diff --git a/src/soc/amd/cezanne/Makefile.inc b/src/soc/amd/cezanne/Makefile.inc
index c4b23d1b3a..2908674774 100644
--- a/src/soc/amd/cezanne/Makefile.inc
+++ b/src/soc/amd/cezanne/Makefile.inc
@@ -219,7 +219,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(PSP_BIOSBIN_FILE)) \
 		$(OPT_APOB_NV_BASE) \
 		$(OPT_VERSTAGE_FILE) \
 		$(OPT_VERSTAGE_SIG_FILE) \
-		--location $(shell printf "%#x" $(CEZANNE_FWM_POSITION)) \
+		--location $(call _tohex,$(CEZANNE_FWM_POSITION)) \
 		--multilevel \
 		--output $@
 
@@ -236,7 +236,7 @@ $(obj)/amdfw_a.rom: $(obj)/amdfw.rom
 		$(AMDFW_COMMON_ARGS) \
 		$(OPT_APOB_NV_SIZE) \
 		$(OPT_APOB_NV_BASE) \
-		--location $(shell printf "%#x" $(CEZANNE_FW_A_POSITION)) \
+		--location $(call _tohex,$(CEZANNE_FW_A_POSITION)) \
 		--anywhere \
 		--multilevel \
 		--output $@
@@ -248,7 +248,7 @@ $(obj)/amdfw_b.rom: $(obj)/amdfw.rom
 		$(AMDFW_COMMON_ARGS) \
 		$(OPT_APOB_NV_SIZE) \
 		$(OPT_APOB_NV_BASE) \
-		--location $(shell printf "%#x" $(CEZANNE_FW_B_POSITION)) \
+		--location $(call _tohex,$(CEZANNE_FW_B_POSITION)) \
 		--anywhere \
 		--multilevel \
 		--output $@
diff --git a/src/soc/amd/glinda/Makefile.inc b/src/soc/amd/glinda/Makefile.inc
index c35c3fea13..a537378372 100644
--- a/src/soc/amd/glinda/Makefile.inc
+++ b/src/soc/amd/glinda/Makefile.inc
@@ -238,7 +238,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(PSP_BIOSBIN_FILE)) \
 		$(OPT_VERSTAGE_FILE) \
 		$(OPT_VERSTAGE_SIG_FILE) \
 		$(OPT_SPL_TABLE_FILE) \
-		--location $(shell printf "%#x" $(GLINDA_FWM_POSITION)) \
+		--location $(call _tohex,$(GLINDA_FWM_POSITION)) \
 		--output $@
 
 $(PSP_BIOSBIN_FILE): $(PSP_ELF_FILE) $(AMDCOMPRESS)
@@ -257,7 +257,7 @@ $(obj)/amdfw_a.rom: $(obj)/amdfw.rom
 		$(OPT_SPL_RW_AB_TABLE_FILE) \
 		$(OPT_SIGNED_AMDFW_A_POSITION) \
 		$(OPT_SIGNED_AMDFW_A_FILE) \
-		--location $(shell printf "%#x" $(GLINDA_FW_A_POSITION)) \
+		--location $(call _tohex,$(GLINDA_FW_A_POSITION)) \
 		--anywhere \
 		--output $@
 
@@ -271,7 +271,7 @@ $(obj)/amdfw_b.rom: $(obj)/amdfw.rom
 		$(OPT_SPL_RW_AB_TABLE_FILE) \
 		$(OPT_SIGNED_AMDFW_B_POSITION) \
 		$(OPT_SIGNED_AMDFW_B_FILE) \
-		--location $(shell printf "%#x" $(GLINDA_FW_B_POSITION)) \
+		--location $(call _tohex,$(GLINDA_FW_B_POSITION)) \
 		--anywhere \
 		--output $@
 
diff --git a/src/soc/amd/mendocino/Makefile.inc b/src/soc/amd/mendocino/Makefile.inc
index 466123461c..d3d5601e13 100644
--- a/src/soc/amd/mendocino/Makefile.inc
+++ b/src/soc/amd/mendocino/Makefile.inc
@@ -262,7 +262,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(PSP_BIOSBIN_FILE)) \
 		$(OPT_VERSTAGE_SIG_FILE) \
 		$(OPT_SPL_TABLE_FILE) \
 		$(OPT_MANIFEST) \
-		--location $(shell printf "%#x" $(MENDOCINO_FWM_POSITION)) \
+		--location $(call _tohex,$(MENDOCINO_FWM_POSITION)) \
 		--output $@
 
