protectedmodeudecoder.java

JPC: x86 PC Hardware Emulator. 牛津大学开发的一个纯JAVA的x86系统结构硬件模拟器。

	    bytesRead += 3;
	    break;
	case 4:
	    immediate = (source.getByte() & 0xff) | ((source.getByte() << 8) & 0xff00) | ((source.getByte() << 16) & 0xff0000) | ((source.getByte() << 24) & 0xff000000);
	    bytesRead += 4;
	    break;
	case 6:
	    immediate = 0xffffffffl & ((source.getByte() & 0xff) | ((source.getByte() << 8) & 0xff00) | ((source.getByte() << 16) & 0xff0000) | ((source.getByte() << 24) & 0xff000000));
	    immediate |= ((source.getByte() & 0xffl) | ((source.getByte() << 8) & 0xff00l)) << 32;
	    bytesRead += 6;
	    break;
	default:
	    System.err.println("Immediate Longer Than 6-bytes");
	    break;
	}

	//write out input operands
	writeInputOperands(prefices, opcode, modrm, sib, displacement, immediate);

	//write out calculation
	writeOperation(prefices, opcode, modrm);

	//write out output operands
	writeOutputOperands(prefices, opcode, modrm, sib, displacement);

	//write out flags
	writeFlags(prefices, opcode, modrm);

	if (isJump(opcode, modrm))
	    return -bytesRead;
	else
	    return bytesRead;
    }
 
    private void writeOperation(int prefices, int opcode, int modrm)
    {
	switch (opcode) {
	case 0x00: //ADD Eb, Gb
	case 0x01: //ADD Ev, Gv
	case 0x02: //ADD Gb, Eb
	case 0x03: //ADD Gv, Ev
	case 0x04: //ADD AL, Ib
	case 0x05: //ADD eAX, Iv
	case 0xfc0: //XADD Eb, Gb
	case 0xfc1: working.write(ADD); break; //XADD Ev, Gv

	case 0x08: //OR  Eb, Gb
	case 0x09: //OR  Ev, Gv
	case 0x0a: //OR  Gb, Eb
	case 0x0b: //OR  Gv, Ev
	case 0x0c: //OR  AL, Ib
	case 0x0d: working.write(OR ); break; //OR  eAX, Iv

	case 0x10: //ADC Eb, Gb
	case 0x11: //ADC Ev, Gv
	case 0x12: //ADC Gb, Eb
	case 0x13: //ADC Gv, Ev
	case 0x14: //ADC AL, Ib
	case 0x15: working.write(ADC); break; //ADC eAX, Iv

	case 0x18: //SBB Eb, Gb
	case 0x19: //SBB Ev, Gv
	case 0x1a: //SBB Gb, Eb
	case 0x1b: //SBB Gv, Ev
	case 0x1c: //SBB AL, Ib
	case 0x1d: working.write(SBB); break; //SBB eAX, Iv

	case 0x20: //AND Eb, Gb
	case 0x21: //AND Ev, Gv
	case 0x22: //AND Gb, Eb
	case 0x23: //AND Gv, Ev
	case 0x24: //AND AL, Ib
	case 0x25: //AND eAX, Iv	
	case 0x84: //TEST Eb, Gb
	case 0x85: //TEST Ev, Gv
	case 0xa8: //TEST AL, Ib
	case 0xa9: working.write(AND); break; //TEST eAX, Iv

	case 0x27: working.write(DAA); break; //DAA

	case 0x28: //SUB Eb, Gb
	case 0x29: //SUB Ev, Gv
	case 0x2a: //SUB Gb, Eb
	case 0x2b: //SUB Gv, Ev
	case 0x2c: //SUB AL, Ib
	case 0x2d: //SUB eAX, Iv
	case 0x38: //CMP Eb, Gb
	case 0x39: //CMP Ev, Gv
	case 0x3a: //CMP Gb, Eb
	case 0x3b: //CMP Gv, Ev
	case 0x3c: //CMP AL, Ib
	case 0x3d: working.write(SUB); break; //CMP eAX, Iv

	case 0x2f: working.write(DAS); break; //DAS

	case 0x30: //XOR Eb, Gb
	case 0x31: //XOR Ev, Gv
	case 0x32: //XOR Gb, Eb
	case 0x33: //XOR Gv, Ev
	case 0x34: //XOR AL, Ib
	case 0x35: working.write(XOR); break; //XOR eAX, Iv

	case 0x37: working.write(AAA); break; //AAA
	case 0x3f: working.write(AAS); break; //AAS

	case 0x40: //INC eAX
	case 0x41: //INC eCX
	case 0x42: //INC eDX
	case 0x43: //INC eBX
	case 0x44: //INC eSP
	case 0x45: //INC eBP
	case 0x46: //INC eSI
	case 0x47: working.write(INC); break; //INC eDI	    

