soc: arm: Unify setting of Cortex-M specifc compiler flags

Moved setting of specific Cortex-M compiler flags in each SoC directory
unify setting them in the arch/arm/soc Makefile.

Add flags for Cortex M0, M0+, M1, M3, M4, and M7.  However only
CONFIG_CPU_CORTEX_M3 and CONFIG_CPU_CORTEX_M4 are supported at this time

As part of this change converted Kbuild files for some SoCs into
Makefiles as the Makefiles would be empty otherwise.

Change-Id: Ie4e0178b141ca761ec482a610ae50e94fe58070f
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

arch/arm/Makefile

@@ -4,6 +4,32 @@ include $(srctree)/arch/$(ARCH)/soc/$(SOC_PATH)/Makefile
 
 cflags-$(CONFIG_LTO) += $(call cc-option,-flto,)
 
+cflags-cortex-m0 = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m0) \
+			$(call cc-option,-mthumb -march=armv6-m)
+cflags-cortex-m0+ = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m0plus) \
+			$(call cc-option,-mthumb -march=armv6-m)
+cflags-cortex-m1 = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m1) \
+			$(call cc-option,-mthumb -march=armv6-m)
+cflags-cortex-m3 = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m3) \
+			$(call cc-option,-mthumb -march=armv7-m)
+cflags-cortex-m4 = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m4) \
+			$(call cc-option,-mthumb -march=armv7e-m)
+cflags-cortex-m7 = $(call cc-option,-mabi=aapcs -mthumb -mcpu=cortex-m7) \
+			$(call cc-option,-mthumb -march=armv7e-m)
+
+aflags-$(CONFIG_CPU_CORTEX_M3) += $(cflags-cortex-m3)
+cflags-$(CONFIG_CPU_CORTEX_M3) += $(cflags-cortex-m3)
+cxxflags-$(CONFIG_CPU_CORTEX_M3) += $(cflags-cortex-m3)
+_arm_isa-$(CONFIG_CPU_CORTEX_M3) = armv7-m
+
+aflags-$(CONFIG_CPU_CORTEX_M4) += $(cflags-cortex-m4)
+cflags-$(CONFIG_CPU_CORTEX_M4) += $(cflags-cortex-m4)
+cxxflags-$(CONFIG_CPU_CORTEX_M4) += $(cflags-cortex-m4)
+_arm_isa-$(CONFIG_CPU_CORTEX_M4) = armv7e-m
+
+_CROSS_COMPILE_arm_isa = $(_arm_isa-y)
+
+KBUILD_AFLAGS += $(aflags-y)
 KBUILD_CFLAGS += $(cflags-y)
 KBUILD_CXXFLAGS += $(cflags-y)
 

arch/arm/soc/atmel_sam3/Kbuild

@@ -1 +0,0 @@
-obj-y += soc.o

arch/arm/soc/atmel_sam3/Makefile

@@ -1,2 +1 @@
-soc-cflags += $(call cc-option,-mthumb -mcpu=cortex-m3) \
-		$(call cc-option,-mthumb -march=armv7-m)
+obj-y += soc.o

arch/arm/soc/nordic_nrf5/nrf52/Kbuild

@@ -1 +0,0 @@
-obj-y += soc.o

arch/arm/soc/nordic_nrf5/nrf52/Makefile

@@ -1,6 +1 @@
-soc-cflags = $(call cc-option,-mthumb -mcpu=cortex-m4) \
-		$(call cc-option,-march=armv7e-m) \
-		$(call cc-option,-mabi=aapcs)
-
-_CROSS_COMPILE_arm_isa = armv7e-m
-export _CROSS_COMPILE_arm_isa
+obj-y += soc.o

arch/arm/soc/nxp_kinetis/k6x/Kbuild

@@ -1,3 +0,0 @@
-obj-y += soc_config.o
-obj-y += soc.o
-obj-y += wdog.o

arch/arm/soc/nxp_kinetis/k6x/Makefile

@@ -1,2 +1,3 @@
-soc-cflags = $(call cc-option,-mthumb -mcpu=cortex-m4) \
-			$(call cc-option,-mthumb -march=armv7e-m)
+obj-y += soc_config.o
+obj-y += soc.o
+obj-y += wdog.o

arch/arm/soc/st_stm32/stm32f1/Kbuild

@@ -1,4 +0,0 @@
-obj-y += soc.o
-
-obj-$(CONFIG_GPIO) += soc_gpio.o
-obj-$(CONFIG_PINMUX) += soc_config.o

arch/arm/soc/st_stm32/stm32f1/Makefile

@@ -1,2 +1,4 @@
-soc-cflags += $(call cc-option,-mthumb -mcpu=cortex-m3) \
-		$(call cc-option,-mthumb -march=armv7-m)
+obj-y += soc.o
+
+obj-$(CONFIG_GPIO) += soc_gpio.o
+obj-$(CONFIG_PINMUX) += soc_config.o

arch/arm/soc/ti_lm3s6965/Kbuild

@@ -1,3 +0,0 @@
-obj-y += soc_config.o
-obj-y += soc.o
-obj-y += scp.o

arch/arm/soc/ti_lm3s6965/Makefile

@@ -1,2 +1,3 @@
-soc-cflags  = $(call cc-option,-mthumb -mcpu=cortex-m3) \
-		$(call cc-option,-mthumb -march=armv7-m)
+obj-y += soc_config.o
+obj-y += soc.o
+obj-y += scp.o