diff --git a/openjdkjvmti/ti_class.cc b/openjdkjvmti/ti_class.cc
index 1697092..9bea18a 100644
--- a/openjdkjvmti/ti_class.cc
+++ b/openjdkjvmti/ti_class.cc
@@ -715,7 +715,7 @@
     if (!klass->IsProxyClass() && klass->GetDexCache() != nullptr) {
       art::StackHandleScope<1> hs(soa.Self());
       art::Handle<art::mirror::Class> h_klass = hs.NewHandle(klass);
-      art::mirror::ObjectArray<art::mirror::String>* str_array =
+      art::ObjPtr<art::mirror::ObjectArray<art::mirror::String>> str_array =
           art::annotations::GetSignatureAnnotationForClass(h_klass);
       if (str_array != nullptr) {
         std::ostringstream oss;
diff --git a/openjdkjvmti/ti_field.cc b/openjdkjvmti/ti_field.cc
index 328e2a1..2a860d9 100644
--- a/openjdkjvmti/ti_field.cc
+++ b/openjdkjvmti/ti_field.cc
@@ -91,7 +91,7 @@
   if (generic_ptr != nullptr) {
     *generic_ptr = nullptr;
     if (!art_field->GetDeclaringClass()->IsProxyClass()) {
-      art::mirror::ObjectArray<art::mirror::String>* str_array =
+      art::ObjPtr<art::mirror::ObjectArray<art::mirror::String>> str_array =
           art::annotations::GetSignatureAnnotationForField(art_field);
       if (str_array != nullptr) {
         std::ostringstream oss;
diff --git a/openjdkjvmti/ti_method.cc b/openjdkjvmti/ti_method.cc
index c0c312c..d0b7224f 100644
--- a/openjdkjvmti/ti_method.cc
+++ b/openjdkjvmti/ti_method.cc
@@ -345,7 +345,7 @@
   if (generic_ptr != nullptr) {
     *generic_ptr = nullptr;
     if (!art_method->GetDeclaringClass()->IsProxyClass()) {
-      art::mirror::ObjectArray<art::mirror::String>* str_array =
+      art::ObjPtr<art::mirror::ObjectArray<art::mirror::String>> str_array =
           art::annotations::GetSignatureAnnotationForMethod(art_method);
       if (str_array != nullptr) {
         std::ostringstream oss;
diff --git a/runtime/arch/stub_test.cc b/runtime/arch/stub_test.cc
index 78516e3..b0c0e43 100644
--- a/runtime/arch/stub_test.cc
+++ b/runtime/arch/stub_test.cc
@@ -21,6 +21,7 @@
 #include "base/callee_save_type.h"
 #include "base/enums.h"
 #include "class_linker-inl.h"
+#include "class_root.h"
 #include "common_runtime_test.h"
 #include "entrypoints/quick/quick_entrypoints_enum.h"
 #include "imt_conflict_table.h"
@@ -2096,7 +2097,7 @@
 
   EXPECT_FALSE(self->IsExceptionPending());
 
-  GcRoot<mirror::Class>& root = mirror::String::java_lang_String_;
+  GcRoot<mirror::Class> root(GetClassRoot<mirror::String>());
   size_t result = Invoke3(reinterpret_cast<size_t>(&root), 0U, 0U, readBarrierForRootSlow, self);
 
   EXPECT_FALSE(self->IsExceptionPending());
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index b882f65..0952723 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -484,27 +484,10 @@
                  mirror::ObjectArray<mirror::Object>::ClassSize(image_pointer_size_))));
   object_array_class->SetComponentType(java_lang_Object.Get());
 
-  // Setup the char (primitive) class to be used for char[].
-  Handle<mirror::Class> char_class(hs.NewHandle(
-      AllocClass(self, java_lang_Class.Get(),
-                 mirror::Class::PrimitiveClassSize(image_pointer_size_))));
-  // The primitive char class won't be initialized by
-  // InitializePrimitiveClass until line 459, but strings (and
-  // internal char arrays) will be allocated before that and the
-  // component size, which is computed from the primitive type, needs
-  // to be set here.
-  char_class->SetPrimitiveType(Primitive::kPrimChar);
-
-  // Setup the char[] class to be used for String.
-  Handle<mirror::Class> char_array_class(hs.NewHandle(
-      AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
-  char_array_class->SetComponentType(char_class.Get());
-
   // Setup String.
   Handle<mirror::Class> java_lang_String(hs.NewHandle(
       AllocClass(self, java_lang_Class.Get(), mirror::String::ClassSize(image_pointer_size_))));
   java_lang_String->SetStringClass();
-  mirror::String::SetClass(java_lang_String.Get());
   mirror::Class::SetStatus(java_lang_String, ClassStatus::kResolved, self);
 
