diff --git a/build/build_sbl.sh b/build/build_sbl.sh
index 0ca678a..9eb86dc 100755
--- a/build/build_sbl.sh
+++ b/build/build_sbl.sh
@@ -50,10 +50,10 @@ export product_line=PLC
 export PATH=/opt/kunlun2/bin/:$PATH
 
 set -o errexit
-make -C .. clobber
+# make -j -C .. clobber
 
 # clean phy lib etc.
-make -C .. sbl_clean
+# make -j -C .. sbl_clean
 
 # build klx ram
-make -C .. sbl opt_build=1
+make -j -C .. sbl opt_build=1
diff --git a/build/build_time_cost_test.py b/build/build_time_cost_test.py
index 9e30c98..054c815 100755
--- a/build/build_time_cost_test.py
+++ b/build/build_time_cost_test.py
@@ -13,6 +13,9 @@ if __name__ == "__main__":
         cmd=f"{' '.join(sys.argv[1:])} > build_log.log"
         if not ('not_clean' in sys.argv[1:]):
             os.system("python3 ../clear_output.py > /dev/null")
+            os.remove("../make_flags.txt")
+            os.remove("../python_script_log.log")
+            os.system("python3 ../praper_vscode.py clear >> ../python_script_log.log")
         path="../tools/gen_img/customer"
         if os.path.exists(path):
             shutil.rmtree(path)
diff --git a/build/makefile.cfg b/build/makefile.cfg
index 5f1e507..5396a35 100644
--- a/build/makefile.cfg
+++ b/build/makefile.cfg
@@ -71,7 +71,14 @@ GET_SRCS	= $(wildcard $(1)/*.c) $(wildcard $(1)/*.cpp) $(wildcard  $(1)/*.S)
 # local .c
 SRCS		+= $(call GET_SRCS, .)
 # every sub dir's .c
-SRCS		+= $(foreach dirname, $(SUB_DIRS), $(call GET_SRCS, $(dirname)))
+# 如果子文件夹包含makefile文件 则不包含这个目录的源文件
+SRC_DIRS    = $(shell for dir in $(SUB_DIRS); do \
+                        if [ ! -f "$$dir/Makefile" ]; then \
+                          echo "$$dir"; \
+                        fi \
+                      done)
+
+SRCS		+= $(foreach dirname, $(SRC_DIRS), $(call GET_SRCS, $(dirname)))
 # ext src
 SRCS        += $(EXT_SRC)
 # all the obj names
@@ -312,6 +319,7 @@ $(OUTPUT_FULL_NAME): $(OUTPUT_DIR) $(BIN_DIR)/.sub_dirs $(BIN_DIR)/.ext_src $(OB
 	@python3 $(TOPDIR)/praper_vscode.py $(TOPDIR)/make_flags.txt $@ >> $(TOPDIR)/python_script_log.log
 	@for d in $(SUB_DIRS); do\
 		if [ -e "$$d/Makefile" ]; then\
+			echo "enter $$d";\
 			$(MAKE) -C $$d || exit 1;\
             if [ 2 -eq $(OUTPUT_TYPE) ];then\
                 if [ -e $(OUTPUT_FULL_NAME) ]; then \
@@ -402,27 +410,21 @@ clean:
 	-$(RM) $(OUTPUT_FULL_NAME) $(OBJECTS) $(DEPS) $(BIN_DIR)/.sub_dirs $(BIN_DIR)/.ext_src
 	@for d in $(SUB_DIRS) ; do\
 		if [ -e "$$d/Makefile" ]; then\
+			echo "clean $$d";\
 			$(MAKE) -C $$d $@ ;\
 		fi;\
 	done
 	-$(RM) $(OUTDIR)
 
 clobber:
-	@for d in $(SUB_DIRS); do\
-		if [ -e "$$d/Makefile" ]; then\
-			$(MAKE) -C $$d $@ ;\
-		fi;\
-	done
-	@-$(RM) $(TOPDIR)/make_flags.txt
-	@-$(RM) $(TOPDIR)/python_script_log.log
-	@-python3 $(TOPDIR)/praper_vscode.py clear >> $(TOPDIR)/python_script_log.log
-	@-$(RM) $(OUTDIR)
+	@echo clobber
 
 # clean obj files only
 clean_objs:
 	-$(RM) $(OBJECTS)
 	@for d in $(SUB_DIRS); do\
 		if [ -e "$$d/Makefile" ]; then\
+			echo "clean_objs $$d";\
 			$(MAKE) -C $$d $@ ;\
 		fi;\
 	done
diff --git a/sbl/src/boot.c b/sbl/src/boot.c
index 0b1d1f7..498c0dd 100644
--- a/sbl/src/boot.c
+++ b/sbl/src/boot.c
@@ -68,6 +68,7 @@ void start_boot(void)
 
 int sbl_main(int fboot_flag)
 {
+    // 保存rom传递的快速启动标志
     sbl_fastboot_flag_set((uint32_t)fboot_flag);
 
     start_boot();