diff --git a/compiler/optimizer/ecma_pipeline.cpp b/compiler/optimizer/ecma_pipeline.cpp
index 276015b0a90151db83c4d13b05582bf45a16ba85..c82c73ea87aed63d80b5fbc390e7e380dc6d925c 100644
--- a/compiler/optimizer/ecma_pipeline.cpp
+++ b/compiler/optimizer/ecma_pipeline.cpp
@@ -54,7 +54,6 @@ bool EcmaPipeline::RunOptimizations()
 {
     auto graph = GetGraph();
 
-    ASSERT(!graph->IsOsrMode() && "We don't support OSR in JS yet");
     graph->RunPass<ExpandIntrinsics>();
     // TODO(schernykh): Find way to inline in AOT and OSR mode
     if (!graph->IsAotMode() && !graph->IsOsrMode()) {
diff --git a/runtime/asm_defines/asm_defines.def b/runtime/asm_defines/asm_defines.def
index 879225c419d1c8437cd65b7471e43ebb7e5d64c5..8786a3f7e817e76e1dfcbb1da42095c6567d4ecf 100644
--- a/runtime/asm_defines/asm_defines.def
+++ b/runtime/asm_defines/asm_defines.def
@@ -2,6 +2,7 @@
  * Copyright (c) Huawei Technologies Co., Ltd. 2019-2021. All rights reserved.
  */
 
+DEFINE_VALUE(ECMA_IFRAME_EXT_SIZE, panda::ecmascript::JSExtFrame::GetExtSize())
 DEFINE_VALUE(ECMASCRIPT_ENVIRONMENT_SIZE, panda::ecmascript::EcmascriptEnvironment::GetSize())
 DEFINE_VALUE(ECMASCRIPT_ENVIRONMENT_PREV_ENVIRONMENT_OFFSET, panda::ecmascript::EcmascriptEnvironment::GetPrevEnvironmentOffset())
 DEFINE_VALUE(ECMASCRIPT_ENVIRONMENT_CONSTANT_POOL_OFFSET, panda::ecmascript::EcmascriptEnvironment::GetConstantPoolOffset())
diff --git a/runtime/asm_defines/defines.h b/runtime/asm_defines/defines.h
index ea28c137bc7f21e8ba385af7dea1789851b4af44..db058e031fd9a95295a72d2753486bd31b0a0f74 100644
--- a/runtime/asm_defines/defines.h
+++ b/runtime/asm_defines/defines.h
@@ -19,6 +19,7 @@
 #include "plugins/ecmascript/compiler/ecmascript_extensions/ecmascript_environment.h"
 #include "plugins/ecmascript/runtime/ic/ic_handler.h"
 #include "plugins/ecmascript/runtime/ic/proto_change_details.h"
+#include "plugins/ecmascript/runtime/interpreter/js_frame.h"
 #include "plugins/ecmascript/runtime/js_array.h"
 #include "plugins/ecmascript/runtime/js_function.h"
 #include "plugins/ecmascript/runtime/js_tagged_value.h"
diff --git a/runtime/ecma_language_context.cpp b/runtime/ecma_language_context.cpp
index 45f1c3ca7db85be0d7bde8f116d7e56df2f060eb..6d879bb1b4b4352ca972a934d8d289db64ca9846 100644
--- a/runtime/ecma_language_context.cpp
+++ b/runtime/ecma_language_context.cpp
@@ -135,4 +135,22 @@ void EcmaLanguageContext::RestorePrevEnv() const
     js_thread->SetEcmascriptEnv(prev_env);
 }
 
+void EcmaLanguageContext::InitializeOsrCframeSlots(ManagedThread *thread, Span<uintptr_t> param_slots,
+                                                   Span<uintptr_t> lang_ext_slots) const
+{
+    auto *cframe_js_env {reinterpret_cast<ecmascript::EcmascriptEnvironment *>(lang_ext_slots.Data())};
+    CHECK_GE(lang_ext_slots.SizeBytes(), sizeof(ecmascript::EcmascriptEnvironment));
+
+    auto *js_thread {JSThread::Cast(thread)};
+    auto *js_env {ecmascript::JSFrame::GetJSEnv(js_thread->GetCurrentFrame())};
+    cframe_js_env->SetConstantPool(js_env->GetConstantPool());
+    cframe_js_env->SetLexicalEnv(js_env->GetLexicalEnv());
+    cframe_js_env->SetThisFunc(js_env->GetThisFunc());
+    cframe_js_env->SetPrevEnvironment(js_env->GetPrevEnvironment());
+
+    std::fill(param_slots.begin(), param_slots.end(), TaggedValue::VALUE_UNDEFINED);
+
+    js_thread->SetEcmascriptEnv(cframe_js_env);
+}
+
 }  // namespace panda
diff --git a/runtime/ecma_language_context.h b/runtime/ecma_language_context.h
index 9259b5575b6b48fabd6ca7ab0d339a831191a857..0b8b474e32a902a171595d021341482b69512204 100644
--- a/runtime/ecma_language_context.h
+++ b/runtime/ecma_language_context.h
@@ -304,6 +304,9 @@ public:
     {
         return false;
     }
+
+    void InitializeOsrCframeSlots(ManagedThread *thread, Span<uintptr_t> param_slots,
+                                  Span<uintptr_t> lang_ext_slots) const override;
 };
 }  // namespace panda