public void X86Orw16_RewriteSegConst()
{
var m = new MemoryOperand(
PrimitiveType.Byte,
Registers.bx,
Constant.Int32(32));
var e = orw.CreateMemoryAccess(instr, m, state);
Assert.AreEqual("Mem0[ds:bx + 0x0020:byte]", e.ToString());
}
private Constant EmitDirectAddress(int reg, MemoryOperand memOp)
{
Debug.Assert(memOp.Offset.IsValid);
if (defaultWordSize == PrimitiveType.Word16)
{
reg |= 0x6;
emitter.EmitByte(reg);
return Constant.Create(PrimitiveType.Word16, memOp.Offset.ToUInt32());
}
else
{
reg |= 0x5;
emitter.EmitByte(reg);
return Constant.Word32(memOp.Offset.ToUInt32());
}
}
public ExternalProcedure ImportedProcedureName(Address addrInstruction, PrimitiveType addrWidth, MemoryOperand mem)
{
if (mem != null && addrWidth == PrimitiveType.Word32 && mem.Base == RegisterStorage.None &&
mem.Index == RegisterStorage.None)
{
return host.GetImportedProcedure(Address.Ptr32(mem.Offset.ToUInt32()), addrInstruction);
}
return null;
}
/// <summary>
/// Memory accesses are translated into expressions.
/// </summary>
/// <param name="mem"></param>
/// <param name="state"></param>
/// <returns></returns>
public Expression EffectiveAddressExpression(IntelInstruction instr, MemoryOperand mem, X86State state)
{
Expression eIndex = null;
Expression eBase = null;
Expression expr = null;
PrimitiveType type = PrimitiveType.CreateWord(mem.Width.Size);
bool ripRelative = false;
if (mem.Base != RegisterStorage.None)
{
if (mem.Base == Registers.rip)
{
ripRelative = true;
}
else
{
eBase = AluRegister(mem.Base);
if (expr != null)
{
expr = new BinaryExpression(Operator.IAdd, eBase.DataType, eBase, expr);
}
else
{
expr = eBase;
}
}
}
if (mem.Offset.IsValid)
{
if (ripRelative)
{
expr = instr.Address + (instr.Length + mem.Offset.ToInt64());
}
else if (expr != null)
{
BinaryOperator op = Operator.IAdd;
long l = mem.Offset.ToInt64();
if (l < 0 && l > -0x800)
{
l = -l;
op = Operator.ISub;
}
DataType dt = (eBase != null) ? eBase.DataType : eIndex.DataType;
Constant cOffset = Constant.Create(dt, l);
expr = new BinaryExpression(op, dt, expr, cOffset);
}
else
{
expr = mem.Offset;
}
}
if (mem.Index != RegisterStorage.None)
{
eIndex = AluRegister(mem.Index);
if (mem.Scale != 0 && mem.Scale != 1)
{
eIndex = new BinaryExpression(
Operator.IMul, eIndex.DataType, eIndex, Constant.Create(mem.Width, mem.Scale));
}
expr = new BinaryExpression(Operator.IAdd, expr.DataType, expr, eIndex);
}
return expr;
}
public Expression CreateMemoryAccess(IntelInstruction instr, MemoryOperand memoryOperand, X86State state)
{
return CreateMemoryAccess(instr, memoryOperand, memoryOperand.Width, state);
}
public void X86Orw32_IndexedAccess()
{
MemoryOperand mem = new MemoryOperand(PrimitiveType.Word32, Registers.eax, Registers.edx, 4, Constant.Word32(0x24));
Expression expr = orw.Transform(instr, mem, PrimitiveType.Word32, state);
Assert.AreEqual("Mem0[eax + 0x00000024 + edx * 0x00000004:word32]", expr.ToString());
}
public void X86Orw32_MemAccess()
{
