hash block php

from:
https://en.bitcoin.it/wiki/Block_hashing_algorithm

<?PHP

function SwapOrder($in){

        $Split = str_split(strrev($in));
        $x='';
        for ($i = 0; $i < count($Split); $i+=2){

            $x .= $Split[$i+1].$Split[$i];
        }

        return $x;
    }


$hash='010000008D77';

$h1=base_convert($hash, 16, 2). "\n";
echo $h1;

echo $hash . '<br/>';
$v1 = hex2bin($hash) ;
//echo 'hex2bin($hash): ' . $v1 . "\n";

$v2 = hash('sha256', $v1 );

echo 'hash(sha256, $v1 ): ' .$v2 . "\n";

$v3 = hex2bin( $v2 );
//echo 'hex2bin( $v2 ): ' .$v3 . "\n";
$v4 = hash('sha256',$v3 );

echo 'hash(sha256,$v3 ): ' .$v4 . "\n";

$v5 = SwapOrder($v4);

echo 'SwapOrder: ' .$v5. "\n";

echo "\n"
?>