(* a list initialized with 0 except its last i elements *)
Definition list_zero_except (i : Z) (size : Z) : list val :=
  (list_repeat (Z.to_nat (size-i)) (Vint Int.zero)) ++ (list_repeat (Z.to_nat i) Vundef).

Lemma body_zeroize: semax_body Vprog Gprog f_mbedtls_zeroize zeroize_spec.