   // Setup java.lang.ref.Reference.
@@ -523,7 +506,6 @@
   SetClassRoot(ClassRoot::kJavaLangObject, java_lang_Object.Get());
   SetClassRoot(ClassRoot::kClassArrayClass, class_array_class.Get());
   SetClassRoot(ClassRoot::kObjectArrayClass, object_array_class.Get());
-  SetClassRoot(ClassRoot::kCharArrayClass, char_array_class.Get());
   SetClassRoot(ClassRoot::kJavaLangString, java_lang_String.Get());
   SetClassRoot(ClassRoot::kJavaLangRefReference, java_lang_ref_Reference.Get());
 
@@ -533,6 +515,7 @@
   // Setup the primitive type classes.
   SetClassRoot(ClassRoot::kPrimitiveBoolean, CreatePrimitiveClass(self, Primitive::kPrimBoolean));
   SetClassRoot(ClassRoot::kPrimitiveByte, CreatePrimitiveClass(self, Primitive::kPrimByte));
+  SetClassRoot(ClassRoot::kPrimitiveChar, CreatePrimitiveClass(self, Primitive::kPrimChar));
   SetClassRoot(ClassRoot::kPrimitiveShort, CreatePrimitiveClass(self, Primitive::kPrimShort));
   SetClassRoot(ClassRoot::kPrimitiveInt, CreatePrimitiveClass(self, Primitive::kPrimInt));
   SetClassRoot(ClassRoot::kPrimitiveLong, CreatePrimitiveClass(self, Primitive::kPrimLong));
@@ -543,13 +526,13 @@
   // Create array interface entries to populate once we can load system classes.
   array_iftable_ = GcRoot<mirror::IfTable>(AllocIfTable(self, 2));
 
-  // Create int array type for AllocDexCache (done in AppendToBootClassPath).
+  // Create int array type for native pointer arrays (for example vtables) on 32-bit archs.
   Handle<mirror::Class> int_array_class(hs.NewHandle(
       AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
   int_array_class->SetComponentType(GetClassRoot(ClassRoot::kPrimitiveInt, this));
   SetClassRoot(ClassRoot::kIntArrayClass, int_array_class.Get());
 
-  // Create long array type for AllocDexCache (done in AppendToBootClassPath).
+  // Create long array type for native pointer arrays (for example vtables) on 64-bit archs.
   Handle<mirror::Class> long_array_class(hs.NewHandle(
       AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_))));
   long_array_class->SetComponentType(GetClassRoot(ClassRoot::kPrimitiveLong, this));
@@ -604,10 +587,6 @@
 
   // now we can use FindSystemClass
 
-  // run char class through InitializePrimitiveClass to finish init
-  InitializePrimitiveClass(char_class.Get(), Primitive::kPrimChar);
-  SetClassRoot(ClassRoot::kPrimitiveChar, char_class.Get());  // needs descriptor
-
   // Set up GenericJNI entrypoint. That is mainly a hack for common_compiler_test.h so that
   // we do not need friend classes or a publicly exposed setter.
   quick_generic_jni_trampoline_ = GetQuickGenericJniStub();
@@ -636,7 +615,7 @@
 
   SetClassRoot(ClassRoot::kByteArrayClass, FindSystemClass(self, "[B"));
 
-  CheckSystemClass(self, char_array_class, "[C");
+  SetClassRoot(ClassRoot::kCharArrayClass, FindSystemClass(self, "[C"));
 
   SetClassRoot(ClassRoot::kShortArrayClass, FindSystemClass(self, "[S"));
 
@@ -685,7 +664,7 @@
                FindSystemClass(self, "Ljava/lang/reflect/Proxy;"));
 
   // Create java.lang.reflect.Field.class root.
-  auto* class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;");
+  ObjPtr<mirror::Class> class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;");
   CHECK(class_root != nullptr);
   SetClassRoot(ClassRoot::kJavaLangReflectField, class_root);
 
@@ -1014,10 +993,6 @@
           spaces[0]->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)));
   mirror::Class::SetClassClass(GetClassRoot(ClassRoot::kJavaLangClass, this));
 
-  // Special case of setting up the String class early so that we can test arbitrary objects
-  // as being Strings or not
-  mirror::String::SetClass(GetClassRoot<mirror::String>(this));
-
   ObjPtr<mirror::Class> java_lang_Object = GetClassRoot<mirror::Object>(this);
   java_lang_Object->SetObjectSize(sizeof(mirror::Object));
   // Allocate in non-movable so that it's possible to check if a JNI weak global ref has been
@@ -2109,7 +2084,6 @@
 
