# Makefile for the Fusion operating system.
# Make things fixable, not autocorrecting

# TODO: Toolchain installation should be documented in the README
# https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack
TOOLPREFIX = riscv-none-elf

CC = $(TOOLPREFIX)-gcc
AS = $(TOOLPREFIX)-gas
LD = $(TOOLPREFIX)-ld
OBJCOPY = $(TOOLPREFIX)-objcopy
OBJDUMP = $(TOOLPREFIX)-objdump

# TODO: Document these options with clear descriptions, it should be readable
# by people not intimately familiar with machine code and/or gcc tooling.
CFLAGS = -Wall -Werror -O -fno-omit-frame-pointer -ggdb -gdwarf-2
CFLAGS += -MD
CFLAGS += -mcmodel=medany
CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax
CFLAGS += -I.
CFLAGS += -fno-pie -no-pie
CFLAGS += -fno-stack-protector
CFLAGS += -march=rv64gc -mabi=lp64

LDFLAGS = -z max-page-size=4096
LDFLAGS += -m elf64lriscv

all: kernel.elf

%.o: %.c
	@echo CC $@
	@$(CC) $(CFLAGS) -nostdinc -I. -c $< -o $@

%.o: %.S
	@echo CC-AS $@
	@$(CC) $(CFLAGS) -c $< -o $@

kernel.elf: trap.o kernelvec.o entry.o start.o kernel.o spinlock.o
	@echo LD $@
	@$(LD) $(LDFLAGS) -T kernel.ld -o $@ $^

kernel.bin: kernel.elf
	$(OBJCOPY) -O binary $< $@

clean:
	rm -f *.o *.d *.elf *.bin

-include *.d