reverted:
--- b/core/lib/Drupal/Core/Field/FormatterPluginManager.php
+++ a/core/lib/Drupal/Core/Field/FormatterPluginManager.php
@@ -9,7 +9,6 @@
 
 use Drupal\Component\Plugin\Factory\DefaultFactory;
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Entity\Field\FieldItemListInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\LanguageManager;
 use Drupal\Core\Plugin\DefaultPluginManager;
@@ -201,26 +200,4 @@
     return isset($info['settings']) ? $info['settings'] : array();
   }
 
-  /**
-   * @todo Document.
-   */
-  public function viewBaseField(FieldItemListInterface $items) {
-    $options = array(
-      'field_definition' => $items->getFieldDefinition(),
-      'view_mode' => 'default',
-      'configuration' => array(
-        'label' => 'hidden',
-      ),
-    );
-    $formatter = $this->getInstance($options);
-
-    $entity = $items->getEntity();
-
-    $items_multi = array($entity->id() => $items);
-    $formatter->prepareView($items_multi);
-    $result = $formatter->view($items);
-    $field_name = $items->getFieldDefinition()->getFieldName();
-    return isset($result[$field_name]) ? $result[$field_name] : array();
-  }
-
 }
reverted:
--- b/core/lib/Drupal/Core/Field/WidgetPluginManager.php
+++ a/core/lib/Drupal/Core/Field/WidgetPluginManager.php
@@ -9,7 +9,6 @@
 
 use Drupal\Component\Plugin\Factory\DefaultFactory;
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Entity\Field\FieldItemListInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\LanguageManager;
 use Drupal\Core\Plugin\DefaultPluginManager;
@@ -205,41 +204,4 @@
     return isset($info['settings']) ? $info['settings'] : array();
   }
 
-  /**
-   * @todo Document.
-   */
-  public function baseFieldForm(FieldItemListInterface $field, array &$form, array &$form_state) {
-    $options = array(
-      'field_definition' => $field->getFieldDefinition(),
-      'form_mode' => 'default',
-      'configuration' => array(),
-    );
-    if (($field_data_definition = $field->getDefinition()) && isset($field_data_definition['default_widget'])) {
-      $options['configuration']['type'] = $field_data_definition['default_widget'];
-    }
-    $widget = $this->getInstance($options);
-
-    $form += array('#parents' => array());
-    $result = $widget->form($field, $form, $form_state);
-    $field_name = $field->getFieldDefinition()->getFieldName();
-    return isset($result[$field_name]) ? $result[$field_name] : array();
-  }
-
-  /**
-   * @todo Document.
-   */
-  public function baseFieldExtractFormValues(FieldItemListInterface $field, array &$form, array &$form_state) {
-    $options = array(
-      'field_definition' => $field->getFieldDefinition(),
-      'form_mode' => 'default',
-      'configuration' => array(),
-    );
-    if (($field_data_definition = $field->getDefinition()) && isset($field_data_definition['default_widget'])) {
-      $options['configuration']['type'] = $field_data_definition['default_widget'];
-    }
-    $widget = $this->getInstance($options);
-
-    $widget->extractFormValues($field, $form, $form_state);
-  }
-
 }
diff -u b/core/modules/edit/lib/Drupal/edit/EditController.php b/core/modules/edit/lib/Drupal/edit/EditController.php
--- b/core/modules/edit/lib/Drupal/edit/EditController.php
+++ b/core/modules/edit/lib/Drupal/edit/EditController.php
@@ -26,7 +26,6 @@
 use Drupal\edit\Ajax\MetadataCommand;
 use Drupal\edit\Form\EditFieldForm;
 use Drupal\user\TempStoreFactory;
-use Drupal\field\FieldInstanceInterface;
 
 /**
  * Returns responses for Edit module routes.
@@ -218,14 +217,7 @@
       // The form submission saved the entity in tempstore. Return the
       // updated view of the field from the tempstore copy.
       $entity = $this->tempStoreFactory->get('edit')->get($entity->uuid());
-
-      $field = $entity->get($field_name);
-      if ($field->getFieldDefinition() instanceof FieldInstanceInterface) {
-        $output = field_view_field($entity, $field_name, $view_mode_id, $langcode);
-      }
-      else {
-        $output = \Drupal::service('plugin.manager.field.formatter')->viewBaseField($field);
-      }
+      $output = field_view_field($entity, $field_name, $view_mode_id, $langcode);
 
