diff --git a/bsp/stm32/stm32f103-dofly-lyc8/Kconfig b/bsp/stm32/stm32f103-dofly-lyc8/Kconfig
index 2b30840a3ebfa46b53ed2aaf36dcd83e1c7ce3dc..7a400db91f4a82292908c8b2b99e87e4193f78d0 100644
--- a/bsp/stm32/stm32f103-dofly-lyc8/Kconfig
+++ b/bsp/stm32/stm32f103-dofly-lyc8/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/bsp/stm32/stm32f103-hw100k-ibox/Kconfig b/bsp/stm32/stm32f103-hw100k-ibox/Kconfig
index 2b30840a3ebfa46b53ed2aaf36dcd83e1c7ce3dc..7a400db91f4a82292908c8b2b99e87e4193f78d0 100644
--- a/bsp/stm32/stm32f103-hw100k-ibox/Kconfig
+++ b/bsp/stm32/stm32f103-hw100k-ibox/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/bsp/stm32/stm32f746-st-disco/Kconfig b/bsp/stm32/stm32f746-st-disco/Kconfig
index d174bcc5856a51419134bbe611db776d611c751e..8cbc7b71a8c0cf95b0cefa5f35f19353215eb570 100644
--- a/bsp/stm32/stm32f746-st-disco/Kconfig
+++ b/bsp/stm32/stm32f746-st-disco/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/bsp/stm32/stm32f767-st-nucleo/Kconfig b/bsp/stm32/stm32f767-st-nucleo/Kconfig
index 768b68bb13fd68e2f1fd5c7f26e68856d3f306bc..8fa7560ee82a22ffc1c85e4665d979263ffda844 100644
--- a/bsp/stm32/stm32f767-st-nucleo/Kconfig
+++ b/bsp/stm32/stm32f767-st-nucleo/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/bsp/stm32/stm32g071-st-nucleo/Kconfig b/bsp/stm32/stm32g071-st-nucleo/Kconfig
index 8c9d8002cf83bab15438b38c935ac564f3dd33f9..79b160b856783cfaea4fc056458bc193e16f13d2 100644
--- a/bsp/stm32/stm32g071-st-nucleo/Kconfig
+++ b/bsp/stm32/stm32g071-st-nucleo/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/bsp/stm32/stm32l432-st-nucleo/Kconfig b/bsp/stm32/stm32l432-st-nucleo/Kconfig
index d174bcc5856a51419134bbe611db776d611c751e..8cbc7b71a8c0cf95b0cefa5f35f19353215eb570 100644
--- a/bsp/stm32/stm32l432-st-nucleo/Kconfig
+++ b/bsp/stm32/stm32l432-st-nucleo/Kconfig
@@ -1,16 +1,16 @@
 mainmenu "RT-Thread Configuration"
 
-config $BSP_DIR
+config BSP_DIR
     string
     option env="BSP_ROOT"
     default "."
 
-config $RTT_DIR
+config RTT_DIR
     string
     option env="RTT_ROOT"
     default "../../.."
 
-config $PKGS_DIR
+config PKGS_DIR
     string
     option env="PKGS_ROOT"
     default "packages"
diff --git a/components/drivers/Kconfig b/components/drivers/Kconfig
index d8dc5e74581600d4aa120032518e00d5849fa49e..6d45e44cfdc42b2253e1b28ba2bbac4a19a1836d 100755
--- a/components/drivers/Kconfig
+++ b/components/drivers/Kconfig
@@ -20,7 +20,12 @@ if RT_USING_SERIAL
     config RT_SERIAL_USING_DMA
         bool "Enable serial DMA mode"
         default y
-endif    
+
+    config RT_SERIAL_RB_BUFSZ
+    int "Set RX buffer size"
+    default 64
+
+endif
 
 config RT_USING_CAN
     bool "Using CAN device drivers"
@@ -120,6 +125,7 @@ config RT_USING_PM
 
 config RT_USING_RTC
     bool "Using RTC device drivers"
+    select RT_USING_LIBC
     default n
 
     if RT_USING_RTC