diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index ec639b0..5cb5a4f 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -311,21 +311,20 @@ function _block_get_renderable_region($list = array()) {
     !in_array($_SERVER['REQUEST_METHOD'], array('GET', 'HEAD'));
 
   foreach ($list as $key => $block) {
-    $build[$key] = array(
-      '#block' => $block,
-      '#weight' => $block->get('weight'),
-      '#theme_wrappers' => array('block'),
-    );
 
     if ($not_cacheable || in_array($block->get('cache'), array(DRUPAL_NO_CACHE, DRUPAL_CACHE_CUSTOM))) {
-      // Non-cached blocks get built immediately. Provides more content
-      // that can be easily manipulated during hook_page_alter().
-      $build[$key] = _block_get_renderable_block($build[$key]);
+      // Non-cached blocks get built immediately.
+      if ($block->access()) {
+        $build[$key] = entity_view($block, 'full');
+      }
     }
     else {
       $key_components = explode('.', $key);
       $id = array_pop($key_components);
-      $build[$key] += array(
+      $build[$key] = array(
+        '#block' => $block,
+        '#weight' => $block->get('weight'),
+        '#theme_wrappers' => array('block'),
         '#pre_render' => array('_block_get_renderable_block'),
         '#cache' => array(
           'keys' => array($id, $block->get('module')),
@@ -342,7 +341,7 @@ function _block_get_renderable_region($list = array()) {
     // to perform contextual actions on the help block, and the links needlessly
     // draw attention on it.
     if (!in_array($block->get('plugin'), array('system_help_block', 'system_main_block'))) {
-      $build[$key]['#contextual_links']['block'] = array('admin/structure/block', array($key));
+      $build[$key]['#contextual_links']['block'] = array('admin/structure/block/manage', array($key));
     }
   }
   return $build;
@@ -408,28 +407,23 @@ function block_themes_enabled($theme_list) {
  */
 function block_theme_initialize($theme) {
   // Initialize theme's blocks if none already registered.
-  $has_blocks = config_get_storage_names_with_prefix('plugin.core.block.' . $theme);
+  $has_blocks = entity_load_multiple_by_properties('block', array('theme' => $theme));
   if (!$has_blocks) {
     $default_theme = variable_get('theme_default', 'stark');
     // Apply only to new theme's visible regions.
     $regions = system_region_list($theme, REGIONS_VISIBLE);
-    $default_theme_blocks = config_get_storage_names_with_prefix('plugin.core.block.' . $default_theme);
-    foreach ($default_theme_blocks as $config_id) {
-      $block_config = config($config_id)->get();
-      $machine_name = explode('.', $config_id);
-      $machine_name = array_pop($machine_name);
-      $new_config_id = 'plugin.core.block.' . $theme . '.' . $machine_name;
-      $new_block = config($new_config_id);
+    $default_theme_blocks = entity_load_multiple_by_properties('block', array('theme' => $default_theme));
+    foreach ($default_theme_blocks as $default_theme_block_id => $default_theme_block) {
+      list(, $machine_name) = explode('.', $default_theme_block_id);
+      $block = $default_theme_block->createDuplicate();
+      $block->set('id', $theme . '.' . $machine_name);
+      $block->set('theme', $theme);
       // If the region isn't supported by the theme, assign the block to the
       // theme's default region.
-      if (!isset($regions[$block_config['region']])) {
-        $new_block->set('region', system_default_region($theme));
-        unset($block_config['region']);
-      }
-      foreach ($block_config as $key => $value) {
-        $new_block->set($key, $value);
+      if (!isset($regions[$block->get('region')])) {
+        $block->set('region', system_default_region($theme));
       }
-      $new_block->save();
+      $block->save();
     }
   }
 }
@@ -480,17 +474,7 @@ function _block_get_renderable_block($element) {
   $block = $element['#block'];
   // Don't bother to build blocks that aren't accessible.
   if ($element['#access'] = $block->access()) {
-    $build = $block->build();
-    if ($build) {
-      if (isset($build['#title'])) {
-        $element['#title'] = $build['#title'];
-      }
-      $element += $build;
-    }
-    else {
-      // @todo Add an inline comment explaining why this line is necessary.
-      $element = array();
-    }
+    $element += entity_view($block, 'full');
   }
   return $element;
 }
@@ -534,7 +518,10 @@ function template_preprocess_block(&$variables) {
   $block_counter = &drupal_static(__FUNCTION__, array());
   $block = $variables['elements']['#block'];
   $variables['block'] = (object) $block->getDefinition();
-  if ($label = $block->label()) {
+  if (!empty($variables['block']->label)) {
+    $variables['block']->subject = $variables['block']->label;
+  }
+  elseif ($label = $block->label()) {
     $variables['block']->subject = $label;
   }
 
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
index bfe5dcc..30d35f5 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/block/block/CustomBlock.php
@@ -29,17 +29,6 @@
 class CustomBlock extends BlockBase {
 