       $response->addCommand(new FieldFormSavedCommand(drupal_render($output)));
     }
diff -u b/core/modules/edit/lib/Drupal/edit/Form/EditFieldForm.php b/core/modules/edit/lib/Drupal/edit/Form/EditFieldForm.php
--- b/core/modules/edit/lib/Drupal/edit/Form/EditFieldForm.php
+++ b/core/modules/edit/lib/Drupal/edit/Form/EditFieldForm.php
@@ -15,7 +15,6 @@
 use Drupal\Core\Form\FormInterface;
 use Drupal\user\TempStoreFactory;
 use Drupal\Core\Entity\EntityChangedInterface;
-use Drupal\field\FieldInstanceInterface;
 
 /**
  * Builds and process a form for editing a single entity field.
@@ -88,13 +87,7 @@
     }
 
     // Add the field form.
-    $field = $entity->get($field_name);
-    if ($field->getFieldDefinition() instanceof FieldInstanceInterface) {
-      field_attach_form($form_state['entity'], $form, $form_state, $form_state['langcode'], array('field_name' =>  $form_state['field_name']));
-    }
-    else {
-      $form[$field_name] = \Drupal::service('plugin.manager.field.widget')->baseFieldForm($field, $form, $form_state, $form_state['langcode']);
-    }
+    field_attach_form($form_state['entity'], $form, $form_state, $form_state['langcode'], array('field_name' =>  $form_state['field_name']));
 
     // Add a dummy changed timestamp field to attach form errors to.
     if ($entity instanceof EntityChangedInterface) {
@@ -135,18 +128,8 @@
     $form_state['field_name'] = $field_name;
 
     // @todo Allow the usage of different form modes by exposing a hook and the
-    // UI for them.
-    $form_display = entity_get_render_form_display($entity, 'default');
-
-    // Let modules alter the form display.
-    $form_display_context = array(
-      'entity_type' => $entity->entityType(),
-      'bundle' => $entity->bundle(),
-      'form_mode' => 'default',
-    );
-    $this->moduleHandler->alter('entity_form_display', $form_display, $form_display_context);
-
-    $form_state['form_display'] = $form_display;
+    //   UI for them.
+    $form_state['form_display'] = entity_get_render_form_display($entity, 'default');
   }
 
   /**
@@ -154,14 +137,7 @@
    */
   public function validateForm(array &$form, array &$form_state) {
     $entity = $this->buildEntity($form, $form_state);
-    $field_name = $form_state['field_name'];
-    $field = $entity->get($field_name);
-    if ($field->getFieldDefinition() instanceof FieldInstanceInterface) {
-      field_attach_form_validate($entity, $form, $form_state, array('field_name' => $field_name));
-    }
-    else {
-      // @todo
-    }
+    field_attach_form_validate($entity, $form, $form_state, array('field_name' =>  $form_state['field_name']));
 
     // Do validation on the changed field as well and assign the error to the
     // dummy form element we added for this. We don't know the name of this
@@ -194,20 +170,14 @@
    */
   protected function buildEntity(array $form, array &$form_state) {
     $entity = clone $form_state['entity'];
-
     $field_name = $form_state['field_name'];
-    $items = $entity->get($field_name);
-    if ($items->getFieldDefinition() instanceof FieldInstanceInterface) {
-      field_attach_extract_form_values($entity, $form, $form_state, array('field_name' => $field_name));
-    }
-    else {
-      \Drupal::service('plugin.manager.field.widget')->baseFieldExtractFormValues($items, $form, $form_state);
-    }
+
+    field_attach_extract_form_values($entity, $form, $form_state, array('field_name' => $field_name));
 
