Is this the movie where the kid lives in a hollow tree?

I think I have the right movie. I was trying to remember this ... I must have
been 13 years old when it came out, and I loved it. It was at the time so
scientific, almost a manual for how to survive in the wild. I am not sure I
would want to dash to bits all of my fond memories of this very cool movie by
seeing it again ... yet I think I would if I could ever find it.

As I recall the boyu runs away from home with bag full of stuff, and finds
a tree to live it that was hollowed out by fire.

He find a falcon and teaches it to hunt, and finds algae and makes food out
of it. All kinds of cool stuff.

There is a lake or river right by him. Then he has another fire and his
life is ruined or something and he goes home?

I just loved this movie. It this the right one??

Anyone know how it holds up to viewing ... 40 years later? ;-)