kumquat-buildroot/board/aarch64-efi/genimage-efi.cfg

image efi-part.vfat {
  vfat {
    file startup.nsh {
      image = "efi-part/startup.nsh"
    }
    file EFI {
      image = "efi-part/EFI"
    }
    file Image {
      image = "Image"
    }
  }
  size = 32M
}

image disk.img {
  hdimage {
    gpt = true
  }

  partition boot {
    image = "efi-part.vfat"
    partition-type-uuid = c12a7328-f81f-11d2-ba4b-00a0c93ec93b
    offset = 32768
    bootable = true
  }

  partition root {
    partition-type-uuid = b921b045-1df0-41c3-af44-4c6f280d3fae
    image = "rootfs.ext2"
  }
}