     // @todo Refine automated log messages and abstract them to all entity
     //   types: http://drupal.org/node/1678002.
     if ($entity->entityType() == 'node' && $entity->isNewRevision() && !isset($entity->log)) {
-      $entity->log = t('Updated the %field-name field through in-place editing.', array('%field-name' => $items->getFieldDefinition()->getFieldLabel()));
+      $entity->log = t('Updated the %field-name field through in-place editing.', array('%field-name' => $entity->get($field_name)->getFieldDefinition()->getFieldLabel()));
     }
 
     return $entity;
reverted:
--- b/core/modules/edit/lib/Drupal/edit/MetadataGenerator.php
+++ a/core/modules/edit/lib/Drupal/edit/MetadataGenerator.php
@@ -77,13 +77,7 @@
     }
 
     // Early-return if no editor is available.
+    $formatter_id = entity_get_render_display($entity, $view_mode)->getRenderer($field_name)->getPluginId();
-    if ($field_definition instanceof FieldInstanceInterface) {
-      $formatter_id = entity_get_render_display($entity, $view_mode)->getRenderer($field_name)->getPluginId();
-    }
-    else {
-      $field_type_info = field_info_field_types($field_definition->getFieldType());
-      $formatter_id = $field_type_info['default_formatter'];
-    }
     $items = $entity->getTranslation($langcode)->get($field_name)->getValue();
     $editor_id = $this->editorSelector->getEditor($formatter_id, $field_definition, $items);
     if (!isset($editor_id)) {
diff -u b/core/modules/field/field.module b/core/modules/field/field.module
--- b/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -4,6 +4,7 @@
  * Attach custom data fields to Drupal entities.
  */
 
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Template\Attribute;
 use Drupal\field\FieldInterface;
@@ -478,7 +479,7 @@
  * The function takes care of invoking the prepare_view steps. It also respects
  * field access permissions.
  *
- * @param \Drupal\Core\Entity\EntityInterface $entity
+ * @param \Drupal\Core\Entity\ContentEntityInterface $entity
  *   The entity containing the field to display.
  * @param $field_name
  *   The name of the field to display.
@@ -511,16 +512,16 @@
  *
  * @see field_view_value()
  */
-function field_view_field(EntityInterface $entity, $field_name, $display_options = array(), $langcode = NULL) {
+function field_view_field(ContentEntityInterface $entity, $field_name, $display_options = array(), $langcode = NULL) {
   $output = array();
   $bundle = $entity->bundle();
   $entity_type = $entity->entityType();
 
   // Return nothing if the field doesn't exist.
-  $instance = field_info_instance($entity_type, $field_name, $bundle);
-  if (!$instance) {
+  if (!$entity->hasField($field_name)) {
     return $output;
   }
+  $field_definition = $entity->get($field_name)->getFieldDefinition();
 
   // Get the formatter object.
   if (is_string($display_options)) {
@@ -531,11 +532,10 @@
     $view_mode = '_custom';
     // hook_field_attach_display_alter() needs to receive the 'prepared'
     // $display_options, so we cannot let preparation happen internally.
-    $field = field_info_field($entity_type, $field_name);
     $formatter_manager = drupal_container()->get('plugin.manager.field.formatter');
-    $display_options = $formatter_manager->prepareConfiguration($field->getFieldType(), $display_options);
+    $display_options = $formatter_manager->prepareConfiguration($field_definition->getFieldType(), $display_options);
     $formatter = $formatter_manager->getInstance(array(
-      'field_definition' => $instance,
+      'field_definition' => $field_definition,
       'view_mode' => $view_mode,
       'prepare' => FALSE,
       'configuration' => $display_options,
@@ -543,7 +543,14 @@
   }
 
   if ($formatter) {
-    $display_langcode = field_language($entity, $field_name, $langcode);
+    // @todo Unify language fallback handling between configurable and base
+    //   fields.
+    if ($field_definition instanceof FieldInstanceInterface) {
+      $display_langcode = field_language($entity, $field_name, $langcode);
+    }
+    else {
+      $display_langcode = $entity->language()->id;
+    }
 
     // Invoke the formatter's prepareView() and view() methods.
     $items = $entity->getTranslation($display_langcode)->get($field_name);
diff -u b/core/modules/node/lib/Drupal/node/NodeFormController.php b/core/modules/node/lib/Drupal/node/NodeFormController.php
--- b/core/modules/node/lib/Drupal/node/NodeFormController.php
+++ b/core/modules/node/lib/Drupal/node/NodeFormController.php
@@ -99,12 +99,6 @@
       '#default_value' => $node->getChangedTime(),
     );
 
