diff --git a/core/lib/Drupal/Core/Entity/Plugin/DataType/MapItem.php b/core/lib/Drupal/Core/Entity/Plugin/DataType/MapItem.php
new file mode 100644
index 0000000..1c8a1a9
--- /dev/null
+++ b/core/lib/Drupal/Core/Entity/Plugin/DataType/MapItem.php
@@ -0,0 +1,49 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Entity\Plugin\DataType\MapItem.
+ */
+
+namespace Drupal\Core\Entity\Plugin\DataType;
+
+use Drupal\Core\TypedData\Annotation\DataType;
+use Drupal\Core\Annotation\Translation;
+use Drupal\Core\Entity\Field\FieldItemBase;
+
+/**
+ * Defines the 'string_field' entity field item.
+ *
+ * @DataType(
+ *   id = "map_field",
+ *   label = @Translation("Map field item"),
+ *   description = @Translation("An entity field containing a map value."),
+ *   list_class = "\Drupal\Core\Entity\Field\Field"
+ * )
+ */
+class MapItem extends FieldItemBase {
+
+  /**
+   * Definitions of the contained properties.
+   *
+   * @see MapItem::getPropertyDefinitions()
+   *
+   * @var array
+   */
+  static $propertyDefinitions;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyDefinitions() {
+
+    if (!isset(static::$propertyDefinitions)) {
+      static::$propertyDefinitions['value'] = array(
+        'type' => 'map',
+        'label' => t('Array values'),
+      );
+    }
+    return static::$propertyDefinitions;
+  }
+
+}
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkInterface.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkInterface.php
index c185dc4..999385b 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkInterface.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkInterface.php
@@ -10,7 +10,6 @@
 use Symfony\Component\Routing\Route;
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Entity\EntityStorageControllerInterface;
 
 /**
  * Provides an interface defining a menu link entity.
@@ -85,7 +84,7 @@ public function setParents(EntityInterface $parent);
    *  - else, for system menu links (derived from hook_menu()), reparent
    *    based on the path hierarchy.
    *
-   * @param \Drupal\Core\Entity\EntityStorageControllerInterface $storage_controller
+   * @param \Drupal\menu_link\MenuLinkStorageControllerInterface $storage_controller
    *   Storage controller object.
    * @param array $parent_candidates
    *   An array of menu link entities keyed by mlid.
@@ -94,5 +93,5 @@ public function setParents(EntityInterface $parent);
    *   A menu link entity structure of the possible parent or FALSE if no valid
    *   parent has been found.
    */
-  public function findParent(EntityStorageControllerInterface $storage_controller, array $parent_candidates = array());
+  public function findParent(MenuLinkStorageControllerInterface $storage_controller, array $parent_candidates = array());
 }
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
index cba2e9c..ebfd73a 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
@@ -125,6 +125,21 @@ protected function attachLoad(&$queried_entities, $load_revision = FALSE) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  protected function mapFromStorageRecords(array $records, $load_revision = FALSE) {
+    $entities = parent::mapFromStorageRecords($records, $load_revision);
+
+    foreach ($entities as &$entity) {
+      foreach (static::$routerItemFields as $router_field) {
+        $entity->offsetSet($router_field, $records[$entity->id()]->{$router_field});
+      }
+    }
+
+    return $entities;
+  }
+
+  /**
    * Overrides DatabaseStorageController::save().
    */
   public function save(EntityInterface $entity) {
@@ -135,6 +150,12 @@ public function save(EntityInterface $entity) {
 
     $transaction = $this->database->startTransaction();
     try {
+      // Ensure we are dealing with the actual entity.
+      $entity = $entity->getNGEntity();
+
+      // Sync the changes made in the fields array to the internal values array.
+      $entity->updateOriginalValues();
+
       // Load the stored entity, if any.
       if (!$entity->isNew() && !isset($entity->original)) {
         $entity->original = entity_load_unchanged($this->entityType, $entity->id());
@@ -158,18 +179,44 @@ public function save(EntityInterface $entity) {
       // $entity may have additional keys left over from building a router entry.
       // The intersect removes the extra keys, allowing a meaningful comparison.
       if ($entity->isNew() || (array_intersect_key($entity->getPropertyValues(), $entity->original->getPropertyValues()) != $entity->original->getPropertyValues())) {
-        $return = drupal_write_record($this->entityInfo['base_table'], $entity, $this->idKey);
+        // Create the storage record to be saved.
+        $record = $this->mapToStorageRecord($entity);
+        $return = drupal_write_record($this->entityInfo['base_table'], $record, $this->idKey);
 
