/**************************************************************************************
 Copyright (c) 2002
      The UbixOS Project

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions, the following disclaimer and the list of authors.
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in the documentation and/or other materials provided with the distribution. Neither the name of the UbixOS Project nor the names of its
contributors may be used to endorse or promote products derived from this software without specific prior written permission.

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WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 $Id: setpageattributes.c,v 1.1 2003/04/20 12:11:30 reddawg Exp $
**************************************************************************************/

#include <vmm/paging.h>

/************************************************************************

Function: void setPageAttributes(uLong pageAddr,int attributes;
Description: This Function Will Set The Page Attributes Such As
             A Read Only Page, Stack Page, COW Page, ETC.
Notes:

************************************************************************/
void setPageAttribute(uLong pageAddr,int attributes) {
  int directoryIndex,tableIndex;
  uLong *pageTable;
  //Get Index To Page Directory
  directoryIndex = (pageAddr/(1024*4096));
  //Get Index To Page Table
  tableIndex = ((pageAddr-(directoryIndex*(1024*4096)))/4096);
  //Set Table Pointer
  pageTable = (uLong *)(tablesBaseAddress + (4096 * directoryIndex));
  //Set Attribute If Page Is Mapped
  if (pageTable[tableIndex] != 0) {
    pageTable[tableIndex] = ((pageTable[tableIndex] & 0xFFFFF000) | attributes);
    }
  //Reload The Page Table;
  asm(
    "movl %cr3,%eax\n"
    "movl %eax,%cr3\n"
    );
  //Return
  return;
  }