-    $node_type = node_type_load($node->getType());
-    if ($node_type->has_title) {
-      $form['title'] = \Drupal::service('plugin.manager.field.widget')->baseFieldForm($node->title, $form, $form_state, $this->getFormLangcode($form_state));
-      $form['title']['#weight'] = -5;
-    }
-
     $language_configuration = module_invoke('language', 'get_default_configuration', 'node', $node->getType());
     $form['langcode'] = array(
       '#title' => t('Language'),
@@ -431,26 +425,26 @@
    * {@inheritdoc}
    */
   public function buildEntity(array $form, array &$form_state) {
-    $node = parent::buildEntity($form, $form_state);
+    $entity = parent::buildEntity($form, $form_state);
     // A user might assign the node author by entering a user name in the node
     // form, which we then need to translate to a user ID.
     if (!empty($form_state['values']['name']) && $account = user_load_by_name($form_state['values']['name'])) {
-      $node->setAuthorId($account->id());
+      $entity->setAuthorId($account->id());
     }
     else {
-      $node->setAuthorId(0);
+      $entity->setAuthorId(0);
     }
 
     if (!empty($form_state['values']['date']) && $form_state['values']['date'] instanceOf DrupalDateTime) {
-      $node->setCreatedTime($form_state['values']['date']->getTimestamp());
+      $entity->setCreatedTime($form_state['values']['date']->getTimestamp());
     }
     else {
-      $node->setCreatedTime(REQUEST_TIME);
+      $entity->setCreatedTime(REQUEST_TIME);
     }
-    \Drupal::service('plugin.manager.field.widget')->baseFieldExtractFormValues($node->title, $form, $form_state);
-    return $node;
+    return $entity;
   }
 
+
   /**
    * Overrides Drupal\Core\Entity\EntityFormController::save().
    */
diff -u b/core/modules/node/node.module b/core/modules/node/node.module
--- b/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -19,6 +19,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Template\Attribute;
 use Drupal\entity\Entity\EntityDisplay;
+use Drupal\entity\Entity\EntityFormDisplay;
 use Drupal\file\Entity\File;
 use Drupal\user\UserInterface;
 
@@ -191,14 +192,40 @@
  * Implements hook_entity_display_alter().
  */
 function node_entity_display_alter(EntityDisplay $display, $context) {
-  // Hide field labels in search index.
-  if ($context['entity_type'] == 'node' && $context['view_mode'] == 'search_index') {
-    foreach ($display->getComponents() as $name => $options) {
-      if (isset($options['label'])) {
-        $options['label'] = 'hidden';
-        $display->setComponent($name, $options);
+  if ($context['entity_type'] == 'node') {
+    // Hide field labels in search index.
+    if ($context['view_mode'] == 'search_index') {
+      foreach ($display->getComponents() as $name => $options) {
+        if (isset($options['label'])) {
+          $options['label'] = 'hidden';
+          $display->setComponent($name, $options);
+        }
       }
     }
+    // @todo Manage base field displays in the YAML.
+    $display->setComponent('title', array(
+      'label' => 'hidden',
+      'type' => 'text_default',
+    ));
+  }
+}
+
+/**
+ * Implements hook_entity_form_display_alter().
+ */
+function node_entity_form_display_alter(EntityFormDisplay $form_display, $context) {
+  if ($context['entity_type'] == 'node') {
+    // @todo Manage base field displays in the YAML.
+    $node_type = node_type_load($context['bundle']);
+    if ($node_type->has_title) {
+      // Title is also registered in node_field_extra_fields().
+      $options = $form_display->getComponent('title') ?: array('weight' => -5);
+      $options['type'] = 'text_textfield';
+      $form_display->setComponent('title', $options);
+    }
+    else {
+      $form_display->removeComponent('title');
+    }
   }
 }
 
