diff --git a/makefiles/vars.inc.mk b/makefiles/vars.inc.mk
index 23cb5f63a8e1d63dcaedda84d7adea38338e1719..dc678d782e3bc597062bd7ae995e9252f01b7289 100644
--- a/makefiles/vars.inc.mk
+++ b/makefiles/vars.inc.mk
@@ -1,3 +1,6 @@
+# set default values for selected global variables
+FLASH_ADDR ?= 0x0
+
 export Q                     # Used in front of Makefile lines to suppress the printing of the command if user did not opt-in to see them.
 export QQ                    # as Q, but be more quiet
 export QUIET                 # The parameter to use whether to show verbose makefile commands or not.
@@ -53,6 +56,7 @@ export WERROR                # Treat all compiler warnings as errors if set to 1
 export GITCACHE              # path to git-cache executable
 export FLASHER               # The command to call on "make flash".
 export FFLAGS                # The parameters to supply to FLASHER.
+export FLASH_ADDR          # Define an offset to flash code into ROM memory.
 export TERMPROG              # The command to call on "make term".
 export TERMFLAGS             # Additional parameters to supply to TERMPROG.
 export PORT                  # The port to connect the TERMPROG to.