################################################
# Toplevel makefile for all Cortex-M targets   #
################################################

ifeq ($(V),)
    Q := @
    # Do not print "Entering directory ...".
    MAKEFLAGS += --no-print-directory
endif

# Use the size optimised nano version of newlib.
# This usually is the version of newlib you want to use, although it has some
# limitations, like printf not having support for floating point vars.
# This relies on your newlib installation to provide a working nano.specs
# file. On Debian you will need at least version 2.1.0+git20141201.db59ff3-2
# of package libnewlib-arm-none-eabi
USE_NANO    := true

# Debian's libnewlib-arm-none-eabi package version 2.2.0+git20150830.5a3d536-1
# ships with a buggy nano.specs file that does not set up a proper include
# path for finding the nano version of newlib.h.
# Also, the nano version has been built with the -fshort-wchar option, making
# it incompatible with object files using the standard ABI. By enabling this
# option atomthreads and libopencm3 will also be compiled with -fshort-wchar.
#FIX_DEBIAN  := true

# Build directory
ifdef O
    build_dir=$(shell readlink -f $(O))
else
    build_dir=$(CURDIR)/build
endif

# Source directory
src_dir=$(CURDIR)

# Clean object list before including board makefile
objs := 
aobjs :=

# set default board if none is given
ifeq ($(BOARD),)
    BOARD = nucleo-f103rb
endif

include $(src_dir)/boards/$(BOARD)/Makefile.include

# Make sure target MCU is set
ifndef TARGET
    $(error TARGET undefined)
endif

# Configure toolchain
CROSS_COMPILE   ?=  arm-none-eabi-

CC      := $(CROSS_COMPILE)gcc
CXX     := $(CROSS_COMPILE)g++
LD      := $(CROSS_COMPILE)gcc
AR      := $(CROSS_COMPILE)ar
AS      := $(CROSS_COMPILE)as
OBJCOPY := $(CROSS_COMPILE)objcopy
OBJDUMP := $(CROSS_COMPILE)objdump
GDB     := $(CROSS_COMPILE)gdb
STFLASH  = $(shell which st-flash)

LDSCRIPT    ?= linker/$(TARGET).ld

# Enable stack-checking. WARNING: the full automated test suite currently
# requires a little over 1KB RAM with stack-checking enabled. If you are 
# using a device with 1KB internal SRAM and no external SRAM then you
# must disable stack-checking to run all of the automated tests.
#STACK_CHECK=true

# Location of atomthreads sources
board_dir=$(src_dir)/boards/$(BOARD)
common_dir=$(src_dir)/common
kernel_dir=$(src_dir)/../../kernel
tests_dir=$(src_dir)/../../tests

# Check if user wants to use external opencm3 lib or if we have to build
# it ourselves
ifeq ($(OPENCM3_DIR),)
    OPENCM3_DIR = $(src_dir)/libopencm3
    build_lib = true
endif

ifneq ($(V),)
    $(info Using $(OPENCM3_DIR) as path to opencm3 library)
endif

# Object files needed by all applications
objs += atomport.o 
objs += atomport-asm.o 

# Kernel object files
objs += atomkernel.o 
objs += atomsem.o 
objs += atommutex.o 
objs += atomtimer.o 
objs += atomqueue.o

# Collection of built objects (excluding test applications)
build_objs  = $(foreach obj,$(objs),$(build_dir)/$(obj))

# Object needed by all test applications, but not user apps
tmobjs = tests-main.o
build_tmobjs     = $(foreach obj,$(tmobjs),$(build_dir)/$(obj))
build_tmobjs    += $(build_objs)

# Set up search paths for libopencm3
INCLUDE_DIR = $(OPENCM3_DIR)/include
LIB_DIR     = $(OPENCM3_DIR)/lib
SCRIPT_DIR  = $(OPENCM3_DIR)/scripts

