walk_di_tree
pnode->child = walk_di_tree(tree, pnode, curnode);
return (walk_di_tree(tree, root, curnode));
pnode->sibling = walk_di_tree(tree, root, curnode);
root_node = walk_di_tree(&sys_tree, NULL, di_root_node);
static Prom_node *walk_di_tree(Sys_tree *tree, Prom_node *root,