rules.mk

##
## This file is part of the libopencm3 project.
##
## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
## Copyright (C) 2010 Piotr Esden-Tempski <piotr@esden.net>
## Copyright (C) 2013 Frantisek Burian <BuFran@seznam.cz>
##
## This library is free software: you can redistribute it and/or modify
## it under the terms of the GNU Lesser General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This library is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU Lesser General Public License for more details.
##
## You should have received a copy of the GNU Lesser General Public License
## along with this library.  If not, see <http://www.gnu.org/licenses/>.
##

# Be silent per default, but 'make V=1' will show all compiler calls.
ifneq ($(V),1)
Q		:= @
NULL		:= 2>/dev/null
endif

###############################################################################
# Executables

PREFIX		?= arm-none-eabi-

CC		:= $(PREFIX)gcc
CXX		:= $(PREFIX)g++
LD		:= $(PREFIX)gcc
AR		:= $(PREFIX)ar
AS		:= $(PREFIX)as
OBJCOPY		:= $(PREFIX)objcopy
OBJDUMP		:= $(PREFIX)objdump
SIZE            := $(PREFIX)size
GDB		:= $(PREFIX)gdb
OPT		:= -Os
DEBUG		:= -ggdb3
CSTD		?= -std=c99


###############################################################################
# Source files

ifeq ($(strip $(OPENCM3_DIR)),)
# user has not specified the library path, so we try to detect it

# where we search for the library
LIBPATHS := $(HOME)/code/c/repos/libopencm3

OPENCM3_DIR := $(wildcard $(LIBPATHS:=/locm3.sublime-project))
OPENCM3_DIR := $(firstword $(dir $(OPENCM3_DIR)))

ifeq ($(strip $(OPENCM3_DIR)),)
$(warning Cannot find libopencm3 library in the standard search paths.)
$(error Please specify it through OPENCM3_DIR variable!)
endif
endif

ifeq ($(V),1)
$(info Using $(OPENCM3_DIR) path to library)
endif

define ERR_DEVICE_LDSCRIPT_CONFLICT
You can either specify DEVICE=blah, and have the LDSCRIPT generated,
or you can provide LDSCRIPT, and ensure CPPFLAGS, LDFLAGS and LDLIBS
all contain the correct values for the target you wish to use.
You cannot provide both!
endef

ifeq ($(strip $(DEVICE)),)
# Old style, assume LDSCRIPT exists
DEFS		+= -I$(OPENCM3_DIR)/include
LDFLAGS		+= -L$(OPENCM3_DIR)/lib
LDLIBS		+= -l$(LIBNAME)
LDSCRIPT	?= $(BINARY).ld
else
# New style, assume device is provided, and we're generating the rest.
ifneq ($(strip $(LDSCRIPT)),)
$(error $(ERR_DEVICE_LDSCRIPT_CONFLICT))
endif
include $(OPENCM3_DIR)/mk/genlink-config.mk
endif

OPENCM3_SCRIPT_DIR = $(OPENCM3_DIR)/scripts
EXAMPLES_SCRIPT_DIR	= $(OPENCM3_DIR)/../scripts

###############################################################################
# C flags

TGT_CFLAGS	+= $(OPT) $(CSTD) $(DEBUG)
TGT_CFLAGS	+= $(ARCH_FLAGS)
TGT_CFLAGS	+= -Wextra -Wshadow -Wimplicit-function-declaration
TGT_CFLAGS	+= -Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes
TGT_CFLAGS	+= -fno-common -ffunction-sections -fdata-sections

###############################################################################
# C++ flags

TGT_CXXFLAGS	+= $(OPT) $(CXXSTD) $(DEBUG)
TGT_CXXFLAGS	+= $(ARCH_FLAGS)
TGT_CXXFLAGS	+= -Wextra -Wshadow -Wredundant-decls  -Weffc++
TGT_CXXFLAGS	+= -fno-common -ffunction-sections -fdata-sections

###############################################################################
# C & C++ preprocessor common flags