 ClassLinker::~ClassLinker() {
   mirror::Class::ResetClass();
-  mirror::String::ResetClass();
   Thread* const self = Thread::Current();
   for (const ClassLoaderData& data : class_loaders_) {
     // CHA unloading analysis is not needed. No negative consequences are expected because
@@ -3561,20 +3535,13 @@
 }
 
 mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) {
-  ObjPtr<mirror::Class> klass =
+  ObjPtr<mirror::Class> primitive_class =
       AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_));
-  if (UNLIKELY(klass == nullptr)) {
+  if (UNLIKELY(primitive_class == nullptr)) {
     self->AssertPendingOOMException();
     return nullptr;
   }
-  return InitializePrimitiveClass(klass, type);
-}
-
-mirror::Class* ClassLinker::InitializePrimitiveClass(ObjPtr<mirror::Class> primitive_class,
-                                                     Primitive::Type type) {
-  CHECK(primitive_class != nullptr);
   // Must hold lock on object when initializing.
-  Thread* self = Thread::Current();
   StackHandleScope<1> hs(self);
   Handle<mirror::Class> h_class(hs.NewHandle(primitive_class));
   ObjectLock<mirror::Class> lock(self, h_class);
@@ -3668,8 +3635,6 @@
       new_class.Assign(GetClassRoot<mirror::ObjectArray<mirror::Object>>(this));
     } else if (strcmp(descriptor, "[Ljava/lang/String;") == 0) {
       new_class.Assign(GetClassRoot<mirror::ObjectArray<mirror::String>>(this));
-    } else if (strcmp(descriptor, "[C") == 0) {
-      new_class.Assign(GetClassRoot<mirror::CharArray>(this));
     } else if (strcmp(descriptor, "[I") == 0) {
       new_class.Assign(GetClassRoot<mirror::IntArray>(this));
     } else if (strcmp(descriptor, "[J") == 0) {
diff --git a/runtime/class_linker.h b/runtime/class_linker.h
index afe5c99..1f94c43 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -793,10 +793,6 @@
   mirror::Class* CreatePrimitiveClass(Thread* self, Primitive::Type type)
       REQUIRES_SHARED(Locks::mutator_lock_)
       REQUIRES(!Roles::uninterruptible_);
-  mirror::Class* InitializePrimitiveClass(ObjPtr<mirror::Class> primitive_class,
-                                          Primitive::Type type)
-      REQUIRES_SHARED(Locks::mutator_lock_)
-      REQUIRES(!Roles::uninterruptible_);
 
   mirror::Class* CreateArrayClass(Thread* self,
                                   const char* descriptor,
diff --git a/runtime/dex/dex_file_annotations.cc b/runtime/dex/dex_file_annotations.cc
index ffa0a90..5cb08dc 100644
--- a/runtime/dex/dex_file_annotations.cc
+++ b/runtime/dex/dex_file_annotations.cc
@@ -849,7 +849,8 @@
   return annotation_value.value_.GetL();
 }
 
-mirror::ObjectArray<mirror::String>* GetSignatureValue(const ClassData& klass,
+static ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureValue(
+    const ClassData& klass,
     const DexFile::AnnotationSetItem* annotation_set)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   const DexFile& dex_file = klass.GetDexFile();
@@ -860,12 +861,9 @@
   if (annotation_item == nullptr) {
     return nullptr;
   }
-  ObjPtr<mirror::Class> string_class = mirror::String::GetJavaLangString();
-  Handle<mirror::Class> string_array_class(hs.NewHandle(
-      Runtime::Current()->GetClassLinker()->FindArrayClass(Thread::Current(), &string_class)));
-  if (string_array_class == nullptr) {
-    return nullptr;
-  }
+  Handle<mirror::Class> string_array_class =
+      hs.NewHandle(GetClassRoot<mirror::ObjectArray<mirror::String>>());
+  DCHECK(string_array_class != nullptr);
   ObjPtr<mirror::Object> obj =
       GetAnnotationValue(klass, annotation_item, "value", string_array_class,
                          DexFile::kDexAnnotationArray);
@@ -880,19 +878,16 @@
     const DexFile::AnnotationSetItem* annotation_set)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   const DexFile& dex_file = klass.GetDexFile();
-  StackHandleScope<1> hs(Thread::Current());
   const DexFile::AnnotationItem* annotation_item =
       SearchAnnotationSet(dex_file, annotation_set, "Ldalvik/annotation/Throws;",
                           DexFile::kDexVisibilitySystem);
   if (annotation_item == nullptr) {
     return nullptr;
   }
-  ObjPtr<mirror::Class> class_class = mirror::Class::GetJavaLangClass();
-  Handle<mirror::Class> class_array_class(hs.NewHandle(
-      Runtime::Current()->GetClassLinker()->FindArrayClass(Thread::Current(), &class_class)));
-  if (class_array_class == nullptr) {
-    return nullptr;
-  }
+  StackHandleScope<1> hs(Thread::Current());
+  Handle<mirror::Class> class_array_class =
+      hs.NewHandle(GetClassRoot<mirror::ObjectArray<mirror::Class>>());
+  DCHECK(class_array_class != nullptr);
   ObjPtr<mirror::Object> obj =
       GetAnnotationValue(klass, annotation_item, "value", class_array_class,
                          DexFile::kDexAnnotationArray);
@@ -1020,7 +1015,7 @@
   return ProcessAnnotationSet(field_class, annotation_set, DexFile::kDexVisibilityRuntime);
 }
 
