cpu.c

wince下著名的视频播放器源码

			remember_xpos[remember_PC_curpos] = cpu2antic_ptr[xpos] + (ypos << 8);
		else
#endif
			remember_xpos[remember_PC_curpos] = xpos + (ypos << 8);
		remember_PC_curpos = (remember_PC_curpos + 1) % REMEMBER_PC_STEPS;

		if (break_addr == GET_PC() || break_ypos == ypos) {
			DO_BREAK;
		}
#endif /* MONITOR_BREAK */

#if defined(WRAP_64K) && !defined(PC_PTR)
		memory[0x10000] = memory[0];
#endif

		insn = GET_CODE_BYTE();

#ifdef MONITOR_BREAKPOINTS
		if (breakpoint_table_size > 0 && breakpoints_enabled) {
			UBYTE optype = optype6502[insn];
			int i;
			switch (optype >> 4) {
			case 1:
				addr = PEEK_CODE_WORD();
				break;
			case 2:
				addr = PEEK_CODE_BYTE();
				break;
			case 3:
				addr = PEEK_CODE_WORD() + X;
				break;
			case 4:
				addr = PEEK_CODE_WORD() + Y;
				break;
			case 5:
				addr = (UBYTE) (PEEK_CODE_BYTE() + X);
				addr = zGetWord(addr);
				break;
			case 6:
				addr = PEEK_CODE_BYTE();
				addr = zGetWord(addr) + Y;
				break;
			case 7:
				addr = (UBYTE) (PEEK_CODE_BYTE() + X);
				break;
			case 8:
				addr = (UBYTE) (PEEK_CODE_BYTE() + Y);
				break;
			/* XXX: case 13 */
			default:
				addr = 0;
				break;
			}
			for (i = 0; i < breakpoint_table_size; i++) {
				int cond;
				int value;
				if (!breakpoint_table[i].enabled)
					continue; /* skip */
				cond = breakpoint_table[i].condition;
				if (cond == BREAKPOINT_OR)
					break; /* fire */
				value = breakpoint_table[i].value;
				if (cond == BREAKPOINT_FLAG_CLEAR) {
					switch (value) {
					case N_FLAG:
						if ((N & 0x80) == 0)
							continue;
						break;
#ifndef NO_V_FLAG_VARIABLE
					case V_FLAG:
						if (V == 0)
							continue;
						break;
#endif
					case Z_FLAG:
						if (Z != 0)
							continue;
						break;
					case C_FLAG:
						if (C == 0)
							continue;
						break;
					default:
						if ((regP & value) == 0)
							continue;
						break;
					}
				}
				else if (cond == BREAKPOINT_FLAG_SET) {
					switch (value) {
					case N_FLAG:
						if ((N & 0x80) != 0)
							continue;
						break;
#ifndef NO_V_FLAG_VARIABLE
					case V_FLAG:
						if (V != 0)
							continue;
						break;
#endif
					case Z_FLAG:
						if (Z == 0)
							continue;
						break;
					case C_FLAG:
						if (C != 0)
							continue;
						break;
					default:
						if ((regP & value) != 0)
							continue;
						break;
					}
				}
				else {
					int val;
					switch (cond >> 3) {
					case BREAKPOINT_PC >> 3:
						val = GET_PC() - 1;
						break;
					case BREAKPOINT_A >> 3:
						val = A;
						break;
					case BREAKPOINT_X >> 3:
						val = X;
						break;
					case BREAKPOINT_Y >> 3:
						val = Y;
						break;
					case BREAKPOINT_S >> 3:
						val = S;
						break;
					case BREAKPOINT_READ >> 3:
						if ((optype & 4) == 0)
							goto cond_failed;
						val = addr;
						break;
					case BREAKPOINT_WRITE >> 3:
						if ((optype & 8) == 0)
							goto cond_failed;
						val = addr;
						break;
					case BREAKPOINT_ACCESS >> 3:
						if ((optype & 12) == 0)
							goto cond_failed;
						val = addr;
						break;
					default:
						/* shouldn't happen */
						continue;
					}
					if ((cond & BREAKPOINT_LESS) != 0 && val < value)
						continue;
					if ((cond & BREAKPOINT_EQUAL) != 0 && val == value)
						continue;
					if ((cond & BREAKPOINT_GREATER) != 0 && val > value)
						continue;
				cond_failed:
					;
				}
				/* a condition failed */
				/* quickly skip AND-connected conditions */
				do {
					if (++i >= breakpoint_table_size)
						goto no_breakpoint;
				} while (breakpoint_table[i].condition != BREAKPOINT_OR || !breakpoint_table[i].enabled);
			}
			/* fire breakpoint */
			PC--;
			DO_BREAK;
			goto breakpoint_return;
		no_breakpoint:
			;
		}
#endif /* MONITOR_BREAKPOINTS */

