diff options
Diffstat (limited to 'src/code/sim86.cpp')
| -rw-r--r-- | src/code/sim86.cpp | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/src/code/sim86.cpp b/src/code/sim86.cpp index 7903fb6..e1ef6a9 100644 --- a/src/code/sim86.cpp +++ b/src/code/sim86.cpp @@ -85,7 +85,7 @@ struct operands_to_values_result s32 *Source; }; internal operands_to_values_result -OperandsToValues(s32 *Registers, +OperandsToValues(s32 *Registers, u8 *Memory, instruction_operand *DestinationOperand, instruction_operand *SourceOperand) { operands_to_values_result Result = {}; @@ -97,7 +97,19 @@ OperandsToValues(s32 *Registers, } else if(DestinationOperand->Type == Operand_Memory) { - Assert(0 && "not implemented yet."); + Result.Destination = (s32 *)(Memory + DestinationOperand->Address.Displacement); + + s32 CompleteDisplacement = DestinationOperand->Address.Displacement; + Assert(DestinationOperand->Address.Terms[0].Register.Count == DestinationOperand->Address.Terms[1].Register.Count); + + u32 Count = DestinationOperand->Address.Terms[0].Register.Index; + u32 Mask = ((u32)((-1)) >> (16 + (16 - Count*8))); + + CompleteDisplacement += (Registers[DestinationOperand->Address.Terms[0].Register.Index] & Mask) + + (Registers[DestinationOperand->Address.Terms[1].Register.Index] & Mask); + + Result.Destination = (s32 *)(Memory + CompleteDisplacement); + Assert(0); } else if(DestinationOperand->Type == Operand_Immediate) { @@ -137,6 +149,8 @@ Run8086(psize DisassemblySize, u8 *Disassembly) u32 FlagsRegister = 0; u32 IPRegister = 0; + local_persist u8 Memory[1*1024*1024*1024] = {}; + while(IPRegister < DisassemblySize) { instruction Decoded; @@ -152,14 +166,13 @@ Run8086(psize DisassemblySize, u8 *Disassembly) instruction_operand *DestinationOperand = Decoded.Operands; instruction_operand *SourceOperand = Decoded.Operands + 1; - operands_to_values_result OperandsValues = OperandsToValues(Registers, DestinationOperand, SourceOperand); + operands_to_values_result OperandsValues = OperandsToValues(Registers, Memory, DestinationOperand, SourceOperand); s32 *Destination = OperandsValues.Destination; s32 *Source = OperandsValues.Source; if(0) {} else if(Decoded.Op == Op_mov) { - Assert(DestinationOperand->Type == Operand_Register); Assert(SourceOperand->Type == Operand_Register || SourceOperand->Type == Operand_Immediate); s32 Old = *Destination; @@ -180,8 +193,11 @@ Run8086(psize DisassemblySize, u8 *Disassembly) } #if SIM86_INTERNAL - printf(" %s:0x%x->0x%x", Sim86_RegisterNameFromOperand(&DestinationOperand->Register), - Old, *Destination); + if(DestinationOperand->Type == Operand_Register) + { + printf(" %s:0x%x->0x%x", Sim86_RegisterNameFromOperand(&DestinationOperand->Register), + Old, *Destination); + } #endif } else if(Decoded.Op == Op_cmp) |