RM= rm
CC= $(CONFIG_TARGET_CC)
AS= $(CONFIG_TARGET_CC)
# NOTE(dinosaure): we must use [aarch64-none-elf-gcc] to compile assembly code
# to be able to include some files and define some macros.
LD= $(CONFIG_TARGET_LD)
AR= aarch64-none-elf-ar # TODO
OBJDUMP= aarch64-none-elf-objdump # TODO
OBJCOPY= $(CONFIG_TARGET_OBJCOPY)

export TOPDIR := $(abspath .)

$(TOPDIR)/Makeconf:
	$(error Makeconf not found, please run ./configure.sh)

include $(TOPDIR)/Makeconf

# armstub8.bin: armstub8.S
# 	@echo "CC -DGIC=1 $<"
# 	@$(CC) -DGIC=1 -o ${<:S=o} -c $<
# 	@echo "LD --section-start=.text=0 ${<:S=o}"
# 	@$(LD) --section-start=.text=0 -o ${<:S=elf} ${<:S=o}
# 	@echo "DUMP ${<:S=elf}"
# 	@$(OBJDUMP) -D ${<:S=elf} > ${<:S=lst}
# 	@echo "COPY ${<:S=elf}"
# 	@$(OBJCOPY) ${<:S=elf} -O binary $@

include/$(CONFIG_TARGET_TRIPLE):
	@echo "GEN $@"
	@./gen-headers.sh $@

CPU ?= -mcpu=cortex-a76 -mlittle-endian
ARCH += -DAARCH=64 $(CPU)
TARGET ?= kernel_2712

DEFINE += -DSSP_GUARD_SYMBOL=__stack_chk_guard \
	-DSSP_FAIL_SYMBOL=__stack_chk_fail

INCLUDE += -I $(TOPDIR)/include -I $(TOPDIR)/include/$(CONFIG_TARGET_TRIPLE) \
	-I $(TOPDIR)/nolibc/include

AFLAGS += $(ARCH) $(DEFINE) $(INCLUDE)

CFLAGS += -std=c11 -ffreestanding -fstack-protector-strong -nostdlib \
	-nostartfiles -mstrict-align -Wall \
	$(ARCH) $(DEFINE) $(INCLUDE) $(CONFIG_TARGET_CC_CFLAGS)

LDFLAGS += -nostdlib -static -Wl,--no-warn-rwx-segments \
	-Wl,--section-start=.init=0x80000 -Wl,--build-id=none \
	-Wl,--start-group -L . -lgilbraltar -L nolibc -lnolibc -L openlibm -lopenlibm -lgcc -Wl,--end-group

SRCS= kernel.c timer.c led.c interrupt_handler.c exception_handler.c \
	mbox.c clock.c crt.c serial.c log.c power.c tag.c coherent_page.c dtb.c \
	synchronize.c spinlock.c memory.c pager.c translation_table.c

ASMS= startup.S exception_stub.S

OBJS= $(SRCS:c=o) $(ASMS:S=o)

%.o: %.S
	@echo "AS $@"
	@$(AS) $(AFLAGS) -c -o $@ $<

%.o: %.c include/$(CONFIG_TARGET_TRIPLE)
	@echo "CC $@"
	@$(CC) $(CFLAGS) -c -o $@ $<

libgilbraltar.a: $(OBJS)
	@echo "AR $@"
	@rm -f $@
	@$(AR) cr $@ $^

.PHONY: phony-openlibm
phony-openlibm: include/$(CONFIG_TARGET_TRIPLE)
	@$(MAKE) -C openlibm \
		"CC=$(CC)" "CPPFLAGS=$(CFLAGS)" libopenlibm.a

openlibm/libopenlibm.a: phony-openlibm

NOLIBC_CFLAGS= $(CFLAGS) -I $(TOPDIR)/nolibc/include -I $(TOPDIR)/openlibm/src -I $(TOPDIR)/openlibm/include

.PHONY: phony-nolibc
phony-nolibc: include/$(CONFIG_TARGET_TRIPLE)
	$(MAKE) -C nolibc libnolibc.a \
		"CC=$(CC)" "FREESTANDING_CFLAGS=$(NOLIBC_CFLAGS)"

nolibc/libnolibc.a: phony-nolibc

.PHONY: all
all: libgilbraltar.a

.PHONY: clean
clean:
	$(RM) -f *.o *.a *.elf *.bin *.lst *.img
	$(RM) -rf include/$(CONFIG_TARGET_TRIPLE)
	$(RM) -f test/*.o
	$(MAKE) -C openlibm clean
	$(MAKE) -C nolibc clean FREESTANDING_CFLAGS=_

.PHONY: distclean
distclean: clean
	$(RM) -f Makeconf

test/%.o: test/%.c
	@echo "CC $@"
	@$(CC) $(CFLAGS) -c -o $@ $<

test01.img: libgilbraltar.a nolibc/libnolibc.a openlibm/libopenlibm.a test/test01.o
	@echo "LD ${@:img=elf}"
	@$(LD) test/${@:img=o} -o ${@:img=elf} $(LDFLAGS) -Wl,-T gilbraltar.ld
	@$(OBJCOPY) ${@:img=elf} -O binary $@

test02.img: libgilbraltar.a nolibc/libnolibc.a openlibm/libopenlibm.a test/test02.o
	@echo "LD ${@:img=elf}"
	@$(LD) test/${@:img=o} -o ${@:img=elf} $(LDFLAGS) -Wl,-T gilbraltar.ld
	@$(OBJCOPY) ${@:img=elf} -O binary $@

test03.img: libgilbraltar.a nolibc/libnolibc.a openlibm/libopenlibm.a test/test03.o
	@echo "LD ${@:img=elf}"
	@$(LD) test/${@:img=o} -o ${@:img=elf} $(LDFLAGS) -Wl,-Map ${@:img=map} -Wl,-T gilbraltar.ld
	@$(OBJCOPY) ${@:img=elf} -O binary $@