         if ($return) {
           if (!$entity->isNew()) {
+            // @todo, should a different value be returned when saving an entity
+            // with $isDefaultRevision = FALSE?
+            if (!$entity->isDefaultRevision()) {
+              $return = FALSE;
+            }
+
+            if ($this->revisionKey) {
+              $record->{$this->revisionKey} = $this->saveRevision($entity);
+            }
+            if ($this->dataTable) {
+              $this->savePropertyData($entity);
+            }
             $this->resetCache(array($entity->id()));
             $entity->postSave($this, TRUE);
             $this->invokeFieldMethod('update', $entity);
             $this->invokeHook('update', $entity);
+            if ($this->dataTable) {
+              $this->invokeTranslationHooks($entity);
+            }
           }
           else {
             $return = SAVED_NEW;
-            $this->resetCache();
+            if ($this->revisionKey) {
+              $record->{$this->revisionKey} = $this->saveRevision($entity);
+            }
+            $entity->{$this->idKey}->value = $record->{$this->idKey};
+            if ($this->dataTable) {
+              $this->savePropertyData($entity);
+            }
+
+            // Reset general caches, but keep caches specific to certain entities.
+            $this->resetCache(array());
 
             $entity->enforceIsNew(FALSE);
             $entity->postSave($this, FALSE);
@@ -210,6 +257,8 @@ public function getPreventReparenting() {
    * {@inheritdoc}
    */
   public function loadUpdatedCustomized(array $router_paths) {
+    $menu_links = array();
+
     // @todo This doesn't really make sense anymore with EntityNG.. and EFQ got
     // OR condition support in the meantime, so convert this query.
     $query = parent::buildQuery(NULL);
@@ -222,9 +271,12 @@ public function loadUpdatedCustomized(array $router_paths) {
         ->condition('customized', 1)
         )
       );
-    $ids = $query->execute()->fetchCol(1);
 
-    return $this->load($ids);
+    if ($ids = $query->execute()->fetchCol(1)) {
+      $menu_links = $this->load($ids);
+    }
+
+    return $menu_links;
   }
 
   /**
@@ -248,13 +300,13 @@ public function loadModuleAdminTasks() {
    */
   public function updateParentalStatus(EntityInterface $entity, $exclude = FALSE) {
     // If plid == 0, there is nothing to update.
-    if ($entity->plid->value) {
+    if ($entity->plid->target_id) {
       // Check if at least one visible child exists in the table.
       $query = \Drupal::entityQuery($this->entityType);
       $query
         ->condition('menu_name', $entity->menu_name->value)
         ->condition('hidden', 0)
-        ->condition('plid', $entity->plid->value)
+        ->condition('plid', $entity->plid->target_id)
         ->count();
 
       if ($exclude) {
@@ -264,7 +316,7 @@ public function updateParentalStatus(EntityInterface $entity, $exclude = FALSE)
       $parent_has_children = ((bool) $query->execute()) ? 1 : 0;
       $this->database->update('menu_links')
         ->fields(array('has_children' => $parent_has_children))
-        ->condition('mlid', $entity->plid->value)
+        ->condition('mlid', $entity->plid->target_id)
         ->execute();
     }
   }
@@ -382,6 +434,11 @@ public function getParentFromHierarchy(EntityInterface $entity) {
    * {@inheritdoc}
    */
   public function baseFieldDefinitions() {
+    $properties['menu_name'] = array(
+      'label' => t('Menu name'),
+      'description' => t('The menu name. All links with the same menu name (such as "tools") are part of the same menu.'),
+      'type' => 'string_field',
+    );
     $properties['mlid'] = array(
       'label' => t('Menu link ID'),
       'description' => t('The menu link ID.'),
@@ -423,7 +480,7 @@ public function baseFieldDefinitions() {
     $properties['options'] = array(
       'label' => t('Options'),
       'description' => t('A serialized array of options to be passed to the url() or l() function, such as a query string or HTML attributes.'),
-      'type' => 'map',
+      'type' => 'map_field',
     );
     $properties['module'] = array(
       'label' => t('Module'),
@@ -522,6 +579,26 @@ public function baseFieldDefinitions() {
       'description' => t('The machine name of a defined Symfony Route this menu item represents.'),
       'type' => 'string_field',
     );
+
+    // @todo Most of these should probably go away.
+    $properties['access'] = array(
+      'label' => t('(old router) Access'),
+      'description' => t(''),
+      'type' => 'boolean_field',
+      'computed' => TRUE,
+    );
+    $properties['in_active_trail'] = array(
+      'label' => t('In active trail'),
+      'description' => t(''),
+      'type' => 'boolean_field',
+      'computed' => TRUE,
+    );
+    $properties['localized_options'] = array(
+      'label' => t('Localized options'),
+      'description' => t(''),
+      'type' => 'map_field',
+      'computed' => TRUE,
+    );
     return $properties;
   }
 
