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1/* FCE Ultra - NES/Famicom Emulator
2 *
3 * Copyright notice for this file:
4 * Copyright (C) 2002 Ben Parnell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <string.h>
22
23#include "types.h"
24#include "x6502.h"
25#include "fce.h"
26#include "sound.h"
27#include "cart.h"
28
29#include "dprintf.h"
30
31#ifdef DEBUG_ASM_6502
32#include <stdio.h>
33#include <stdlib.h>
34extern uint32 PC_prev, OP_prev;
35extern uint8 dreads[4];
36extern uint32 dwrites_c[2];
37extern int dread_count_c, dwrite_count_c;
38extern int mapirq_cyc_c;
39extern void (*MapIRQHook)(int a);
40#define DummyRdMem(...)
41#else
42#define DummyRdMem RdMem
43void FP_FASTAPASS(1) (*MapIRQHook)(int a);
44#endif
45
46X6502 X;
47uint32 timestamp;
48
49#define _PC X.PC
50#define _A X.A
51#define _X X.X
52#define _Y X.Y
53#define _S X.S
54#define _P X.P
55#define _PI X.mooPI
56//#define _PZ X.PZ // unused?
57#define _DB X.DB
58#define _count X.count
59#define _tcount X.tcount
60#define _IRQlow X.IRQlow
61#define _jammed X.jammed
62
63
64static INLINE uint8 RdMem(unsigned int A)
65{
66 // notaz: try to avoid lookup of every address at least for ROM and RAM areas
67 // I've verified that if ARead[0xfff0] points to CartBR, it is always normal ROM read.
68#if 0
69 if ((A&0x8000)/* && ARead[0xfff0] == CartBR*/) {
70 return (_DB=Page[A>>11][A]);
71 }
72#endif
73#if 0 // enabling this causes 4fps slowdown. Why?
74 if ((A&0xe000) == 0) { // RAM area (always 0-0x1fff)
75 return (_DB=RAM[A&0x7FF]);
76 }
77#endif
78 _DB=ARead[A](A);
79#ifdef DEBUG_ASM_6502
80 //printf("a == %x, pc == %x\n", A, _PC);
81 if (A >= 0x2000 && A != _PC && A != _PC - 1 && A != _PC + 1) {
82 dreads[dread_count_c++] = _DB;
83 if (dread_count_c > 4) { printf("dread_count out of range\n"); exit(1); }
84 }
85#endif
86 return _DB;
87}
88
89static INLINE void WrMem(unsigned int A, uint8 V)
90{
91 //printf("w [%04x] %02x\n", A, V);
92 if ((A&0xe000) == 0) { // RAM area (always 0-0x1fff)
93 RAM[A&0x7FF] = V;
94 return;
95 }
96 BWrite[A](A,V);
97#ifdef DEBUG_ASM_6502
98 dwrites_c[dwrite_count_c++] = (A<<8)|V;
99 if (dwrite_count_c > 2) { printf("dwrite_count_c out of range\n"); exit(1); }
100#endif
101}
102
103static INLINE uint8 RdRAM(unsigned int A)
104{
105 return((_DB=RAM[A]));
106}
107
108static INLINE void WrRAM(unsigned int A, uint8 V)
109{
110 RAM[A]=V;
111}
112
113static INLINE void ADDCYC(int x)
114{
115 _tcount+=x;
116 _count-=x*48;
117 timestamp+=x;
118}
119
120void FASTAPASS(1) X6502_AddCycles_c(int x)
121{
122 ADDCYC(x);
123}
124
125static INLINE void PUSH(uint8 V)
126{
127 WrRAM(0x100+_S,V);
128 _S--;
129}
130
131static INLINE uint8 POP(void)
132{
133 _S++;
134 return(RdRAM(0x100+_S));
135}
136
137#if 0
138static uint8 ZNTable[256] = {
139 Z_FLAG,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
140 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
141 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
142 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
143 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
144 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
145 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
146 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
147 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
148 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
149 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
150 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
151 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
152 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
153 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,
154 N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG,N_FLAG
155};
156#endif
157/* Some of these operations will only make sense if you know what the flag
158 constants are. */
159//#define X_ZN(zort) _P&=~(Z_FLAG|N_FLAG);_P|=ZNTable[zort]
160//#define X_ZNT(zort) _P|=ZNTable[zort]
