CFLAGS=-mcpu=cortex-a7 -ffreestanding -std=gnu11 -Wall -Wextra -O2 -fPIC -I.
ELFFLAGS=-nostdlib -lgcc

ARM_OBJECTS=kernel.o paging.o demo_functionality.o PL0_test.o uart.o loader_stage1.o loader_stage2.o

RAMFS_FILES=PL_0_test.img

all : kernel.img

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

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

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

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

PL_0_test.elf : PL0_test.o uart.o
	arm-none-eabi-gcc -T PL0_test.ld -o $@ $(ELFFLAGS) $^

kernel.elf : boot.o kernel.o uart.o demo_functionality.o paging.o interrupt_vector.o interrupts.o ramfs_embeddable.o ramfs.o
	arm-none-eabi-gcc -T linker.ld -o $@ $(ELFFLAGS) $^

loader.elf : boot.o loader_stage1.o loader_stage2.o uart.o
	arm-none-eabi-gcc -T loader_linker.ld -o $@ $(ELFFLAGS) $^

loader.img : loader.elf
	arm-none-eabi-objcopy $^ -O binary $@
# check if the resulting image is not too big
	test -n "$$(find $@ -size -16384c)" || exit -1

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

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

run-on-rpi : kernel.img pipe_image
	./pipe_image --stdout | sudo socat FILE:/dev/ttyUSB0,b115200,raw -
	screen  /dev/ttyUSB0 115200,cs8,-parenb,-cstopb,-hupcl

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

makefs : makefs.c
	gcc -Wall -std=gnu99 -O3 $^ -o $@

ramfs.img : makefs $(RAMFS_FILES)
	./makefs $(RAMFS_FILES) > $@

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

.PHONY: all qemu-elf qemu-bin clean