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_map_page(void * phys, void * virt)
{
pageinfo pginf = vmmngr_virt_to_page_index(virt);
pdirectory * page_directory = kernel_page_dir; //vmmngr_get_directory();
pd_entry * e = &page_directory->m_entries[PAGE_DIRECTORY_INDEX((uint32_t) virt)];
if (!pd_entry_is_present(*e))
{
ptable * new_table = (ptable *) pmmngr_alloc_block();
if (!new_table)
{
return;
}
ptable * virtual_table = (ptable *) (0xFFC00000 + (pginf.pagetable * 0x1000));
pd_entry * entry = &kernel_page_dir->m_entries[pginf.pagetable];
pd_entry_add_attrib(entry, I86_PDE_PRESENT);
pd_entry_add_attrib(entry, I86_PDE_WRITABLE);
pd_entry_set_frame(entry, (physical_addr) new_table);
memset(virtual_table, 0, sizeof(ptable));
pt_entry * page = &virtual_table->m_entries[pginf.page];
pt_entry_set_frame(page, (physical_addr) phys);
pt_entry_add_attrib(page, I86_PTE_PRESENT);
pt_entry_add_attrib(page, I86_PTE_WRITABLE);
return;
}
ptable * table = (ptable *) PAGE_GET_PHYSICAL_ADDRESS(e);
pt_entry * page = &table->m_entries[PAGE_TABLE_INDEX((uint32_t) virt)];
pt_entry_set_frame(page, (physical_addr) phys);
pt_entry_add_attrib(page, I86_PTE_PRESENT);
pt_entry_add_attrib(page, I86_PTE_WRITABLE);
}
int vmmngr_commit_page(pt_entry * e)
{
void *p = pmmngr_alloc_block();
if (!p)
{
return 0;
}
pt_entry_set_frame(e, (physical_addr) p);
pt_entry_add_attrib(e, I86_PTE_PRESENT);
pt_entry_add_attrib(e, I86_PTE_WRITABLE);
return 1;
}
void vmmngr_initialize(physical_addr dir_address)
{
int i = 0;
int frame = 0;
int virt = 0;
ptable * table = (ptable *) pmmngr_alloc_block();
if (!table)
{
return;
}
ptable * table2 = (ptable *) pmmngr_alloc_block();
if (!table2)
{
pmmngr_free_block(table);
return;
}
memset(table, 0, sizeof(ptable));
for (i = 0, frame = 0x0, virt = 0x00000000; i < 1024; ++i, frame+=4096, virt+=4096)
{
pt_entry page = 0;
pt_entry_add_attrib(&page, I86_PTE_PRESENT);
pt_entry_set_frame(&page, frame);
table->m_entries[PAGE_TABLE_INDEX(virt)] = page;
}
for (i = 0, frame = 0x0, virt = 0xc0000000; i < 1024; ++i, frame+=4096, virt+=4096)
{
pt_entry page = 0;
pt_entry_add_attrib(&page, I86_PTE_PRESENT);
pt_entry_set_frame(&page, frame);
table2->m_entries[PAGE_TABLE_INDEX(virt)] = page;
}
pdirectory * dir = (pdirectory *) dir_address;// pmmngr_alloc_block();
if (!dir)
{
pmmngr_free_block(table);
pmmngr_free_block(table2);
return;
}
memset(dir, 0, sizeof(pdirectory));
pd_entry * entry = &dir->m_entries[PAGE_DIRECTORY_INDEX(0x00000000)];
pd_entry_add_attrib(entry, I86_PDE_PRESENT);
pd_entry_add_attrib(entry, I86_PDE_WRITABLE);
pd_entry_set_frame(entry, (physical_addr) table);
pd_entry * entry2 = &dir->m_entries[PAGE_DIRECTORY_INDEX(0xc0000000)];
pd_entry_add_attrib(entry2, I86_PDE_PRESENT);
pd_entry_add_attrib(entry2, I86_PDE_WRITABLE);
pd_entry_set_frame(entry2, (physical_addr) table2);
pd_entry * entry3 = &dir->m_entries[PAGE_DIRECTORY_INDEX(0xFFC00000)];
pd_entry_add_attrib(entry3, I86_PDE_PRESENT);
pd_entry_add_attrib(entry3, I86_PDE_WRITABLE);
pd_entry_set_frame(entry3, (physical_addr) dir);
vmmngr_switch_pdirectory(dir);
pmmngr_paging_enable(1);
}