	case 0x48: //DEC eAX
	case 0x49: //DEC eCX
	case 0x4a: //DEC eDX
	case 0x4b: //DEC eBX
	case 0x4c: //DEC eSP
	case 0x4d: //DEC eBP
	case 0x4e: //DEC eSI
	case 0x4f: working.write(DEC); break; //DEC eDI

	case 0x06: //PUSH ES
	case 0x0e: //PUSH CS
	case 0x16: //PUSH SS
	case 0x1e: //PUSH DS
	case 0x50: //PUSH eAX
	case 0x51: //PUSH eCX
	case 0x52: //PUSH eDX
	case 0x53: //PUSH eBX
	case 0x54: //PUSH eSP
	case 0x55: //PUSH eBP
	case 0x56: //PUSH eSI
	case 0x57: //PUSH eDI
	case 0x68: //PUSH Iv
	case 0x6a: //PUSH Ib
	case 0xfa0: //PUSH FS
	case 0xfa8: //PUSH GS
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(PUSH_O16_A16); break;
	    case PREFICES_OPERAND:
		working.write(PUSH_O32_A16); break;
	    case PREFICES_ADDRESS:
		working.write(PUSH_O16_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(PUSH_O32_A32); break;
	    }
	    break;

	case 0x9c: //PUSHF
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(PUSHF_O16_A16); break;
	    case PREFICES_OPERAND:
		working.write(PUSHF_O32_A16); break;
	    case PREFICES_ADDRESS:
		working.write(PUSHF_O16_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(PUSHF_O32_A32); break;
	    }
	    break;

	case 0x07: //POP ES
	case 0x17: //POP SS
	case 0x1f: //POP DS
	case 0x58: //POP eAX
	case 0x59: //POP eCX
	case 0x5a: //POP eDX
	case 0x5b: //POP eBX
	case 0x5c: //POP eSP
	case 0x5d: //POP eBP
	case 0x5e: //POP eSI
	case 0x5f: //POP eDI
	case 0x8f: //POP Ev
	case 0xfa1: //POP FS
	case 0xfa9: //POP GS
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(POP_O16_A16); break;
	    case PREFICES_OPERAND:
		working.write(POP_O32_A16); break;
	    case PREFICES_ADDRESS:
		working.write(POP_O16_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(POP_O32_A32); break;
	    }
	    break;

	case 0x9d: //POPF
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(POPF_O16_A16); break;
	    case PREFICES_OPERAND:
		working.write(POPF_O32_A16); break;
	    case PREFICES_ADDRESS:
		working.write(POPF_O16_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(POPF_O32_A32); break;
	    }
	    break;

	case 0x60: //PUSHA/D
	    switch (prefices & PREFICES_OPERAND) {
	    case 0:
		working.write(PUSHAD_A16); break;
	    case PREFICES_OPERAND:
		working.write(PUSHAD_A32); break;
	    }
	    break;

	case 0x61: //POPA/D
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(POPA_A16); break;
	    case PREFICES_OPERAND:
		working.write(POPAD_A16); break;
	    case PREFICES_ADDRESS:
		working.write(POPA_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(POPAD_A32); break;
	    }
	    break;

	case 0x62: //BOUND
	    if ((prefices & PREFICES_OPERAND) != 0)
		working.write(BOUND_O32);
	    else
		working.write(BOUND_O16);
	    break;

	case 0x69: //IMUL Gv, Ev, Iv
	case 0x6b: //IMUL Gv, Ev, Ib
	case 0xfaf: //IMUL Gv, Ev
	    if ((prefices & PREFICES_OPERAND) != 0)
		working.write(IMUL_O32);
	    else
		working.write(IMUL_O16);
	    break;

	case 0x6c: //INSB
	    if ((prefices & PREFICES_REP) != 0) {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(REP_INSB_A32);
		else
		    working.write(REP_INSB_A16);
	    } else {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(INSB_A32);
		else
		    working.write(INSB_A16);
	    }
	    break;

	case 0x6d: //INSW/D
	    if ((prefices & PREFICES_OPERAND) != 0) {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_INSD_A32);
		    else
			working.write(REP_INSD_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(INSD_A32);
		    else
			working.write(INSD_A16);
		}
	    } else {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_INSW_A32);
		    else
			working.write(REP_INSW_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(INSW_A32);
		    else
			working.write(INSW_A16);
		}
	    }
	    break;

	case 0x6e: //OUTSB
	    if ((prefices & PREFICES_REP) != 0) {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(REP_OUTSB_A32);
		else
		    working.write(REP_OUTSB_A16);
	    } else {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(OUTSB_A32);
		else
		    working.write(OUTSB_A16);
	    }
	    break;