   /**
-   * Overrides \Drupal\block\BlockBase::blockSettings().
-   */
-  public function blockSettings() {
-    // By default, use a blank block title rather than the block description
-    // (which is "Custom Block").
-    return array(
-      'subject' => '',
-    );
-  }
-
-  /**
    * Overrides \Drupal\block\BlockBase::getConfig().
    */
   public function getConfig() {
@@ -94,7 +83,7 @@ public function blockSubmit($form, &$form_state) {
       'bid' => is_numeric($bid) ? $bid : NULL,
     );
     drupal_write_record('block_custom', $block, !is_null($block['bid']) ? array('bid') : array());
-    $this->configuration['id'] = 'custom_block:' . $block['bid'];
+    $form_state['entity']->set('plugin', 'custom_block:' . $block['bid']);
     // Invalidate the block cache to update custom block-based derivatives.
     if (module_exists('block')) {
       drupal_container()->get('plugin.manager.block')->clearCachedDefinitions();
@@ -106,6 +95,7 @@ public function blockSubmit($form, &$form_state) {
    */
   public function blockBuild() {
     // Populate the block with the user-defined block body.
+    $this->getConfig();
     return array(
       '#theme' => 'custom_block_block',
       '#body' => $this->configuration['body'],
diff --git a/core/modules/block/lib/Drupal/block/BlockRenderController.php b/core/modules/block/lib/Drupal/block/BlockRenderController.php
new file mode 100644
index 0000000..dd2ee22
--- /dev/null
+++ b/core/modules/block/lib/Drupal/block/BlockRenderController.php
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockRenderController.
+ */
+
+namespace Drupal\block;
+
+use Drupal\Core\Entity\EntityRenderControllerInterface;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Provides a Block access controller.
+ */
+class BlockRenderController implements EntityRenderControllerInterface {
+
+  /**
+   * Implements \Drupal\Core\Entity\EntityRenderControllerInterface::buildContent().
+   */
+  public function buildContent(array $entities = array(), $view_mode = 'full', $langcode = NULL) {
+    return array();
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\EntityRenderControllerInterface::view().
+   */
+  public function view(EntityInterface $entity, $view_mode = 'full', $langcode = NULL) {
+    $build = $this->viewMultiple(array($entity), $view_mode, $langcode);
+    return reset($build);
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\EntityRenderControllerInterface::viewMultiple().
+   */
+  public function viewMultiple(array $entities = array(), $view_mode = 'full', $langcode = NULL) {
+    $build = array();
+    foreach ($entities as $entity_id => $entity) {
+      $build[$entity_id] = array(
+        '#block' => $entity,
+        '#weight' => $entity->get('weight'),
+        '#theme_wrappers' => array('block'),
+      ) + $entity->getPlugin()->blockBuild();
+
+      $id = str_replace(':', '__', $entity->get('plugin'));
+      list(, $name) = $entity->id();
+      drupal_alter(array('block_view', "block_view_$id", "block_view_$name"), $build[$entity_id], $entity);
+    }
+    return $build;
+  }
+
+}
diff --git a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
index f23588d..c457008 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
@@ -20,6 +20,7 @@
  *   module = "block",
  *   controller_class = "Drupal\block\BlockStorageController",
  *   access_controller_class = "Drupal\block\BlockAccessController",
+ *   render_controller_class = "Drupal\block\BlockRenderController",
  *   form_controller_class = {
  *     "default" = "Drupal\block\BlockFormController"
  *   },
@@ -187,34 +188,4 @@ public function getExportProperties() {
     return $properties;
   }
 
-  /**
-   * Implements \Drupal\block\BlockInterface::build().
-   *
-   * Allows blocks to be altered after they are built.
-   *
-   * Most block plugins should not override this method. To define how a
-   * particular block is rendered, implement the abstract method
-   * BlockBase::blockBuild().
-   *
-   * @return array $build
-   *   A renderable array of data.
-   *   - #title: The default localized title of the block.
-   *
-   * @todo Add specific examples of $id and $name below.
-   *
-   * @see \Drupal\block\BlockBase::blockBuild()
-   */
-  public function build() {
-    // Allow modules to modify the block before it is viewed, via either
-    // hook_block_view_alter(), hook_block_view_ID_alter(), or
-    // hook_block_view_NAME_alter().
-    $id = str_replace(':', '__', $this->getPlugin()->getPluginId());
-
-    $name = '';
-
-    $build = $this->getPlugin()->blockBuild();
-    drupal_alter(array('block_view', "block_view_$id", "block_view_$name"), $build, $this);
-    return $build;
-  }
-
 }
diff --git a/core/modules/block/lib/Drupal/block/Tests/BlockTest.php b/core/modules/block/lib/Drupal/block/Tests/BlockTest.php
index ba0ca9a..5ff4cdf 100644
--- a/core/modules/block/lib/Drupal/block/Tests/BlockTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockTest.php
@@ -118,7 +118,7 @@ public function testCustomBlock() {
     $this->assertText(t('The block configuration has been saved.'), 'Custom block successfully created.');
 
     // Check that block_block_view() returns the correct title and content.
-    $data = $block->build();
+    $data = entity_view($block, 'full');
     $this->assertEqual(check_markup($custom_block['body[value]'], $block->get('format')), render($data), 'BlockInterface::build() provides correct block content.');
 
     // Check whether the block can be moved to all available regions.
diff --git a/core/modules/menu/menu.module b/core/modules/menu/menu.module
index fd5b5df..5515387 100644
--- a/core/modules/menu/menu.module
+++ b/core/modules/menu/menu.module
@@ -482,7 +482,7 @@ function menu_reset_item($link) {
  */
 function menu_block_view_alter(&$build, $block) {
   // Add contextual links for system menu blocks.
-  if ($block instanceof SystemMenuBlock) {
+  if ($block->getPlugin() instanceof SystemMenuBlock) {
     foreach (element_children($build) as $key) {
       $build['#contextual_links']['menu'] = array('admin/structure/menu/manage', array($build[$key]['#original_link']['menu_name']));
     }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
index 296212c..6d74ee4 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
@@ -74,7 +74,7 @@ public function blockForm($form, &$form_state) {
   public function blockBuild() {
     $output = $this->view->executeDisplay($this->displayID);
     // Set the subject to the title configured in the view.
-    $this->configuration['subject'] = filter_xss_admin($this->view->getTitle());
+    $this->configuration['label'] = filter_xss_admin($this->view->getTitle());
     // Before returning the block output, convert it to a renderable array
     // with contextual links.
     views_add_block_contextual_links($output, $this->view, $this->displayID);