/*
* Maps a page (PAE).
* uint64_t VirtAddr -> the virtual address where to map the frame to.
* uint64_t PhysAddr -> the physical address of the frame to map to the page.
*/
void PAEPagingMap(uint64_t VirtAddr, uint64_t PhysAddr)
{
char _CONST *ErrorFrameAlloc = "ERROR: Unable to allocate pages for the VMM.";
PageDirEntry_t *PageDir;
PageTableEntry_t *PageTable;
PageDir = (PageDirEntry_t*)(uint32_t)(PDPT[PDPT_INDEX(VirtAddr)] & PAGE_MASK);
// If page table isn't present, make one.
if(!(PageDir[PD_INDEX(VirtAddr)] & PRESENT_BIT))
{
PageTable = (PageTableEntry_t*)AllocFrameFunc(POOL_BITMAP);
if(!PageTable)
{
// Switch to text mode.
VideoAPIFunc(VIDEO_VGA_SWITCH_MODE, MODE_80_25_TEXT);
AbortBootFunc(ErrorFrameAlloc);
}
memset(PageTable, 0x00000000, PAGE_SIZE);
PageDir[PD_INDEX(VirtAddr)] = (PageDirEntry_t)PageTable | PRESENT_BIT;
}
else
{
PageTable = (PageTableEntry_t*)(uint32_t)(PageDir[PD_INDEX(VirtAddr)] & PAGE_MASK);
}
PageTable[PT_INDEX(VirtAddr)] = PhysAddr | PRESENT_BIT;
}
void setup_initial_mapping(void)
{
pte_t * const pg0_phys = PA(pg0);
pte_t * const pg1_phys = PA(pg0);
pde_t * const pgdir_phys = PA(pgdir);
pte_t const pte_flags = PTE_P | PTE_W;
pde_t const pde_flags = PDE_P | PDE_W;
for (size_t index = 0; index != PT_SIZE; ++index) {
*(pg0_phys + index) = (index * PAGE_SIZE) | pte_flags;
*(pg1_phys + index) = (index * PAGE_SIZE) | pte_flags;
}
*(pgdir_phys + PD_INDEX(0)) = (pde_t)pg0_phys | pde_flags;
*(pgdir_phys + PD_INDEX(VIRTUAL_ADDRESS_BASE)) = (pde_t)pg1_phys | pde_flags;
}
/*
* Initializes PAE paging.
*/
void PAEPagingInit()
{
char _CONST *ErrorFrameAlloc = "ERROR: Unable to allocate pages for the VMM.";
// Allocate a page for the page directory.
PageDirEntry_t *PageDir[4];
for(uint32_t i = 0; i < 4; i++)
{
// Allocate a page for the page directory.
PageDir[i] = (PageDirEntry_t*)AllocFrameFunc(POOL_BITMAP);
if(!PageDir[i])
{
// Switch to text mode.
VideoAPIFunc(VIDEO_VGA_SWITCH_MODE, MODE_80_25_TEXT);
AbortBootFunc(ErrorFrameAlloc);
}
memset(PageDir[i], 0x00000000, PAGE_SIZE);
// Mark it in the PDPT.
PDPT[i] = (PageDirPTEntry_t)PageDir[i] | PRESENT_BIT;
}
// Allocate page for the page table.
PageTableEntry_t *BaseTable = (PageTableEntry_t*)AllocFrameFunc(POOL_BITMAP);
if(!BaseTable)
{
// Switch to text mode.
VideoAPIFunc(VIDEO_VGA_SWITCH_MODE, MODE_80_25_TEXT);
AbortBootFunc(ErrorFrameAlloc);
}
memset(BaseTable, 0x00000000, PAGE_SIZE);
// Mark the page table in the page directory.
(PageDir[0])[PD_INDEX(0x00000000)] = (PageDirEntry_t)BaseTable | PRESENT_BIT;
for(uint32_t Index = 0x0000; Index < 0x100000; Index += 0x1000)
{
BaseTable[PT_INDEX(Index)] = Index | PRESENT_BIT;
}
// Self-recursive trick, ftw!
(PageDir[3])[508] = (PageDirEntry_t)PageDir[0] | PRESENT_BIT;
(PageDir[3])[509] = (PageDirEntry_t)PageDir[1] | PRESENT_BIT;
(PageDir[3])[510] = (PageDirEntry_t)PageDir[2] | PRESENT_BIT;
(PageDir[3])[511] = (PageDirEntry_t)PageDir[3] | PRESENT_BIT;
}
bool arch_mm_context_read(struct vmm_context *ctx, void *output, addr_t address, size_t length)
{
int pml4idx = PML4_INDEX(address);
int pdptidx = PDPT_INDEX(address);
int pdidx = PD_INDEX(address);
addr_t destp;
addr_t offset;
addr_t *pml4v = (addr_t *)ctx->root_virtual;
if(!pml4v[pml4idx]) {
return false;
}
addr_t *pdptv = (addr_t *)((pml4v[pml4idx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!pdptv[pdptidx]) {
return false;
}
addr_t *pdv = (addr_t *)((pdptv[pdptidx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!(pdv[pdidx] & PAGE_LARGE)) {
int ptidx = PT_INDEX(address);
offset = address & (0x1000 - 1);
if(offset + length > 0x1000)
PANIC(0, "mm_context_read crossed page boundary", EFAULT);
if(!pdv[pdidx]) {
return false;
}
addr_t *ptv = (addr_t *)((pdv[pdidx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!ptv[ptidx]) {
return false;
}
destp = ptv[ptidx] & PAGE_MASK_PHYSICAL;
} else {
offset = address & (0x200000 - 1);
if(offset + length > 0x200000)
PANIC(0, "mm_context_read crossed page boundary", EFAULT);
if(!pdv[pdidx]) {
return false;
}
destp = pdv[pdidx] & PAGE_MASK_PHYSICAL;
}
memcpy(output, (void *)(destp + PHYS_PAGE_MAP + offset), length);
return true;
}
bool arch_mm_context_virtual_getmap(struct vmm_context *ctx, addr_t address, addr_t *phys, int *flags)
{
int pml4idx = PML4_INDEX(address);
int pdptidx = PDPT_INDEX(address);
int pdidx = PD_INDEX(address);
addr_t destp;
addr_t *pml4v = (addr_t *)ctx->root_virtual;
if(!pml4v[pml4idx]) {
return false;
}
addr_t *pdptv = (addr_t *)((pml4v[pml4idx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!pdptv[pdptidx]) {
return false;
}
addr_t *pdv = (addr_t *)((pdptv[pdptidx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!(pdv[pdidx] & PAGE_LARGE)) {
int ptidx = PT_INDEX(address);
if(!pdv[pdidx]) {
return false;
}
addr_t *ptv = (addr_t *)((pdv[pdidx] & PAGE_MASK_PHYSICAL) + PHYS_PAGE_MAP);
if(!ptv[ptidx]) {
return false;
}
destp = ptv[ptidx];
} else {
if(!pdv[pdidx]) {
return false;
}
destp = pdv[pdidx];
}
if(phys)
*phys = destp & PAGE_MASK_PHYSICAL;
if(flags)
*flags = destp & ATTRIB_MASK;
return true;
}
