diff --git a/Makefile.include b/Makefile.include
index 058b3466cc..1e92115e95 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -340,9 +340,9 @@ ifeq ($(RIOT_CI_BUILD),1)
 endif
 
 # if you want to publish the board into the sources as an uppercase #define
-BOARDDEF := $(shell echo $(BOARD) | tr 'a-z' 'A-Z' | tr '-' '_')
-CPUDEF := $(shell echo $(CPU) | tr 'a-z' 'A-Z' | tr '-' '_')
-MCUDEF := $(shell echo $(MCU) | tr 'a-z' 'A-Z' | tr '-' '_')
+BOARDDEF = $(call uppercase_and_underscore,$(BOARD))
+CPUDEF = $(call uppercase_and_underscore,$(CPU))
+MCUDEF = $(call uppercase_and_underscore,$(MCU))
 CFLAGS += -DRIOT_APPLICATION=\"$(APPLICATION)\"
 CFLAGS += -DBOARD_$(BOARDDEF)=\"$(BOARD)\" -DRIOT_BOARD=BOARD_$(BOARDDEF)
 CFLAGS += -DCPU_$(CPUDEF)=\"$(CPU)\" -DRIOT_CPU=CPU_$(CPUDEF)
diff --git a/cpu/efm32/Makefile.include b/cpu/efm32/Makefile.include
index c2d33eea57..0a05483293 100644
--- a/cpu/efm32/Makefile.include
+++ b/cpu/efm32/Makefile.include
@@ -4,7 +4,7 @@ export CPU_ARCH = $(EFM32_ARCHITECTURE)
 export CPU_FAM = $(EFM32_FAMILY)
 
 # the em_device.h header requires a global define with the cpu model
-CFLAGS += -D$(shell echo $(CPU_MODEL) | tr 'a-z' 'A-Z')
+CFLAGS += -D$(call uppercase_and_underscore,$(CPU_MODEL))
 
 # include Gecko SDK package
 USEPKG += gecko_sdk
diff --git a/cpu/msp430_common/Makefile.include b/cpu/msp430_common/Makefile.include
index f71d8b40a2..afcc202c1e 100644
--- a/cpu/msp430_common/Makefile.include
+++ b/cpu/msp430_common/Makefile.include
@@ -2,8 +2,7 @@ PSEUDOMODULES += msp430_malloc
 
 INCLUDES += -I$(RIOTCPU)/msp430_common/include/
 
-MODEL = $(shell echo $(CPU_MODEL) | tr 'a-z' 'A-Z')
-CFLAGS += -DCPU_MODEL_$(MODEL)
+CFLAGS += -DCPU_MODEL_$(call uppercase_and_underscore,$(CPU_MODEL))
 
 export UNDEF += $(BINDIR)/msp430_common/startup.o
 export USEMODULE += msp430_common msp430_common_periph msp430_malloc
diff --git a/cpu/nrf5x_common/Makefile.include b/cpu/nrf5x_common/Makefile.include
index c29694c333..9dc47f49b0 100644
--- a/cpu/nrf5x_common/Makefile.include
+++ b/cpu/nrf5x_common/Makefile.include
@@ -1,5 +1,4 @@
-FAM = $(shell echo $(CPU_FAM) | tr 'a-z-' 'A-Z_')
-CFLAGS += -DCPU_FAM_$(FAM)
+CFLAGS += -DCPU_FAM_$(call uppercase_and_underscore,$(CPU_FAM))
 
 # include nrf5x common periph drivers
 USEMODULE += nrf5x_common_periph
diff --git a/cpu/sam0_common/Makefile.include b/cpu/sam0_common/Makefile.include
index 085bccb5f5..19b777fbe7 100644
--- a/cpu/sam0_common/Makefile.include
+++ b/cpu/sam0_common/Makefile.include
@@ -1,5 +1,5 @@
 # Define the CPU family so we can differentiate between them in the code
-CFLAGS += -DCPU_FAM_$(shell echo $(CPU_FAM) | tr 'a-z-' 'A-Z_')
+CFLAGS += -DCPU_FAM_$(call uppercase_and_underscore,$(CPU_FAM))
 
 # Set ROM and RAM lengths according to CPU model
 ifneq (,$(filter samd21g18a samd21j18a saml21j18b saml21j18a samr21e18a \
diff --git a/cpu/sam_common/Makefile.include b/cpu/sam_common/Makefile.include
index 23a94e2b22..37d07c52e4 100644
--- a/cpu/sam_common/Makefile.include
+++ b/cpu/sam_common/Makefile.include
@@ -1,5 +1,5 @@
 # Define the CPU family so we can differentiate between them in the code
-CFLAGS += -DCPU_FAM_$(shell echo $(CPU_FAM) | tr 'a-z-' 'A-Z_')
+CFLAGS += -DCPU_FAM_$(call uppercase_and_underscore,$(CPU_FAM))
 
 # this CPU implementation doesn't use CMSIS initialization
 CFLAGS += -DDONT_USE_CMSIS_INIT
diff --git a/cpu/stm32_common/Makefile.include b/cpu/stm32_common/Makefile.include
index 2b7f0294f4..264a2f6276 100644
--- a/cpu/stm32_common/Makefile.include
+++ b/cpu/stm32_common/Makefile.include
@@ -1,5 +1,4 @@
-FAM = $(shell echo $(CPU_FAM) | tr 'a-z-' 'A-Z_')
-CFLAGS += -DCPU_FAM_$(FAM)
+CFLAGS += -DCPU_FAM_$(call uppercase_and_underscore,$(CPU_FAM))
 
 # All stm32 families provide pm support
 USEMODULE += pm_layered
diff --git a/makefiles/arch/cortexm.inc.mk b/makefiles/arch/cortexm.inc.mk
index b55d5f4fa5..895342d4ae 100644
--- a/makefiles/arch/cortexm.inc.mk
+++ b/makefiles/arch/cortexm.inc.mk
@@ -81,10 +81,8 @@ endif
 endif
 endif
 
-MODEL = $(shell echo $(CPU_MODEL) | tr 'a-z' 'A-Z')
-CFLAGS += -DCPU_MODEL_$(MODEL)
-ARCH = $(shell echo $(CPU_ARCH) | tr 'a-z-' 'A-Z_')
-CFLAGS += -DCPU_ARCH_$(ARCH)
+CFLAGS += -DCPU_MODEL_$(call uppercase_and_underscore,$(CPU_MODEL))
+CFLAGS += -DCPU_ARCH_$(call uppercase_and_underscore,$(CPU_ARCH))
 
 # set the compiler specific CPU and FPU options
 ifneq (,$(filter $(CPU_ARCH),cortex-m4f cortex-m7))
diff --git a/makefiles/modules.inc.mk b/makefiles/modules.inc.mk
index e337750439..0426fc6e0b 100644
--- a/makefiles/modules.inc.mk
+++ b/makefiles/modules.inc.mk
@@ -3,7 +3,7 @@ _ALLMODULES = $(sort $(USEMODULE) $(USEPKG))
 # Define MODULE_MODULE_NAME preprocessor macros for all modules.
 ED = $(addprefix MODULE_,$(_ALLMODULES))
 # EXTDEFINES will be put in CFLAGS_WITH_MACROS
-EXTDEFINES = $(addprefix -D,$(shell echo '$(ED)' | tr 'a-z-' 'A-Z_'))
+EXTDEFINES = $(addprefix -D,$(call uppercase_and_underscore,$(ED)))
 
 # filter "pseudomodules" from "real modules", but not "no_pseudomodules"
 REALMODULES += $(filter-out $(PSEUDOMODULES), $(_ALLMODULES))