MemoryOperand mem = new MemoryOperand(PrimitiveType.Word32);
mem.Base = Registers.ecx;
mem.Offset = Constant.Word32(4);
Expression expr = orw.Transform(instr, mem, PrimitiveType.Word32, state);
Assert.AreEqual("Mem0[ecx + 0x00000004:word32]", expr.ToString());
}
private ParsedOperand Mem(
PrimitiveType width,
SegmentRegister seg,
RegisterStorage @base,
RegisterStorage index,
int scale,
string offset)
{
int val;
MemoryOperand mem;
Symbol sym = null;
if (offset != null)
{
if (symtab.Equates.TryGetValue(offset, out val))
{
mem = new MemoryOperand(width, @base, IntegralConstant(val, @base.DataType));
sym = null;
}
else
{
sym = symtab.CreateSymbol(offset);
val = (int)this.addrBase.Offset;
Constant off = Constant.Create(@base == null
? seg != null ? PrimitiveType.Word16 : PrimitiveType.Word32
: @base.DataType,
val);
mem = new MemoryOperand(width, @base ?? RegisterStorage.None, off);
}
}
else
{
mem = new MemoryOperand(width)
{
};
}
if (seg != null)
{
mem.SegOverride = seg;
this.SegmentOverride = seg;
}
mem.Scale = (byte)scale;
if (scale > 1)
{
if (index == null)
{
mem.Index = mem.Base;
mem.Base = RegisterStorage.None;
}
else
{
mem.Index = index;
mem.Base = @base;
}
}
return new ParsedOperand(mem, sym);
}
/// <summary>
/// Emits the ModRM byte (and SIB byte if applicable)
/// </summary>
/// <param name="reg"></param>
/// <param name="memOp"></param>
/// <returns>The offset value to be emitted as the last piece of the instructon</returns>
public Constant EmitModRMPrefix(int reg, MemoryOperand memOp)
{
offset = null;
reg <<= 3;
if (memOp.Base != RegisterStorage.None || memOp.Index != RegisterStorage.None)
{
PrimitiveType baseWidth = memOp.Base.DataType;
PrimitiveType indexWidth = memOp.Index.DataType;
if (memOp.Base != RegisterStorage.None && memOp.Index != RegisterStorage.None)
{
if (baseWidth != indexWidth)
{
OnError("mismatched base and index registers");
return null;
}
}
// Add the 'mod' bits
if (memOp.Offset != null)
{
Debug.Assert(memOp.Offset.IsValid);
if (memOp.Offset.DataType == PrimitiveType.SByte)
{
reg |= 0x40;
offset = memOp.Offset;
}
else
{
reg |= 0x80;
offset = Constant.Create(defaultWordSize, memOp.Offset.ToInt32());
}
}
bool fNeedsSib = false;
int sib = 0;
if (baseWidth == PrimitiveType.Word16)
{
reg |= Get16AddressingModeMask(memOp);
}
else if (baseWidth == PrimitiveType.Word32 || indexWidth == PrimitiveType.Word32)
{
if (memOp.Index == RegisterStorage.None)
{
if (memOp.Base != Registers.esp)
{
reg |= X86Assembler.RegisterEncoding(memOp.Base);
if (memOp.Offset == null && memOp.Base == Registers.ebp)
{
reg |= 0x40;
offset = Constant.Byte(0);
}
}
else
{
reg |= 0x04;
fNeedsSib = true;
sib = 0x24;
}
}
else
{
reg |= 0x04;
fNeedsSib = true;
switch (memOp.Scale)
{
case 1: sib = 0; break;
case 2: sib = 0x40; break;
case 4: sib = 0x80; break;
case 8: sib = 0xC0; break;
default: OnError("Scale factor must be 1, 2, 4, or 8"); return Constant.Invalid;
}
if (memOp.Base == RegisterStorage.None)
{
sib |= 0x05;
reg &= ~0xC0; // clear mod part of modRM.
