PROGRAM = sifive-welcome
TARGET = sifive-hifive1-revb

# The configuration defaults to Debug. Valid choices are:
#   - debug
#   - release
CONFIGURATION ?= debug

BSP_DIR ?= $(abspath bsp)
SRC_DIR ?= $(abspath src)

# Include the BSP settings
include $(BSP_DIR)/settings.mk

ifeq ($(RISCV_LIBC),)
	RISCV_LIBC=nano
endif

ifeq ($(RISCV_LIBC),nano)
	# 裸机需要使用libgloss底层库
	LIBMETAL_EXTRA=-lmetal-gloss
	METAL_WITH_EXTRA=--with-builtin-libgloss
	SPEC=nano
endif

LINK_TARGET = default
RISCV_XLEN := 32
MTIME_RATE_HZ_DEF=32768

RISCV_ARCH = rv32imac
RISCV_ABI = ilp32
RISCV_CMODEL = medlow
RISCV_SERIES = sifive-3-series

TARGET_TAGS = board jlink
TARGET_DHRY_ITERS = 20000000
TARGET_CORE_ITERS = 5000
TARGET_FREERTOS_WAIT_MS = 1000
TARGET_INTR_WAIT_CYCLE  = 0

CROSS_COMPILE ?= riscv64-unknown-elf

RISCV_GCC     := $(CROSS_COMPILE)-gcc
SEGGER_JLINK_EXE := JLinkExe
SEGGER_JLINK_GDB_SERVER := JLinkGDBServer

# Turn on garbage collection for unused sections
RISCV_LDFLAGS += -Wl,--gc-sections
# Turn on linker map file generation
RISCV_LDFLAGS += -Wl,-Map,$(PROGRAM).map
# Turn off the C standard library
RISCV_LDFLAGS += -nostartfiles -nostdlib
# Find the archive files and linker scripts
RISCV_LDFLAGS += -L$(sort $(dir $(abspath $(filter %.a,$^)))) -T$(abspath $(filter %.lds,$^))

# Link to the relevant libraries
RISCV_LDLIBS += -Wl,--start-group -lc -lgcc -lm -lmetal $(LIBMETAL_EXTRA) -Wl,--end-group

# Load the configuration Makefile
CONFIGURATION_FILE = $(wildcard $(CONFIGURATION).mk)
include $(CONFIGURATION).mk

# Set the optimization level
RISCV_ASFLAGS += -O0
RISCV_CFLAGS += -O0
RISCV_CXXFLAGS += -O0

# Enable debug
RISCV_ASFLAGS += -g
RISCV_CFLAGS += -g
RISCV_CXXFLAGS += -g

PROGRAM_ELF ?= $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).elf
PROGRAM_HEX ?= $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).hex
PROGRAM_LST ?= $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).lst

.PHONY: all
all: software

.PHONY: software
software: $(PROGRAM_ELF)
software: $(PROGRAM_HEX)

# 代码文件，所有src/目录下的c/h/S文件
PROGRAM_SRCS = $(wildcard $(SRC_DIR)/*.c) $(wildcard $(SRC_DIR)/*.h) $(wildcard $(SRC_DIR)/*.S)

# elf: srcs, *.a, default.lds
$(PROGRAM_ELF): \
		$(PROGRAM_SRCS) \
		$(BSP_DIR)/install/lib/$(CONFIGURATION)/libmetal.a \
		$(BSP_DIR)/install/lib/$(CONFIGURATION)/libmetal-gloss.a \
		$(BSP_DIR)/metal.$(LINK_TARGET).lds
	mkdir -p $(dir $@)
	$(MAKE) -C $(SRC_DIR) $(basename $(notdir $@)) \
		PORT_DIR=$(PORT_DIR) \
		PROGRAM=$(PROGRAM) \
		AR=$(RISCV_AR) \
		CC=$(RISCV_GCC) \
		CXX=$(RISCV_GXX) \
		ASFLAGS="$(RISCV_ASFLAGS)" \
		CCASFLAGS="$(RISCV_CCASFLAGS)" \
		CFLAGS="$(RISCV_CFLAGS)" \
		CXXFLAGS="$(RISCV_CXXFLAGS)" \
		XCFLAGS="$(RISCV_XCFLAGS)" \
		LDFLAGS="$(RISCV_LDFLAGS)" \
		LDLIBS="$(RISCV_LDLIBS)" \
		FREERTOS_METAL_VENV_PATH="$(FREERTOS_METAL_VENV_PATH)"
	mv $(SRC_DIR)/$(basename $(notdir $@)) $@
	mv $(SRC_DIR)/$(basename $(notdir $@)).map $(dir $@)
	touch -c $@
	$(RISCV_OBJDUMP) --source --all-headers --demangle --line-numbers --wide $@ > $(PROGRAM_LST)
	$(RISCV_SIZE) $@

