- * a line) as a base, then add 3 (as the network select field is
- * takes 3 lines), and n_interfaces (as the network interface field
- * has n_interfaces lines).
+ * a line) as a base, then:
+ * - add 6 (as the network select & boot device select fields take 3
+ * lines each),
+ * - add n_interfaces for every field in the network select field, and
+ * - add (n_blockdevs + n_interfaces) for every field in the boot device
+ * select field