/*
* map_4kb_page
* DESCRIPTION: map 4kb page based on passed address
* INPUTS: address - address of desired 4kb page
* flags - indicates supervisor, read/write, presence
* OUTPUTS: none
* RETURN VALUE: none
* SIDE EFFECTS: Sets entry of page directory
*/
void map_4kb_page (uint32_t address, uint32_t flags){
int i; // for iterations
int j = 0; // used for representing correct address
// calculate index from passed address
uint16_t page_dir_index = (address & PD_INDEX_MASK) >> 22;
uint16_t page_table_index = (address & PT_INDEX_MASK) >> 12;
// initialize all pages to not present when creating new page table
if ((page_directory[page_dir_index] & PRESENT_MASK) == 0){
for (i=0;i<INDEX_SIZE;i++){
page_table[i] = j | NOT_PRESENT_WRITE; // initialize to supervisor, read/write, not present
j = j + SIZE_OF_PAGE; // increment by one 4kb page
}
}
// map a 4kb page at address passed
page_table[page_table_index] = address | flags; // initialize passed flags
// set constructed page table to correct index of page directory
page_directory[page_dir_index] = (uint32_t)page_table | PRESENT_WRITE;
flush_TLB(page_directory);
return;
}
void vmmngr_flush_tld_entry(virtual_addr addr)
{
flush_TLB(addr);
}