1all: kernel pit boot 2 3kernel: 4 $(MAKE) -C kernel 5.PHONY: kernel 6 7pit: 8 $(MAKE) -C pit 9.PHONY: pit 10 11boot: 12 $(MAKE) -C boot 13.PHONY: boot 14 15clean: 16 $(MAKE) -C kernel clean 17 $(MAKE) -C pit clean 18 $(MAKE) -C boot clean 19.PHONY: clean 20