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForField(ArtField* field) {
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForField(ArtField* field) {
   const DexFile::AnnotationSetItem* annotation_set = FindAnnotationSetForField(field);
   if (annotation_set == nullptr) {
     return nullptr;
@@ -1171,9 +1166,10 @@
                                               annotation_class);
 }
 
-bool GetParametersMetadataForMethod(ArtMethod* method,
-                                    MutableHandle<mirror::ObjectArray<mirror::String>>* names,
-                                    MutableHandle<mirror::IntArray>* access_flags) {
+bool GetParametersMetadataForMethod(
+    ArtMethod* method,
+    /*out*/ MutableHandle<mirror::ObjectArray<mirror::String>>* names,
+    /*out*/ MutableHandle<mirror::IntArray>* access_flags) {
   const DexFile::AnnotationSetItem* annotation_set =
       FindAnnotationSetForMethod(method);
   if (annotation_set == nullptr) {
@@ -1193,12 +1189,10 @@
   StackHandleScope<4> hs(Thread::Current());
 
   // Extract the parameters' names String[].
-  ObjPtr<mirror::Class> string_class = mirror::String::GetJavaLangString();
-  Handle<mirror::Class> string_array_class(hs.NewHandle(
-      Runtime::Current()->GetClassLinker()->FindArrayClass(Thread::Current(), &string_class)));
-  if (UNLIKELY(string_array_class == nullptr)) {
-    return false;
-  }
+  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+  Handle<mirror::Class> string_array_class =
+      hs.NewHandle(GetClassRoot<mirror::ObjectArray<mirror::String>>(class_linker));
+  DCHECK(string_array_class != nullptr);
 
   ClassData data(method);
   Handle<mirror::Object> names_obj =
@@ -1212,10 +1206,8 @@
   }
 
   // Extract the parameters' access flags int[].
-  Handle<mirror::Class> int_array_class(hs.NewHandle(GetClassRoot<mirror::IntArray>()));
-  if (UNLIKELY(int_array_class == nullptr)) {
-    return false;
-  }
+  Handle<mirror::Class> int_array_class(hs.NewHandle(GetClassRoot<mirror::IntArray>(class_linker)));
+  DCHECK(int_array_class != nullptr);
   Handle<mirror::Object> access_flags_obj =
       hs.NewHandle(GetAnnotationValue(data,
                                       annotation_item,
@@ -1226,12 +1218,12 @@
     return false;
   }
 
-  names->Assign(names_obj.Get()->AsObjectArray<mirror::String>());
-  access_flags->Assign(access_flags_obj.Get()->AsIntArray());
+  names->Assign(names_obj->AsObjectArray<mirror::String>());
+  access_flags->Assign(access_flags_obj->AsIntArray());
   return true;
 }
 
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForMethod(ArtMethod* method) {
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForMethod(ArtMethod* method) {
   const DexFile::AnnotationSetItem* annotation_set = FindAnnotationSetForMethod(method);
   if (annotation_set == nullptr) {
     return nullptr;
@@ -1345,12 +1337,9 @@
     return nullptr;
   }
   StackHandleScope<1> hs(Thread::Current());
-  ObjPtr<mirror::Class> class_class = mirror::Class::GetJavaLangClass();
-  Handle<mirror::Class> class_array_class(hs.NewHandle(
-      Runtime::Current()->GetClassLinker()->FindArrayClass(hs.Self(), &class_class)));
-  if (class_array_class == nullptr) {
-    return nullptr;
-  }
+  Handle<mirror::Class> class_array_class =
+      hs.NewHandle(GetClassRoot<mirror::ObjectArray<mirror::Class>>());
+  DCHECK(class_array_class != nullptr);
   ObjPtr<mirror::Object> obj =
       GetAnnotationValue(data, annotation_item, "value", class_array_class,
                          DexFile::kDexAnnotationArray);
@@ -1446,7 +1435,7 @@
       DexFile::kDexAnnotationMethod);
 }
 
