Add a Makefile to build flash stubs.

flashstub/Makefile

@@ -0,0 +1,33 @@
+CROSS_COMPILE ?= arm-none-eabi-
+AS = $(CROSS_COMPILE)as
+CC = $(CROSS_COMPILE)gcc
+OBJCOPY = $(CROSS_COMPILE)objcopy
+HEXDUMP = hexdump
+
+ifneq ($(V), 1)
+Q = @
+endif
+
+CFLAGS=-mcpu=cortex-m3 -mthumb -I../libopencm3/include
+ASFLAGS=-mcpu=cortex-m3 -mthumb
+
+all:	lmi.stub stm32.stub stm32f4.stub nrf51.stub
+
+%.o:	%.s
+	$(Q)echo "  AS      $<"
+	$(Q)$(AS) $(ASFLAGS) -o $@ $<
+
+%.bin:	%.o
+	$(Q)echo "  OBJCOPY $@"
+	$(Q)$(OBJCOPY) -O binary $< $@
+
+%.stub:	%.bin
+	$(Q)echo "  HEXDUMP $@"
+	$(Q)$(HEXDUMP) -v -e '/2 "0x%04X, "' $< > $@
+
+.PHONY: clean
+
+clean:
+	$(Q)echo "  CLEAN"
+	-$(Q)rm -f *.o *.bin *.stub
+