diff --git a/examples/device/cdc_msc_hid/Makefile b/examples/device/cdc_msc_hid/Makefile
index 21dd059c7..84f313887 100644
--- a/examples/device/cdc_msc_hid/Makefile
+++ b/examples/device/cdc_msc_hid/Makefile
@@ -21,7 +21,6 @@ include $(TOP)/hw/bsp/$(BOARD)/board.mk
 
 CC = $(CROSS_COMPILE)gcc
 CXX = $(CROSS_COMPILE)g++
-LD = $(CROSS_COMPILE)ld
 OBJCOPY = $(CROSS_COMPILE)objcopy
 SIZE = $(CROSS_COMPILE)size
 MKDIR = mkdir
@@ -106,7 +105,7 @@ $(OBJ_DIRS):
 
 $(BUILD)/$(BOARD)-firmware.elf: $(OBJ)
 	@echo LINK $@
-	@$(CC) -o $@ $(LDFLAGS) $^ -Wl,--start-group $(LIBS) -Wl,--end-group
+	$(CC) -o $@ $(LDFLAGS) $^ -Wl,--start-group $(LIBS) -Wl,--end-group
 
 $(BUILD)/$(BOARD)-firmware.bin: $(BUILD)/$(BOARD)-firmware.elf
 	@echo CREATE $@
@@ -136,6 +135,7 @@ vpath %.s . $(TOP)
 $(BUILD)/obj/%.o: %.s
 	@echo AS $(notdir $@)
 	$(AS) -o $@ $<
+	#$(CC) -x assembler-with-cpp $(ASFLAGS) -c -o $@ $<
 
 # ASM sources upper case .S
 vpath %.S . $(TOP)
@@ -150,12 +150,18 @@ else
   JLINKEXE = JLinkExe
 endif
 
-flash: $(BUILD)/$(BOARD)-firmware.hex
+# default jlink interface is swd
+ifeq ($(JLINK_IF),)
+  JLINK_IF = swd
+endif
+
+flash-jlink: $(BUILD)/$(BOARD)-firmware.hex
 	@echo halt > $(BUILD)/$(BOARD).jlink
 	@echo loadfile $^ >> $(BUILD)/$(BOARD).jlink
+	@echo r >> $(BUILD)/$(BOARD).jlink
 	@echo go >> $(BUILD)/$(BOARD).jlink
 	@echo exit >> $(BUILD)/$(BOARD).jlink
-	#$(JLINKEXE) -device stm32f407vg -if swd -speed auto -CommandFile $(BUILD)/$(BOARD).jlink
+	$(JLINKEXE) -device $(JLINK_DEVICE) -if $(JLINK_IF) -speed auto -CommandFile $(BUILD)/$(BOARD).jlink
 
 size: $(BUILD)/$(BOARD)-firmware.elf
 	-@echo ''
diff --git a/hw/bsp/metro_m0_express/board.mk b/hw/bsp/metro_m0_express/board.mk
index f1dfa4cde..559d50ad1 100644
--- a/hw/bsp/metro_m0_express/board.mk
+++ b/hw/bsp/metro_m0_express/board.mk
@@ -33,3 +33,8 @@ INC += \
 
 VENDOR = microchip
 CHIP_FAMILY = samd21
+
+JLINK_DEVICE = ATSAMD21G18
+
+# flash using jlink
+flash: flash-jlink
diff --git a/hw/bsp/metro_m4_express/board.mk b/hw/bsp/metro_m4_express/board.mk
index b5127221a..b0938c7b5 100644
--- a/hw/bsp/metro_m4_express/board.mk
+++ b/hw/bsp/metro_m4_express/board.mk
@@ -32,3 +32,8 @@ INC += \
 
 VENDOR = microchip
 CHIP_FAMILY = samd51
+
+JLINK_DEVICE = ATSAMD51J19
+
+# flash using jlink
+flash: flash-jlink
diff --git a/hw/bsp/stm32f407g_disc1/board.mk b/hw/bsp/stm32f407g_disc1/board.mk
index d7fdd9e1f..ddf280c61 100644
--- a/hw/bsp/stm32f407g_disc1/board.mk
+++ b/hw/bsp/stm32f407g_disc1/board.mk
@@ -26,6 +26,8 @@ INC += \
 VENDOR = st
 CHIP_FAMILY = stm32f4
 
+JLINK_DEVICE = stm32f407vg
+
 # Path to STM32 Cube Programmer CLI
 ifeq ($(OS),Windows_NT)
 	STM32Prog = C:/Program Files/STMicroelectronics/STM32Cube/STM32CubeProgrammer/bin/STM32_Programmer_CLI
@@ -42,5 +44,5 @@ else
 endif
 
 # flash target using on-board stlink
-flash-stlink: $(BUILD)/$(BOARD)-firmware.elf
+flash: $(BUILD)/$(BOARD)-firmware.elf
 	$(STM32Prog) --connect port=swd --write $< --go