.PHONY: clean-software
clean-software:
	$(MAKE) -C $(SRC_DIR) PORT_DIR=$(PORT_DIR) clean
	rm -rf $(SRC_DIR)/$(CONFIGURATION)
.PHONY: clean
clean: clean-software

#############################################################
# Configuration
#############################################################

# Allows users to create Makefile.local or ../Makefile.project with
# configuration variables, so they don't have to be set on the command-line
# every time.
extra_configs := $(wildcard Makefile.local ../Makefile.project)
ifneq ($(extra_configs),)
$(info Obtaining additional make variables from $(extra_configs))
include $(extra_configs)
endif

TARGET_ROOT  ?= $(abspath .)
PROGRAM_ROOT ?= $(abspath .)

# Allow BOARD as a synonym for TARGET
# 允许BOARD作为TARGET的同义词
ifneq ($(BOARD),)
TARGET ?= $(BOARD) # TARGET=sparkfun-redv
endif

# Default PROGRAM and TARGET
PROGRAM ?= hello # PROGRAM=sparkfun-welcome
TARGET ?= $(shell find $(TARGET_ROOT)/bsp/* -type d | head -n 1 | rev | cut -d '/' -f 1 | rev)

# The configuration defaults to Debug. Valid choices are:
#  - debug
#  - release
CONFIGURATION ?= debug

# Setup differences between host platforms
ifeq ($(OS),Windows_NT)
    SED_RE_FLAG = -r
else
    UNAME_S := $(shell uname -s)
    ifeq ($(UNAME_S),Linux)
        SED_RE_FLAG = -r
    endif
    ifeq ($(UNAME_S),Darwin)
        SED_RE_FLAG = -E
    endif
endif

# Default to use relase configuration For Benchmark programs, like Coremark and Dhrystone.
# 默认使用relase配置 对于基准测试程序，如Coremark和Dhrystone。
ifeq ($(PROGRAM),dhrystone)
CONFIGURATION = release
endif

# Coremark require PORT_DIR set for different OS, freedom-metal for us!
# Coremark要求为不同的操作系统设置 PORT_DIR，对我们来说是freedom-metal
ifeq ($(PROGRAM),coremark)
CONFIGURATION = release
ifeq ($(PORT_DIR),)
PORT_DIR = freedom-metal
endif
endif

# SRC_DIR = ./software/sparkfun-welcome
SRC_DIR = $(PROGRAM_ROOT)/software/$(PROGRAM)

# PROGRAM_ELF = $(SRC_DIR)/release/sparkfun-welcome.elf
PROGRAM_ELF = $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).elf
PROGRAM_HEX = $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).hex
PROGRAM_LST = $(SRC_DIR)/$(CONFIGURATION)/$(PROGRAM).lst

#############################################################
# BSP Loading
#############################################################

# Finds the directory in which this BSP is located, ensuring that there is
# exactly one.
# 找到bsp目录：
BSP_DIR := $(wildcard $(TARGET_ROOT)/bsp/$(TARGET))

ifeq ($(words $(BSP_DIR)),0)
$(error Unable to find BSP for $(TARGET), expected to find "bsp/$(TARGET)")
endif
ifneq ($(words $(BSP_DIR)),1)
$(error Found multiple BSPs for $(TARGET): "$(BSP_DIR)")
endif

#############################################################
# Standalone Script Include 独立的脚本包括
#############################################################

# The standalone script is included here because it needs $(SRC_DIR) and
# $(BSP_DIR) to be set.
#
# The standalone Makefile handles the following tasks:
#  - Including $(BSP_DIR)/settings.mk and validating RISCV_ARCH, RISCV_ABI
#  - Setting the toolchain path with CROSS_COMPILE and RISCV_PATH
#  - Providing the software and $(PROGRAM_ELF) Make targets for Metal
# 独立的 Makefile 处理以下任务。
# - 包括 $(BSP_DIR)/settings.mk 并验证 RISCV_ARCH, RISCV_ABI
# - 用CROSS_COMPILE和RISCV_PATH设置工具链路径
# - 为Metal提供软件和$(PROGRAM_ELF) 制作目标