 ifeq ($(CONFIG_CBFS_VERIFICATION)$(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK),yy)
@@ -288,8 +288,8 @@ $(obj)/amdfw_a.rom: $(obj)/amdfw.rom
 		$(OPT_SIGNED_AMDFW_A_POSITION) \
 		$(OPT_SIGNED_AMDFW_A_FILE) \
 		$(OPT_PSP_LOAD_MP2_FW) \
-		--location $(shell printf "%#x" $(MENDOCINO_FW_A_POSITION)) \
-		--body-location $(shell printf "%#x" $$(($(MENDOCINO_FW_A_POSITION) + $(MENDOCINO_FW_BODY_OFFSET)))) \
+		--location $(call _tohex,$(MENDOCINO_FW_A_POSITION)) \
+		--body-location $(call _tohex,$$(($(MENDOCINO_FW_A_POSITION) + $(MENDOCINO_FW_BODY_OFFSET)))) \
 		--anywhere \
 		--output $@
 
@@ -304,8 +304,8 @@ $(obj)/amdfw_b.rom: $(obj)/amdfw.rom
 		$(OPT_SIGNED_AMDFW_B_POSITION) \
 		$(OPT_SIGNED_AMDFW_B_FILE) \
 		$(OPT_PSP_LOAD_MP2_FW) \
-		--location $(shell printf "%#x" $(MENDOCINO_FW_B_POSITION)) \
-		--body-location $(shell printf "%#x" $$(($(MENDOCINO_FW_B_POSITION) + $(MENDOCINO_FW_BODY_OFFSET)))) \
+		--location $(call _tohex,$(MENDOCINO_FW_B_POSITION)) \
+		--body-location $(call _tohex,$$(($(MENDOCINO_FW_B_POSITION) + $(MENDOCINO_FW_BODY_OFFSET)))) \
 		--anywhere \
 		--output $@
 
diff --git a/src/soc/amd/phoenix/Makefile.inc b/src/soc/amd/phoenix/Makefile.inc
index c65c36979a..b15b5d6a47 100644
--- a/src/soc/amd/phoenix/Makefile.inc
+++ b/src/soc/amd/phoenix/Makefile.inc
@@ -134,14 +134,14 @@ PSP_BIOSBIN_DEST=$(shell $(READELF_bootblock) -Wl $(PSP_ELF_FILE) | grep LOAD |
 # type = 0x63 - construct APOB NV base/size from flash map
 # The flashmap section used for this is expected to be named RW_MRC_CACHE
 APOB_NV_SIZE=$(call get_fmap_value,FMAP_SECTION_RW_MRC_CACHE_SIZE)
-APOB_NV_BASE=$(shell printf "%#x" $(call int-subtract, \
+APOB_NV_BASE=$(call _tohex,$(call int-subtract, \
 	$(call get_fmap_value,FMAP_SECTION_RW_MRC_CACHE_START) $(FMAP_FLASH_START)))
 
 ifeq ($(CONFIG_HAS_RECOVERY_MRC_CACHE),y)
 # On boards with recovery MRC cache, point type 0x63 entry to RECOVERY_MRC_CACHE.
 # Else use RW_MRC_CACHE. This entry will be added in the RO section.
 APOB_NV_RO_SIZE=$(call get_fmap_value,FMAP_SECTION_RECOVERY_MRC_CACHE_SIZE)
-APOB_NV_RO_BASE=$(shell printf "%#x" $(call int-subtract, \
+APOB_NV_RO_BASE=$(call _tohex,$(call int-subtract, \
 	$(call get_fmap_value,FMAP_SECTION_RECOVERY_MRC_CACHE_START) $(FMAP_FLASH_START)))
 else
 APOB_NV_RO_SIZE=$(APOB_NV_SIZE)
@@ -263,7 +263,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(PSP_BIOSBIN_FILE)) \
 		$(OPT_VERSTAGE_FILE) \
 		$(OPT_VERSTAGE_SIG_FILE) \
 		$(OPT_SPL_TABLE_FILE) \
-		--location $(shell printf "%#x" $(PHOENIX_FWM_POSITION)) \
+		--location $(call _tohex,$(PHOENIX_FWM_POSITION)) \
 		--output $@
 
