PROJ_NAME = hello_world
DEBUG = yes
BENCH = no
MULDIV = no

SRCS = $(wildcard src/*.c) \
       $(wildcard src/*.cpp) \
       $(wildcard src/*.S) \
       src/stub_stdlib.c

OBJDIR = build

INC  =
LIBS =
LIBSINC = -L$(OBJDIR)
LDSCRIPT = ./src/linker.ld

# Set it to yes if you are using the sifive precompiled GCC pack
GCC_PACK ?= yes

ifeq ($(GCC_PACK),yes)
	RISCV_NAME ?= riscv32-unknown-elf
	RISCV_PATH ?= /home/user/riscv/opt/rv32im/
endif

MABI = ilp32
MARCH := rv32i_zicsr
ifeq ($(MULDIV),yes)
	MARCH := $(MARCH)m
endif

ifeq ($(DEBUG),yes)
#	CFLAGS += -g3 -O0
	CFLAGS += -g3 -gdwarf-3 -O0 -DDEBUG
	CXXFLAGS += -g3 -gdwarf-3 -O0 -DDEBUG
	LDFLAGS += -g3 -gdwarf-3
endif

ifeq ($(DEBUG),no)
	CFLAGS += -g -Os
endif

ifeq ($(BENCH),yes)
	CFLAGS += -fno-inline
endif

ifeq ($(SIFIVE_GCC_PACK),yes)
	RISCV_CLIB=$(RISCV_PATH)/$(RISCV_NAME)/lib/$(MARCH)/$(MABI)/
else
	RISCV_CLIB=$(RISCV_PATH)/$(RISCV_NAME)/lib/
endif

RISCV_OBJCOPY = $(RISCV_PATH)/bin/$(RISCV_NAME)-objcopy
RISCV_OBJDUMP = $(RISCV_PATH)/bin/$(RISCV_NAME)-objdump
RISCV_CC = $(RISCV_PATH)/bin/$(RISCV_NAME)-gcc
CXX = $(RISCV_PATH)/bin/$(RISCV_NAME)-g++

CFLAGS += -march=$(MARCH) \
          -mabi=$(MABI) \
          -DNDEBUG \
          -fno-pic \
          -ffreestanding \
          -MD \
          -fstrict-volatile-bitfields \
          -fno-strict-aliasing

CXXFLAGS += -march=$(MARCH) \
            -mabi=$(MABI) \
            -DNDEBUG \
            -fno-pic \
            -ffreestanding \
            -MD \
            -fstrict-volatile-bitfields \
            -fno-strict-aliasing \
            -std=c++11

LDFLAGS += -march=$(MARCH) \
           -mabi=$(MABI) \
           -lc \
           -lgcc \
           -nostdlib \
           -nostartfiles \
           -mcmodel=medany \
           -ffreestanding \
           -Wl,-Bstatic,-T,$(LDSCRIPT),-Map,$(OBJDIR)/$(PROJ_NAME).map

OBJS := $(SRCS)
OBJS := $(OBJS:.c=.o)
OBJS := $(OBJS:.cpp=.o)
OBJS := $(OBJS:.S=.o)
OBJS := $(addprefix $(OBJDIR)/,$(OBJS))

all: $(OBJDIR)/$(PROJ_NAME).elf $(OBJDIR)/$(PROJ_NAME).hex $(OBJDIR)/$(PROJ_NAME).asm $(OBJDIR)/$(PROJ_NAME).v

$(OBJDIR)/%.elf: $(OBJS) | $(OBJDIR)
	$(CXX) $(CXXFLAGS) -o $@ $^ $(LDFLAGS) $(LIBSINC) $(LIBS)

%.hex: %.elf
	$(RISCV_OBJCOPY) -O ihex $^ $@

%.bin: %.elf
	$(RISCV_OBJCOPY) -O binary $^ $@

%.v: %.elf
	$(RISCV_OBJCOPY) -O verilog $^ $@

%.asm: %.elf
	$(RISCV_OBJDUMP) -S -d $^ > $@

$(OBJDIR)/%.o: %.c
	mkdir -p $(dir $@)
	$(RISCV_CC) -c $(CFLAGS) $(INC) -o $@ $^

$(OBJDIR)/%.o: %.cpp
	mkdir -p $(dir $@)
	$(CXX) -c $(CXXFLAGS) $(INC) -o $@ $^

$(OBJDIR)/%.o: %.S
	mkdir -p $(dir $@)
	$(RISCV_CC) -c $(CFLAGS) -o $@ $^ -D__ASSEMBLY__=1

$(OBJDIR):
	mkdir -p $@

.PHONY: clean
clean:
	rm -rf $(OBJDIR)/src
	rm -f $(OBJDIR)/$(PROJ_NAME).elf
	rm -f $(OBJDIR)/$(PROJ_NAME).hex
	rm -f $(OBJDIR)/$(PROJ_NAME).map
	rm -f $(OBJDIR)/$(PROJ_NAME).v
	rm -f $(OBJDIR)/$(PROJ_NAME).asm
	find $(OBJDIR) -type f -name '*.o' -print0 | xargs -0 -r rm
	find $(OBJDIR) -type f -name '*.d' -print0 | xargs -0 -r rm

clean-all: clean

.SECONDARY: $(OBJS)