#ifndef CYCLES_PER_OPCODE
		xpos += cycles[insn];
#endif

#ifdef MONITOR_PROFILE
		instruction_count[insn]++;
#endif

#ifdef PREFETCH_CODE
		addr = PEEK_CODE_WORD();
#endif

#ifdef NO_GOTO
		switch (insn) {
#else
		goto *opcode[insn];
#endif

	OPCODE(00)				/* BRK */
#ifdef MONITOR_BREAK
		if (break_brk) {
			DO_BREAK;
		}
		else
#endif
		{
			PC++;
			PHPC;
			PHPB1;
			SetI;
			SET_PC(dGetWordAligned(0xfffe));
			INC_RET_NESTING;
		}
		DONE

	OPCODE(01)				/* ORA (ab,x) */
		INDIRECT_X;
		ORA(GetByte(addr));
		DONE

	OPCODE(03)				/* ASO (ab,x) [unofficial - ASL then ORA with Acc] */
		INDIRECT_X;

	aso:
		RMW_GetByte(data, addr);
		C = (data & 0x80) ? 1 : 0;
		data <<= 1;
		PutByte(addr, data);
		Z = N = A |= data;
		DONE

	OPCODE_ALIAS(04)		/* NOP ab [unofficial - skip byte] */
	OPCODE_ALIAS(44)
	OPCODE(64)
		PC++;
		DONE

	OPCODE_ALIAS(14)		/* NOP ab,x [unofficial - skip byte] */
	OPCODE_ALIAS(34)
	OPCODE_ALIAS(54)
	OPCODE_ALIAS(74)
	OPCODE_ALIAS(d4)
	OPCODE(f4)
		PC++;
		DONE

	OPCODE_ALIAS(80)		/* NOP #ab [unofficial - skip byte] */
	OPCODE_ALIAS(82)
	OPCODE_ALIAS(89)
	OPCODE_ALIAS(c2)
	OPCODE(e2)
		PC++;
		DONE

	OPCODE(05)				/* ORA ab */
		ZPAGE;
		ORA(dGetByte(addr));
		DONE

	OPCODE(06)				/* ASL ab */
		ZPAGE;
		data = dGetByte(addr);
		C = (data & 0x80) ? 1 : 0;
		Z = N = data << 1;
		dPutByte(addr, Z);
		DONE

	OPCODE(07)				/* ASO ab [unofficial - ASL then ORA with Acc] */
		ZPAGE;

	aso_zpage:
		data = dGetByte(addr);
		C = (data & 0x80) ? 1 : 0;
		data <<= 1;
		dPutByte(addr, data);
		Z = N = A |= data;
		DONE

	OPCODE(08)				/* PHP */
		PHPB1;
		DONE

	OPCODE(09)				/* ORA #ab */
		ORA(IMMEDIATE);
		DONE

	OPCODE(0a)				/* ASL */
		C = (A & 0x80) ? 1 : 0;
		Z = N = A <<= 1;
		DONE

	OPCODE_ALIAS(0b)		/* ANC #ab [unofficial - AND then copy N to C (Fox) */
	OPCODE(2b)
		AND(IMMEDIATE);
		C = N >= 0x80;
		DONE

	OPCODE(0c)				/* NOP abcd [unofficial - skip word] */
		PC += 2;
		DONE

	OPCODE(0d)				/* ORA abcd */
		ABSOLUTE;
		ORA(GetByte(addr));
		DONE

	OPCODE(0e)				/* ASL abcd */
		ABSOLUTE;
		RMW_GetByte(data, addr);
		C = (data & 0x80) ? 1 : 0;
		Z = N = data << 1;
		PutByte(addr, Z);
		DONE