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/Plugin/Core/Entity/MenuLink.php b/core/modules/menu_link/lib/Drupal/menu_link/Plugin/Core/Entity/MenuLink.php
index 2f4d217..f7ad7ce 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/Plugin/Core/Entity/MenuLink.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/Plugin/Core/Entity/MenuLink.php
@@ -14,6 +14,7 @@
 use Drupal\Core\Entity\EntityStorageControllerInterface;
 use Drupal\Core\Language\Language;
 use Drupal\menu_link\MenuLinkInterface;
+use Drupal\menu_link\MenuLinkStorageControllerInterface;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -280,6 +281,31 @@ class MenuLink extends EntityNG implements \ArrayAccess, MenuLinkInterface {
   protected $routeObject;
 
   /**
+   * Crap coming from the old routing system.
+   *
+   * @todo Remove when we rip out the old routing system.
+   *
+   * @var array
+   */
+  protected $oldRouterItem = array();
+
+  /**
+   * Properties of the old routing system.
+   *
+   * @todo Remove when we rip out the old routing system.
+   *
+   * @var array
+   */
+  protected $oldRoutingProperties = array(
+    'path', 'load_functions', 'to_arg_functions', 'access_callback',
+    'access_arguments', 'page_callback', 'page_arguments', 'fit',
+    'number_parts', 'context', 'tab_parent', 'tab_root', 'title',
+    'title_callback', 'title_arguments', 'theme_callback', 'theme_arguments',
+    'type', 'description', 'description_callback', 'description_arguments',
+    'position', 'include_file', 'route_name',
+  );
+
+  /**
    * {@inheritdoc}
    */
   public function id() {
@@ -406,7 +432,11 @@ public static function buildFromRouterItem(array $item) {
    * {@inheritdoc}
    */
   public function offsetExists($offset) {
-    return $this->get($offset)->offsetGet(0)->__isset();
+    if (in_array($offset, $this->oldRoutingProperties)) {
+      return isset($this->oldRouterItem[$offset]);
+    }
+
+    return isset($this->{$offset}->value);
 //    return isset($this->{$offset});
   }
 
@@ -414,7 +444,11 @@ public function offsetExists($offset) {
    * {@inheritdoc}
    */
   public function offsetGet($offset) {
-    return $this->get($offset)->offsetGet(0)->get('value');
+    if (in_array($offset, $this->oldRoutingProperties)) {
+      return $this->oldRouterItem[$offset];
+    }
+
+    return $this->{$offset}->value;
 //    return $this->{$offset};
   }
 
@@ -422,7 +456,12 @@ public function offsetGet($offset) {
    * {@inheritdoc}
    */
   public function offsetSet($offset, $value) {
-    $this->get($offset)->offsetGet(0)->set('value', $value);
+    if (in_array($offset, $this->oldRoutingProperties)) {
+      $this->oldRouterItem[$offset] = $value;
+    }
+    else {
+      $this->{$offset}->value = $value;
+    }
 //    $this->{$offset} = $value;
   }
 
@@ -430,13 +469,27 @@ public function offsetSet($offset, $value) {
    * {@inheritdoc}
    */
   public function offsetUnset($offset) {
-    $this->get($offset)->offsetGet(0)->set('value', NULL);
+    if (in_array($offset, $this->oldRoutingProperties)) {
+      unset($this->oldRouterItem[$offset]);
+    }
+    else {
+      $this->{$offset}->value = NULL;
+    }
 //    unset($this->{$offset});
   }
 
