linux-arkmicro/buildroot-2021.02.2/board/sifive/hifive-unleashed/genimage_spi-nor.cfg

image spi-nor.img {
	size = 32M

	hdimage {
		gpt = true
	}

	partition u-boot-spl {
		image = "u-boot-spl.bin"
		offset = 20K
		partition-type-uuid = 5B193300-FC78-40CD-8002-E86C45580B47
	}

	partition u-boot {
		image = "u-boot.itb"
		offset = 1044K
		partition-type-uuid = 2E54B353-1271-4842-806F-E436D6AF6985
	}
}