arch/x86/kernel/acpi/Makefile - maze/linux - Git at Google

 obj-$(CONFIG_ACPI)		+= boot.o
 obj-$(CONFIG_ACPI_SLEEP)	+= sleep_$(BITS).o wakeup_$(BITS).o

 ifneq ($(CONFIG_ACPI_PROCESSOR),)
 obj-y				+= cstate.o processor.o
 endif
	obj-$(CONFIG_ACPI) += boot.o
	obj-$(CONFIG_ACPI_SLEEP) += sleep_$(BITS).o wakeup_$(BITS).o

	ifneq ($(CONFIG_ACPI_PROCESSOR),)
	obj-y += cstate.o processor.o
	endif