# GCC flags
CFLAGS       =  -Os -g
CFLAGS      += -Wall -Werror
CFLAGS      += -Wredundant-decls -Wstrict-prototypes
CFLAGS      += -fno-common -ffunction-sections -fdata-sections

# Enable stack-checking (disable if not required)
ifeq ($(STACK_CHECK),true)
    CFLAGS  += -DATOM_STACK_CHECKING -DTESTS_LOG_STACK_USAGE
endif

# C & C++ preprocessor common flags
CPPFLAGS    += -MD
CPPFLAGS    += -Wall -Wundef -Werror
CPPFLAGS    += -I$(INCLUDE_DIR) $(DEFS)
CPPFLAGS    += -I$(board_dir) -I$(common_dir) -I$(src_dir) -I$(kernel_dir) -I$(tests_dir)

# Assembler flags
ASFLAGS     += -D__ASSEMBLY__ 
ASFLAGS     += -D__NEWLIB__

# Linker flags
LDFLAGS     += --static -nostartfiles
LDFLAGS     += -L$(LIB_DIR)
LDFLAGS     += -T$(LDSCRIPT)
LDFLAGS     += -Wl,-Map=$(build_dir)/$(*).map
LDFLAGS     += -Wl,--gc-sections
LDFLAGS     += -Wl,--fatal-warnings
ifeq ($(V),99)
LDFLAGS     += -Wl,--print-gc-sections
endif

## Used libraries
# Target specific version libopencm3
LDLIBS		+= -l$(LIBNAME)

## Gather newlib libraries and set up specfiles.
NEWLIBS	    += -lc -lgcc

ifneq ($(BOARD),qemu)
ifeq ($(USE_NANO),true)
SPECS       := -specs=nano.specs

ifeq ($(FIX_DEBIAN),true)
SPECS       += -I/usr/include/newlib/nano
LOCM3_FLAGS += -fshort-wchar
CFLAGS      += -fshort-wchar
endif
endif

# Uncomment to link against libnosys if you do not want to use the provided
# stubs.
# Be advised that heap management will probably break in interesting ways.
# This is because libnosys' standard _sbrk() expects the stack to start at 
# the top end of memory while the threads' stacks are positioned inside 
# the BSS.
#NEWLIBS    += -lnosys

else
# Special LDLIBS for qemu target to enable semi-hosting. 
# TODO: Check if this is also useful for real hardware  
NEWLIBS     += -lrdimon
SPECS       := -specs=rdimon.specs
endif

# add all required newlib libraries as a group
LDLIBS      += -Wl,--start-group $(NEWLIBS) -Wl,--end-group

.PHONY: all
all: build_all

# Generate a direct make target for a test application 
define build_test
.PHONY: $(1)
$(1): $(build_dir)/$(1).elf
endef

# Target application filenames .elf for each test object
tobjs = $(notdir $(patsubst %.c,%.o,$(wildcard $(tests_dir)/*.c)))
telfs = $(patsubst %.o,%.elf,$(tobjs))
tbins = $(patsubst %.o,%.bin,$(tobjs))
thexs = $(patsubst %.o,%.hex,$(tobjs))
build_tobjs = $(foreach tobj,$(tobjs),$(build_dir)/$(tobj))
build_telfs = $(foreach telf,$(telfs),$(build_dir)/$(telf))
build_tbins = $(foreach tbin,$(tbins),$(build_dir)/$(tbin))
build_thexs = $(foreach thex,$(thexs),$(build_dir)/$(thex))

# Add a direct make target for every test app
$(foreach test,$(patsubst %.o,%,$(tobjs)),$(eval $(call build_test,$(test))))

# Define an explicit target and linker rule for an application not in the
# test suite. This will be a stand-alone applications located in the board
# or common directory
define build_app
.PHONY: $(1)
$(1): $(build_dir)/$(1).elf