@@ -640,7 +667,8 @@
 
   $uri = $node->uri();
   $variables['node_url']  = url($uri['path'], $uri['options']);
-  $variables['label'] = Drupal::service('plugin.manager.field.formatter')->viewBaseField($node->get('title'));
+  $variables['label'] = $variables['elements']['title'];
+  unset($variables['elements']['title']);
   $variables['page'] = $variables['view_mode'] == 'full' && node_is_page($node);
 
   // Helpful $content variable for templates.
only in patch2:
unchanged:
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -723,6 +723,14 @@ function entity_get_render_display(EntityInterface $entity, $view_mode) {
   $display = entity_get_display($entity_type, $bundle, $render_view_mode);
   $display->originalMode = $view_mode;
 
+  // Let modules alter the display.
+  $display_context = array(
+    'entity_type' => $entity_type,
+    'bundle' => $bundle,
+    'view_mode' => $view_mode,
+  );
+  drupal_alter('entity_display', $display, $display_context);
+
   return $display;
 }
 
@@ -823,6 +831,14 @@ function entity_get_render_form_display(EntityInterface $entity, $form_mode) {
   $form_display = entity_get_form_display($entity_type, $bundle, $render_form_mode);
   $form_display->originalMode = $form_mode;
 
+  // Let modules alter the form display.
+  $form_display_context = array(
+    'entity_type' => $entity_type,
+    'bundle' => $bundle,
+    'form_mode' => $form_mode,
+  );
+  drupal_alter('entity_form_display', $form_display, $form_display_context);
+
   return $form_display;
 }
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Entity/EntityFormController.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormController.php
@@ -125,15 +125,6 @@ protected function init(array &$form_state) {
     $this->prepareEntity();
 
     $form_display = entity_get_render_form_display($this->entity, $this->getOperation());
-
-    // Let modules alter the form display.
-    $form_display_context = array(
-      'entity_type' => $this->entity->entityType(),
-      'bundle' => $this->entity->bundle(),
-      'form_mode' => $this->getOperation(),
-    );
-    $this->moduleHandler->alter('entity_form_display', $form_display, $form_display_context);
-
     $this->setFormDisplay($form_display, $form_state);
 
     // Invoke the prepare form hooks.
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Entity/EntityRenderController.php
+++ b/core/lib/Drupal/Core/Entity/EntityRenderController.php
@@ -176,20 +176,9 @@ public function viewMultiple(array $entities = array(), $view_mode = 'full', $la
       // Store entities for rendering by view_mode.
       $view_modes[$entity_view_mode][$entity->id()] = $entity;
 
-      // Load the corresponding display settings if not stored yet.
+      // Get the corresponding display settings.
       if (!isset($displays[$entity_view_mode][$bundle])) {
-        // Get the display object for this bundle and view mode.
-        $display = entity_get_render_display($entity, $entity_view_mode);
-
-        // Let modules alter the display.
-        $display_context = array(
-          'entity_type' => $this->entityType,
-          'bundle' => $bundle,
-          'view_mode' => $entity_view_mode,
-        );
-        drupal_alter('entity_display', $display, $display_context);
-
-        $displays[$entity_view_mode][$bundle] = $display;
+        $displays[$entity_view_mode][$bundle] = entity_get_render_display($entity, $entity_view_mode);
       }
     }
 
only in patch2:
unchanged:
--- a/core/modules/entity/lib/Drupal/entity/Entity/EntityDisplay.php
+++ b/core/modules/entity/lib/Drupal/entity/Entity/EntityDisplay.php
@@ -53,9 +53,8 @@ public function getRenderer($field_name) {
 
     // Instantiate the formatter object from the stored display properties.
     if ($configuration = $this->getComponent($field_name)) {
-      $instance = field_info_instance($this->targetEntityType, $field_name, $this->bundle);
       $formatter = $this->pluginManager->getInstance(array(
-        'field_definition' => $instance,
+        'field_definition' => $this->getFieldDefinition($field_name),
         'view_mode' => $this->originalMode,
         // No need to prepare, defaults have been merged in setComponent().
         'prepare' => FALSE,
only in patch2:
unchanged:
--- a/core/modules/entity/lib/Drupal/entity/Entity/EntityFormDisplay.php
+++ b/core/modules/entity/lib/Drupal/entity/Entity/EntityFormDisplay.php
@@ -53,9 +53,8 @@ public function getRenderer($field_name) {
 
