At lease CPUID instruction does not crash.

captainys · Dec 19, 2024 · a8bce69 · a8bce69
1 parent fa45a29
commit a8bce69
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diff --git a/src/cpu/i486inst.cpp b/src/cpu/i486inst.cpp
@@ -356,6 +356,7 @@ void i486DXCommon::MakeOpCodeRenumberTable(void)
 	opCodeRenumberTable[I486_OPCODE_CMPXCHG_RM_R]=I486_RENUMBER_CMPXCHG_RM_R;
 	opCodeRenumberTable[I486_OPCODE_XADD_RM8_R8]=I486_RENUMBER_XADD_RM8_R8;
 	opCodeRenumberTable[I486_OPCODE_XADD_RM_R]=I486_RENUMBER_XADD_RM_R;
+	opCodeRenumberTable[I486_OPCODE_CPUID]=I486_RENUMBER_CPUID;
 
 
 
@@ -462,6 +463,7 @@ void i486DXCommon::MakeOpCodeRenumberTable(void)
 	opCodeNeedOperandTable[I486_OPCODE_XCHG_EAX_ESI]=I486_NEEDOPERAND_NONE;
 	opCodeNeedOperandTable[I486_OPCODE_XCHG_EAX_EDI]=I486_NEEDOPERAND_NONE;
 	opCodeNeedOperandTable[I486_OPCODE_XLAT]=I486_NEEDOPERAND_NONE;
+	opCodeNeedOperandTable[I486_OPCODE_CPUID]=I486_NEEDOPERAND_NONE;
 
 
 	// RM_IMM8
@@ -3378,6 +3380,10 @@ std::string i486DXCommon::Instruction::Disassemble(const Operand &op1In,const Op
 		op2.DecodeMODR_MForRegister(operandSize,operand[0]);
 		disasm=DisassembleTypicalTwoOperands("XADD",op1,op2,cs.value,eip,symTable);
 		break;
+
+	case I486_OPCODE_CPUID:
+		disasm="CPUID";
+		break;
 	}
 
 	if(INST_PREFIX_LOCK==instPrefix)

diff --git a/src/cpu/i486inst.h b/src/cpu/i486inst.h
@@ -557,6 +557,8 @@ enum
 
 	I486_OPCODE_XADD_RM8_R8= 0x0FC0,
 	I486_OPCODE_XADD_RM_R=   0x0FC1,
+
+	I486_OPCODE_CPUID=       0x0FA2,
 };
 
 enum
@@ -1212,6 +1214,8 @@ enum
 	I486_RENUMBER_XADD_RM8_R8,
 	I486_RENUMBER_XADD_RM_R,
 
+	I486_RENUMBER_CPUID,
+
 	I486_RENUMBER_REALLY_UNDEFINED,
 
 I486_NUM_SUPPORTED_INSTRUCTIONS,

diff --git a/src/cpu/i486runinstruction.h b/src/cpu/i486runinstruction.h
@@ -8581,6 +8581,19 @@ unsigned int i486DXFidelityLayer<FIDELITY>::RunOneInstruction(Memory &mem,InOut
 		}
 		break;
 
+	case I486_RENUMBER_CPUID:
+		switch(GetEAX())
+		{
+		case 0:
+			state.NULL_and_reg32[REG_EAX]=0;
+			state.NULL_and_reg32[REG_EBX]=0x4C465359; // 'YSFL'
+			state.NULL_and_reg32[REG_EDX]=0x54484749; // 'IGHT'
+			state.NULL_and_reg32[REG_ECX]=0x4D4F432E; // '.COM'
+			break;
+		}
+		clocksPassed=1;
+		break;
+
 	case I486_RENUMBER_REALLY_UNDEFINED:
 		clocksPassed=0;
 		break;