diff --git a/src/Symfony/Bundle/DoctrineBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/DoctrineBundle/DependencyInjection/Configuration.php
new file mode 100644
index 000000000000..ed38e10af759
--- /dev/null
+++ b/src/Symfony/Bundle/DoctrineBundle/DependencyInjection/Configuration.php
@@ -0,0 +1,195 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bundle\DoctrineBundle\DependencyInjection;
+
+use Symfony\Component\Config\Definition\Builder\NodeBuilder;
+use Symfony\Component\Config\Definition\Builder\TreeBuilder;
+
+/**
+ * This class contains the configuration information for the bundle
+ *
+ * This information is solely responsible for how the different configuration
+ * sections are normalized, and merged.
+ *
+ * @author Christophe Coevoet <stof@notk.org>
+ */
+class Configuration
+{
+    /**
+     * Generates the configuration tree.
+     *
+     * @return \Symfony\Component\Config\Definition\NodeInterface
+     */
+    public function getConfigTree()
+    {
+        $treeBuilder = new TreeBuilder();
+        $rootNode = $treeBuilder->root('doctrine', 'array');
+
+        $this->addDbalSection($rootNode);
+        $this->addOrmSection($rootNode);
+
+        return $treeBuilder->buildTree();
+    }
+
+    private function addDbalSection(NodeBuilder $node)
+    {
+        $node
+            ->arrayNode('dbal')
+                ->beforeNormalization()
+                    ->ifTrue(function($v){ return is_array($v) && !array_key_exists('connections', $v) && !array_key_exists('connection', $v); })
+                    ->then(function($v) {
+                        $connection = array ();
+                        $keys = array ('dbname', 'host', 'port', 'user', 'password', 'driver', 'driver_class', 'options', 'path', 'memory', 'unix_socket', 'wrapper_class', 'platform_service', 'charset', 'logging');
+                        foreach ($keys as $key) {
+                            if (array_key_exists($key, $v)) {
+                                $connection[$key] = $v[$key];
+                                unset($v[$key]);
+                            }
+                        }
+                        $defaultConnection = isset($v['default_connection']) ? (string) $v['default_connection'] : 'default';
+                        $v['connections'] = array ($defaultConnection => $connection);
+                        $v['default_connection'] = $defaultConnection;
+                        return $v;
+                    })
+                ->end()
+                ->scalarNode('default_connection')->isRequired()->cannotBeEmpty()->end()
+                ->fixXmlConfig('type')
+                ->arrayNode('types')
+                    ->useAttributeAsKey('name')
+                    ->prototype('scalar')
+                        ->beforeNormalization()
+                            ->ifTrue(function($v) { return is_array($v) && isset($v['class']); })
+                            ->then(function($v) { return $v['class']; })
+                        ->end()
+                    ->end()
+                ->end()
+                ->fixXmlConfig('connection')
+                ->builder($this->getDbalConnectionsNode())
+            ->end()
+        ;
+    }
+
+    private function getDbalConnectionsNode()
+    {
+        $node = new NodeBuilder('connections', 'array');
+        $node
+            ->useAttributeAsKey('name')
+            ->prototype('array')
+                ->scalarNode('dbname')->end()
+                ->scalarNode('host')->defaultValue('localhost')->end()
+                ->scalarNode('port')->defaultNull()->end()
+                ->scalarNode('user')->defaultValue('root')->end()
+                ->scalarNode('password')->defaultNull()->end()
+                ->scalarNode('driver')->defaultValue('pdo_mysql')->end()
+                ->scalarNode('driver_class')->end()
+                ->arrayNode('options')
+                    ->useAttributeAsKey('key')
+                    ->prototype('scalar')->end()
+                ->end()
+                ->scalarNode('path')->end()
+                ->booleanNode('memory')->end()
+                ->scalarNode('unix_socket')->end()
+                ->scalarNode('wrapper_class')->end()
+                ->scalarNode('platform_service')->end()
+                ->scalarNode('charset')->defaultValue('UTF-8')->end()
+                ->booleanNode('logging')->defaultFalse()->end()
+            ->end()
+        ;
+
+        return $node;
+    }
+
+    private function addOrmSection(NodeBuilder $node)
+    {
+        $node
+            ->arrayNode('orm')
+                ->beforeNormalization()
+                    ->ifTrue(function($v){ return is_array($v) && !array_key_exists('entity_managers', $v) && !array_key_exists('entity_manager', $v); })
+                    ->then(function($v) {
+                        $entityManager = array ();
+                        $keys = array ('result_cache_driver', 'metadata_cache_driver', 'query_cache_driver', 'mappings');
+                        foreach ($keys as $key) {
+                            if (array_key_exists($key, $v)) {
+                                $entityManagers[$key] = $v[$key];
+                                unset($v[$key]);
+                            }
+                        }
+                        if (!empty ($entityManager)) {
+                            $defaultEntityManager = isset($v['default_entity_manager']) ? (string) $v['default_entity_manager'] : 'default';
+                            $v['entity_managers'] = array ($defaultEntityManager => $entityManager);
+                            $v['default_entity_manager'] = $defaultEntityManager;
+                        }
+                        return $v;
+                    })
+                ->end()
+                ->scalarNode('default_entity_manager')->isRequired()->cannotBeEmpty()->end()
+                ->booleanNode('auto_generate_proxy_classes')->defaultFalse()->end()
+                ->fixXmlConfig('entity_manager')
+                ->builder($this->getOrmEntityManagersNode())
+            ->end()
+        ;
+    }
+
+    private function getOrmEntityManagersNode()
+    {
+        $node = new NodeBuilder('entity_managers', 'array');
+        $node
+            ->useAttributeAsKey('name')
+            ->prototype('array')
+                ->addDefaultsIfNotSet()
+                ->builder($this->getOrmCacheDriverNode('query_cache_driver'))
+                ->builder($this->getOrmCacheDriverNode('metadata_cache_driver'))
+                ->builder($this->getOrmCacheDriverNode('result_cache_driver'))
+                ->scalarNode('connection')->end()
+                ->scalarNode('proxy_dir')->defaultValue('%kernel.cache_dir%/doctrine/orm/Proxies')->end()
+                ->scalarNode('proxy_namespace')->defaultValue('Proxies')->end()
+                ->scalarNode('class_metadata_factory_name')->end()
+                ->fixXmlConfig('mapping')
+                ->arrayNode('mappings')
+                    ->useAttributeAsKey('name')
+                    ->treatNullLike(array ())
+                    ->prototype('array')
+                        ->beforeNormalization()
+                            ->ifString()
+                            ->then(function($v) { return array ('type' => $v); })
+                        ->end()
+                        ->scalarNode('type')->end()
+                        ->scalarNode('dir')->end()
+                        ->scalarNode('alias')->end()
+                        ->scalarNode('prefix')->end()
+                        ->booleanNode('is_bundle')->end()
+                        ->performNoDeepMerging()
+                    ->end()
+                ->end()
+            ->end()
+        ;
+
+        return $node;
+    }
+
+    private function getOrmCacheDriverNode($name)
+    {
+        $node = new NodeBuilder($name, 'array');
+        $node
+            ->beforeNormalization()
+                ->ifString()
+                ->then(function($v) { return array ('type' => $v); })
+            ->end()
+            ->scalarNode('type')->defaultValue('array')->end()
+            ->scalarNode('host')->end()
+            ->scalarNode('port')->end()
+            ->scalarNode('instance_class')->end()
+        ;
+
+        return $node;
+    }
+}