compiling) {
-        LOG(INFO) << "Compiling " << PrettyMethod(method);
-    } else {
-        LOG(INFO) << "not compiling " << PrettyMethod(method);
-        return false;
-    }
+    LOG(INFO) << "Compiling " << PrettyMethod(method) << "...";
 
     CompilationUnit cUnit;
     art::ClassLinker* class_linker = art::Runtime::Current()->GetClassLinker();
@@ -930,6 +897,9 @@
     method->SetFrameSizeInBytes(cUnit.frameSize);
     method->SetCoreSpillMask(cUnit.coreSpillMask);
     method->SetFpSpillMask(cUnit.fpSpillMask);
+    LOG(INFO) << "Compiled " << PrettyMethod(method)
+              << " code at " << reinterpret_cast<void*>(managed_code->GetData())
+              << " (" << managed_code->GetLength() << " bytes)";
     // TODO: Transmit mapping table to caller
 
 #if 0
diff --git a/src/compiler/codegen/arm/Thumb2/Gen.cc b/src/compiler/codegen/arm/Thumb2/Gen.cc
index d0b0683..9ea9e70 100644
--- a/src/compiler/codegen/arm/Thumb2/Gen.cc
+++ b/src/compiler/codegen/arm/Thumb2/Gen.cc
@@ -361,6 +361,9 @@
  */
 static void markGCCard(CompilationUnit* cUnit, int valReg, int tgtAddrReg)
 {
+#if 1
+  UNIMPLEMENTED(WARNING);
+#else
     int regCardBase = oatAllocTemp(cUnit);
     int regCardNo = oatAllocTemp(cUnit);
     ArmLIR* branchOver = genCmpImmBranch(cUnit, kArmCondEq, valReg, 0);
@@ -374,6 +377,7 @@
     branchOver->generic.target = (LIR*)target;
     oatFreeTemp(cUnit, regCardBase);
     oatFreeTemp(cUnit, regCardNo);
+#endif
 }
 
 static void genIGetX(CompilationUnit* cUnit, MIR* mir, OpSize size,
diff --git a/src/compiler_test.cc b/src/compiler_test.cc
index 656c7d4..e3ff47f 100644
--- a/src/compiler_test.cc
+++ b/src/compiler_test.cc
@@ -26,7 +26,7 @@
     jclass c = env->FindClass(klass);
     CHECK(c != NULL) << "Class not found " << klass;
     jmethodID m = env->GetStaticMethodID(c, method, signature);
-    CHECK(m != NULL) << "Method not found " << method;
+    CHECK(m != NULL) << "Method not found: " << klass << "." << method << signature;
 #if defined(__arm__)
     va_list args;
     va_start(args, expected);
@@ -44,7 +44,7 @@
     jclass c = env->FindClass(klass);
     CHECK(c != NULL) << "Class not found " << klass;
     jmethodID m = env->GetStaticMethodID(c, method, signature);
-    CHECK(m != NULL) << "Method not found " << method;
+    CHECK(m != NULL) << "Method not found: " << klass << "." << method << signature;
 #if defined(__arm__)
     va_list args;
     va_start(args, expected);
@@ -263,5 +263,41 @@
                         111);
 }
 