     // Instantiate the widget object from the stored display properties.
     if ($configuration = $this->getComponent($field_name)) {
-      $instance = field_info_instance($this->targetEntityType, $field_name, $this->bundle);
       $widget = $this->pluginManager->getInstance(array(
-        'field_definition' => $instance,
+        'field_definition' => $this->getFieldDefinition($field_name),
         'form_mode' => $this->originalMode,
         // No need to prepare, defaults have been merged in setComponent().
         'prepare' => FALSE,
only in patch2:
unchanged:
--- a/core/modules/entity/lib/Drupal/entity/EntityDisplayBase.php
+++ b/core/modules/entity/lib/Drupal/entity/EntityDisplayBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\entity;
 
 use Drupal\Core\Config\Entity\ConfigEntityBase;
+use Drupal\Core\Entity\ContentEntityInterface;
 
 /**
  * Base class for config entity types that store configuration for entity forms
@@ -44,6 +45,16 @@
   public $bundle;
 
   /**
+   * A partial entity, created via _field_create_entity_from_ids() from
+   * $targetEntityType and $bundle.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface
+   *
+   * @todo Remove when getFieldDefinition() is fixed to not need it.
+   */
+  private $targetEntity;
+
+  /**
    * View or form mode to be displayed.
    *
    * @var string
@@ -194,9 +205,7 @@ public function getComponent($name) {
       // visibility.
       if (isset($this->content[$name])) {
         if ($this->content[$name]['visible']) {
-          return array(
-            'weight' => $this->content[$name]['weight'],
-          );
+          return $this->content[$name];
         }
         else {
           return NULL;
@@ -231,8 +240,8 @@ public function setComponent($name, array $options = array()) {
       $options['weight'] = isset($max) ? $max + 1 : 0;
     }
 
-    if ($instance = field_info_instance($this->targetEntityType, $name, $this->bundle)) {
-      $options = $this->pluginManager->prepareConfiguration($instance->getFieldType(), $options);
+    if ($field_definition = $this->getFieldDefinition($name)) {
+      $options = $this->pluginManager->prepareConfiguration($field_definition->getFieldType(), $options);
 
       // Clear the persisted plugin, if any.
       unset($this->plugins[$name]);
@@ -290,4 +299,17 @@ public function getHighestWeight() {
     return $weights ? max($weights) : NULL;
   }
 
+  /**
+   * Returns the field definition of a field.
+   */
+  protected function getFieldDefinition($field_name) {
+    // @todo Replace this entire implementation with
+    //   \Drupal::entityManager()->getFieldDefinition() after [#2047229] lands.
+    if (!isset($this->targetEntity)) {
+      $this->targetEntity = _field_create_entity_from_ids((object) array('entity_type' => $this->targetEntityType, 'bundle' => $this->bundle, 'entity_id' => NULL));
+    }
+    if (($this->targetEntity instanceof ContentEntityInterface) && $this->targetEntity->hasField($field_name)) {
+      return $this->targetEntity->get($field_name)->getFieldDefinition();
+    }
+  }
 }
only in patch2:
unchanged:
--- a/core/modules/field/field.attach.inc
+++ b/core/modules/field/field.attach.inc
@@ -6,7 +6,9 @@
  */
 
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\Field\FieldDefinitionInterface;
 use Drupal\entity\Entity\EntityFormDisplay;
+use Drupal\field\FieldInstanceInterface;
 
 /**
  * @defgroup field_attach Field Attach API
@@ -63,7 +65,7 @@
  * @param string $method
  *   The name of the method to invoke.
  * @param callable $target_function
- *   A function that receives an $instance object and returns the object on
+ *   A function that receives a field definition and returns the object on
  *   which the method should be invoked.
  * @param \Drupal\Core\Entity\EntityInterface $entity
  *   The fully formed $entity_type entity.
@@ -100,27 +102,31 @@ function field_invoke_method($method, $target_function, EntityInterface $entity,
   $options += $default_options;
 
