1# 2# Build targets for a Cortex-M-based processor 3# 4 5# Cortex-M Environment Checks ################################################## 6 7# If building for the Cortex-M target, ensure that the user has specified a path 8# to the Cortex-M toolchain that they wish to use. 9ifeq ($(CORTEXM_TOOLS_PREFIX),) 10$(error "You must supply a CORTEXM_TOOLS_PREFIX environment variable \ 11 containing a path to the Cortex-M toolchain. Example: \ 12 export CORTEXM_TOOLS_PREFIX=$$HOME/bin/gcc-arm-none-eabi-5_3-2016q1") 13endif 14 15# Cortex-M Tools ############################################################### 16 17TARGET_AR = $(CORTEXM_TOOLS_PREFIX)/bin/arm-none-eabi-ar 18TARGET_CC = $(CORTEXM_TOOLS_PREFIX)/bin/arm-none-eabi-g++ 19TARGET_LD = $(CORTEXM_TOOLS_PREFIX)/bin/arm-none-eabi-g++ 20 21# Cortex-M Compiler Flags ###################################################### 22 23# Add Cortex-M compiler flags. 24TARGET_CFLAGS += $(CORTEXM_CFLAGS) 25 26# Code generation flags. 27TARGET_CFLAGS += -mthumb 28TARGET_CFLAGS += -mfloat-abi=softfp 29TARGET_CFLAGS += -mno-thumb-interwork 30TARGET_CFLAGS += -ffast-math 31TARGET_CFLAGS += -fsingle-precision-constant 32 33# Sadly we must disable double promotion warnings due to logging macros. There 34# is a bug for this here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53431 35TARGET_CFLAGS += -Wno-double-promotion 36 37# Cortex-M Shared Object Linker Flags ########################################## 38 39TARGET_SO_LDFLAGS += -shared 40 41# Supported Cortex-M Architectures ############################################# 42 43CORTEXM_SUPPORTED_ARCHS = m4 44 45# Environment Checks ########################################################### 46 47# Ensure that an architecture is chosen. 48ifeq ($(filter $(CORTEXM_ARCH), $(CORTEXM_SUPPORTED_ARCHS)),) 49$(error "The CORTEXM_ARCH argument must be set to a supported architecture (\ 50 $(CORTEXM_SUPPORTED_ARCHS))") 51endif 52 53# Target Architecture ########################################################## 54 55# Set the Cortex-M architecture. 56ifeq ($(CORTEXM_ARCH), m4) 57TARGET_CFLAGS += -mcpu=cortex-m4 58TARGET_CFLAGS += -mfpu=fpv4-sp-d16 59endif 60 61# Optimization Level ########################################################### 62 63TARGET_CFLAGS += -O$(OPT_LEVEL) 64 65# Variant Specific Sources ##################################################### 66 67TARGET_VARIANT_SRCS += $(CORTEXM_SRCS) 68