TOOLPREFIX = riscv64-linux-gnu
# TOOLPREFIX = toolchain/xpack-riscv-none-elf-gcc-14.2.0-3/bin/riscv-none-elf
# TOOLPREFIX = toolchain/gcc/bin/riscv-none-elf

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

ASFLAGS = -march=rv64gc -mabi=lp64

LDFLAGS = -Tkern/kernel.ld
LDFLAGS += -m elf64lriscv

CFLAGS = -Wall -Werror -O
CFLAGS += -Wno-unused-result
CFLAGS += -mcmodel=medany
CFLAGS += -march=rv64gc -mabi=lp64
CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax

CFLAGS += -fno-stack-protector # Prevents code that needs libc / runtime support
CFLAGS += -MD # Generate header dependency files (.d)
CFLAGS += -fno-pie -no-pie # Fixed address linking
CFLAGS += -ggdb -gdwarf-2 # GDB debug info
CFLAGS += -fno-omit-frame-pointer # More reliable backtraces in GDB

CFLAGS += -I.
CFLAGS += -I./kern
CFLAGS += -I./kern/libkern

all: kern/kernel.elf

main: main.o

kern/kernel.elf: kern/entry.o kern/start.o kern/libkern/string.o kern/libkern/proc.o kern/libkern/uart.o kern/libkern/panic.o kern/kalloc.o kern/libkern/memory.o kern/ispinlock.o kern/libkern/spinlock.o kern/libkern/string.o kern/libkern/mini-printf.o
	@echo LD $@
	@$(LD) $(LDFLAGS) -o $@ $^

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

%.o: %.S
	@echo AS $@
	@$(AS) $(ASFLAGS) -o $@ $<

qemu: kern/kernel.elf
	@echo QEMU $<
	@qemu-system-riscv64 -machine virt -bios none -nographic -m 128M -smp 4 -kernel kernel.elf

clean:
	rm -f *.o *.elf *.d lib/*.o lib/*.d
	find . -type f -name '*.[od]' -exec rm -f {} +

-include *.d

.PHONY: all