src/mainboard/siemens/mc_apl1/variants/mc_apl6/Makefile.inc - coreboot - Gitiles

 bootblock-y += gpio.c

 ramstage-y += gpio.c
 ramstage-y += mainboard.c
	bootblock-y += gpio.c

	ramstage-y += gpio.c
	ramstage-y += mainboard.c