	case 0x6f: //OUTS DX, Xv
	    if ((prefices & PREFICES_OPERAND) != 0) {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_OUTSD_A32);
		    else
			working.write(REP_OUTSD_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(OUTSD_A32);
		    else
			working.write(OUTSD_A16);
		}
	    } else {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_OUTSW_A32);
		    else
			working.write(REP_OUTSW_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(OUTSW_A32);
		    else
			working.write(OUTSW_A16);
		}
	    }
	    break;

	case 0x70: working.write(JO_O8); break;  //JC Jb
	case 0x71: working.write(JNO_O8); break; //JNC Jb
	case 0x72: working.write(JC_O8); break;  //JC Jb
	case 0x73: working.write(JNC_O8); break; //JNC Jb
	case 0x74: working.write(JZ_O8); break;  //JZ Jb
	case 0x75: working.write(JNZ_O8); break; //JNZ Jb
	case 0x76: working.write(JNA_O8); break; //JNA Jb
	case 0x77: working.write(JA_O8); break;  //JA Jb
	case 0x78: working.write(JS_O8); break;  //JS Jb 
	case 0x79: working.write(JNS_O8); break; //JNS Jb
	case 0x7a: working.write(JP_O8); break;  //JP Jb 
	case 0x7b: working.write(JNP_O8); break; //JNP Jb
	case 0x7c: working.write(JL_O8); break;  //JL Jb 
	case 0x7d: working.write(JNL_O8); break; //JNL Jb
	case 0x7e: working.write(JNG_O8); break;  //JNG Jb 
	case 0x7f: working.write(JG_O8); break; //JG Jb

	case 0x80: //IMM GP1 Eb, Ib
	case 0x81: //IMM GP1 Ev, Iv
	case 0x82: //IMM GP1 Eb, Ib
	case 0x83: //IMM GP1 Ev, Ib (will have been sign extended to short/int)
	    switch (modrm & 0x38) {
	    case 0x00:
		working.write(ADD); break;
	    case 0x08:
		working.write(OR); break;
	    case 0x10:
		working.write(ADC); break;
	    case 0x18:
		working.write(SBB); break;
	    case 0x20:
		working.write(AND); break;
	    case 0x28:
	    case 0x38: //CMP
		working.write(SUB); break;
	    case 0x30:
		working.write(XOR); break;
	    }
	    break;

	case 0x98: //CBW/CWDE
	    if ((prefices & PREFICES_OPERAND) != 0) {
		working.write(LOAD0_AX);
		working.write(SIGN_EXTEND_16_32);
		working.write(STORE0_EAX);
	    } else {
		working.write(LOAD0_AL);
		working.write(SIGN_EXTEND_8_16);
		working.write(STORE0_AX);
	    }
	    break;

	case 0x99:
	    if ((prefices & PREFICES_OPERAND) != 0)
		working.write(CDQ);
	    else
		working.write(CWD);
	    break;

	case 0x9a: //CALLF
	    switch (prefices & (PREFICES_OPERAND | PREFICES_ADDRESS)) {
	    case 0:
		working.write(CALL_FAR_O16_A16); break;
	    case PREFICES_OPERAND:
		working.write(CALL_FAR_O32_A16); break;
	    case PREFICES_ADDRESS:
		working.write(CALL_FAR_O16_A32); break;
	    case PREFICES_ADDRESS | PREFICES_OPERAND:
		working.write(CALL_FAR_O32_A32); break;
	    }
	    break;

	case 0x9b: working.write(FWAIT); break; //FWAIT

	case 0x9e: working.write(SAHF); break;
	case 0x9f: working.write(LAHF); break;

	case 0xa4: //MOVSB
	    if ((prefices & PREFICES_REP) != 0) {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(REP_MOVSB_A32);
		else
		    working.write(REP_MOVSB_A16);
	    } else {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(MOVSB_A32);
		else
		    working.write(MOVSB_A16);
	    }
	    break;

	case 0xa5: //MOVSW/D
	    if ((prefices & PREFICES_OPERAND) != 0) {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_MOVSD_A32);
		    else
			working.write(REP_MOVSD_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(MOVSD_A32);
		    else
			working.write(MOVSD_A16);
		}
	    } else {
		if ((prefices & PREFICES_REP) != 0) {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(REP_MOVSW_A32);
		    else
			working.write(REP_MOVSW_A16);
		} else {
		    if ((prefices & PREFICES_ADDRESS) != 0)
			working.write(MOVSW_A32);
		    else
			working.write(MOVSW_A16);
		}
	    }
	    break;

	case 0xa6: //CMPSB
	    if ((prefices & PREFICES_REPE) != 0) {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(REPE_CMPSB_A32);
		else
		    working.write(REPE_CMPSB_A16);
	    } else if ((prefices & PREFICES_REPNE) != 0) {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(REPNE_CMPSB_A32);
		else
		    working.write(REPNE_CMPSB_A16);
	    } else {
		if ((prefices & PREFICES_ADDRESS) != 0)
		    working.write(CMPSB_A32);
		else