   $entity_type = $entity->entityType();
-  // Determine the list of instances to iterate on.
-  $instances = _field_invoke_get_instances($entity_type, $entity->bundle(), $options);
+  // Determine the list of fields to iterate on.
+  $field_definitions = _field_invoke_get_field_definitions($entity_type, $entity->bundle(), $options);
 
-  // Iterate through the instances and collect results.
+  // Iterate through the fields and collect results.
   $return = array();
-  foreach ($instances as $instance) {
+  foreach ($field_definitions as $field_definition) {
 
     // Let the function determine the target object on which the method should be
     // called.
-    $target = call_user_func($target_function, $instance);
+    $target = call_user_func($target_function, $field_definition);
 
     if (method_exists($target, $method)) {
-      $field = $instance->getField();
-      $field_name = $field->getFieldName();
-
       // Determine the list of languages to iterate on.
-      $available_langcodes = field_available_languages($entity_type, $field);
-      $langcodes = _field_language_suggestion($available_langcodes, $options['langcode'], $field_name);
+      // @todo Unify language fallback handling between configurable and base
+      //   fields.
+      if ($field_definition instanceof FieldInstanceInterface) {
+        $available_langcodes = field_available_languages($entity_type, $field_definition->getField());
+        $langcodes = _field_language_suggestion($available_langcodes, $options['langcode'], $field_definition->getFieldName());
+      }
+      else {
+        $langcodes = array($entity->language()->id);
+      }
 
       foreach ($langcodes as $langcode) {
-        $items = $entity->getTranslation($langcode)->get($field_name);
+        $items = $entity->getTranslation($langcode)->get($field_definition->getFieldName());
         $items->filterEmptyValues();
 
         $result = $target->$method($items, $a, $b);
@@ -198,7 +204,7 @@ function field_invoke_method_multiple($method, $target_function, array $entities
     $entity_type = $entity->entityType();
 
     // Determine the list of instances to iterate on.
-    $entity_instances = _field_invoke_get_instances($entity_type, $entity->bundle(), $options);
+    $entity_instances = _field_invoke_get_field_definitions($entity_type, $entity->bundle(), $options);
 
     foreach ($entity_instances as $instance) {
       $instance_uuid = $instance->uuid();
@@ -260,7 +266,7 @@ function field_invoke_method_multiple($method, $target_function, array $entities
 }
 
 /**
- * Retrieves a list of instances to operate on.
+ * Retrieves a list of field definitions to operate on.
  *
  * Helper for field_invoke_method().
  *
@@ -277,9 +283,9 @@ function field_invoke_method_multiple($method, $target_function, array $entities
  *   See field_invoke_method() for details.
  *
  * @return
- *   The array of selected instance definitions.
+ *   The array of selected field definitions.
  */
-function _field_invoke_get_instances($entity_type, $bundle, $options) {
+function _field_invoke_get_field_definitions($entity_type, $bundle, $options) {
   if ($options['deleted']) {
     // Deleted fields are not included in field_info_instances(), and need to
     // be fetched from the database with field_read_instances().
@@ -290,12 +296,24 @@ function _field_invoke_get_instances($entity_type, $bundle, $options) {
       // option.
       $params['field_id'] = $options['field_id'];
     }
-    $instances = field_read_instances($params, array('include_deleted' => TRUE));
+    $field_definitions = field_read_instances($params, array('include_deleted' => TRUE));
   }
   elseif (isset($options['field_name'])) {
-    // Single-field mode by field name: field_info_instance() does the
-    // filtering.
-    $instances = array(field_info_instance($entity_type, $options['field_name'], $bundle));
+    // @todo Replace with \Drupal::entityManager()->getFieldDefinition() after
+    //   [#2047229] lands.
+    $entity = _field_create_entity_from_ids((object) array('entity_type' => $entity_type, 'bundle' => $bundle, 'entity_id' => NULL));
+    $field_definitions = array($entity->get($options['field_name'])->getFieldDefinition());
+  }
+  elseif (isset($options['display'])) {
+    // @todo Replace with \Drupal::entityManager()->getFieldDefinitions() after
+    //   [#2047229] lands.
+    $entity = _field_create_entity_from_ids((object) array('entity_type' => $entity_type, 'bundle' => $bundle, 'entity_id' => NULL));
+    $field_definitions = array();
+    foreach ($options['display']->getComponents() as $name => $component_options) {
+      if ($entity->hasField($name)) {
+        $field_definitions[] = $entity->get($name)->getFieldDefinition();
+      }
+    }
   }
   else {
     $instances = field_info_instances($entity_type, $bundle);
@@ -309,15 +327,16 @@ function _field_invoke_get_instances($entity_type, $bundle, $options) {
         }
       }
     }
+    $field_definitions = $instances;
   }
 
