/// <summary>
/// Sets up the GDT table and entries
/// </summary>
public static void Setup(Addr addr)
{
KernelMessage.Write("Setup GDT...");
GdtTableAddress = addr;
GdtTable = (DescriptorTable *)GdtTableAddress;
GdtTable->Clear();
GdtTable->AdressOfEntries = GdtTableAddress + DescriptorTable.StructSize;
//Null segment
var nullEntry = DescriptorTableEntry.CreateNullDescriptor();
GdtTable->AddEntry(nullEntry);
//code segment
var codeEntry = DescriptorTableEntry.CreateCode(0, 0xFFFFFFFF);
codeEntry.CodeSegment_Readable = true;
codeEntry.PriviligeRing = 0;
codeEntry.Present = true;
codeEntry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
//codeEntry.CodeSegment_Confirming = true;
GdtTable->AddEntry(codeEntry);
//data segment
var dataEntry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
dataEntry.DataSegment_Writable = true;
dataEntry.PriviligeRing = 0;
dataEntry.Present = true;
dataEntry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(dataEntry);
Flush();
KernelMessage.WriteLine("Done");
}
/// <summary>
/// Sets up the GDT table and entries
/// </summary>
public static void Setup(Addr addr)
{
KernelMessage.Write("Setup GDT...");
GdtTableAddress = addr;
GdtTable = (DescriptorTable *)GdtTableAddress;
GdtTable->Clear();
GdtTable->AdressOfEntries = GdtTableAddress + DescriptorTable.StructSize;
// 0 - Null segment
var entry = DescriptorTableEntry.CreateNullDescriptor();
GdtTable->AddEntry(entry);
// 1 - code segment
entry = DescriptorTableEntry.CreateCode(0, 0xFFFFFFFF);
entry.CodeSegment_Readable = true;
entry.PriviligeRing = 0;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
//codeEntry.CodeSegment_Confirming = true;
GdtTable->AddEntry(entry);
// 2 - data segment
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 0;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
// 3 - reserved
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 0;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
// 4 - kernel thread storage
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 0;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
// 5 - reserved
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 0;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
// ---
// 6 - user code segment
entry = DescriptorTableEntry.CreateCode(0, 0xFFFFFFFF);
entry.CodeSegment_Readable = true;
entry.PriviligeRing = 3;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
entry.CodeSegment_Confirming = false;
GdtTable->AddEntry(entry);
// 7 - user data segment
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 3;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
// 8 - thread storage segment for FS register
entry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
entry.DataSegment_Writable = true;
entry.PriviligeRing = 3;
entry.Present = true;
entry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(entry);
Flush();
KernelMessage.WriteLine("Done");
}
public static void SetupUserMode(Addr tssAddr)
{
KernelMessage.WriteLine("Setup GDT UserMode");
if (KConfig.UseTaskStateSegment)
{
TssAddr = tssAddr;
TssTable = (TaskStateSegmentTable *)tssAddr;
TssTable->Clear();
TssTable->AdressOfEntries = TssAddr + TaskStateSegmentTable.StructSize;
}
//code segment
var codeEntry = DescriptorTableEntry.CreateCode(0, 0xFFFFFFFF);
codeEntry.CodeSegment_Readable = true;
codeEntry.PriviligeRing = 3;
codeEntry.Present = true;
codeEntry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
codeEntry.CodeSegment_Confirming = false;
GdtTable->AddEntry(codeEntry);
//data segment
var dataEntry = DescriptorTableEntry.CreateData(0, 0xFFFFFFFF);
dataEntry.DataSegment_Writable = true;
dataEntry.PriviligeRing = 3;
dataEntry.Present = true;
dataEntry.AddressMode = DescriptorTableEntry.EAddressMode.Bits32;
GdtTable->AddEntry(dataEntry);
if (KConfig.UseTaskStateSegment)
{
//TSS
Tss = AddTSS();
//tss->esp0 = kernelStackPointer;
Tss->SS0 = 0x10;
Tss->Trace_bitmap = 0xdfff;
KernelMessage.WriteLine("Addr of tss: {0:X8}", (uint)Tss);
var tssEntry = DescriptorTableEntry.CreateTSS(Tss);
tssEntry.PriviligeRing = 0;
tssEntry.TSS_AVL = true;
tssEntry.Present = true;
GdtTable->AddEntry(tssEntry);
}
Flush();
if (KConfig.UseTaskStateSegment)
{
KernelMessage.WriteLine("LoadTaskRegister...");
//LoadTaskRegister();
//Debug, for breakpoint
//clockTicks++;
//DebugFunction1();
}
KernelMessage.WriteLine("Done");
}