buildroot/board/sifive/hifive-unleashed/genimage_sdcard.cfg

image sdcard.img {
	hdimage {
		gpt = true
	}

	partition u-boot-spl {
		image = "u-boot-spl.bin"
		offset = 17K
		partition-type-uuid = 5B193300-FC78-40CD-8002-E86C45580B47
	}

	partition u-boot {
		image = "u-boot.itb"
		offset = 1041K
		partition-type-uuid = 2E54B353-1271-4842-806F-E436D6AF6985
	}

	partition rootfs {
		image = "rootfs.ext4"
		partition-type-uuid = 0FC63DAF-8483-4772-8E79-3D69D8477DE4
		bootable = true
	}
}