src/mainboard/google/skyrim/variants/baseboard/Makefile.inc - coreboot - Gitiles

 bootblock-y += gpio.c

 romstage-y += gpio.c

 ramstage-y += gpio.c

 verstage-$(CONFIG_VBOOT_STARTS_BEFORE_BOOTBLOCK) += gpio.c

 smm-y += gpio.c
 smm-y += smihandler.c
	bootblock-y += gpio.c

	romstage-y += gpio.c

	ramstage-y += gpio.c

	verstage-$(CONFIG_VBOOT_STARTS_BEFORE_BOOTBLOCK) += gpio.c

	smm-y += gpio.c
	smm-y += smihandler.c