# Error on any uset variable
MAKEFLAGS=--warn-undefined-variables

# Default to a silent build. Run make with --trace for a verbose build.
.SILENT:

# Mac and Linux stat have different options required, set them up here
ifeq ($(shell uname), Darwin)
    STAT = "stat -f '%z'"
else
    STAT = "stat -c '%s'"
endif

BOARD ?= qemu_mps2_an385

$(info Building for $(BOARD))

# Set to 1 to build with templates/memfault_platform_port.c instead of
# FreeRTOS platform functions. Used to test compilation with template files
MEMFAULT_TEST_USE_PORT_TEMPLATE ?= 0

ifeq ($(MEMFAULT_TEST_USE_PORT_TEMPLATE),1)
  ifneq (qemu_mps2_an385,$(BOARD))
    $(error Testing with the template port only supported on the qemu_mps2_an385 board)
  endif
endif

BOARD_DIR := boards/$(BOARD)

BUILD_DIR := build/$(BOARD)

ELF = $(BUILD_DIR)/main.elf

ARM_CC ?= arm-none-eabi-gcc
ARM_CXX ?= arm-none-eabi-g++
# if cc isn't set by the user, set it to ARM_CC
ifeq ($(origin CC),default)
CC := $(ARM_CC)
CXX := $(ARM_CXX)
endif
# use ccache if available
CCACHE := $(shell command -v ccache 2> /dev/null)
ifdef CCACHE
CC := ccache $(CC)
CXX := ccache $(CXX)
endif
OBJCOPY ?= $(shell $(CC) -print-prog-name=objcopy)
SIZE ?= $(shell $(CC) -print-prog-name=size)
READELF ?= $(shell $(CC) -print-prog-name=readelf)

# Check if FreeRTOS location set, add rule to download if not
FREERTOS_DIR ?=
ifeq ($(FREERTOS_DIR),)
FREERTOS_DIR = FreeRTOS-Kernel
FREERTOS_VER = V11.2.0
FREERTOS_SHA = 0adc196d4bd52a2d91102b525b0aafc1e14a2386

# Verify the FreeRTOS directory is present and matches expected SHA
FREERTOS_STALE = \
    $(shell \
        if ! (echo "$(FREERTOS_SHA)" | diff -q $(FREERTOS_DIR)/.git/HEAD - > /dev/null 2>&1); then \
            echo FREERTOS_STALE; \
        fi \
    )
.PHONY: FREERTOS_STALE
$(FREERTOS_DIR)/.git/HEAD: $(FREERTOS_STALE)
	$(info FREERTOS_DIR needs updating, deleting stale copy (if present) and fetching from git)
	rm -rf $(FREERTOS_DIR)
	git -c advice.detachedHead=false clone --branch $(FREERTOS_VER) --depth 1 https://github.com/FreeRTOS/FreeRTOS-Kernel.git $(FREERTOS_DIR)

.DEFAULT_GOAL :=
endif

include $(BOARD_DIR)/Makefile

# Gather list of FreeRTOS sources
FREERTOS_SRCS += \
    $(FREERTOS_DIR)/tasks.c \
    $(FREERTOS_DIR)/queue.c \
    $(FREERTOS_DIR)/list.c \
    $(FREERTOS_DIR)/timers.c \
    $(FREERTOS_DIR)/portable/MemMang/heap_4.c \

# Add application sources
SRCS += \
    src/main.c \
    src/compact_log.cpp \
    src/console.c \
    src/heap_task.c \
    src/metrics.c \
    src/mpu.c \
    src/memfault/memfault_platform_port.c \
    $(BOARD_DIR)/startup.c \
    $(BOARD_DIR)/memfault_platform_impl.c \
    $(FREERTOS_SRCS) \

# Use Memfault SDK worker to gather initial Memfault SDK sources and include dirs
MEMFAULT_SDK_ROOT := ../..
MEMFAULT_COMPONENTS ?= core util panics metrics demo
include $(MEMFAULT_SDK_ROOT)/makefiles/MemfaultWorker.mk

# Add CFLAGS defines for each of the memfault components enabled above
CFLAGS += $(foreach each, $(MEMFAULT_COMPONENTS), -DMEMFAULT_COMPONENT_$(each)_)

# Add additional SDK sources to project for FreeRTOS and RAM-backed coredump.
# Intentionally using a wildcard to trap any new features added- it's nice to
# have them enabled in this example app.
SRCS += \
    $(MEMFAULT_COMPONENTS_SRCS) \
        $(MEMFAULT_SDK_ROOT)/ports/panics/src/memfault_platform_ram_backed_coredump.c \

ifneq ($(MEMFAULT_TEST_USE_PORT_TEMPLATE), 1)
    SRCS += \
        $(wildcard $(MEMFAULT_SDK_ROOT)/ports/freertos/src/*.c)
endif


# Fixup build path for objects of the Memfault SDK, all build output kept within build/
OBJS := $(subst $(MEMFAULT_SDK_ROOT),memfault-firmware-sdk,$(SRCS:%=$(BUILD_DIR)/%.o))

INCLUDE_PATHS += \
    -I$(FREERTOS_DIR)/include \
    -I. \
    -Isrc \
    -Isrc/memfault \
    -I$(MEMFAULT_COMPONENTS_INC_FOLDERS) \
    -I$(MEMFAULT_SDK_ROOT)/ports/include \
    -I$(MEMFAULT_SDK_ROOT) \
    -I$(FREERTOS_DIR)/portable/GCC/$(FREERTOS_PORT) \