if (memOp.Offset == null)
{
offset = Constant.Word32(0);
}
}
else
{
sib |= X86Assembler.RegisterEncoding(memOp.Base);
}
if (memOp.Index != Registers.esp)
{
sib |= X86Assembler.RegisterEncoding(memOp.Index) << 3;
}
else
throw new ApplicationException("ESP register can't be used as an index register");
}
}
else
{
throw new ApplicationException("unexpected address width");
}
emitter.EmitByte(reg);
if (fNeedsSib)
emitter.EmitByte(sib);
return offset;
}
else
return EmitDirectAddress(reg, memOp);
}
private ParsedOperand ParseMemoryOperand(RegisterStorage segOver)
{
MemoryOperand memOp = new MemoryOperand(null);
memOp.SegOverride = segOver;
this.segOverride = segOver;
ParseMemoryFactor(memOp);
for (;;)
{
Token token = lexer.GetToken();
switch (token)
{
default:
OnError("Unexpected token: " + token);
return null;
case Token.KET:
if (totalInt != 0 || sym != null)
{
if (addrWidth == null || sym != null)
memOp.Offset = Constant.Create(defaultAddressWidth, totalInt);
else
memOp.Offset = X86Assembler.IntegralConstant(totalInt, addrWidth);
}
return new ParsedOperand(memOp, sym);
case Token.PLUS:
break;
case Token.MINUS:
Expect(Token.INTEGER);
totalInt -= lexer.Integer;
continue;
case Token.ID:
break;
}
ParseMemoryFactor(memOp);
}
}
public int Get16AddressingModeMask(MemoryOperand memOp)
{
int mask = (1 << memOp.Base.Number);
if (memOp.Index != RegisterStorage.None)
{
mask |= (1 << memOp.Index.Number);
}
if (mask == ((1<<Registers.bx.Number)|(1<<Registers.si.Number)))
return 0;
if (mask == ((1<<Registers.bx.Number)|(1<<Registers.di.Number)))
return 1;
if (mask == ((1<<Registers.bp.Number)|(1<<Registers.si.Number)))
return 2;
if (mask == ((1<<Registers.bp.Number)|(1<<Registers.di.Number)))
return 3;
if (mask == 1<<Registers.si.Number)
return 4;
if (mask == 1<<Registers.di.Number)
return 5;
if (mask == 1<<Registers.bp.Number)
{
mask = 6;
if (memOp.Offset == null || !memOp.Offset.IsValid)
{
mask |= 0x40;
offset = Constant.Byte(0);
}
return mask;
}
if (mask == 1<<(int) Registers.bx.Number)
return 7;
OnError(string.Format("Illegal 16-bit addressing mode: {0} ", memOp.ToString()));
return 0;
}
private void ParseMemoryFactor(MemoryOperand memOp)
{
Token token = lexer.GetToken();
RegisterStorage reg = RegisterStorage.None;
switch (token)
{
default:
OnError("unexpected token: " + token);
return;
case Token.INTEGER:
totalInt += lexer.Integer;
break;
case Token.REGISTER:
{
reg = lexer.Register;
PrimitiveType width = reg.DataType;
if (addrWidth == null)
addrWidth = width;
else if (addrWidth != width)
throw new ApplicationException("Conflicting address widths");
break;
}
case Token.ID:
{
int v;
if (symtab.Equates.TryGetValue(lexer.StringLiteral.ToLower(), out v))
{
totalInt += v;
}
else
{
sym = symtab.CreateSymbol(lexer.StringLiteral);
totalInt += unchecked((int) addrBase.Offset);
}
break;
}
}
if (lexer.PeekToken() == Token.TIMES)
{
if (reg == RegisterStorage.None)
throw new ApplicationException("Scale factor must be preceded by a register");
lexer.GetToken();
if (memOp.Index != RegisterStorage.None)
throw new ApplicationException("Scale can only be used once in an addressing form");
Expect(Token.INTEGER, "Expected an integer scale");
if (lexer.Integer != 1 && lexer.Integer != 2 && lexer.Integer != 4 && lexer.Integer != 8)
throw new ApplicationException("Only scales 1, 2, 4, and 8 are supported");