-bool GetInnerClass(Handle<mirror::Class> klass, ObjPtr<mirror::String>* name) {
+bool GetInnerClass(Handle<mirror::Class> klass, /*out*/ ObjPtr<mirror::String>* name) {
   ClassData data(klass);
   const DexFile::AnnotationSetItem* annotation_set = FindAnnotationSetForClass(data);
   if (annotation_set == nullptr) {
@@ -1513,7 +1502,8 @@
   return true;
 }
 
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForClass(Handle<mirror::Class> klass) {
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForClass(
+    Handle<mirror::Class> klass) {
   ClassData data(klass);
   const DexFile::AnnotationSetItem* annotation_set = FindAnnotationSetForClass(data);
   if (annotation_set == nullptr) {
diff --git a/runtime/dex/dex_file_annotations.h b/runtime/dex/dex_file_annotations.h
index 9645a7f..bde7891 100644
--- a/runtime/dex/dex_file_annotations.h
+++ b/runtime/dex/dex_file_annotations.h
@@ -41,7 +41,7 @@
     REQUIRES_SHARED(Locks::mutator_lock_);
 ObjPtr<mirror::ObjectArray<mirror::Object>> GetAnnotationsForField(ArtField* field)
     REQUIRES_SHARED(Locks::mutator_lock_);
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForField(ArtField* field)
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForField(ArtField* field)
     REQUIRES_SHARED(Locks::mutator_lock_);
 bool IsFieldAnnotationPresent(ArtField* field, Handle<mirror::Class> annotation_class)
     REQUIRES_SHARED(Locks::mutator_lock_);
@@ -64,11 +64,11 @@
                                                        uint32_t parameter_idx,
                                                        Handle<mirror::Class> annotation_class)
     REQUIRES_SHARED(Locks::mutator_lock_);
-bool GetParametersMetadataForMethod(ArtMethod* method,
-                                    MutableHandle<mirror::ObjectArray<mirror::String>>* names,
-                                    MutableHandle<mirror::IntArray>* access_flags)
-    REQUIRES_SHARED(Locks::mutator_lock_);
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForMethod(ArtMethod* method)
+bool GetParametersMetadataForMethod(
+    ArtMethod* method,
+    /*out*/ MutableHandle<mirror::ObjectArray<mirror::String>>* names,
+    /*out*/ MutableHandle<mirror::IntArray>* access_flags) REQUIRES_SHARED(Locks::mutator_lock_);
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForMethod(ArtMethod* method)
     REQUIRES_SHARED(Locks::mutator_lock_);
 // Check whether `method` is annotated with `annotation_class`.
 // If `lookup_in_resolved_boot_classes` is true, look up any of the
@@ -101,12 +101,12 @@
     REQUIRES_SHARED(Locks::mutator_lock_);
 ObjPtr<mirror::Object> GetEnclosingMethod(Handle<mirror::Class> klass)
     REQUIRES_SHARED(Locks::mutator_lock_);
-bool GetInnerClass(Handle<mirror::Class> klass, ObjPtr<mirror::String>* name)
+bool GetInnerClass(Handle<mirror::Class> klass, /*out*/ ObjPtr<mirror::String>* name)
     REQUIRES_SHARED(Locks::mutator_lock_);
 bool GetInnerClassFlags(Handle<mirror::Class> klass, uint32_t* flags)
     REQUIRES_SHARED(Locks::mutator_lock_);
-mirror::ObjectArray<mirror::String>* GetSignatureAnnotationForClass(Handle<mirror::Class> klass)
-    REQUIRES_SHARED(Locks::mutator_lock_);
+ObjPtr<mirror::ObjectArray<mirror::String>> GetSignatureAnnotationForClass(
+    Handle<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_);
 const char* GetSourceDebugExtension(Handle<mirror::Class> klass)
     REQUIRES_SHARED(Locks::mutator_lock_);
 bool IsClassAnnotationPresent(Handle<mirror::Class> klass,
diff --git a/runtime/interpreter/interpreter_common.h b/runtime/interpreter/interpreter_common.h
index 37234e1..0ee780d 100644
--- a/runtime/interpreter/interpreter_common.h
+++ b/runtime/interpreter/interpreter_common.h
@@ -35,6 +35,7 @@
 #include "base/macros.h"
 #include "base/mutex.h"
 #include "class_linker-inl.h"
+#include "class_root.h"
 #include "common_dex_operations.h"
 #include "common_throws.h"
 #include "dex/dex_file-inl.h"
@@ -328,7 +329,7 @@
                                                    ShadowFrame& shadow_frame,
                                                    dex::StringIndex string_idx)
     REQUIRES_SHARED(Locks::mutator_lock_) {
-  ObjPtr<mirror::Class> java_lang_string_class = mirror::String::GetJavaLangString();
+  ObjPtr<mirror::Class> java_lang_string_class = GetClassRoot<mirror::String>();
   if (UNLIKELY(!java_lang_string_class->IsInitialized())) {
     ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
     StackHandleScope<1> hs(self);
diff --git a/runtime/interpreter/unstarted_runtime_test.cc b/runtime/interpreter/unstarted_runtime_test.cc
index 9bb760c..88cfafb 100644
--- a/runtime/interpreter/unstarted_runtime_test.cc
+++ b/runtime/interpreter/unstarted_runtime_test.cc
@@ -388,7 +388,7 @@
 TEST_F(UnstartedRuntimeTest, StringInit) {
   Thread* self = Thread::Current();
   ScopedObjectAccess soa(self);
-  ObjPtr<mirror::Class> klass = mirror::String::GetJavaLangString();
+  ObjPtr<mirror::Class> klass = GetClassRoot<mirror::String>();
   ArtMethod* method =
       klass->FindConstructor("(Ljava/lang/String;)V",
                              Runtime::Current()->GetClassLinker()->GetImagePointerSize());
@@ -537,7 +537,7 @@
                  tmp,
                  false,
                  object_class.Get(),
-                 mirror::String::GetJavaLangString(),
+                 GetClassRoot<mirror::String>(),
                  hs_src,
                  1,
                  hs_dst,
@@ -551,7 +551,7 @@
   {
     StackHandleScope<3> hs_src(self);
     hs_src.NewHandle(mirror::String::AllocFromModifiedUtf8(self, "1"));
-    hs_src.NewHandle(mirror::String::GetJavaLangString());
+    hs_src.NewHandle(GetClassRoot<mirror::String>());
     hs_src.NewHandle(mirror::String::AllocFromModifiedUtf8(self, "3"));
 