$(build_dir)/$(1).elf $(build_dir)/$(1).map: $(LIB_DIR)/lib$(LIBNAME).a $(build_dir)/$(1).o $(build_objs) $(LDSCRIPT)
	$$(Q)mkdir -p `dirname $$@`
	$$(if $$(Q), @echo " (ELF)       $$(subst $$(build_dir)/,,$$@)")
	$$(Q)$$(LD) $$(SPECS) $$(LDFLAGS) $$(ARCH_FLAGS) $$(build_objs) $$(build_dir)/$(1).o $(LDLIBS) -o $$@
endef

# Target application filenames .elf for each user app object
aelfs  = $(patsubst %.o,%.elf,$(aobjs))
abins  = $(patsubst %.o,%.bin,$(aobjs))
ahexs  = $(patsubst %.o,%.hex,$(aobjs))
build_aobjs = $(foreach aobj,$(aobjs),$(build_dir)/$(aobj))
build_aelfs = $(foreach aelf,$(aelfs),$(build_dir)/$(aelf))
build_abins = $(foreach abin,$(abins),$(build_dir)/$(abin))
build_ahexs = $(foreach ahex,$(ahexs),$(build_dir)/$(ahex))

# add a direct make target for every standalone app
$(foreach app,$(patsubst %.o,%,$(aobjs)),$(eval $(call build_app,$(app))))

# Build all test and user applications
all_bins	= $(build_tbins) $(build_abins)
all_hexs	= $(build_thexs) $(build_ahexs)
all_elfs	= $(build_telfs) $(build_aelfs)
all_objs	= $(build_tobjs) $(build_aobjs) $(build_tmobjs)

.PHONY: build_all
build_all: $(LIB_DIR)/lib$(LIBNAME).a $(all_bins) $(all_hexs) $(all_elfs) $(all_objs) Makefile $(board_dir)/Makefile.include

# Add build dependency for local libopencm3 if no external libopencm3 is used 
ifeq ($(build_lib),true)
$(LIB_DIR)/lib$(LIBNAME).a: 
	$(Q)if [ ! -f libopencm3/Makefile ] ; then \
		printf "######## ERROR ########\n"; \
		printf "\tlibopencm3 is not initialized.\n"; \
		printf "\tPlease run:\n"; \
		printf "\t$$ git submodule init\n"; \
		printf "\t$$ git submodule update\n"; \
		printf "\tbefore running make.\n"; \
		printf "######## ERROR ########\n"; \
		exit 1; \
		fi
	$(Q)$(MAKE) -C libopencm3 V=$(V) CFLAGS=$(LOCM3_FLAGS)
endif

$(build_dir)/%.bin: $(build_dir)/%.elf
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (OBJCOPY)   $(subst $(build_dir)/,,$@)")
	$(Q)$(OBJCOPY) -O binary $< $@

$(build_dir)/%.hex: $(build_dir)/%.elf
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (OBJCOPY)   $(subst $(build_dir)/,,$@)")
	$(Q)$(OBJCOPY) -O ihex $< $@

$(build_dir)/%.srec: $(build_dir)/%.elf
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (OBJCOPY)   $(subst $(build_dir)/,,$@)")
	$(Q)$(OBJCOPY) -O srec $< $@

$(build_dir)/%.list: $(build_dir)/%.elf
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (OBJDUMP)   $(subst $(build_dir)/,,$@)")
	$(Q)$(OBJDUMP) -S $< > $@

# This is the default rule for linking the test suite applications.
# User applications defined in a board Makefile fragment are linked
# by an explicitly generated rule.
$(build_dir)/%.elf $(build_dir)/%.map: $(LIB_DIR)/lib$(LIBNAME).a $(build_dir)/%.o $(build_tmobjs) $(LDSCRIPT)
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (ELF)       $(subst $(build_dir)/,,$@)")
	$(Q)$(LD) $(SPECS) $(LDFLAGS) $(ARCH_FLAGS) $(build_tmobjs) $(build_dir)/$(*).o $(LDLIBS) -o $@

