int vmmngr_alloc_page(virtual_addr virt)
{
pdirectory * pd = (pdirectory *) PAGE_DIRECTORY_ADDRESS;
pd_entry * pde = &pd->m_entries[PAGE_DIRECTORY_INDEX(virt)];
if ((!pd) || (!pde))
{
return 0;
}
if (!pd_entry_is_present(*pde))
{
ptable *newpt = pmmngr_alloc_block();
if (!newpt)
{
return 0;
}
*pde = (pd_entry) 0;
pd_entry_add_attrib(pde, I86_PDE_PRESENT);
pd_entry_add_attrib(pde, I86_PDE_WRITABLE);
pd_entry_set_frame(pde, (physical_addr) newpt);
memset(vmmngr_get_ptable_address(virt), 0, sizeof(ptable));
}
ptable * pt = vmmngr_get_ptable_address(virt);
pt_entry *pte = &pt->m_entries[PAGE_TABLE_INDEX(virt)];
if (pt_entry_is_present(*pte))
{
return 1;
}
if (!vmmngr_commit_page(pte))
{
return 0;
}
return 1;
}
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);
}
error_t vmmngr_create_table(pdirectory* dir, virtual_addr addr, uint32 flags)
{
pd_entry* entry = vmmngr_pdirectory_lookup_entry(dir, addr);
if (!entry)
return ERROR_OCCUR;
if (pd_entry_is_present(*entry) == false)
{
ptable* table = (ptable*)pmmngr_alloc_block();
if (!table)
return ERROR_OCCUR; // not enough memory!!
memset(table, 0, sizeof(ptable));
pd_entry_set_frame(entry, (physical_addr)table);
*entry |= flags;
return ERROR_OK;
}
// TODO: Is the above test required? Since the check is done outside
// entry already exists
return ERROR_OK;
}
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);
}
