CFLAGS=-mcpu=cortex-a7 -ffreestanding -std=gnu99 -Wall -Wextra -I.

ELFFLAGS=-ffreestanding -O2 -nostdlib -lgcc -I.

all : kernel7.img

kernel.o : kernel.c
	arm-none-eabi-gcc $(CFLAGS) -c $^ -o $@

uart.o : uart.c
	arm-none-eabi-gcc $(CFLAGS) -c $^ -o $@

boot.o : boot.S
	arm-none-eabi-as -mcpu=cortex-a7 $^ -o $@

kernel.elf : boot.o kernel.o uart.o
	arm-none-eabi-gcc -T linker.ld -o $@ $(ELFFLAGS) $^

kernel7.img : kernel.elf
	arm-none-eabi-objcopy $^ -O binary $@

loader_stage2.o : loader_stage2.c
	arm-none-eabi-gcc $(CFLAGS) -c $^ -o $@

loader_stage2.elf : loader_stage2.o uart.o
	arm-none-eabi-gcc -T loader_stage2.ld -o $@ $(ELFFLAGS) $^

loader_stage2.img : loader_stage2.elf
	arm-none-eabi-objcopy $^ -O binary $@
	test -n "$$(find $@ -size -16384c)" || exit -1

loader_stage2_embeddable.o : loader_stage2.img
	arm-none-eabi-objcopy -I binary -O elf32-littlearm -B arm --rename-section .data=.rodata $^ $@

loader_stage1.o : loader_stage1.c
	arm-none-eabi-gcc $(CFLAGS) -c $^ -o $@

loader.elf : boot.o loader_stage1.o loader_stage2_embeddable.o
	arm-none-eabi-gcc -T loader_stage1.ld -o $@ $(ELFFLAGS) $^

loader.img : loader.elf
	arm-none-eabi-objcopy $^ -O binary $@

qemu-elf : kernel.elf
	qemu-system-arm -m 256 -M raspi2 -serial stdio -kernel $^

qemu-bin : loader.elf kernel7.img pipe_image
	./pipe_image | qemu-system-arm -m 256 -M raspi2 -serial stdio -kernel $<

run-on-rpi : kernel7.img pipe_image
	./pipe_image | socat FILE:/dev/ttyUSB0,b115200,raw -
	sleep 1
	screen  /dev/ttyUSB0 115200,cs8,-parenb,-cstopb,-hupcl

pipe_image : pipe_image.c RS-232/rs232.c
	gcc -Wall -std=gnu99 -O3 $^ -o $@

clean :
	-rm *.img *.elf *.o pipe_image

.PHONY: all qemu-elf qemu-bin clean