   /**
    * {@inheritdoc}
    */
+  public static function preCreate(EntityStorageControllerInterface $storage_controller, array &$values) {
+    if (empty($values['menu_name'])) {
+      $values['menu_name'] = $values['bundle'] = 'tools';
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public static function preDelete(EntityStorageControllerInterface $storage_controller, array $entities) {
     // Nothing to do if we don't want to reparent children.
     if ($storage_controller->getPreventReparenting()) {
@@ -446,9 +499,9 @@ public static function preDelete(EntityStorageControllerInterface $storage_contr
     foreach ($entities as $entity) {
       // Children get re-attached to the item's parent.
       if ($entity->has_children->value) {
-        $children = $storage_controller->loadByProperties(array('plid' => $entity->plid->value));
+        $children = $storage_controller->loadByProperties(array('plid' => $entity->plid->target_id));
         foreach ($children as $child) {
-          $child->plid->value = $entity->plid->value;
+          $child->plid->target_id = $entity->plid->target_id;
           $storage_controller->save($child);
         }
       }
@@ -490,16 +543,16 @@ public function preSave(EntityStorageControllerInterface $storage_controller) {
     $parent_candidates = !empty($this->parentCandidates) ? $this->parentCandidates : array();
     $parent = $this->findParent($storage_controller, $parent_candidates);
     if ($parent) {
-      $this->plid->value = $parent->id();
+      $this->plid->target_id = $parent->id();
       $this->menu_name->value = $parent->menu_name->value;
     }
     // If no corresponding parent link was found, move the link to the top-level.
     else {
-      $this->plid->value = 0;
+      $this->plid->target_id = 0;
     }
 
     // Directly fill parents for top-level links.
-    if ($this->plid->value == 0) {
+    if ($this->plid->target_id == 0) {
       $this->p1->value = $this->id();
       for ($i = 2; $i <= MENU_MAX_DEPTH; $i++) {
         $parent_property = "p$i";
@@ -524,7 +577,7 @@ public function preSave(EntityStorageControllerInterface $storage_controller) {
     }
 
     // Need to check both plid and menu_name, since plid can be 0 in any menu.
-    if (isset($this->original) && ($this->plid->value != $this->original->plid->value || $this->menu_name->value != $this->original->menu_name->value)) {
+    if (isset($this->original) && ($this->plid->target_id != $this->original->plid->target_id || $this->menu_name->value != $this->original->menu_name->value)) {
       $storage_controller->moveChildren($this, $this->original);
     }
     // Find the router_path.
@@ -552,9 +605,9 @@ public function postSave(EntityStorageControllerInterface $storage_controller, $
     // Check the has_children status of the parent.
     $storage_controller->updateParentalStatus($this);
 
-    menu_cache_clear($this->menu_name);
-    if (isset($this->original) && $this->menu_name != $this->original->menu_name) {
-      menu_cache_clear($this->original->menu_name);
+    menu_cache_clear($this->menu_name->value);
+    if (isset($this->original) && $this->menu_name->value != $this->original->menu_name->value) {
+      menu_cache_clear($this->original->menu_name->value);
     }
 
     // Now clear the cache.
@@ -585,23 +638,23 @@ public static function findRouteName($link_path) {
    */
   public function setParents(EntityInterface $parent) {
     $i = 1;
-    while ($i < $this->depth) {
+    while ($i < $this->depth->value) {
       $p = 'p' . $i++;
-      $this->{$p} = $parent->{$p};
+      $this->{$p}->value = $parent->{$p}->value;
     }
     $p = 'p' . $i++;
     // The parent (p1 - p9) corresponding to the depth always equals the mlid.
-    $this->{$p} = $this->id();
+    $this->{$p}->value = $this->id();
     while ($i <= MENU_MAX_DEPTH) {
       $p = 'p' . $i++;
-      $this->{$p} = 0;
+      $this->{$p}->value = 0;
     }
   }
 
   /**
    * {@inheritdoc}
    */
-  public function findParent(EntityStorageControllerInterface $storage_controller, array $parent_candidates = array()) {
+  public function findParent(MenuLinkStorageControllerInterface $storage_controller, array $parent_candidates = array()) {
     $parent = FALSE;
 
     // This item is explicitely top-level, skip the rest of the parenting.
@@ -638,7 +691,7 @@ public function findParent(EntityStorageControllerInterface $storage_controller,
     // If everything else failed, try to derive the parent from the path
     // hierarchy. This only makes sense for links derived from menu router
     // items (ie. from hook_menu()).
-    if ($this->module == 'system') {
+    if ($this->module->value == 'system') {
       $parent = $storage_controller->getParentFromHierarchy($this);
     }