CHROOT_CMD := chroot build/rootfs /bin/bash -c

FILES = $(shell find src/ -type f -print | sed -e 's|^src/|build/rootfs/|')

all: $(FILES) build/rootfs/initrd.img

clean:
	rm -r build/rootfs

build/rootfs/initrd.img: $(FILES) | build/rootfs
	chmod +x build/rootfs/etc/initramfs-tools/scripts/local-top/download.sh
	$(CHROOT_CMD) "apt update && apt install -y linux-image-4.19.0-6-amd64"
	$(CHROOT_CMD) "update-initramfs -c -kall"

build/rootfs/%: src/% | build/rootfs
		mkdir -p $(@D)
		cp $< $@

build/rootfs: build/cache
	rm -r build/rootfs || true
	cp -r build/cache build/rootfs

build/cache:
	rm -r build/cache || true
	debootstrap buster build/cache