 ifeq ($(CONFIG_AMDFW_SPLIT),y)
@@ -288,7 +288,7 @@ $(obj)/amdfw_a.rom: $(obj)/amdfw.rom
 		$(OPT_SPL_RW_AB_TABLE_FILE) \
 		$(OPT_SIGNED_AMDFW_A_POSITION) \
 		$(OPT_SIGNED_AMDFW_A_FILE) \
-		--location $(shell printf "%#x" $(PHOENIX_FW_A_POSITION)) \
+		--location $(call _tohex,$(PHOENIX_FW_A_POSITION)) \
 		--anywhere \
 		--output $@
 
@@ -302,7 +302,7 @@ $(obj)/amdfw_b.rom: $(obj)/amdfw.rom
 		$(OPT_SPL_RW_AB_TABLE_FILE) \
 		$(OPT_SIGNED_AMDFW_B_POSITION) \
 		$(OPT_SIGNED_AMDFW_B_FILE) \
-		--location $(shell printf "%#x" $(PHOENIX_FW_B_POSITION)) \
+		--location $(call _tohex,$(PHOENIX_FW_B_POSITION)) \
 		--anywhere \
 		--output $@
 
diff --git a/src/soc/amd/picasso/Makefile.inc b/src/soc/amd/picasso/Makefile.inc
index 1d275b02fb..948e272235 100644
--- a/src/soc/amd/picasso/Makefile.inc
+++ b/src/soc/amd/picasso/Makefile.inc
@@ -236,7 +236,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(PSP_BIOSBIN_FILE)) \
 		$(OPT_APOB0_NV_BASE) \
 		$(OPT_VERSTAGE_FILE) \
 		$(OPT_VERSTAGE_SIG_FILE) \
-		--location $(shell printf "%#x" $(PICASSO_FWM_POSITION)) \
+		--location $(call _tohex,$(PICASSO_FWM_POSITION)) \
 		--output $@
 
 $(PSP_BIOSBIN_FILE): $(PSP_ELF_FILE) $(AMDCOMPRESS)
@@ -252,7 +252,7 @@ $(obj)/amdfw_a.rom: $(obj)/amdfw.rom
 		$(AMDFW_COMMON_ARGS) \
 		$(OPT_APOB_NV_SIZE) \
 		$(OPT_APOB_NV_BASE) \
-		--location $(shell printf "%#x" $(PICASSO_FW_A_POSITION)) \
+		--location $(call _tohex,$(PICASSO_FW_A_POSITION)) \
 		--anywhere \
 		--output $@
 
@@ -263,7 +263,7 @@ $(obj)/amdfw_b.rom: $(obj)/amdfw.rom
 		$(AMDFW_COMMON_ARGS) \
 		$(OPT_APOB_NV_SIZE) \
 		$(OPT_APOB_NV_BASE) \
-		--location $(shell printf "%#x" $(PICASSO_FW_B_POSITION)) \
+		--location $(call _tohex,$(PICASSO_FW_B_POSITION)) \
 		--anywhere \
 		--output $@
 
diff --git a/src/soc/amd/stoneyridge/Makefile.inc b/src/soc/amd/stoneyridge/Makefile.inc
index 65edea048b..33328fa958 100644
--- a/src/soc/amd/stoneyridge/Makefile.inc
+++ b/src/soc/amd/stoneyridge/Makefile.inc
@@ -137,7 +137,7 @@ $(obj)/amdfw.rom:	$(call strip_quotes, $(CONFIG_STONEYRIDGE_XHCI_FWM_FILE)) \
 		$(OPT_DEBUG_AMDFWTOOL) \
 		--config $(CONFIG_AMDFW_CONFIG_FILE) \
 		--flashsize $(CONFIG_ROM_SIZE) \
-		--location $(shell printf "0x%x" $(STONEYRIDGE_FWM_POSITION)) \
+		--location $(call _tohex,$(STONEYRIDGE_FWM_POSITION)) \
 		--output	$@
 
 ifeq ($(CONFIG_AMDFW_OUTSIDE_CBFS),y)