Definition main_params (ge: genv) start : Prop :=
exists b, exists func,
Genv.find_symbol ge start = Some b /\
Genv.find_funct ge (Vptr b Ptrofs.zero) = Some (Internal func) /\
func.(fn_params) = nil.

(* there's a place this lemma should be applied, perhaps in proof of semax_call *)
Lemma funassert_rho:
forall G rho rho', ge_of rho = ge_of rho' -> funassert G rho |-- funassert G rho'.