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void enable_paging()
{
unsigned long *page_directory = (unsigned long *) 0x9C000;
unsigned long *page_table = (unsigned long *) 0x9D000;
unsigned long address=0; // holds the physical address of where a page is
unsigned int i;

// map the first 4MB of memory
for(i=0; i<1024; i++)
{
   page_table[i] = address | 3; // attribute set to: supervisor level, read/write, present(011 in binary)
   address = address + 4096;
};

page_directory[0] = page_table; // HERE I GET THIS WARNING "warning: assignment makes integer from pointer without a cast"
page_directory[0] = page_directory[0] | 3;

for(i=1; i<1024; i++)
{
   page_directory[i] = 0 | 2; // attribute set to: supervisor level, read/write, not present(010 in binary)
};
write_cr3(page_directory); // put that page directory address into CR3
write_cr0(read_cr0() | 0x80000000); // set the paging bit in CR0 to 1
}

Code: Select all

[global _read_cr0]
_read_cr0:
   mov eax, cr0
   retn

[global _write_cr0]
_write_cr0:
   push ebp
   mov ebp, esp
   mov eax, [ebp+8]
   mov cr0,  eax
   pop ebp
   retn

[global _read_cr3]
_read_cr3:
   mov eax, cr3
   retn

[global _write_cr3]
_write_cr3:
   push ebp
   mov ebp, esp
   mov eax, [ebp+8]
   mov cr3, eax
   pop ebp
   retn