include scripts/standalone.mk

#############################################################
# Prints help message
#############################################################
.PHONY: help
help:
	@echo " SiFive Freedom E Software Development Kit "
	@echo " Makefile targets:"
	@echo ""
	@echo " software [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]"
	@echo "          [CONFIGURATION=$(CONFIGURATION)]:"
	@echo "    Builds the requested PROGRAM for the TARGET using the"
	@echo "    specified build CONFIGURATION."
	@echo ""
	@echo " metal [TARGET=$(TARGET)] [CONFIGURATION=$(CONFIGURATION)]"
	@echo "    Builds the Freedom Metal library for TARGET."
	@echo ""
	@echo " clean [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]"
	@echo "       [CONFIGURATION=$(CONFIGURATION)]:"
	@echo "    Cleans compiled objects for a specified "
	@echo "    software program."
	@echo ""
	@echo " upload [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]"
	@echo "        [CONFIGURATION=$(CONFIGURATION)]:"
	@echo "    For board and FPGA TARGETs, uploads the program to the"
	@echo "    on-board flash."
	@echo ""
	@echo " debug [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]"
	@echo "       [CONFIGURATION=$(CONFIGURATION)]:"
	@echo "    For board and FPGA TARGETs, attaches GDB to the"
	@echo "    running program."
	@echo ""
	@echo " simulate [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]"
	@echo "          [CONFIGURATION=$(CONFIGURATION)]:"
	@echo "    Simulates the program in the QEMU emulator."
	@echo ""
	@echo " standalone STANDALONE_DEST=/path/to/desired/location"
	@echo "            [PROGRAM=$(PROGRAM)] [TARGET=$(TARGET)]:"
	@echo "    Exports a program for a single target into a standalone"
	@echo "    project directory at STANDALONE_DEST."
	@echo ""
	@echo " open-docs"
	@echo "    Opens the Freedom E SDK documentation in your HTML"
	@echo "    viewer of choice. The documentation can also be found"
	@echo "    online at"
	@echo "      https://sifive.github.io/freedom-e-sdk-docs/index.html"

.PHONY: open-docs
open-docs: scripts/open-docs
	$^

.PHONY: clean
clean:

#############################################################
# Enumerate BSPs and Programs
#
# List all available boards and programs in a form that
# Freedom Studio knows how to parse.  Do not change the
# format or fixed text of the output without consulting the
# Freedom Studio dev team.
#############################################################
# 枚举BSP和程序
#
# 列出所有可用的板卡和程序的形式，以便于
# Freedom Studio知道如何解析。 请不要改变
# 格式或固定的输出文本，除非咨询
# Freedom Studio开发团队。
#############################################################

# Find all settings.mk with TARGET_REQUIRE_TAGS in TARGET_TAGS
# 在TARGET_TAGS中找到所有带有TARGET_REQUIRE_TAGS的设置.mk
MATCHING_SETTINGS = $(shell scripts/filter-targets $(TARGET_ROOT)/bsp $(TARGET_REQUIRE_TAGS))

# Get the name of the containing directory of all matching settings.mk
# 获取所有匹配设置的包含目录的名称.mk
MATCHING_TARGETS = $(patsubst $(TARGET_ROOT)/bsp/%/,%,$(dir $(MATCHING_SETTINGS)))

.PHONY: list-targets
list-targets:
	@echo bsp-list: $(sort $(MATCHING_TARGETS))

# Lists all available TARGET_TAGS
#
#  1. Find all settings.mk
#  2. Extract the TARGET_TAGS line
#  3. Extract the value of TARGET_TAGS
#  4. Split each tag onto a newline
#  5. Sort the lines
#  6. Find unique tags
#
.PHONY: list-target-tags
list-target-tags:
	@echo target-tags: $(shell find $(TARGET_ROOT)/bsp -name settings.mk | \
		xargs grep -he "TARGET_TAGS" | \
		sed $(SED_RE_FLAG) 's/TARGET_TAGS.*=(.*)/\1/' | \
		tr ' ' '\n' | \
		sort | \
		uniq)

# Metal programs are any submodules in the software folder
# 金属程序是软件文件夹中的任何子模块
.PHONY: list-programs
list-programs:
	@echo program-list: $(shell ls $(PROGRAM_ROOT)/software)

.PHONY: list-options
list-options: list-programs list-targets

#############################################################
# Import rules to build Freedom Metal
# 在这里进行编译
#############################################################

include scripts/libmetal.mk # 编译出hex、bin等文件

#############################################################
# Standalone Project Export
#############################################################

ifeq ($(STANDALONE_DEST),)
standalone:
	$(error Please provide STANDALONE_DEST to create a standalone project)
else # STANDALONE_DEST != ""

