reducing copy-pasta - would this work?

firmware/Makefile

@@ -228,6 +228,7 @@ $(info LDSCRIPT:      $(LDSCRIPT))
 # check.c goes first to throw error as soon as possible
 CSRC =  check.c \
 	$(ALLCSRC) \
+	$(BOARDSRC) \
 	$(CHIBIOS)/os/various/syscalls.c \
 	$(CHIBIOS_CONTRIB)/os/various/ramdisk.c \
 	$(CHIBIOS)/os/various/evtimer.c \
@@ -252,6 +253,7 @@ CSRC =  check.c \
 # C++ sources that can be compiled in ARM or THUMB mode depending on the global
 # setting.
 CPPSRC = $(ALLCPPSRC) \
+    $(BOARDCPPSRC) \
 	$(TRIGGER_SRC_CPP) \
 	$(TRIGGER_DECODERS_SRC_CPP) \
 	$(DEV_SRC_CPP) \

firmware/config/boards/hellen/cypress/board.mk

@@ -27,5 +27,4 @@ LDSCRIPT= $(STARTUPLD_CYPRESS)/cypress_S6E2CxAH.ld
 
 # Shared variables
 ALLCSRC   += $(BOARDSRC)
-ALLCPPSRC += $(BOARDCPPSRC)
 ALLINC    += $(BOARDINC)

firmware/config/boards/hellen/hellen-nb1/board.mk

@@ -37,5 +37,4 @@ DDEFS += -DEFI_CONSOLE_TX_BRAIN_PIN=GPIOD_6 -DEFI_CONSOLE_RX_BRAIN_PIN=GPIOD_5 -
 DDEFS += -DHW_HELLEN=1
 
 # Shared variables
-ALLCPPSRC += $(BOARDCPPSRC)
 ALLINC    += $(BOARDINC)

firmware/config/boards/hellen/hellen121vag/board.mk

@@ -35,5 +35,4 @@ DDEFS += -DEFI_LOGIC_ANALYZER=FALSE
 DDEFS += -DHW_HELLEN=1
 
 # Shared variables
-ALLCPPSRC += $(BOARDCPPSRC)
 ALLINC    += $(BOARDINC)

firmware/config/boards/hellen/hellen154hyundai/board.mk

@@ -35,5 +35,4 @@ DDEFS += -DEFI_LOGIC_ANALYZER=FALSE
 DDEFS += -DHW_HELLEN=1
 
 # Shared variables
-ALLCPPSRC += $(BOARDCPPSRC)
 ALLINC    += $(BOARDINC)

firmware/config/boards/hellen/hellen81/board.mk

@@ -51,5 +51,4 @@ DDEFS += -DEFI_OVERRIDE_FAST_ADC_FOR_STM32H7=TRUE -DADC_FAST_DEVICE=ADCD1 -DEFI_
 DDEFS += -DHW_HELLEN=1
 
 # Shared variables
-ALLCPPSRC += $(BOARDCPPSRC)
 ALLINC    += $(BOARDINC)