TGT_CPPFLAGS	+= -MD
TGT_CPPFLAGS	+= -Wall -Wundef
TGT_CPPFLAGS	+= $(DEFS)

###############################################################################
# Linker flags

TGT_LDFLAGS		+= --static -nostartfiles
TGT_LDFLAGS		+= -T$(LDSCRIPT)
TGT_LDFLAGS		+= $(ARCH_FLAGS) $(DEBUG)
TGT_LDFLAGS		+= -Wl,-Map=$(*).map -Wl,--cref
TGT_LDFLAGS		+= -Wl,--gc-sections
ifeq ($(V),99)
TGT_LDFLAGS		+= -Wl,--print-gc-sections
endif

###############################################################################
# Used libraries

LDLIBS		+= -Wl,--start-group -lc -lgcc -lnosys -Wl,--end-group

###############################################################################
###############################################################################
###############################################################################

.SUFFIXES: .elf .bin .hex .srec .list .map .images
.SECONDEXPANSION:
.SECONDARY:

all: elf

elf: $(BINARY).elf
bin: $(BINARY).bin
hex: $(BINARY).hex
srec: $(BINARY).srec
list: $(BINARY).list
GENERATED_BINARIES=$(BINARY).elf $(BINARY).bin $(BINARY).hex $(BINARY).srec $(BINARY).list $(BINARY).map

$(OPENCM3_DIR)/lib/lib$(LIBNAME).a:
ifeq (,$(wildcard $@))
	$(warning $(LIBNAME).a not found, attempting to rebuild in $(OPENCM3_DIR))
	$(MAKE) -C $(OPENCM3_DIR)
endif

# Define a helper macro for debugging make errors online
# you can type "make print-OPENCM3_DIR" and it will show you
# how that ended up being resolved by all of the included
# makefiles.
print-%:
	@echo $*=$($*)

%.bin: %.elf
	@#printf "  OBJCOPY $(*).bin\n"
	$(Q)$(OBJCOPY) -Obinary $(*).elf $(*).bin

%.hex: %.elf
	@#printf "  OBJCOPY $(*).hex\n"
	$(Q)$(OBJCOPY) -Oihex $(*).elf $(*).hex

%.srec: %.elf
	@#printf "  OBJCOPY $(*).srec\n"
	$(Q)$(OBJCOPY) -Osrec $(*).elf $(*).srec

%.list: %.elf
	@#printf "  OBJDUMP $(*).list\n"
	$(Q)$(OBJDUMP) -S $(*).elf > $(*).list

%.elf: $(OBJS) $(LDSCRIPT) $(OPENCM3_DIR)/lib/lib$(LIBNAME).a
	@#printf "  LD      $(*).elf\n"
	$(Q)$(LD) $(TGT_LDFLAGS) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(*).elf

obj/%.o: %.c
	@mkdir -p $(dir $@)
	@#printf "  CC      $(*).c\n"
	$(Q)$(CC) $(TGT_CFLAGS) $(CFLAGS) $(TGT_CPPFLAGS) $(CPPFLAGS) -o $@ -c $<

obj/%.o: %.cxx
	@mkdir -p $(dir $@)
	@#printf "  CXX     $(*).cxx\n"
	$(Q)$(CXX) $(TGT_CXXFLAGS) $(CXXFLAGS) $(TGT_CPPFLAGS) $(CPPFLAGS) -o $@ -c $<

obj/%.o: %.cpp
	@mkdir -p $(dir $@)
	@#printf "  CXX     $(*).cpp\n"
	$(Q)$(CXX) $(TGT_CXXFLAGS) $(CXXFLAGS) $(TGT_CPPFLAGS) $(CPPFLAGS) -o $@ -c $<

clean:
	@#printf "  CLEAN\n"
	$(Q)$(RM) $(GENERATED_BINARIES) generated.* $(OBJS) $(OBJS:%.o=%.d)

.PHONY: images clean elf bin hex srec list

-include $(OBJS:.o=.d)