memOp.Scale = (byte) lexer.Integer;
memOp.Index = reg;
}
else if (reg != RegisterStorage.None)
{
if (memOp.Base == RegisterStorage.None)
memOp.Base = reg;
else if (memOp.Index == RegisterStorage.None)
{
memOp.Index = reg;
memOp.Scale = 1;
}
else
throw new ApplicationException("Can't have more than two registers in an addressing form");
}
}
public void ModRm16Memop()
{
MemoryOperand m;
PrimitiveType w = PrimitiveType.Word16;
ModRmBuilder mrm = new ModRmBuilder(w, null);
m = new MemoryOperand(w, Registers.bx, Registers.si, 1, Constant.Invalid);
Assert.AreEqual(0, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.bx, Registers.di, 1, Constant.Invalid);
Assert.AreEqual(1, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.bp, Registers.si, 1, Constant.Invalid);
Assert.AreEqual(2, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.bp, Registers.di, 1, Constant.Invalid);
Assert.AreEqual(3, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.si, Constant.Invalid);
Assert.AreEqual(4, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.di, Constant.Invalid);
Assert.AreEqual(5, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.bp, Constant.Invalid);
Assert.AreEqual(0x46, mrm.Get16AddressingModeMask(m));
m = new MemoryOperand(w, Registers.bx, Constant.Invalid);
Assert.AreEqual(7, mrm.Get16AddressingModeMask(m));
}
internal void EmitModRM(int reg, MemoryOperand memOp, byte b, Symbol sym)
{
Constant offset = modRm.EmitModRMPrefix(reg, memOp);
emitter.EmitByte(b);
int offsetPosition = emitter.Position;
EmitOffset(offset);
if (sym != null)
ReferToSymbol(sym, emitter.Position, offset.DataType);
}
public Expression CreateMemoryAccess(IntelInstruction instr, MemoryOperand mem, DataType dt, X86State state)
{
var exp = ImportedProcedureName(instr.Address, mem.Width, mem);
if (exp != null)
return new ProcedureConstant(arch.PointerType, exp);
Expression expr = EffectiveAddressExpression(instr, mem, state);
if (IsSegmentedAccessRequired ||
(mem.DefaultSegment != Registers.ds && mem.DefaultSegment != Registers.ss))
{
Expression seg = ReplaceCodeSegment(mem.DefaultSegment, state);
if (seg == null)
seg = AluRegister(mem.DefaultSegment);
return new SegmentedAccess(MemoryIdentifier.GlobalMemory, seg, expr, dt);
}
else
{
return new MemoryAccess(MemoryIdentifier.GlobalMemory, expr, dt);
}
}
private void RewriteLxs(RegisterStorage seg)
{
var reg = (RegisterOperand)instrCur.op1;
MemoryOperand mem = (MemoryOperand)instrCur.op2;
if (!mem.Offset.IsValid)
{
mem = new MemoryOperand(mem.Width, mem.Base, mem.Index, mem.Scale, Constant.Create(instrCur.addrWidth, 0));
}
var ass = emitter.Assign(
frame.EnsureSequence(orw.AluRegister(seg), orw.AluRegister(reg.Register),
PrimitiveType.Pointer32),
SrcOp(mem, PrimitiveType.SegPtr32));
}
private TWord GetEffectiveAddress(MemoryOperand m)
{
TWord ea = 0;
if (m.Offset.IsValid)
ea += m.Offset.ToUInt32();
if (m.Index != RegisterStorage.None)
ea += ReadRegister(m.Index) * m.Scale;
if (m.Base != null && m.Base != RegisterStorage.None)
{
ea += ReadRegister(m.Base);
}
return ea;
}
public ParsedOperand MemW(SegmentRegister seg, RegisterStorage @base, int offset)
{
var mem = new MemoryOperand(PrimitiveType.Word16);
mem.Base = @base;
mem.Offset = IntegralConstant(offset);
mem.SegOverride = seg;
return new ParsedOperand(mem);
}
