//=========================================================
// Copy the given page and all consecutive subsequent ones
//=========================================================
void CopyPages(long address, struct Task *task)
{
address &= PageMask;
// Get physical address of current PT
struct PML4 *pml4 = (struct PML4 *) (task->cr3);
struct PML4 *current_pml4 = (struct PML4 *) (currentTask->cr3);
while (1)
{
struct PT *pt = GetPT(pml4, address, task->pid);
struct PT *currentPT = GetPT(current_pml4, address, currentTask->pid);
int i = GetPTIndex(address);
if (!(VIRT(PT,currentPT) ->entries[i].value))
break;
// Copy the physical memory
p_Address data = AllocPage(task->pid);
//data += VAddr / 8;
CreatePTEWithPT((struct PML4 *)task->cr3, data, address, task->pid,
US | RW | P | 0x800);
memcpy(
(void *) PAGE(((VIRT(PT, pt)) ->entries[i].value)) + VAddr,
(void *) PAGE(((VIRT(PT, currentPT)) ->entries[i].value)) + VAddr, PageSize);
address += PageSize;
}
}
//=====================================================
// Create a Page Table for a new process
// Return a pointer to the Page Directory of this table
//=====================================================
void * VCreatePageDir(unsigned short pid, unsigned short parentPid)
{
struct PML4 *pml4;
struct PD *pd;
// Allocate the base page for the Page Table
pml4 = (struct PML4 *) AllocPage(pid);
VIRT(PML4,pml4) ->entries[GetPML4Index(VAddr)].value = virtualPDP | P
| RW; // Physical to virtual addresses
pd = GetPD(pml4, 0, pid);
VIRT(PD,pd) ->entries[GetPDIndex(0)].value = kernelPT | P | RW; // Kernel entries
if (parentPid == 0) // Just create some default PTEs
// We need these two entries so that NewKernelTask can
// access the data and stack pages of the new process.
{
long c;
struct PT *pt = GetPT(pml4, UserData, pid);
VIRT(PT,pt) ->entries[GetPTIndex(UserData)].value =
AllocAndCreatePTE(TempUserData, pid, RW | P);
c = TempUserData;
asm ("invlpg %0;"
:
:"m"(*(char *)TempUserData)
);
pt = GetPT(pml4, KernelStack, pid);
VIRT(PT,pt) ->entries[GetPTIndex(KernelStack)].value =
AllocAndCreatePTE(TempUStack, pid, RW | P);
pt = GetPT(pml4, UserStack, pid);
VIRT(PT,pt) ->entries[GetPTIndex(UserStack)].value =
AllocAndCreatePTE(TempUStack, pid, RW | P);
c = TempUStack;
asm ("invlpg %0;"
:
:"m"(*(char *)TempUStack)
);
}