# generic (non-arch-specific) CFLAGS
CFLAGS += \
    -nostartfiles \
    -Werror \
    -Wall \
    -Wextra \
    -Werror=undef \
    -ffunction-sections \
    -fdata-sections \
    -ggdb3 \
    -Og \
    -MD \
    -fdebug-prefix-map="$(shell pwd)"=. \
    -DBOARD=\"$(BOARD)\" \
    $(ARCH_CFLAGS) \

# Enable the self test by default
MEMFAULT_DEMO_CLI_SELF_TEST ?= 1
CFLAGS += \
  -DMEMFAULT_DEMO_CLI_SELF_TEST=$(MEMFAULT_DEMO_CLI_SELF_TEST) \
  -DMEMFAULT_TEST_USE_PORT_TEMPLATE=$(MEMFAULT_TEST_USE_PORT_TEMPLATE)

LINKER_SCRIPT = $(BOARD_DIR)/linker.ld

LDFLAGS += \
    -Wl,-T$(LINKER_SCRIPT) \
    -Wl,--gc-sections \
    --specs=nano.specs \
    --specs=rdimon.specs \
    -Wl,-lc \
    -Wl,-lrdimon \
    -Wl,-Map=$(BUILD_DIR)/main.map \
    -Wl,--build-id \
    -Wl,--print-memory-usage \

# Check if the compiler is = 4.9.3, if so, disable some incopatible flags. The
# warnings they emit are due to incomplete support for C99 braced initializers
# in this old version of GCC.
GCC_VERSION := $(shell $(CC) -dumpversion)
ifeq ($(GCC_VERSION),4.9.3)
    $(info Detected GCC 4.9.3, disabling some flags)
    CFLAGS += \
        -Wno-error=missing-braces \
        -Wno-error=missing-field-initializers \

    # remove -Wl,--print-memory-usage from LDFLAGS
    COMMA=,
    LDFLAGS := $(filter-out -Wl$(COMMA)--print-memory-usage,$(LDFLAGS))
endif


.PHONY: all
all: $(ELF)

# Require clone to complete as prereq for sources
$(SRCS): $(FREERTOS_DIR)/.git/HEAD

# Store computed cflags in a file; it's a prerequisite for all objects. Use a
# shell hack to check if the current cflags are different from the stored file,
# and make it out of date if so
# If CFLAGS differ from last build, rebuild all files
RAW_CFLAGS := $(CFLAGS) $(LDFLAGS)
CFLAGS_STALE = \
    $(shell \
        if ! (echo "$(RAW_CFLAGS)" | diff -q $(BUILD_DIR)/cflags - > /dev/null 2>&1); then \
            echo CFLAGS_STALE; \
        fi \
    )
.PHONY: CFLAGS_STALE
$(BUILD_DIR)/cflags: $(CFLAGS_STALE) Makefile
	mkdir -p $(dir $@)
	echo "$(RAW_CFLAGS)" > $@

# Add rules for patched build objects from SDK
$(BUILD_DIR)/memfault-firmware-sdk/%.c.o: $(MEMFAULT_SDK_ROOT)/%.c $(BUILD_DIR)/cflags
	mkdir -p $(dir $@)
	$(info Compiling $<)
	$(CC) -std=gnu11 $(CFLAGS) $(INCLUDE_PATHS) -c $< -o $@

$(BUILD_DIR)/%.c.o: %.c $(BUILD_DIR)/cflags
	mkdir -p $(dir $@)
	$(info Compiling $<)
	$(CC) -std=gnu11 $(CFLAGS) $(INCLUDE_PATHS) -c $< -o $@

$(BUILD_DIR)/%.cpp.o: %.cpp $(BUILD_DIR)/cflags
	mkdir -p $(dir $@)
	$(info Compiling $<)
	$(CXX) -std=gnu++11 $(CFLAGS) $(INCLUDE_PATHS) -c $< -o $@

$(ELF).uncompressed: $(OBJS) $(LINKER_SCRIPT)
	$(info Linking $@)
	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) -o $@

$(ELF): $(ELF).uncompressed
	echo -n 'Compressing debug info... '
	$(OBJCOPY) --compress-debug-sections $^ $@
	echo From $$("$(STAT)" $^) to $$("$(STAT)" $@) bytes
	$(SIZE) $@
	$(READELF) -n $@ | grep 'Build ID'


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

.PHONY: debug
debug: $(ELF)
	$(info Starting debugger)
	$(DEBUG_COMMAND)

.PHONY: gdb
gdb: $(ELF)
	$(GDB_COMMAND)

.PHONY: run
run: $(ELF)
	$(RUN_COMMAND)

# This target dumps the preprocessed output of the memfault_metrics.c file
.PHONY: memfault_metrics.c
memfault_metrics.c: # build/qemu_mps2_an385/memfault-firmware-sdk/components/metrics/src/memfault_metrics.c.o
	$(CC) $(CFLAGS:-MD=) $(INCLUDE_PATHS) -c $(MEMFAULT_SDK_ROOT)/components/metrics/src/memfault_metrics.c -E -P -o -

.PHONY: clean
clean:
	rm -rf build