     StackHandleScope<3> hs_dst(self);
@@ -568,7 +568,7 @@
                  tmp,
                  true,
                  object_class.Get(),
-                 mirror::String::GetJavaLangString(),
+                 GetClassRoot<mirror::String>(),
                  hs_src,
                  0,
                  hs_dst,
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index e6bfe55..cb2708d 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -1461,12 +1461,12 @@
   // circularity issue during loading the names of its members
   DCHECK(IsIdxLoaded<kVerifyFlags>() || IsRetired<kVerifyFlags>() ||
          IsErroneous<static_cast<VerifyObjectFlags>(kVerifyFlags & ~kVerifyThis)>() ||
-         this == String::GetJavaLangString())
+         this == GetClassRoot<String>())
               << "IsIdxLoaded=" << IsIdxLoaded<kVerifyFlags>()
               << " IsRetired=" << IsRetired<kVerifyFlags>()
               << " IsErroneous=" <<
               IsErroneous<static_cast<VerifyObjectFlags>(kVerifyFlags & ~kVerifyThis)>()
-              << " IsString=" << (this == String::GetJavaLangString())
+              << " IsString=" << (this == GetClassRoot<String>())
               << " status= " << GetStatus<kVerifyFlags>()
               << " descriptor=" << PrettyDescriptor();
 }
diff --git a/runtime/mirror/string-inl.h b/runtime/mirror/string-inl.h
index e6079c0..8fa2c6c 100644
--- a/runtime/mirror/string-inl.h
+++ b/runtime/mirror/string-inl.h
@@ -25,6 +25,7 @@
 #include "base/globals.h"
 #include "base/utils.h"
 #include "class.h"
+#include "class_root.h"
 #include "common_throws.h"
 #include "dex/utf.h"
 #include "gc/heap-inl.h"
@@ -211,7 +212,8 @@
   // http://b/23528461
   size_t alloc_size = RoundUp(size, kObjectAlignment);
 
-  Class* string_class = GetJavaLangString();
+  Runtime* runtime = Runtime::Current();
+  ObjPtr<Class> string_class = GetClassRoot<String>(runtime->GetClassLinker());
   // Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
   // Do this by comparing with the maximum length that will _not_ cause an overflow.
   const size_t overflow_length = (-header_size) / block_size;   // Unsigned arithmetic.
@@ -227,7 +229,7 @@
     return nullptr;
   }
 