+TEST_F(CompilerTest, SystemMethodsTest) {
+  CompileDirectMethod(NULL, "java.lang.Object", "<init>", "()V");
+
+  CompileDirectMethod(NULL, "java.lang.String", "<clinit>", "()V");
+  CompileDirectMethod(NULL, "java.lang.String", "<init>", "(II[C)V");
+  CompileDirectMethod(NULL, "java.lang.String", "<init>", "([CII)V");
+  CompileVirtualMethod(NULL, "java.lang.String", "charAt", "(I)C");
+  CompileVirtualMethod(NULL, "java.lang.String", "length", "()I");
+  CompileVirtualMethod(NULL, "java.lang.String", "_getChars", "(II[CI)V");
+
+  CompileDirectMethod(NULL, "java.lang.AbstractStringBuilder", "<init>", "(I)V");
+  CompileVirtualMethod(NULL, "java.lang.AbstractStringBuilder", "append0", "(Ljava/lang/String;)V");
+  CompileVirtualMethod(NULL, "java.lang.AbstractStringBuilder", "append0", "(C)V");
+  CompileVirtualMethod(NULL, "java.lang.AbstractStringBuilder", "appendNull", "()V");
+  CompileDirectMethod(NULL, "java.lang.AbstractStringBuilder", "enlargeBuffer", "(I)V");
+  CompileVirtualMethod(NULL, "java.lang.AbstractStringBuilder", "toString", "()Ljava/lang/String;");
+
+  CompileDirectMethod(NULL, "java.lang.StringBuilder", "<init>", "(I)V");
+  CompileVirtualMethod(NULL, "java.lang.StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;");
+  CompileVirtualMethod(NULL, "java.lang.StringBuilder", "append", "(C)Ljava/lang/StringBuilder;");
+  CompileVirtualMethod(NULL, "java.lang.StringBuilder", "toString", "()Ljava/lang/String;");
+
+  // TODO: we can't compile these yet.
+  //  CompileDirectMethod(NULL, "java.lang.Long", "toString", "(JI)Ljava/lang/String;");
+  //  CompileDirectMethod(NULL, "java.lang.IntegralToString", "longToString", "(JI)Ljava/lang/String;");
+
+  CompileDirectMethod(NULL, "java.lang.System", "arraycopy", "(Ljava/lang/Object;ILjava/lang/Object;II)V");
+  CompileDirectMethod(NULL, "java.lang.System", "log", "(CLjava/lang/String;Ljava/lang/Throwable;)V");
+  CompileDirectMethod(NULL, "java.lang.System", "logI", "(Ljava/lang/String;Ljava/lang/Throwable;)V");
+  CompileDirectMethod(NULL, "java.lang.System", "logI", "(Ljava/lang/String;)V");
+  CompileDirectMethod(NULL, "java.lang.System", "currentTimeMillis", "()J");
+
+  const ClassLoader* class_loader = LoadDex("SystemMethods");
+  AssertStaticIntMethod(class_loader, "SystemMethods", "test2", "()I", 123);
+}
+
 
 }  // namespace art
diff --git a/src/java_lang_System.cc b/src/java_lang_System.cc
index e45519e..2bb767d 100644
--- a/src/java_lang_System.cc
+++ b/src/java_lang_System.cc
@@ -213,14 +213,14 @@
   Class* initialElementClass = NULL;
   if (length > 0 && srcObj[0] != NULL) {
     initialElementClass = srcObj[0]->GetClass();
-    if (!Class::CanPutArrayElementFromCode(initialElementClass, dstClass)) {
+    if (!Class::CanPutArrayElement(initialElementClass, dstClass)) {
       initialElementClass = NULL;
     }
   }
 
   int copyCount;
   for (copyCount = 0; copyCount < length; copyCount++) {
-    if (srcObj[copyCount] != NULL && srcObj[copyCount]->GetClass() != initialElementClass && !Class::CanPutArrayElementFromCode(srcObj[copyCount]->GetClass(), dstClass)) {
+    if (srcObj[copyCount] != NULL && srcObj[copyCount]->GetClass() != initialElementClass && !Class::CanPutArrayElement(srcObj[copyCount]->GetClass(), dstClass)) {
       // Can't put this element into the array.
       // We'll copy up to this point, then throw.
       break;
diff --git a/src/object.cc b/src/object.cc
index d60b4c8..5d99cb6 100644
--- a/src/object.cc
+++ b/src/object.cc
@@ -595,9 +595,20 @@
   return false;
 }
 
