WordPress/wp-content/themes/twentytwelve/homepage.php

<?php
/**
 * Template Name: Homepage
 *
 * @package WordPress
 * @subpackage Twenty_Twelve
 * @since Twenty Twelve 1.0
 */

get_header(); ?>

	<div id="primary" class="site-content">
		<div id="content" role="main">

			<?php while ( have_posts() ) : the_post(); ?>
				<?php if ( has_post_thumbnail() ) { ?>
					<div class="entry-page-image">
						<?php the_post_thumbnail(); ?>
					</div>
				<?php } ?>

				<?php get_template_part( 'content', 'page' ); ?>

			<?php endwhile; // end of the loop. ?>

		</div><!-- #content -->
	</div><!-- #primary .site-content -->

<?php get_sidebar( 'home' ); ?>
<?php get_footer(); ?>