-  gc::Heap* heap = Runtime::Current()->GetHeap();
+  gc::Heap* heap = runtime->GetHeap();
   return down_cast<String*>(
       heap->AllocObjectWithAllocator<kIsInstrumented, true>(self, string_class, alloc_size,
                                                             allocator_type, pre_fence_visitor));
diff --git a/runtime/mirror/string.cc b/runtime/mirror/string.cc
index 6208a96..b76ca19 100644
--- a/runtime/mirror/string.cc
+++ b/runtime/mirror/string.cc
@@ -35,9 +35,6 @@
 namespace art {
 namespace mirror {
 
-// TODO: get global references for these
-GcRoot<Class> String::java_lang_String_;
-
 int32_t String::FastIndexOf(int32_t ch, int32_t start) {
   int32_t count = GetLength();
   if (start < 0) {
@@ -52,18 +49,6 @@
   }
 }
 
-void String::SetClass(ObjPtr<Class> java_lang_String) {
-  CHECK(java_lang_String_.IsNull());
-  CHECK(java_lang_String != nullptr);
-  CHECK(java_lang_String->IsStringClass());
-  java_lang_String_ = GcRoot<Class>(java_lang_String);
-}
-
-void String::ResetClass() {
-  CHECK(!java_lang_String_.IsNull());
-  java_lang_String_ = GcRoot<Class>(nullptr);
-}
-
 int String::ComputeHashCode() {
   int32_t hash_code = 0;
   if (IsCompressed()) {
@@ -372,10 +357,6 @@
   return count_diff;
 }
 
-void String::VisitRoots(RootVisitor* visitor) {
-  java_lang_String_.VisitRootIfNonNull(visitor, RootInfo(kRootStickyClass));
-}
-
 CharArray* String::ToCharArray(Thread* self) {
   StackHandleScope<1> hs(self);
   Handle<String> string(hs.NewHandle(this));
diff --git a/runtime/mirror/string.h b/runtime/mirror/string.h
index 270ace1..598175b 100644
--- a/runtime/mirror/string.h
+++ b/runtime/mirror/string.h
@@ -228,15 +228,6 @@
         : length;
   }
 
-  static Class* GetJavaLangString() REQUIRES_SHARED(Locks::mutator_lock_) {
-    DCHECK(!java_lang_String_.IsNull());
-    return java_lang_String_.Read();
-  }
-
-  static void SetClass(ObjPtr<Class> java_lang_String) REQUIRES_SHARED(Locks::mutator_lock_);
-  static void ResetClass() REQUIRES_SHARED(Locks::mutator_lock_);
-  static void VisitRoots(RootVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_);
-
   // Returns a human-readable equivalent of 'descriptor'. So "I" would be "int",
   // "[[I" would be "int[][]", "[Ljava/lang/String;" would be
   // "java.lang.String[]", and so forth.
@@ -281,10 +272,7 @@
     uint8_t value_compressed_[0];
   };
 
-  static GcRoot<Class> java_lang_String_;
-
   friend struct art::StringOffsets;  // for verifying offset information
-  ART_FRIEND_TEST(art::StubTest, ReadBarrierForRoot);  // For java_lang_String_.
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(String);
 };
diff --git a/runtime/mirror/var_handle_test.cc b/runtime/mirror/var_handle_test.cc
index 2c12832..cb2d628 100644
--- a/runtime/mirror/var_handle_test.cc
+++ b/runtime/mirror/var_handle_test.cc
@@ -92,8 +92,7 @@
     ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
     Handle<Class> var_type = hs.NewHandle(view_array_class->GetComponentType());
     Handle<Class> index_type = hs.NewHandle(class_linker->FindPrimitiveClass('I'));
-    ObjPtr<mirror::Class> byte_class = class_linker->FindPrimitiveClass('B');
-    Handle<Class> byte_array_class(hs.NewHandle(class_linker->FindArrayClass(self, &byte_class)));
+    Handle<Class> byte_array_class(hs.NewHandle(GetClassRoot<mirror::ByteArray>()));
     InitializeVarHandle(bvh.Get(), var_type, byte_array_class, index_type, access_modes_bit_mask);
     bvh->SetFieldBoolean<false>(ByteArrayViewVarHandle::NativeByteOrderOffset(), native_byte_order);
     return bvh.Get();
@@ -234,8 +233,7 @@
   ScopedObjectAccess soa(self);
   StackHandleScope<3> hs(self);
   int ptypes_count = static_cast<int>(descriptors.size()) - 1;
-  ObjPtr<mirror::Class> class_type = mirror::Class::GetJavaLangClass();
-  ObjPtr<mirror::Class> array_of_class = class_linker->FindArrayClass(self, &class_type);
+  ObjPtr<mirror::Class> array_of_class = GetClassRoot<mirror::ObjectArray<mirror::Class>>();
   Handle<ObjectArray<Class>> ptypes = hs.NewHandle(
       ObjectArray<Class>::Alloc(Thread::Current(), array_of_class, ptypes_count));
   Handle<mirror::ClassLoader> boot_class_loader = hs.NewHandle<mirror::ClassLoader>(nullptr);
@@ -599,10 +597,10 @@
                                     VarHandle::AccessMode::kGetAndBitwiseXorRelease,
                                     VarHandle::AccessMode::kGetAndBitwiseXorAcquire);
 
