CC = $(TARGET)-gcc
LD = $(TARGET)-ld
AS = $(TARGET)-gcc

KERN_WARNINGS = -Wall -Wextra -Wpedantic -Wuninitialized -Wunused-result
KERN_FLAGS = -ffreestanding -nostartfiles -nostdlib -nodefaultlibs --std=gnu2x
MACHINE_FLAGS = -march=rv64gc -mabi=lp64 -mcmodel=medany
PATH_FLAGS = -I./

CFLAGS = ${MACHINE_FLAGS} -g -O0 ${KERN_WARNINGS} ${KERN_FLAGS} ${PATH_FLAGS}
LDFLAGS = -m elf64lriscv --gc-sections -T rv64-sifive_u.ld
ASFLAGS = ${CFLAGS}

.SUFFIXES: .c .o .S

.c.o:
	${CC} ${CFLAGS} -o $@ -c $<

.S.o:
	${AS} ${ASFLAGS} -o $@ -c $<

kernel.elf: kernel.o crt0.o platform/FU740/uart.o platform/FU740/clock.o
	${LD} ${LDFLAGS} -o kernel.elf kernel.o crt0.o platform/FU740/uart.o platform/FU740/clock.o

kernel.o: kernel.c

platform/FU740/uart.o: platform/FU740/uart.c

platform/FU740/clock.o: platform/FU740/clock.c

crt0.o: crt0.S

.PHONY: all test clean
all: kernel.img

test:

clean:
	rm -f kernel.elf kernel.o crt0.o platform/FU740/uart.o platform/FU740/clock.o