UPPERCASE

[FROM] := a b c d e f g h i j k l m n o p q r s t u v w x y z - .
[TO]   := A B C D E F G H I J K L M N O P Q R S T U V W X Y Z _ _
 
UPPERCASE = $(strip $(eval __tmp := $1) \
     $(foreach c, $(join $(addsuffix :,$([FROM])),$([TO])), \
    $(eval __tmp :=    \
        $(subst $(word 1,$(subst :, ,$c)),$(word 2,$(subst :, ,$c)),\
            $(__tmp)))) \
$(__tmp))
 
 
 
BOARD_CFLAGS += -DBOARD_$(call UPPERCASE,$(BOARD))
BOARD_ASMFLAGS += -DBOARD_$(call UPPERCASE,$(BOARD))