diff --git a/boards/samr21-xpro/Makefile.include b/boards/samr21-xpro/Makefile.include
index 116df742ab..abd4714439 100644
--- a/boards/samr21-xpro/Makefile.include
+++ b/boards/samr21-xpro/Makefile.include
@@ -1,54 +1,21 @@
-# define the cpu used by the arduino due board
+# define the cpu used by SAMR21 Xplained Pro board
 export CPU = samd21
 export CPU_MODEL = samr21g18a
 
-# set the default port
-export PORT ?= /dev/ttyACM0
+#
+CFLAGS_OPT = -O0
 
-# define tools used for building the project
-export PREFIX = arm-none-eabi-
-export CC = $(PREFIX)gcc
-export CXX = $(PREFIX)g++
-export AR = $(PREFIX)ar
-export AS = $(PREFIX)as
-export LINK = $(PREFIX)gcc
-export SIZE = $(PREFIX)size
-export OBJCOPY = $(PREFIX)objcopy
-export DBG = $(PREFIX)gdb
-export TERMPROG = $(RIOTBASE)/dist/tools/pyterm/pyterm
-export FLASHER = $(RIOTBASE)/dist/tools/openocd/openocd.sh
-export DEBUGGER = $(RIOTBASE)/dist/tools/openocd/openocd.sh
-export DEBUGSERVER = $(RIOTBASE)/dist/tools/openocd/openocd.sh
-export RESET = $(RIOTBASE)/dist/tools/openocd/openocd.sh
+# set default port depending on operating system
+PORT_LINUX ?= /dev/ttyACM0
 
-# define build specific options
-export CPU_USAGE = -mcpu=cortex-m0plus
-FPU_USAGE =
-export CFLAGS += -ggdb -g3 -std=gnu99 -O0 -Wall -Wstrict-prototypes $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian -mthumb -mno-thumb-interwork -nostartfiles
-export CFLAGS += -ffunction-sections -fdata-sections -fno-builtin
-export ASFLAGS += -ggdb -g3 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian
-export LINKFLAGS += -g3 -ggdb -std=gnu99 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian -static -lgcc -mthumb -mno-thumb-interwork -nostartfiles
-# linkerscript specified in cpu/Makefile.include
-export LINKFLAGS += -T$(LINKERSCRIPT)
-export OFLAGS = -O ihex
-export TERMFLAGS += -p "$(PORT)"
-export FFLAGS = flash
-ifneq (,$(SERIAL))
-export FFLAGS += "-c cmsis_dap_serial $(SERIAL)"
-endif
-export DEBUGGER_FLAGS = debug
-export DEBUGSERVER_FLAGS = debug-server
-export RESET_FLAGS = reset
-
-# unwanted (CXXUWFLAGS) and extra (CXXEXFLAGS) flags for c++
-export CXXUWFLAGS +=
-export CXXEXFLAGS +=
-
-# use the nano-specs of the NewLib when available
-ifeq ($(shell $(LINK) -specs=nano.specs -E - 2>/dev/null >/dev/null </dev/null ; echo $$?),0)
-export LINKFLAGS += -specs=nano.specs -lc -lnosys
-endif
-
-# export board specific includes to the global includes-listing
-export INCLUDES += -I$(RIOTBOARD)/$(BOARD)/include/
+#
 include $(RIOTBOARD)/$(BOARD)/Makefile.dep
+
+# setup serial terminal
+include $(RIOTBOARD)/Makefile.include.serial
+
+# this board uses openocd
+include $(RIOTBOARD)/Makefile.include.openocd
+
+# include cortex defaults
+include $(RIOTBOARD)/Makefile.include.cortex_common
diff --git a/cpu/samd21/Makefile.include b/cpu/samd21/Makefile.include
index cff4a5f71b..6125983322 100644
--- a/cpu/samd21/Makefile.include
+++ b/cpu/samd21/Makefile.include
@@ -1,5 +1,4 @@
-# this CPU implementation is using the new core/CPU interface
-export CFLAGS += -DCOREIF_NG=1
+export CORTEX = cortex-m0
 
 # this CPU implementation doesn't use CMSIS initialisation
 export CFLAGS += -DDONT_USE_CMSIS_INIT