-  return $instances;
+  return $field_definitions;
 }
 
 /**
  * Defines a 'target function' for field_invoke_method().
  *
- * Used to invoke methods on an instance's widget.
+ * Used to invoke methods on a field's widget.
  *
  * @param \Drupal\entity\Entity\EntityFormDisplay $form_display
  *   An EntityFormDisplay object.
@@ -326,8 +345,8 @@ function _field_invoke_get_instances($entity_type, $bundle, $options) {
  *   A 'target function' for field_invoke_method().
  */
 function _field_invoke_widget_target($form_display) {
-  return function ($instance) use ($form_display) {
-    return $form_display->getRenderer($instance->getFieldName());
+  return function (FieldDefinitionInterface $field_definition) use ($form_display) {
+    return $form_display->getRenderer($field_definition->getFieldName());
   };
 }
 
only in patch2:
unchanged:
--- a/core/modules/field/field.deprecated.inc
+++ b/core/modules/field/field.deprecated.inc
@@ -7,10 +7,10 @@
 
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Entity\Field\FieldDefinitionInterface;
 use Drupal\entity\Entity\EntityDisplay;
 use Drupal\field\Field;
 
-
 /**
  * Returns information about field types.
  *
@@ -561,6 +561,7 @@ function field_attach_form(EntityInterface $entity, &$form, &$form_state, $langc
 
   // Get the entity_form_display object for this form.
   $form_display = $form_state['form_display'];
+  $options['display'] = $form_display;
 
   // If no language is provided use the default site language.
   $options['langcode'] = field_valid_language($langcode);
@@ -628,7 +629,9 @@ function field_attach_form_validate(ContentEntityInterface $entity, $form, &$for
 
   if ($has_violations) {
     // Map errors back to form elements.
-    field_invoke_method('flagErrors', _field_invoke_widget_target($form_state['form_display']), $entity, $form, $form_state, $options);
+    $form_display = $form_state['form_display'];
+    $options['display'] = $form_display;
+    field_invoke_method('flagErrors', _field_invoke_widget_target($form_display), $entity, $form, $form_state, $options);
   }
 }
 
@@ -655,6 +658,7 @@ function field_attach_form_validate(ContentEntityInterface $entity, $form, &$for
 function field_attach_extract_form_values(EntityInterface $entity, $form, &$form_state, array $options = array()) {
   // Extract field values from submitted values.
   $form_display = $form_state['form_display'];
+  $options['display'] = $form_display;
   field_invoke_method('extractFormValues', _field_invoke_widget_target($form_display), $entity, $form, $form_state, $options);
 
   // Let other modules act on submitting the entity.
@@ -754,14 +758,15 @@ function field_attach_prepare_view($entity_type, array $entities, array $display
  * @deprecated as of Drupal 8.0. Use the entity system instead.
  */
 function field_attach_view(EntityInterface $entity, EntityDisplay $display, $langcode = NULL, array $options = array()) {
+  $options['display'] = $display;
   // Determine the actual language code to display for each field, given the
   // language codes available in the field data.
   $options['langcode'] = field_language($entity, NULL, $langcode);
 
-  // For each instance, call the view() method on the formatter object handed
+  // For each field, call the view() method on the formatter object handed
   // by the entity display.
-  $target_function = function ($instance) use ($display) {
-    return $display->getRenderer($instance->getFieldName());
+  $target_function = function (FieldDefinitionInterface $field_definition) use ($display) {
+    return $display->getRenderer($field_definition->getFieldName());
   };
   $null = NULL;
   $output = field_invoke_method('view', $target_function, $entity, $null, $null, $options);