diff --git a/src/trace.cc b/src/trace.cc
new file mode 100644
index 0000000..0a41a2e
--- /dev/null
+++ b/src/trace.cc
@@ -0,0 +1,190 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+
+#include "trace.h"
+
+#include "class_linker.h"
+#include "dex_cache.h"
+#include "runtime_support.h"
+#include "thread.h"
+
+namespace art {
+
+#if defined(__arm__)
+static bool InstallStubsClassVisitor(Class* klass, void* trace_stub) {
+  for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
+    Method* method = klass->GetDirectMethod(i);
+    if (method->GetCode() != trace_stub) {
+      Trace::SaveAndUpdateCode(method, trace_stub);
+    }
+  }
+
+  for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
+    Method* method = klass->GetVirtualMethod(i);
+    if (method->GetCode() != trace_stub) {
+      Trace::SaveAndUpdateCode(method, trace_stub);
+    }
+  }
+
+  if (!klass->IsArrayClass() && !klass->IsPrimitive()) {
+    CodeAndDirectMethods* c_and_dm = klass->GetDexCache()->GetCodeAndDirectMethods();
+    for (size_t i = 0; i < c_and_dm->NumCodeAndDirectMethods(); i++) {
+      Method* method = c_and_dm->GetResolvedMethod(i);
+      if (method != NULL && (size_t) method != i) {
+        c_and_dm->SetResolvedDirectMethodTraceEntry(i, trace_stub);
+      }
+    }
+  }
+  return true;
+}
+
+static bool UninstallStubsClassVisitor(Class* klass, void* trace_stub) {
+  for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
+    Method* method = klass->GetDirectMethod(i);
+    if (Trace::GetSavedCodeFromMap(method) != NULL) {
+      Trace::ResetSavedCode(method);
+    }
+  }
+
+  for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
+    Method* method = klass->GetVirtualMethod(i);
+    if (Trace::GetSavedCodeFromMap(method) != NULL) {
+      Trace::ResetSavedCode(method);
+    }
+  }
+
+  if (!klass->IsArrayClass() && !klass->IsPrimitive()) {
+    CodeAndDirectMethods* c_and_dm = klass->GetDexCache()->GetCodeAndDirectMethods();
+    for (size_t i = 0; i < c_and_dm->NumCodeAndDirectMethods(); i++) {
+      const void* code = c_and_dm->GetResolvedCode(i);
+      if (code == trace_stub) {
+        Method* method = klass->GetDexCache()->GetResolvedMethod(i);
+        if (Trace::GetSavedCodeFromMap(method) != NULL) {
+          Trace::ResetSavedCode(method);
+        }
+        c_and_dm->SetResolvedDirectMethod(i, method);
+      }
+    }
+  }
+  return true;
+}
+
+static void TraceRestoreStack(Thread* t, void*) {
+  uintptr_t trace_exit = reinterpret_cast<uintptr_t>(art_trace_exit_from_code);
+
+  Frame frame = t->GetTopOfStack();
+  if (frame.GetSP() != 0) {
+    for ( ; frame.GetMethod() != 0; frame.Next()) {
+      if (t->IsTraceStackEmpty()) {
+        break;
+      }
+      uintptr_t pc = frame.GetReturnPC();
+      Method* method = frame.GetMethod();
+      if (trace_exit == pc) {
+        TraceStackFrame trace_frame = t->PopTraceStackFrame();
+        frame.SetReturnPC(trace_frame.return_pc_);
+        CHECK(method == trace_frame.method_);
+      }
+    }
+  }
+}
+#endif
+
+bool Trace::method_tracing_active_ = false;
+std::map<const Method*, const void*> Trace::saved_code_map_;
+
+void Trace::AddSavedCodeToMap(const Method* method, const void* code) {
+  saved_code_map_.insert(std::make_pair(method, code));
+}
+
+void Trace::RemoveSavedCodeFromMap(const Method* method) {
+  saved_code_map_.erase(method);
+}
+
+const void* Trace::GetSavedCodeFromMap(const Method* method) {
+  return saved_code_map_.find(method)->second;
+}
+
+void Trace::SaveAndUpdateCode(Method* method, const void* new_code) {
+  CHECK(GetSavedCodeFromMap(method) == NULL);
+  AddSavedCodeToMap(method, method->GetCode());
+  method->SetCode(new_code);
+}
+
+void Trace::ResetSavedCode(Method* method) {
+  CHECK(GetSavedCodeFromMap(method) != NULL);
+  method->SetCode(GetSavedCodeFromMap(method));
+  RemoveSavedCodeFromMap(method);
+}
+
+bool Trace::IsMethodTracingActive() {
+  return method_tracing_active_;
+}
+
+void Trace::SetMethodTracingActive(bool value) {
+  method_tracing_active_ = value;
+}
+
+void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags, bool direct_to_ddms) {
+  LOG(INFO) << "Starting method tracing...";
+  if (IsMethodTracingActive()) {
+    // TODO: Stop the trace, then start it up again instead of returning
+    LOG(INFO) << "Trace already in progress, stopping";
+    return;
+  }
+
+  SetMethodTracingActive(true);
+  InstallStubs();
+  LOG(INFO) << "Method tracing started";
+}
+
+void Trace::Stop() {
+  LOG(INFO) << "Stopping method tracing...";
+  if (!IsMethodTracingActive()) {
+    LOG(INFO) << "Trace stop requested, but not running";
+    return;
+  }
+
+  UninstallStubs();
+  SetMethodTracingActive(false);
+  LOG(INFO) << "Method tracing stopped";
+}
+
+void Trace::InstallStubs() {
+#if defined(__arm__)
+  {
+    ScopedThreadStateChange tsc(Thread::Current(), Thread::kRunnable);
+    Runtime::Current()->GetThreadList()->SuspendAll(false);
+  }
+
+  void* trace_stub = reinterpret_cast<void*>(art_trace_entry_from_code);
+  Runtime::Current()->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, trace_stub);
+
+  Runtime::Current()->GetThreadList()->ResumeAll(false);
+#else
+  UNIMPLEMENTED(WARNING);
+#endif
+}
+
+void Trace::UninstallStubs() {
+#if defined(__arm__)
+  {
+    ScopedThreadStateChange tsc(Thread::Current(), Thread::kRunnable);
+    Runtime::Current()->GetThreadList()->SuspendAll(false);
+  }
+
+  void* trace_stub = reinterpret_cast<void*>(art_trace_entry_from_code);
+  Runtime::Current()->GetClassLinker()->VisitClasses(UninstallStubsClassVisitor, trace_stub);
+
+  // Restore stacks of all threads
+  {
+    ScopedThreadListLock thread_list_lock;
+    Runtime::Current()->GetThreadList()->ForEach(TraceRestoreStack, NULL);
+  }
+
+  Runtime::Current()->GetThreadList()->ResumeAll(false);
+#else
+  UNIMPLEMENTED(WARNING);
+#endif
+}
+
+}  // namespace art