In your first snippet, you seem to be assuming that JMP is direct, and in the second, you seem to be assuming that JMP is indirect. It appears to be direct: https://github.com/GenTiradentes/tinyvm/blob/master/tvm.c#L5...

You could, of course, do it with self-modifying code if that's possible. (I'm not familiar enough with the VM to know if it is.)