diff --git a/hw/bsp/lpcxpresso51u68/board.mk b/hw/bsp/lpcxpresso51u68/board.mk
index 21b6c55fc..98bef6758 100644
--- a/hw/bsp/lpcxpresso51u68/board.mk
+++ b/hw/bsp/lpcxpresso51u68/board.mk
@@ -1,4 +1,5 @@
-DEPS_SUBMODULES += hw/mcu/nxp/mcux-sdk
+SDK_DIR = hw/mcu/nxp/mcux-sdk
+DEPS_SUBMODULES += $(SDK_DIR)
 
 CFLAGS += \
   -flto \
@@ -13,7 +14,7 @@ CFLAGS += \
 # mcu driver cause following warnings
 CFLAGS += -Wno-error=unused-parameter
 
-MCU_DIR = hw/mcu/nxp/mcux-sdk/devices/LPC51U68
+MCU_DIR = $(SDK_DIR)/devices/LPC51U68
 
 # All source paths should be relative to the top level.
 LD_FILE = $(MCU_DIR)/gcc/LPC51U68_flash.ld
@@ -22,14 +23,20 @@ SRC_C += \
 	src/portable/nxp/lpc_ip3511/dcd_lpc_ip3511.c \
 	$(MCU_DIR)/system_LPC51U68.c \
 	$(MCU_DIR)/drivers/fsl_clock.c \
-	$(MCU_DIR)/drivers/fsl_gpio.c \
 	$(MCU_DIR)/drivers/fsl_power.c \
-	$(MCU_DIR)/drivers/fsl_reset.c
+	$(MCU_DIR)/drivers/fsl_reset.c \
+	$(SDK_DIR)/drivers/lpc_gpio/fsl_gpio.c \
+	$(SDK_DIR)/drivers/flexcomm/fsl_flexcomm.c \
+	$(SDK_DIR)/drivers/flexcomm/fsl_usart.c
 
 INC += \
 	$(TOP)/$(MCU_DIR)/../../CMSIS/Include \
 	$(TOP)/$(MCU_DIR) \
-	$(TOP)/$(MCU_DIR)/drivers
+	$(TOP)/$(MCU_DIR)/drivers \
+	$(TOP)/$(SDK_DIR)/drivers/common \
+	$(TOP)/$(SDK_DIR)/drivers/flexcomm \
+	$(TOP)/$(SDK_DIR)/drivers/lpc_iocon \
+	$(TOP)/$(SDK_DIR)/drivers/lpc_gpio	
 
 SRC_S += $(MCU_DIR)/gcc/startup_LPC51U68.S
 
@@ -38,9 +45,8 @@ LIBS += $(TOP)/$(MCU_DIR)/gcc/libpower.a
 # For freeRTOS port source
 FREERTOS_PORT = ARM_CM0
 
-# For flash-jlink target
 JLINK_DEVICE = LPC51U68
+PYOCD_TARGET = LPC51U68
 
 # flash using pyocd (51u68 is not supported yet)
-flash: $(BUILD)/$(PROJECT).hex
-	pyocd flash -t LPC51U68 $<
+flash: flash-pyocd