public static void Init()
{
pageStates = new byte[((Multiboot.GetTotalMemory() * 1024 * 1024) / 4096) / 8];
for (uint i = 0; i < Multiboot.GetTotalMemory() * 1024 * 1024; i += 4096)
{
if (i <= Heap.heapPointer)
{
Set(i);
}
else
{
Clear(i);
}
}
}
public static void Init()
{
directory = (DirectoryHeader *)PageManager.GetFreePage(totalPagesForDirectory);
directory->location = (uint)directory;
entryCount = (uint)((4096 * totalPagesForDirectory) - sizeof(DirectoryHeader));
for (int i = 0; i < entryCount; i++)
{
var entry = directory->GetEntry(i);
entry->used = false;
}
Console.Write("Total System Memory ");
Console.Write((int)Multiboot.GetTotalMemory());
Console.NewLine();
Console.Write("Useable Memory ");
Console.Write(Multiboot.GetTotalMemory() - (heapPointer / 1024 / 1024));
Console.NewLine();
}
public static uint GetFreePage(int count)
{
uint startedAt = currentPage;
bool skip = true;
while (true)
{
for (; currentPage < Multiboot.GetTotalMemory() * 1024 * 1024; currentPage += 4096)
{
if (startedAt == currentPage)
{
if (skip)
{
skip = false;
}
else
{
return(0);
}
}
if (!IsSet(currentPage))
{
int f = 0;
for (f = 0; f < count; f++)
{
if (IsSet(currentPage + (f * 4096)))
{
break;
}
}
if (f >= count)
{
for (f = 0; f < count; f++)
{
Set(currentPage + (f * 4096));
}
Utils.memset((byte *)(currentPage), 0, (uint)(count * 4096));
return(currentPage);
}
}
}
currentPage = 0;
}
}
private static uint internalAllocation(uint size, bool allign)
{
totalAllocations++;
tryAgain :;
uint returnable = 0;
if (Settings.HeapUseBasic || entryCount == 0)
{
if (heapPointer == 0)
{
heapPointer = Utils.allign4K(Multiboot.GetEndOfKernel()) + 4096;
}
if (allign)
{
heapPointer = Utils.allign4K(heapPointer) + 4096;
}
uint tmp = heapPointer;
heapPointer += size;
returnable = tmp;
goto allocationEnd;
}
mutex.Lock();
if (currentEntry >= entryCount)
{
currentEntry = 0;
}
var entry = directory->GetEntry(currentEntry);
if (entry->used)
{
currentEntry++;
goto tryAgain;
}
if (!allign && size < 4096)
{
if (entry->size <= size && entry->location != 0)
{
entry->used = true;
returnable = entry->location;
goto allocationEnd;
}
if (size > pageSpace)
{
pageSpace = 4096;
heapPointer = PageManager.GetFreePage();
if (heapPointer == 0)
{
// need to to a GC scan and free some pages
Console.WriteLine("RAN OUT OF RAM");
ACPI.Shutdown();
while (true)
{
}
}
}
pageSpace -= size;
entry->size = size;
entry->location = heapPointer;
heapPointer += size;
entry->used = true;
returnable = entry->location;
goto allocationEnd;
}
else
{
int num = (int)(size / 4096);
int remainder = (int)(size % 4096);
if (remainder > 0)
{
num++;
}
entry->used = true;
entry->location = PageManager.GetFreePage(num);
entry->size = (uint)num * 4096;
returnable = entry->location;
goto allocationEnd;
}
allocationEnd :;
Utils.memset((byte *)returnable, 0, size);
mutex.Unlock();
return(returnable);
}