When a defendant enters a plea of guilty or no contest, can he challenge the validity of the plea on appeal?

When a defendant enters a plea of guilty or no contest, he may not challenge the validity of the plea on appeal unless he "has sought, and the trial court has issued, a certificate of probable cause `showing reasonable constitutional, jurisdictional, or other grounds going to the legality of the proceedings.'" (People v. Emery (2006) 140 Cal.App.4th 560, 562; see Pen. Code, 1237.5.) Only two types of issues may be raised without a certificate of probable cause: "(1) search and seizure issues for which an appeal is provided under [Penal Code] section 1538.5, subdivision (m); and (2) issues regarding proceedings held subsequent to the plea for the purpose of determining the degree of the crime and the penalty to be imposed." (People v. Panizzon (1996) 13 Cal.4th 68, 74-75.)