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 += $(CORTEXM_CFLAGS)
25
26# TODO: Add more Cortex-M flags from the Nanohub build
27
28# Code generation flags.
29TARGET_CFLAGS += -mthumb
30TARGET_CFLAGS += -mfloat-abi=softfp
31TARGET_CFLAGS += -mno-thumb-interwork
32TARGET_CFLAGS += -ffast-math
33TARGET_CFLAGS += -fsingle-precision-constant
34
35# Sadly we must disable double promotion warnings due to logging macros. There
36# is a bug for this here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53431
37TARGET_CFLAGS += -Wno-double-promotion
38
39# Cortex-M Shared Object Linker Flags ##########################################
40
41TARGET_SO_LDFLAGS += -shared
42
43# Supported Cortex-M Architectures #############################################
44
45CORTEXM_SUPPORTED_ARCHS = m4
46
47# Environment Checks ###########################################################
48
49# Ensure that an architecture is chosen.
50ifeq ($(filter $(CORTEXM_ARCH), $(CORTEXM_SUPPORTED_ARCHS)),)
51$(error "The CORTEXM_ARCH argument must be set to a supported architecture (\
52         $(CORTEXM_SUPPORTED_ARCHS))")
53endif
54
55# Target Architecture ##########################################################
56
57# Set the Cortex-M architecture.
58ifeq ($(CORTEXM_ARCH), m4)
59TARGET_CFLAGS += -mcpu=cortex-m4
60TARGET_CFLAGS += -mfpu=fpv4-sp-d16
61endif
62
63# Optimization Level ###########################################################
64
65TARGET_CFLAGS += -O$(OPT_LEVEL)
66
67# Variant Specific Sources #####################################################
68
69TARGET_VARIANT_SRCS += $(CORTEXM_SRCS)
70