	OPCODE(0f)				/* ASO abcd [unofficial - ASL then ORA with Acc] */
		ABSOLUTE;
		goto aso;

	OPCODE(10)				/* BPL */
		BRANCH(!(N & 0x80))

	OPCODE(11)				/* ORA (ab),y */
		INDIRECT_Y;
		NCYCLES_Y;
		ORA(GetByte(addr));
		DONE

	OPCODE(13)				/* ASO (ab),y [unofficial - ASL then ORA with Acc] */
		INDIRECT_Y;
		goto aso;

	OPCODE(15)				/* ORA ab,x */
		ZPAGE_X;
		ORA(dGetByte(addr));
		DONE

	OPCODE(16)				/* ASL ab,x */
		ZPAGE_X;
		data = dGetByte(addr);
		C = (data & 0x80) ? 1 : 0;
		Z = N = data << 1;
		dPutByte(addr, Z);
		DONE

	OPCODE(17)				/* ASO ab,x [unofficial - ASL then ORA with Acc] */
		ZPAGE_X;
		goto aso_zpage;

	OPCODE(18)				/* CLC */
		C = 0;
		DONE

	OPCODE(19)				/* ORA abcd,y */
		ABSOLUTE_Y;
		NCYCLES_Y;
		ORA(GetByte(addr));
		DONE

	OPCODE(1b)				/* ASO abcd,y [unofficial - ASL then ORA with Acc] */
		ABSOLUTE_Y;
		goto aso;

	OPCODE_ALIAS(1c)		/* NOP abcd,x [unofficial - skip word] */
	OPCODE_ALIAS(3c)
	OPCODE_ALIAS(5c)
	OPCODE_ALIAS(7c)
	OPCODE_ALIAS(dc)
	OPCODE(fc)
		if (OP_BYTE + X >= 0x100)
			xpos++;
		PC += 2;
		DONE

	OPCODE(1d)				/* ORA abcd,x */
		ABSOLUTE_X;
		NCYCLES_X;
		ORA(GetByte(addr));
		DONE

	OPCODE(1e)				/* ASL abcd,x */
		ABSOLUTE_X;
		RMW_GetByte(data, addr);
		C = (data & 0x80) ? 1 : 0;
		Z = N = data << 1;
		PutByte(addr, Z);
		DONE

	OPCODE(1f)				/* ASO abcd,x [unofficial - ASL then ORA with Acc] */
		ABSOLUTE_X;
		goto aso;

	OPCODE(20)				/* JSR abcd */
		{
			UWORD retaddr = GET_PC() + 1;
#ifdef MONITOR_BREAK
			remember_JMP[remember_jmp_curpos] = GET_PC() - 1;
			remember_jmp_curpos = (remember_jmp_curpos + 1) % REMEMBER_JMP_STEPS;
			ret_nesting++;
#endif
			PHW(retaddr);
		}
		SET_PC(OP_WORD);
		DONE

	OPCODE(21)				/* AND (ab,x) */
		INDIRECT_X;
		AND(GetByte(addr));
		DONE

	OPCODE(23)				/* RLA (ab,x) [unofficial - ROL Mem, then AND with A] */
		INDIRECT_X;

	rla:
		RMW_GetByte(data, addr);
		if (C) {
			C = (data & 0x80) ? 1 : 0;
			data = (data << 1) + 1;
		}
		else {
			C = (data & 0x80) ? 1 : 0;
			data = (data << 1);
		}
		PutByte(addr, data);
		Z = N = A &= data;
		DONE

	OPCODE(24)				/* BIT ab */
		ZPAGE;
		N = dGetByte(addr);
#ifndef NO_V_FLAG_VARIABLE
		V = N & 0x40;
#else
		regP = (regP & 0xbf) + (N & 0x40);
#endif
		Z = (A & N);
		DONE

	OPCODE(25)				/* AND ab */
		ZPAGE;
		AND(dGetByte(addr));
		DONE

	OPCODE(26)				/* ROL ab */
		ZPAGE;
		data = dGetByte(addr);
		Z = N = (data << 1) + C;
		C = (data & 0x80) ? 1 : 0;
		dPutByte(addr, Z);
		DONE

