// /app/config/config.yml
framework:
    charset:       UTF-8
    error_handler: null
    csrf_protection:
        enabled: true
        secret: xxxxxxxxxx
    router:        { resource: "%kernel.root_dir%/config/routing.yml" }
    validation:    { enabled: true, annotations: true }
    templating:    { engines: ['twig'] } #assets_version: SomeVersionScheme
    session:
        default_locale: en
        lifetime:       3600
        auto_start:     true
        name:           staystory

# Twig Configuration
twig:
    debug:            %kernel.debug%
    strict_variables: %kernel.debug%

# Assetic Configuration
assetic: ~

## Doctrine Configuration
doctrine:
   dbal:
       dbname:   diem7
       user:     root
       password: salut
       logging:  %kernel.debug%
   orm:
       auto_generate_proxy_classes: %kernel.debug%
       default_entity_manager: default
       proxy_namespace: Proxies
       proxy_dir: %kernel.cache_dir%/doctrine/orm/Proxies
       default_connection: default
       metadata_cache_driver: apc
       query_cache_driver: apc
       result_cache_driver: apc
       entity_managers:
           default:
               connection: default
       mappings:
           DiemCoreBundle: ~
           DiemAdminBundle: ~
           DiemFrontBundle: ~
           StaystoryBundle: ~

# Swiftmailer Configuration
swiftmailer:
    transport:  smtp
    encryption: ssl
    auth_mode:  login
    host:       smtp.gmail.com
    username:   xxxxxxxx
    password:   xxxxxxxx


// /src/Diem/CoreBundle/Entity/User.php
<?php

namespace Diem\CoreBundle\Entity;

/**
 * @orm:Entity
 */
class User
{
	/**
	 * @orm:Id
	 * @orm:Column(type="integer")
	 * @orm:GeneratedValue(strategy="IDENTITY")
	 */
	protected $id;

	/**
	 * @orm:Column(type="string", length="255")
	 */
	protected $name;
}

When running doctrine:generate:entities DiemCoreBundle
I get this :
[InvalidArgumentException]
  The parameter "doctrine.orm.entity_managers" must be defined.