$(build_dir)/%.o: $(src_dir)/%.S Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (AS)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) $(ASFLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(src_dir)/%.c Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (CC)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(board_dir)/%.S Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (AS)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) $(ASFLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(board_dir)/%.c Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (CC)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(common_dir)/%.S Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (AS)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) $(ASFLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(common_dir)/%.c Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (CC)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(kernel_dir)/%.c Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (CC)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) -I`dirname $<` -c $< -o $@

$(build_dir)/%.o: $(tests_dir)/%.c Makefile $(board_dir)/Makefile.include
	$(Q)mkdir -p `dirname $@`
	$(if $(Q), @echo " (CC)        $(subst $(build_dir)/,,$@)")
	$(Q)$(CC) $(SPECS) $(CFLAGS) $(CPPFLAGS) $(ARCH_FLAGS) -I`dirname $<` -c $< -o $@

# Clean. Remove only atomthread's object files and images
.PHONY: clean
clean:
	rm -rf doxygen-kernel
	rm -rf doxygen-opencm3
	rm -rf $(build_dir)

# Real clean. Also clean libopencm3 if it was built in tree
.PHONY: realclean
realclean: clean
ifeq ($(build_lib),true)
	$(Q)$(MAKE) -C libopencm3 V=$(V) clean
endif

# Docs
.PHONY: doxygen
doxygen:
	doxygen $(kernel_dir)/Doxyfile
ifeq ($(build_lib),true)
	$(Q)$(MAKE) -C libopencm3 V=$(V) doc
endif

#################################################################################
# Target flashing recipes "borrowed" from libopencm3-examples. Mostly untested. #
#################################################################################

%.stlink-flash: $(build_dir)/%.bin
	$(if $(Q), @echo " (FLASH)     $(subst $(build_dir)/,,$<)")
	$(Q)$(STFLASH) write $< 0x8000000

ifeq ($(STLINK_PORT),)
ifeq ($(BMP_PORT),)
ifeq ($(OOCD_SERIAL),)
%.flash: $(build_dir)/%.hex
	$(if $(Q), @echo " (FLASH)     $(subst $(build_dir)/,,$<)")
	@# IMPORTANT: Don't use "resume", only "reset" will work correctly!
	-$(Q)$(OOCD) -f interface/$(OOCD_INTERFACE).cfg \
		    -f board/$(OOCD_BOARD).cfg \
		    -c "init" -c "reset init" \
		    -c "flash write_image erase $<" \
		    -c "reset" \
		    -c "shutdown" $(NULL)
else
%.flash: $(build_dir)/%.hex
	$(if $(Q), @echo " (FLASH)     $(subst $(build_dir)/,,$<)")
	@# IMPORTANT: Don't use "resume", only "reset" will work correctly!
	-$(Q)$(OOCD) -f interface/$(OOCD_INTERFACE).cfg \
		    -f board/$(OOCD_BOARD).cfg \
		    -c "ft2232_serial $(OOCD_SERIAL)" \
		    -c "init" -c "reset init" \
		    -c "flash write_image erase $<" \
		    -c "reset" \
		    -c "shutdown" $(NULL)
endif
else
%.flash: $(build_dir)/%.elf
	$(if $(Q), @echo " (GDB)       $(subst $(build_dir)/,,$<)")
	$(Q)$(GDB) --batch \
		   -ex 'target extended-remote $(BMP_PORT)' \
		   -x $(SCRIPT_DIR)/black_magic_probe_flash.scr \
		   $<
endif
else
%.flash: $(build_dir)/%.elf
	$(if $(Q), @echo " (GDB)       $(subst $(build_dir)/,,$<)")
	$(Q)$(GDB) --batch \
		   -ex 'target extended-remote $(STLINK_PORT)' \
		   -x $(SCRIPT_DIR)/stlink_flash.scr \
		   $<
endif

# Include auto-generated dependencies
-include $(all_objs:.o=.d)