bootstrap.php

<?php
include_once autoload.php
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\Config\Loader\LoaderResolver;
use Symfony\Component\Config\Loader\DelegatingLoader;

$container = new ContainerBuilder();
$locator = new FileLocator(__DIR__.'/path/to/config');
$resolver = new LoaderResolver(array(
  new XmlFileLoader($container, $locator),
  new YamlFileLoader($container, $locator),
  new PhpFileLoader($container, $locator),
));
 $loader = new DelegatingLoader($resolver);
 $loader->load('my_service_config.xml')