diff --git a/CMakeLists.txt b/CMakeLists.txt
index 18b547b..ab73f42 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,6 +25,8 @@ if (CHATGLM_ENABLE_PYBIND)
 endif ()
 
 # third-party libraries
+
+# ggml
 if (GGML_CUDA)
     add_compile_definitions(GGML_USE_CUDA)
     enable_language(CUDA)
@@ -42,9 +44,19 @@ if (GGML_CUDA)
     set(CMAKE_CUDA_ARCHITECTURES ${CUDA_ARCH_LIST} CACHE STRING "")
 endif ()
 
+if (GGML_METAL)
+    add_compile_definitions(GGML_USE_METAL)
+    set(GGML_METAL_EMBED_LIBRARY ON CACHE BOOL "" FORCE)
+endif ()
+
+if (GGML_PERF)
+    add_compile_definitions(GGML_PERF)
+endif ()
+
 include_directories(third_party/ggml/include/ggml third_party/ggml/src)
 add_subdirectory(third_party/ggml)
 
+# sentencepiece
 set(SPM_ENABLE_SHARED OFF CACHE BOOL "chatglm: disable sentencepiece shared libraries by default")
 set(SPM_ENABLE_TCMALLOC OFF CACHE BOOL "chatglm: disable tcmalloc by default")
 include_directories(third_party/sentencepiece/src)
@@ -52,23 +64,17 @@ add_subdirectory(third_party/sentencepiece)
 
 include_directories(third_party/sentencepiece/third_party/protobuf-lite)
 
+# absl
 set(ABSL_ENABLE_INSTALL ON CACHE BOOL "" FORCE)
 set(ABSL_PROPAGATE_CXX_STD ON CACHE BOOL "" FORCE)
 add_subdirectory(third_party/abseil-cpp)
 
+# re2
 add_subdirectory(third_party/re2)
 
+# stb
 include_directories(third_party/stb)
 
-if (GGML_METAL)
-    add_compile_definitions(GGML_USE_METAL)
-    configure_file(third_party/ggml/src/ggml-metal.metal ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/ggml-metal.metal COPYONLY)
-endif ()
-
-if (GGML_PERF)
-    add_compile_definitions(GGML_PERF)
-endif ()
-
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
 file(GLOB CPP_SOURCES
diff --git a/chatglm.cpp b/chatglm.cpp
index c9f943b..a9ed601 100644
--- a/chatglm.cpp
+++ b/chatglm.cpp
@@ -1118,8 +1118,27 @@ ggml_tensor *GLMBlock::forward(ModelContext *mctx, ggml_tensor *hidden_states, g
     return output;
 }
 
+static void alloc_weight_context(ModelContext *mctx, const ggml_backend_buffer_t sd_buf) {
+    void *sd_buf_base = ggml_backend_buffer_get_base(sd_buf);
+    const size_t sd_buf_size = ggml_backend_buffer_get_size(sd_buf);
+    if (ggml_backend_is_cpu(mctx->backend.get())) {
+        mctx->buf_w = unique_ggml_backend_buffer_t(ggml_backend_cpu_buffer_from_ptr(sd_buf_base, sd_buf_size));
+    }
+#ifdef GGML_USE_METAL
+    else if (ggml_backend_is_metal(mctx->backend.get())) {
+        const size_t max_size = ggml_get_max_tensor_size(mctx->ctx_w.get());
+        mctx->buf_w =
+            unique_ggml_backend_buffer_t(ggml_backend_metal_buffer_from_ptr(sd_buf_base, sd_buf_size, max_size));
+    }
+#endif
+    else {
+        mctx->buf_w =
+            unique_ggml_backend_buffer_t(ggml_backend_alloc_ctx_tensors(mctx->ctx_w.get(), mctx->backend.get()));
+    }
+}
+
 void ChatGLMForCausalLM::load_state_dict(const StateDict &sd) {
-    alloc_weight_context(sd.buf.get());
+    alloc_weight_context(mctx_.get(), sd.buf.get());
 
     StateDict self_sd = state_dict();
     for (auto &item : self_sd.kv) {
@@ -1259,7 +1278,7 @@ bool ChatGLM2Tokenizer::is_special_id(int id) const {
 }
 
 void ChatGLM2ForCausalLM::load_state_dict(const StateDict &sd) {
-    alloc_weight_context(sd.buf.get());
+    alloc_weight_context(mctx_.get(), sd.buf.get());
 
     if (config.num_virtual_tokens > 0) {
         ggml_tensor *past_key_values = sd.kv.at("past_key_values");
@@ -1959,7 +1978,7 @@ int ChatGLM4VForCausalLM::count_tokens(const std::vector<int> &input_ids, const
 }
 
 void ChatGLM4VForCausalLM::load_state_dict(const StateDict &sd) {
-    alloc_weight_context(sd.buf.get());
+    alloc_weight_context(mctx_.get(), sd.buf.get());
 
     auto self_sd = state_dict();
     ChatGLM2ForCausalLM::load_state_dict(mctx_.get(), self_sd, sd);
diff --git a/chatglm.h b/chatglm.h
index bc91024..9872e82 100644
--- a/chatglm.h
+++ b/chatglm.h
@@ -999,26 +999,6 @@ class BasicModelForCausalLM : public BaseModelForCausalLM {
 
     void load_prefix_cache(ggml_tensor *past_key_values) { transformer.load_prefix_cache(config, past_key_values); }
 
-  protected:
-    void alloc_weight_context(const ggml_backend_buffer_t sd_buf) const {
-        void *sd_buf_base = ggml_backend_buffer_get_base(sd_buf);
-        const size_t sd_buf_size = ggml_backend_buffer_get_size(sd_buf);
-        if (ggml_backend_is_cpu(mctx_->backend.get())) {
-            mctx_->buf_w = unique_ggml_backend_buffer_t(ggml_backend_cpu_buffer_from_ptr(sd_buf_base, sd_buf_size));
-        }
-#ifdef GGML_USE_METAL
-        else if (ggml_backend_is_metal(mctx_->backend.get())) {
-            const size_t max_size = ggml_get_max_tensor_size(mctx_->ctx_w.get());
-            mctx_->buf_w =
-                unique_ggml_backend_buffer_t(ggml_backend_metal_buffer_from_ptr(sd_buf_base, sd_buf_size, max_size));
-        }
-#endif
-        else {
-            mctx_->buf_w =
-                unique_ggml_backend_buffer_t(ggml_backend_alloc_ctx_tensors(mctx_->ctx_w.get(), mctx_->backend.get()));
-        }
-    }
-
   public:
     Model transformer;
     Linear lm_head;
diff --git a/chatglm_cpp/__init__.py b/chatglm_cpp/__init__.py
index 209bf24..73d3302 100644
--- a/chatglm_cpp/__init__.py
+++ b/chatglm_cpp/__init__.py
@@ -6,7 +6,7 @@
 import chatglm_cpp._C as _C
 from chatglm_cpp._C import ChatMessage, Image
 
-__version__ = "0.4.1"
+__version__ = "0.4.2"
 
 
 @dataclass