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IDT

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This commit is contained in:
kudzu_cp 2011-07-14 19:42:33 +00:00
parent e025f29841
commit 05dcef2f88
1 changed files with 31 additions and 10 deletions
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41
source2/IL2CPU/Cosmos.IL2CPU.X86/CosmosAssembler.cs
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@ -87,6 +87,8 @@ namespace Cosmos.IL2CPU.X86 {
return xResult;
}
byte mGdCode;
byte mGdData;
public void CreateGDT() {
new Comment(this, "BEGIN - Create GDT");
var xGDT = new List<byte>();
@ -94,10 +96,10 @@ namespace Cosmos.IL2CPU.X86 {
// Not used, but required by many emulators.
xGDT.AddRange(new byte[8] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
// Code Segment
byte xCodeSelector = (byte)xGDT.Count;
mGdCode = (byte)xGDT.Count;
xGDT.AddRange(GdtDescriptor(0x00000000, 0xFFFFFFFF, true));
// Data Segment - Selector
byte xDataSelector = (byte)xGDT.Count;
mGdData = (byte)xGDT.Count;
xGDT.AddRange(GdtDescriptor(0x00000000, 0xFFFFFFFF, false));
DataMembers.Add(new DataMember("_NATIVE_GDT_Contents", xGDT.ToArray()));
@ -118,7 +120,7 @@ namespace Cosmos.IL2CPU.X86 {
new Lgdt { DestinationReg = Registers.EAX, DestinationIsIndirect = true };
new Comment("Set data segments");
new Move { DestinationReg = Registers.AX, SourceValue = xDataSelector };
new Move { DestinationReg = Registers.AX, SourceValue = mGdData };
new Move { DestinationReg = Registers.DS, SourceReg = Registers.AX };
new Move { DestinationReg = Registers.ES, SourceReg = Registers.AX };
new Move { DestinationReg = Registers.FS, SourceReg = Registers.AX };
@ -126,21 +128,40 @@ namespace Cosmos.IL2CPU.X86 {
new Move { DestinationReg = Registers.SS, SourceReg = Registers.AX };
new Comment("Force reload of code segment");
new JumpToSegment { Segment = xCodeSelector, DestinationLabel = "Boot_FlushCsGDT" };
new JumpToSegment { Segment = mGdCode, DestinationLabel = "Boot_FlushCsGDT" };
new Label("Boot_FlushCsGDT");
new Comment(this, "END - Create GDT");
}
protected void SetIdtDescriptor(byte[] aIDT, int aNo) {
protected void SetIdtDescriptor(int aNo, string aLabel) {
int xOffset = aNo * 8;
new Move { DestinationReg = Registers.EAX, SourceRef = ElementReference.New(aLabel) };
var xIDT = ElementReference.New("_NATIVE_IDT_Contents");
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset, SourceReg = Registers.AL };
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 1, SourceReg = Registers.AH };
new ShiftRight { DestinationReg = Registers.EAX, SourceValue = 16 };
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 6, SourceReg = Registers.AL };
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 7, SourceReg = Registers.AH };
// Code Segment
//TODO: Selectors are 16 bit, convert it to 16 bit but also check GDT settings first (prob just old code)
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 2, SourceValue = mGdCode, Size = 8 };
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 3, SourceValue = 0x00, Size = 8 };
// Reserved
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 4, SourceValue = 0x00, Size = 8 };
// Type
new Move { DestinationRef = xIDT, DestinationIsIndirect = true, DestinationDisplacement = xOffset + 5, SourceValue = 0x8E, Size = 8 };
}
public void CreateIDT() {
new Comment(this, "BEGIN - Create IDT");
var xIDT = new byte[8 * 256];
SetIdtDescriptor(xIDT, 3);
DataMembers.Add(new DataMember("_NATIVE_IDT_Contents", xIDT));
DataMembers.Add(new DataMember("_NATIVE_IDT_Pointer", new UInt16[] { (UInt16)xIDT.Length, 0, 0 }));
UInt16 xIdtSize = 8 * 256;
DataMembers.Add(new DataMember("_NATIVE_IDT_Contents", new byte[xIdtSize]));
DataMembers.Add(new DataMember("_NATIVE_IDT_Pointer", new UInt16[] { xIdtSize, 0, 0 }));
SetIdtDescriptor(3, "DebugStub_INT3");
new Label("DebugStub_INT3");
new Comment(this, "END - Create IDT");
}