I vaguely remember this movie. A plane crashes somewhere in Africa and the only survivor is a boy. I remember a scene when he was looking for Ostrich eggs and he broke the egg and cooked it in the hot baking sun. So he was all alone surviving in the dessert. I think he was rescued at the end. Like I said, I vaguely remember he was travelling with his parents.
Sounds like Lost in the Desert (AKA Dirkie) from 1969 about a kid wandering the Kalahari desert with his dog after surviving a plane crash. He fries an ostrich egg on a rock at some point and his father finds him in the end. The entire movie is available on Youtube (the ostrich egg scene is around 42:57):