poky/meta/classes/kernel-uboot.bbclass

uboot_prep_kimage() {
	if test -e arch/${ARCH}/boot/compressed/vmlinux ; then
		vmlinux_path="arch/${ARCH}/boot/compressed/vmlinux"
		linux_suffix=""
		linux_comp="none"
	else
		vmlinux_path="vmlinux"
		linux_suffix=".gz"
		linux_comp="gzip"
	fi

	${OBJCOPY} -O binary -R .note -R .comment -S "${vmlinux_path}" linux.bin

	if [ "${linux_comp}" != "none" ] ; then
		gzip -9 linux.bin
		mv -f "linux.bin${linux_suffix}" linux.bin
	fi

	echo "${linux_comp}"
}