$(STANDALONE_DEST):
$(STANDALONE_DEST)/%:
	mkdir -p $@

ifneq ($(filter rtl,$(TARGET_TAGS)),)
# TARGETs with the "rtl" TARGET_TAG need elf2hex in their standalone project
standalone: \
		$(STANDALONE_DEST) \
		$(STANDALONE_DEST)/bsp \
		$(STANDALONE_DEST)/src \
		$(SRC_DIR) \
		freedom-metal \
		debug.mk \
		release.mk \
		scripts/elf2hex \
		scripts/standalone.mk \
		scripts/libmetal.mk
	cp -r $(addprefix $(BSP_DIR)/,$(filter-out build,$(shell ls $(BSP_DIR)))) $</bsp/

	cp -r freedom-metal $</

	find $</freedom-metal -name ".git*" | xargs rm -rf

	mkdir -p $</scripts
	cp -r scripts/elf2hex $</scripts

	find $</scripts/elf2hex -name ".git*" | xargs rm -rf

ifeq ($(PORT_DIR),)
	$(MAKE) -C $(SRC_DIR) clean
else
	$(MAKE) -C $(SRC_DIR) PORT_DIR=${PORT_DIR} clean
endif
	cp -r $(SRC_DIR)/* $</src/

	cp debug.mk $</debug.mk
	cp release.mk $</release.mk

	echo "PROGRAM = $(PROGRAM)" > $</Makefile
	echo "TARGET = ${TARGET}" >> $</Makefile
ifneq ($(PORT_DIR),)
	echo "PORT_DIR = $(PORT_DIR)" >> $</Makefile
endif
	echo "" >> $</Makefile
	echo "# The configuration defaults to Debug. Valid choices are:" >> $</Makefile
	echo "#   - debug" >> $</Makefile
	echo "#   - release" >> $</Makefile
	echo "CONFIGURATION ?= ${CONFIGURATION}" >> $</Makefile
	echo "" >> $</Makefile
	cat scripts/standalone.mk >> $</Makefile
	cat scripts/libmetal.mk >> $</Makefile
else # "rtl" not in TARGET_TAGS
standalone: \
		$(STANDALONE_DEST) \
		$(STANDALONE_DEST)/bsp \
		$(STANDALONE_DEST)/src \
		$(SRC_DIR) \
		freedom-metal \
		debug.mk \
		release.mk \
		scripts/standalone.mk \
		scripts/libmetal.mk
	cp -r $(addprefix $(BSP_DIR)/,$(filter-out build,$(shell ls $(BSP_DIR)))) $</bsp/

	cp -r freedom-metal $</

	find $</freedom-metal -name ".git*" | xargs rm -rf

ifeq ($(PORT_DIR),)
	$(MAKE) -C $(SRC_DIR) clean
else
	$(MAKE) -C $(SRC_DIR) PORT_DIR=${PORT_DIR} clean
endif
	cp -r $(SRC_DIR)/* $</src/

	cp debug.mk $</debug.mk
	cp release.mk $</release.mk

	echo "PROGRAM = $(PROGRAM)" > $</Makefile
	echo "TARGET = ${TARGET}" >> $</Makefile
ifneq ($(PORT_DIR),)
	echo "PORT_DIR = $(PORT_DIR)" >> $</Makefile
endif
	echo "" >> $</Makefile
	echo "# The configuration defaults to Debug. Valid choices are:" >> $</Makefile
	echo "#   - debug" >> $</Makefile
	echo "#   - release" >> $</Makefile
	echo "CONFIGURATION ?= ${CONFIGURATION}" >> $</Makefile
	echo "" >> $</Makefile
	cat scripts/standalone.mk >> $</Makefile
	cat scripts/libmetal.mk >> $</Makefile
endif # rtl in TARGET_TAGS

endif # STANDALONE_DEST

#############################################################
# Upload and Debug
#############################################################

ifneq ($(RISCV_OPENOCD_PATH),)
RISCV_OPENOCD=$(RISCV_OPENOCD_PATH)/bin/openocd
else
#if RISCV_OPENOCD_PATH is not set, just look on the PATH
RISCV_OPENOCD=openocd
endif

ifneq ($(filter jlink,$(TARGET_TAGS)),)
upload: $(PROGRAM_HEX)
	scripts/upload --hex $(PROGRAM_HEX) --jlink $(SEGGER_JLINK_EXE)
else
upload: $(PROGRAM_ELF)
	scripts/upload --elf $(PROGRAM_ELF) --openocd $(RISCV_OPENOCD) --gdb $(RISCV_GDB) --openocd-config bsp/$(TARGET)/openocd.cfg
endif

