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Calculating Indexs from a virtual address
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| PML4 Directory Ptr Page Directory Page Table Page Offset | |
| x-xxxx-xxxx x-xxxx-xxxx x-xxxx-xxxx x-xxxx-xxxx XXXX-XXXX-XXXX | |
| $address = 0xFF8000000000; | |
| $pml4 = ($address & 0xFF8000000000) >> 39; | |
| $pdp = ($address & 0x7FC0000000) >> 30; | |
| $pd = ($address & 0x3FE00000) >> 21; | |
| $pt = ($address & 0x1FF000) >> 12; | |
| $offset = ($address & 0xFFF); |
Author
segrax
commented
Mar 10, 2015
> 39;
$pdp = ($address & 0x7fc0000000) >> 30;
$pd = ($address & 0x3fe00000) >> 21;
$pt = ($address & 0x1FF000) >> 12;
$offset = ($address & 0xFFF);
echo "Address: 0x".dechex($address)."\n\n";
echo "Page Offset:0x" . dechex($offset)."\n\n";
echo "PML4 Index: $pml4\n";
echo "PDP Index: $pdp\n";
echo "PD Index: $pd\n";
echo "PT Index: $pt\n";
> 39) & 0x1FF;
}
function GetPageDirectoryPointer_Index( $pVirtual ) {
return ($pVirtual >> 30) & 0x1FF;
}
function GetPageDirectory_Index( $pVirtual ) {
return ($pVirtual >> 21) & 0x1FF;
}
function getPageDirectoryTable_Index( $pVirtual ) {
return ($pVirtual >> 12) & 0x1FF;
}
function GetPageTableEntryForAddress( $pVirtual ) {
```
$PML4 = GetPageMapLevel4_Index( $pVirtual );
$PDP = GetPageDirectoryPointer_Index( $pVirtual );
$PD = GetPageDirectory_Index( $pVirtual );
$PT = GetpageDirectoryTable_Index( $pVirtual );
$Address = 0xFFFFFF8000000000 + (0x40000000 * $PDP) + (0x200000 * $PD) + (0x1000 * $PT);
return $Address;
```
}
echo "0x" . dechex( GetPageTableEntryForAddress( 0x2000 ) ) . "\n";
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