-  ObjPtr<mirror::Class> string_class = mirror::String::GetJavaLangString();
-  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  Handle<Class> string_array_class(hs.NewHandle(class_linker->FindArrayClass(self, &string_class)));
-  Handle<mirror::ArrayElementVarHandle> vh(hs.NewHandle(CreateArrayElementVarHandle(self, string_array_class, mask)));
+  Handle<mirror::Class> string_array_class = hs.NewHandle(
+      GetClassRoot<mirror::ObjectArray<mirror::String>>());
+  Handle<mirror::ArrayElementVarHandle> vh(
+      hs.NewHandle(CreateArrayElementVarHandle(self, string_array_class, mask)));
   EXPECT_FALSE(vh.IsNull());
 
   // Check access modes
@@ -746,11 +744,10 @@
                                     VarHandle::AccessMode::kGetAndBitwiseXor,
                                     VarHandle::AccessMode::kGetAndBitwiseXorAcquire);
 
-  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  ObjPtr<mirror::Class> char_class = class_linker->FindPrimitiveClass('C');
-  Handle<Class> char_array_class(hs.NewHandle(class_linker->FindArrayClass(self, &char_class)));
+  Handle<Class> char_array_class(hs.NewHandle(GetClassRoot<mirror::CharArray>()));
   const bool native_byte_order = true;
-  Handle<mirror::ByteArrayViewVarHandle> vh(hs.NewHandle(CreateByteArrayViewVarHandle(self, char_array_class, native_byte_order, mask)));
+  Handle<mirror::ByteArrayViewVarHandle> vh(
+      hs.NewHandle(CreateByteArrayViewVarHandle(self, char_array_class, native_byte_order, mask)));
   EXPECT_FALSE(vh.IsNull());
   EXPECT_EQ(native_byte_order, vh->GetNativeByteOrder());
 
@@ -895,11 +892,10 @@
                                     VarHandle::AccessMode::kGetAndBitwiseXor,
                                     VarHandle::AccessMode::kGetAndBitwiseXorAcquire);
 
-  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  ObjPtr<mirror::Class> double_class = class_linker->FindPrimitiveClass('D');
-  Handle<Class> double_array_class(hs.NewHandle(class_linker->FindArrayClass(self, &double_class)));
+  Handle<Class> double_array_class(hs.NewHandle(GetClassRoot<mirror::DoubleArray>()));
   const bool native_byte_order = false;
-  Handle<mirror::ByteBufferViewVarHandle> vh(hs.NewHandle(CreateByteBufferViewVarHandle(self, double_array_class, native_byte_order, mask)));
+  Handle<mirror::ByteBufferViewVarHandle> vh(hs.NewHandle(
+      CreateByteBufferViewVarHandle(self, double_array_class, native_byte_order, mask)));
   EXPECT_FALSE(vh.IsNull());
   EXPECT_EQ(native_byte_order, vh->GetNativeByteOrder());
 
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index 32d9d68..6384d01 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -1979,7 +1979,6 @@
   // Visit the classes held as static in mirror classes, these can be visited concurrently and only
   // need to be visited once per GC since they never change.
   mirror::Class::VisitRoots(visitor);
-  mirror::String::VisitRoots(visitor);
   mirror::ClassExt::VisitRoots(visitor);
   // Visiting the roots of these ArtMethods is not currently required since all the GcRoots are
   // null.
diff --git a/runtime/verifier/reg_type.cc b/runtime/verifier/reg_type.cc
index cbfbb40..73e516c 100644
--- a/runtime/verifier/reg_type.cc
+++ b/runtime/verifier/reg_type.cc
@@ -723,6 +723,7 @@
       // mechanics to continue.
       return reg_types->FromUnresolvedMerge(*this, incoming_type, verifier);
     } else {  // Two reference types, compute Join
+      // Do not cache the classes as ClassJoin() can suspend and invalidate ObjPtr<>s.
       DCHECK(GetClass() != nullptr && !GetClass()->IsPrimitive());
       DCHECK(incoming_type.GetClass() != nullptr && !incoming_type.GetClass()->IsPrimitive());
       ObjPtr<mirror::Class> join_class = ClassJoin(GetClass(), incoming_type.GetClass());