add dfu generate target for fomu

hw/bsp/fomu/board.mk

@@ -14,7 +14,7 @@ BSP_DIR = hw/bsp/fomu
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/fomu.ld
 
-SRC_S += hw/bsp/fomu/crt0-vexriscv.S
+SRC_S += hw/bsp/$(BOARD)/crt0-vexriscv.S
 
 INC += \
 	$(TOP)/$(BSP_DIR)/include
@@ -27,5 +27,9 @@ CHIP_FAMILY = eptri
 FREERTOS_PORT = RISC-V
 
 # flash using dfu-util
+$(BUILD)/$(BOARD)-firmware.dfu: $(BUILD)/$(BOARD)-firmware.bin
+	@echo "Create $@"
+	python $(TOP)/hw/bsp/$(BOARD)/dfu.py -b $^ -D 0x1209:0x5bf0 $@
+	
 flash: $(BUILD)/$(BOARD)-firmware.dfu
 	dfu-util -D $^