ifneq ($(filter jlink,$(TARGET_TAGS)),)
debug: $(PROGRAM_ELF)
	scripts/debug --elf $(PROGRAM_ELF) --jlink $(SEGGER_JLINK_GDB_SERVER) --gdb $(RISCV_GDB)
else
debug: $(PROGRAM_ELF)
	scripts/debug --elf $(PROGRAM_ELF) --openocd $(RISCV_OPENOCD) --gdb $(RISCV_GDB) --openocd-config bsp/$(TARGET)/openocd.cfg
endif

ifeq ($(findstring qemu,$(TARGET)),qemu)
ifeq ($(findstring rv32,$(RISCV_ARCH)),rv32)
simulate: $(PROGRAM_ELF)
	scripts/simulate --elf $(PROGRAM_ELF) --qemu $(QEMU_RISCV32) --qemu-config bsp/$(TARGET)/qemu.cfg
else # findstring rv32
simulate: $(PROGRAM_ELF)
	scripts/simulate --elf $(PROGRAM_ELF) --qemu $(QEMU_RISCV64) --qemu-config bsp/$(TARGET)/qemu.cfg
endif
else # findstring qemu
simulate:
	@echo "QEMU can't simulate target $(TARGET)!"
endif

#############################################################
# Compiles an instance of Metal targeted at $(TARGET)
# 编译一个针对$(TARGET)的Metal实例
#############################################################
METAL_SOURCE_PATH ?= freedom-metal
# 链接脚本：freedom-e-sdk/bsp/sparkfun-redv/metal.default.lds
METAL_LDSCRIPT	   = $(BSP_DIR)/metal.$(LINK_TARGET).lds
METAL_HEADER	   = $(BSP_DIR)/metal.h
METAL_INLINE       = $(BSP_DIR)/metal-inline.h
PLATFORM_HEADER	   = $(BSP_DIR)/metal-platform.h

METAL_PREFIX       = $(abspath $(BSP_DIR)/install)
METAL_BUILD_DIR    = $(abspath $(BSP_DIR)/build/$(CONFIGURATION))
METAL_LIB_DIR	   = $(abspath $(BSP_DIR)/install/lib/$(CONFIGURATION))

.PHONY: metal
metal: $(METAL_LIB_DIR)/stamp

$(METAL_BUILD_DIR)/Makefile:
	@rm -rf $(dir $@)
	@mkdir -p $(dir $@)
	cd $(dir $@) && \
		CFLAGS="$(RISCV_CFLAGS)" \
		$(abspath $(METAL_SOURCE_PATH)/configure) \
		--host=$(CROSS_COMPILE) \
		--prefix=$(METAL_PREFIX) \
		--libdir=$(METAL_LIB_DIR) \
		--disable-maintainer-mode \
		--with-preconfigured \
		--with-machine-name=$(TARGET) \
		--with-machine-header=$(abspath $(METAL_HEADER)) \
    --with-machine-inline=$(abspath $(METAL_INLINE)) \
		--with-platform-header=$(abspath $(PLATFORM_HEADER)) \
		--with-machine-ldscript=$(abspath $(METAL_LDSCRIPT)) \
		--with-builtin-libgloss
	touch -c $@

$(METAL_LIB_DIR)/stamp: $(BSP_DIR)/build/$(CONFIGURATION)/Makefile
	$(MAKE) -C $(abspath $(BSP_DIR)/build/$(CONFIGURATION)) install
	date > $@

$(METAL_LIB_DIR)/libriscv%.a: $(METAL_LIB_DIR)/stamp ;@:

$(METAL_LIB_DIR)/libmetal.a: $(METAL_LIB_DIR)/libriscv__mmachine__$(TARGET).a
	cp $< $@

$(METAL_LIB_DIR)/libmetal-gloss.a: $(METAL_LIB_DIR)/libriscv__menv__metal.a
	cp $< $@

# If we're cleaning the last Metal library for a TARGET, then remove
# the install directory, otherwise just remove the built libs for that
# CONFIGURATION.
ifeq ($(words $(wildcard $(METAL_PREFIX)/lib/*)),1)
METAL_CLEAN = $(METAL_PREFIX)
else
METAL_CLEAN = $(METAL_LIB_DIR)
endif

.PHONY: clean-metal
clean-metal:
	rm -rf $(METAL_CLEAN)
	rm -rf $(METAL_BUILD_DIR)
clean: clean-metal

metal_install: metal
	$(MAKE) -C $(METAL_SOURCE_PATH) install