-bool Class::CanPutArrayElementFromCode(const Class* elementClass, const Class* arrayClass) {
-  UNIMPLEMENTED(FATAL);
-  return false;
+bool Class::CanPutArrayElement(const Class* object_class, const Class* array_class) {
+  if (object_class->IsArrayClass()) {
+    return array_class->IsArrayAssignableFromArray(object_class);
+  } else {
+    return array_class->GetComponentType()->IsAssignableFrom(object_class);
+  }
+}
+
+void Class::CanPutArrayElementFromCode(const Class* object_class, const Class* array_class) {
+  if (!CanPutArrayElement(object_class, array_class)) {
+    LOG(ERROR) << "Can't put a " << PrettyDescriptor(object_class->GetDescriptor())
+               << " into a " << PrettyDescriptor(array_class->GetDescriptor());
+    UNIMPLEMENTED(FATAL) << "need to throw ArrayStoreException and unwind stack";
+  }
 }
 
 // Determine whether "this" is assignable from "klazz", where both of these
@@ -617,7 +628,7 @@
 //   Serializable[][] = Y[][] --> false (unless Y is Serializable)
 //
 // Don't forget about primitive types.
-//   int[] instanceof Object[]     --> false
+//   Object[]         = int[] --> false
 //
 bool Class::IsArrayAssignableFromArray(const Class* klass) const {
   DCHECK(IsArrayClass());
@@ -854,6 +865,7 @@
 }
 
 Array* Array::Alloc(Class* array_class, int32_t component_count, size_t component_size) {
+  DCHECK(array_class != NULL);
   DCHECK_GE(component_count, 0);
   DCHECK(array_class->IsArrayClass());
   size_t size = SizeOf(component_count, component_size);
diff --git a/src/object.h b/src/object.h
index 4edae14..fa09782 100644
--- a/src/object.h
+++ b/src/object.h
@@ -1092,7 +1092,7 @@
   }
 
   void SetLength(int32_t length) {
-    CHECK_LE(0, length);
+    CHECK_GE(length, 0);
     SetField32(OFFSET_OF_OBJECT_MEMBER(Array, length_), length, false);
   }
 
@@ -1421,7 +1421,12 @@
     return !IsPrimitive() && GetSuperClass() == NULL;
   }
 
-  static bool CanPutArrayElementFromCode(const Class* elementClass, const Class* arrayClass);
+  // Tests whether an element of type 'object_class' can be
+  // assigned into an array of type 'array_class'.
+  static bool CanPutArrayElement(const Class* object_class, const Class* array_class);
+  // Like CanPutArrayElement, but throws an exception and
+  // unwinds the stack instead of returning false.
+  static void CanPutArrayElementFromCode(const Class* object_class, const Class* array_class);
 
   // Given the context of a calling Method, use its DexCache to
   // resolve a type to a Class. If it cannot be resolved, throw an
diff --git a/src/thread.cc b/src/thread.cc
index a617fb4..5da02ae 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -176,7 +176,7 @@
 Mutex* Mutex::Create(const char* name) {
   Mutex* mu = new Mutex(name);
   int result = pthread_mutex_init(&mu->lock_impl_, NULL);
-  CHECK_EQ(0, result);
+  CHECK_EQ(result, 0);
   return mu;
 }
 
diff --git a/src/thread.h b/src/thread.h
index 070933b..8749689 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -214,7 +214,7 @@
   void (*pSet64Static)(uint32_t, const Method*, uint64_t);
   Object* (*pGetObjStatic)(uint32_t, const Method*);
   void (*pSetObjStatic)(uint32_t, const Method*, Object*);
-  bool (*pCanPutArrayElementFromCode)(const Class*, const Class*);
+  void (*pCanPutArrayElementFromCode)(const Class*, const Class*);
   int (*pInstanceofNonTrivialFromCode) (const Class*, const Class*);
   Method* (*pFindInterfaceMethodInCache)(Class*, uint32_t, const Method*, struct DvmDex*);
   bool (*pUnlockObjectFromCode)(Thread*, Object*);