arch: arm: set the architecture via Kconfig

Currently the build system has hardcoded values for the -march/-mcpu
which identify what architecture should be used when compiling ARM code.
For processors such as the STM32 this will need to be defined by a per
SOC process.

Change-Id: Ia8158cd687d8d0432ea420e204bb2bc67d33a054
Signed-off-by: Dan Kalowsky <daniel.kalowsky@intel.com>

arch/arm/Makefile

@@ -7,6 +7,12 @@ cflags-$(CONFIG_LTO) += $(call cc-option,-flto,)
 KBUILD_CFLAGS += $(cflags-y)
 KBUILD_CXXFLAGS += $(cflags-y)
 
+ifeq ($(CONFIG_CPU_CORTEX_M3),y)
+arch-cflags += $(call cc-option, -mthumb -mcpu=cortex-m3)
+else ifeq ($(CONFIG_CPU_CORTEX_M4),y)
+arch-cflags += $(call cc-option, -mthumb -mcpu=cortex-m4)
+endif
+
 QEMU_CPU_TYPE_arm = cortex-m3
 QEMU_FLAGS_arm = -cpu  $(QEMU_CPU_TYPE_arm) \
 		-machine lm3s6965evb -nographic

arch/arm/soc/atmel_sam3/Makefile

@@ -1,6 +1,5 @@
 
-arch-cflags += $(call cc-option,-mthumb -mcpu=cortex-m3) \
+arch-cflags += $(call cc-option,-mthumb -march=armv7-m)
-		$(call cc-option,-mthumb -march=armv7-m)
 
 KBUILD_AFLAGS += $(arch-cflags)
 KBUILD_CXXFLAGS += $(arch-cflags)

arch/arm/soc/fsl_frdm_k64f/Makefile

@@ -1,7 +1,5 @@
 
-
+arch-cflags = $(call cc-option,-mthumb -march=armv7e-m)
-arch-cflags = $(call cc-option,-mthumb -mcpu=cortex-m4) \
-			$(call cc-option,-mthumb -march=armv7e-m)
 
 KBUILD_CFLAGS += $(arch-cflags)
 KBUILD_CXXFLAGS += $(arch-cflags)

arch/arm/soc/ti_lm3s6965/Makefile

@@ -1,6 +1,5 @@
 
-arch-cflags  = $(call cc-option,-mthumb -mcpu=cortex-m3) \
+arch-cflags  = $(call cc-option,-mthumb -march=armv7-m)
-		$(call cc-option,-mthumb -march=armv7-m)
 
 KBUILD_CFLAGS += $(arch-cflags)
 KBUILD_CXXFLAGS += $(arch-cflags)