src/soc/amd/common/block/smbus/Makefile.inc - coreboot - Gitiles

 ifeq ($(CONFIG_SOC_AMD_COMMON_BLOCK_SMBUS),y)

 bootblock-y += smbus_early_fch.c
 romstage-y += smbus.c
 ramstage-y += smbus.c
 ramstage-y += sm.c

 endif # CONFIG_SOC_AMD_COMMON_BLOCK_SMBUS
	ifeq ($(CONFIG_SOC_AMD_COMMON_BLOCK_SMBUS),y)

	bootblock-y += smbus_early_fch.c
	romstage-y += smbus.c
	ramstage-y += smbus.c
	ramstage-y += sm.c

	endif # CONFIG_SOC_AMD_COMMON_BLOCK_SMBUS