static void MapKernelImage()
{
var phys = Address.KernelElfSection;
var diff = Address.KernelBaseVirt - Address.KernelBasePhys;
var endPhys = phys + OriginalKernelElf.TotalFileSize;
var addr = phys;
KernelMessage.WriteLine("Mapping Kernel Image from physical {0:X8} to virtual {1:X8}", phys, phys + diff);
while (addr < endPhys)
{
PageTable.MapVirtualAddressToPhysical(addr + diff, addr);
addr += 0x1000;
}
}
/// <summary>
/// Returns raw, unmanaged Memory.
/// Consumer: Kernel, Memory allocators
/// Shoud be used for larger Chunks.
/// </summary>
internal unsafe static Addr RequestRawVirtalMemoryPages(uint pages)
{
Addr virt = _nextVirtAddr;
var head = PageFrameManager.AllocatePages(PageFrameRequestFlags.Default, pages);
if (head == null)
{
return(Addr.Zero);
}
var p = head;
for (var i = 0; i < pages; i++)
{
PageTable.MapVirtualAddressToPhysical(_nextVirtAddr, p->PhysicalAddress);
_nextVirtAddr += 4096;
p = p->Next;
}
return(virt);
}
public unsafe static void InitialKernelProtect_MakeWritable_BySize(uint virtAddr, uint size)
{
if (!UseKernelWriteProtection)
{
return;
}
//KernelMessage.WriteLine("Unprotect Memory: Start={0:X}, End={1:X}", virtAddr, virtAddr + size);
var pages = KMath.DivCeil(size, 4096);
for (var i = 0; i < pages; i++)
{
var entry = PageTable.GetTableEntry(virtAddr);
entry->Writable = true;
virtAddr += 4096;
}
Native.SetCR3(PageTable.AddrPageDirectory);
}
public static void Main()
{
//Screen.BackgroundColor = ScreenColor.Green;
//Screen.Color = ScreenColor.Red;
//Screen.Clear();
//Screen.Goto(0, 0);
//Screen.Write('A');
//Serial.SetupPort(Serial.COM1);
//Serial.Write(Serial.COM1, "Hello");
BootMemory.Setup();
// Setup Kernel Log
var kmsgHandler = new KernelMessageWriter();
KernelMessage.SetHandler(kmsgHandler);
KernelMessage.WriteLine("<LOADER:CONSOLE:BEGIN>");
// Parse Boot Informations
Multiboot.Setup();
// Parse Kernel ELF section
SetupOriginalKernelElf();
// Print all section of Kernel ELF (for information only)
DumpElfInfo();
// Copy Section to a final destination
SetupKernelSection();
// Collection informations we need to pass to the kernel
BootInfo_.Setup();
// Setup Global Descriptor Table
var map = BootMemory.AllocateMemoryMap(0x1000, BootInfoMemoryType.GDT);
BootInfo_.AddMap(map);
GDT.Setup(map.Start);
// Now we enable Paging. It's important that we do not cause a Page Fault Exception,
// Because IDT is not setup yet, that could handle this kind of exception.
map = BootMemory.AllocateMemoryMap(PageTable.InitalPageDirectorySize, BootInfoMemoryType.PageDirectory);
BootInfo_.AddMap(map);
var map2 = BootMemory.AllocateMemoryMap(PageTable.InitalPageTableSize, BootInfoMemoryType.PageTable);
BootInfo_.AddMap(map2);
PageTable.Setup(map.Start, map2.Start);
// Because Kernel is compiled in virtual address space, we need to remap the pages
MapKernelImage();
// Get Entry Point of Kernel
uint kernelEntry = GetKernelStartAddr();
if (kernelEntry == 0)
{
KernelMessage.WriteLine("No kernel entry point found {0:X8}");
KernelMessage.WriteLine("Is the name of entry point correct?");
KernelMessage.WriteLine("Are symbols emitted?");
KernelMessage.WriteLine("System halt!");
while (true)
{
Native.Nop();
}
}
KernelMessage.WriteLine("Call Kernel Start at {0:X8}", kernelEntry);
// Start Kernel.
CallAddress(kernelEntry);
// If we hit this code location, the Kernel Main method returned.
// This would be a general fault. Normally, this code section will overwritten
// by the kernel, so normally, it can never reach this code position.
KernelMessage.WriteLine("Unexpected return from Kernel Start");
Debug.Break();
}
