error_t vmmngr_map_page(pdirectory* dir, physical_addr phys, virtual_addr virt, uint32 flags)
{
// our goal is to get the pt_entry indicated by virt and set its frame to phys.
pd_entry* e = vmmngr_pdirectory_lookup_entry(dir, virt);
if (pd_entry_test_attrib(e, I86_PDE_PRESENT) == false) // table is not present
if (vmmngr_create_table(dir, virt, flags) != ERROR_OK)
return ERROR_OCCUR;
// here we have a guaranteed working table (perhaps empty)
ptable* table = (ptable*)pd_entry_get_frame(*e);
pt_entry* page = vmmngr_ptable_lookup_entry(table, virt); // we have the page
if (page == 0)
{
//PANIC("HERE");
return ERROR_OCCUR;
}
//*page = 0; // delete possible previous information (pt_entry is just a uint32)
*page |= flags; // and reset
pt_entry_set_frame(page, phys);
vmmngr_flush_TLB_entry(virt);
return ERROR_OK;
}
void vmmngr_free_page_addr(virtual_addr addr)
{
pd_entry* e = vmmngr_pdirectory_lookup_entry(vmmngr_get_directory(), addr);
ptable* table = (ptable*)pd_entry_get_frame(*e);
pt_entry* page = vmmngr_ptable_lookup_entry(table, addr);
vmmngr_free_page(page);
}
void vmmngr_set_user(virtual_addr addr, int user)
{
ptable * ptable = vmmngr_get_ptable_address(addr);
pt_entry * pte = vmmngr_ptable_lookup_entry(ptable, addr);
if (user)
{
pt_entry_add_attrib(pte, I86_PTE_USER);
}
else
{
pt_entry_del_attrib(pte, I86_PTE_USER);
}
}
void vmmngr_set_writeable(virtual_addr addr, int writeable)
{
ptable * ptable = vmmngr_get_ptable_address(addr);
pt_entry * pte = vmmngr_ptable_lookup_entry(ptable, addr);
if (writeable)
{
pt_entry_add_attrib(pte, I86_PTE_WRITABLE);
}
else
{
pt_entry_del_attrib(pte, I86_PTE_WRITABLE);
}
}
bool vmmngr_is_page_present(virtual_addr addr)
{
pd_entry* e = vmmngr_pdirectory_lookup_entry(vmmngr_get_directory(), addr);
if (e == 0 || pd_entry_is_present(*e) == false)
return false;
ptable* table = (ptable*)pd_entry_get_frame(*e);
if (table == 0)
return false;
pt_entry* page = vmmngr_ptable_lookup_entry(table, addr);
if (page == 0 || pt_entry_is_present(*page) == false)
return false;
return true;
}
physical_addr vmmngr_get_phys_addr(virtual_addr addr)
{
pd_entry* e = vmmngr_pdirectory_lookup_entry(vmmngr_get_directory(), addr);
if (!e)
return 0;
ptable* table = (ptable*)pd_entry_get_frame(*e);
pt_entry* page = vmmngr_ptable_lookup_entry(table, addr);
if (!page)
return 0;
physical_addr p_addr = pt_entry_get_frame(*page);
p_addr += (addr & 0xfff); // add in-page offset
return p_addr;
}
