fdt_begin_node
err |= fdt_begin_node(root, "");
err |= fdt_begin_node(fdt, "");
err |= fdt_begin_node(fdt, "data");
err |= fdt_begin_node(fdt, "");
err |= fdt_begin_node(fdt, map->name);
err = fdt_begin_node(buf, "");
int fdt_begin_node(void *fdt, const char *name);