	OPCODE(27)				/* RLA ab [unofficial - ROL Mem, then AND with A] */
		ZPAGE;

	rla_zpage:
		data = dGetByte(addr);
		if (C) {
			C = (data & 0x80) ? 1 : 0;
			data = (data << 1) + 1;
		}
		else {
			C = (data & 0x80) ? 1 : 0;
			data = (data << 1);
		}
		dPutByte(addr, data);
		Z = N = A &= data;
		DONE

	OPCODE(28)				/* PLP */
		PLP;
		CPUCHECKIRQ;
		DONE

	OPCODE(29)				/* AND #ab */
		AND(IMMEDIATE);
		DONE

	OPCODE(2a)				/* ROL */
		Z = N = (A << 1) + C;
		C = (A & 0x80) ? 1 : 0;
		A = Z;
		DONE

	OPCODE(2c)				/* BIT abcd */
		ABSOLUTE;
		N = GetByte(addr);
#ifndef NO_V_FLAG_VARIABLE
		V = N & 0x40;
#else
		regP = (regP & 0xbf) + (N & 0x40);
#endif
		Z = (A & N);
		DONE

	OPCODE(2d)				/* AND abcd */
		ABSOLUTE;
		AND(GetByte(addr));
		DONE

	OPCODE(2e)				/* ROL abcd */
		ABSOLUTE;
		RMW_GetByte(data, addr);
		Z = N = (data << 1) + C;
		C = (data & 0x80) ? 1 : 0;
		PutByte(addr, Z);
		DONE

	OPCODE(2f)				/* RLA abcd [unofficial - ROL Mem, then AND with A] */
		ABSOLUTE;
		goto rla;

	OPCODE(30)				/* BMI */
		BRANCH(N & 0x80)

	OPCODE(31)				/* AND (ab),y */
		INDIRECT_Y;
		NCYCLES_Y;
		AND(GetByte(addr));
		DONE

	OPCODE(33)				/* RLA (ab),y [unofficial - ROL Mem, then AND with A] */
		INDIRECT_Y;
		goto rla;

	OPCODE(35)				/* AND ab,x */
		ZPAGE_X;
		AND(dGetByte(addr));
		DONE

	OPCODE(36)				/* ROL ab,x */
		ZPAGE_X;
		data = dGetByte(addr);
		Z = N = (data << 1) + C;
		C = (data & 0x80) ? 1 : 0;
		dPutByte(addr, Z);
		DONE

	OPCODE(37)				/* RLA ab,x [unofficial - ROL Mem, then AND with A] */
		ZPAGE_X;
		goto rla_zpage;

	OPCODE(38)				/* SEC */
		C = 1;
		DONE

	OPCODE(39)				/* AND abcd,y */
		ABSOLUTE_Y;
		NCYCLES_Y;
		AND(GetByte(addr));
		DONE

	OPCODE(3b)				/* RLA abcd,y [unofficial - ROL Mem, then AND with A] */
		ABSOLUTE_Y;
		goto rla;

	OPCODE(3d)				/* AND abcd,x */
		ABSOLUTE_X;
		NCYCLES_X;
		AND(GetByte(addr));
		DONE

	OPCODE(3e)				/* ROL abcd,x */
		ABSOLUTE_X;
		RMW_GetByte(data, addr);
		Z = N = (data << 1) + C;
		C = (data & 0x80) ? 1 : 0;
		PutByte(addr, Z);
		DONE

	OPCODE(3f)				/* RLA abcd,x [unofficial - ROL Mem, then AND with A] */
		ABSOLUTE_X;
		goto rla;

	OPCODE(40)				/* RTI */
		PLP;
		data = PL;
		SET_PC((PL << 8) + data);
		CPUCHECKIRQ;
#ifdef MONITOR_BREAK
		if (break_ret && --ret_nesting <= 0)
			break_step = TRUE;
#endif
		DONE

	OPCODE(41)				/* EOR (ab,x) */
		INDIRECT_X;
		EOR(GetByte(addr));
		DONE

	OPCODE(43)				/* LSE (ab,x) [unofficial - LSR then EOR result with A] */
		INDIRECT_X;

	lse:
		RMW_GetByte(data, addr);
		C = data & 1;
		data >>= 1;
		PutByte(addr, data);
		Z = N = A ^= data;
		DONE

	OPCODE(45)				/* EOR ab */
		ZPAGE;
		EOR(dGetByte(addr));
		DONE