161#define X_ZN(zort) _P&=~(Z_FLAG|N_FLAG);if(!zort) _P|=Z_FLAG;else _P|=zort&N_FLAG
162#define X_ZNT(zort) if(!zort) _P|=Z_FLAG;else _P|=(zort&N_FLAG)
163
164/* Care must be taken if you want to turn this into a macro. Use { and }. */
165#define JR(); \
166{ \
167 uint32 tmp; \
168 int8 disp; \
169 disp=RdMem(_PC++); \
170 ADDCYC(1); \
171 tmp=_PC; \
172 _PC+=disp; \
173 if((tmp^_PC)&0x100) \
174 ADDCYC(1); \
175}
176
177#define LDA _A=x;X_ZN(_A)
178#define LDX _X=x;X_ZN(_X)
179#define LDY _Y=x;X_ZN(_Y)
180
181/* All of the freaky arithmetic operations. */
182#define AND _A&=x;X_ZN(_A)
183//#define BIT _P&=~(Z_FLAG|V_FLAG|N_FLAG);_P|=ZNTable[x&_A]&Z_FLAG;_P|=x&(V_FLAG|N_FLAG)
184#define BIT _P&=~(Z_FLAG|V_FLAG|N_FLAG);if(!(x&_A)) _P|=Z_FLAG;_P|=x&(V_FLAG|N_FLAG)
185#define EOR _A^=x;X_ZN(_A)
186#define ORA _A|=x;X_ZN(_A)
187
188#define ADC { \
189 uint32 l=_A+x+(_P&1); \
190 _P&=~(Z_FLAG|C_FLAG|N_FLAG|V_FLAG); \
191 _P|=((((_A^x)&0x80)^0x80) & ((_A^l)&0x80))>>1; \
192 _P|=(l>>8)&C_FLAG; \
193 _A=l; \
194 X_ZNT(_A); \
195 }
196#define SBC { \
197 uint32 l=_A-x-((_P&1)^1); \
198 _P&=~(Z_FLAG|C_FLAG|N_FLAG|V_FLAG); \
199 _P|=((_A^l)&(_A^x)&0x80)>>1; \
200 _P|=((l>>8)&C_FLAG)^C_FLAG; \
201 _A=l; \
202 X_ZNT(_A); \
203 }
204
205#define CMPL(a1,a2) { \
206 uint32 t=a1-a2; \
207 X_ZN(t&0xFF); \
208 _P&=~C_FLAG; \
209 _P|=((t>>8)&C_FLAG)^C_FLAG; \
210 }
211
212/* Special undocumented operation. Very similar to CMP. */
213#define AXS { \
214 uint32 t=(_A&_X)-x; \
215 X_ZN(t&0xFF); \
216 _P&=~C_FLAG; \
217 _P|=((t>>8)&C_FLAG)^C_FLAG; \
218 _X=t; \
219 }
220
221#define CMP CMPL(_A,x)
222#define CPX CMPL(_X,x)
223#define CPY CMPL(_Y,x)
224
225/* The following operations modify the byte being worked on. */
226#define DEC x--;X_ZN(x)
227#define INC x++;X_ZN(x)
228
229#define ASL _P&=~C_FLAG;_P|=x>>7;x<<=1;X_ZN(x)
230#define LSR _P&=~(C_FLAG|N_FLAG|Z_FLAG);_P|=x&1;x>>=1;X_ZNT(x)
231
232/* For undocumented instructions, maybe for other things later... */
233#define LSRA _P&=~(C_FLAG|N_FLAG|Z_FLAG);_P|=_A&1;_A>>=1;X_ZNT(_A)
234
235#define ROL { \
236 uint8 l=x>>7; \
237 x<<=1; \
238 x|=_P&C_FLAG; \
239 _P&=~(Z_FLAG|N_FLAG|C_FLAG); \
240 _P|=l; \
241 X_ZNT(x); \
242 }
243#define ROR { \
244 uint8 l=x&1; \
245 x>>=1; \
246 x|=(_P&C_FLAG)<<7; \
247 _P&=~(Z_FLAG|N_FLAG|C_FLAG); \
248 _P|=l; \
249 X_ZNT(x); \
250 }
251
252/* Icky icky thing for some undocumented instructions. Can easily be
253 broken if names of local variables are changed.
254*/
255
256/* Absolute */
257#define GetAB(target) \
258{ \
259 target=RdMem(_PC++); \
260 target|=RdMem(_PC++)<<8; \
261}
262
263/* Absolute Indexed(for reads) */
264#define GetABIRD(target, i) \
265{ \
266 unsigned int tmp; \
267 GetAB(tmp); \
268 target=tmp; \
269 target+=i; \
270 if((target^tmp)&0x100) \
271 { \
272 target&=0xFFFF; \
273 DummyRdMem(target^0x100); \
274 ADDCYC(1); \
275 } \
276}
277
278/* Absolute Indexed(for writes and rmws) */
279#define GetABIWR(target, i) \
280{ \
281 unsigned int rt; \
282 GetAB(rt); \
283 target=rt; \
284 target+=i; \
285 target&=0xFFFF; \
286 DummyRdMem((target&0x00FF)|(rt&0xFF00)); \
287}
288
289/* Zero Page */
290#define GetZP(target) \
291{ \
292 target=RdMem(_PC++); \
293}
294
295/* Zero Page Indexed */
296#define GetZPI(target,i) \
297{ \
298 target=i+RdMem(_PC++); \
299}
300
301/* Indexed Indirect */
302#define GetIX(target) \
303{ \
304 uint8 tmp; \
305 tmp=RdMem(_PC++); \
306 tmp+=_X; \
307 target=RdRAM(tmp++); \
308 target|=RdRAM(tmp)<<8; \
309}
310
311/* Indirect Indexed(for reads) */
312#define GetIYRD(target) \
313{ \
314 unsigned int rt; \
315 uint8 tmp; \
316 tmp=RdMem(_PC++); \
317 rt=RdRAM(tmp++); \
318 rt|=RdRAM(tmp)<<8; \
319 target=rt; \
320 target+=_Y; \
321 if((target^rt)&0x100) \
322 { \
323 target&=0xFFFF; \
324 DummyRdMem(target^0x100); \
325 ADDCYC(1); \
326 } \
327}
328
329/* Indirect Indexed(for writes and rmws) */
330#define GetIYWR(target) \
331{ \
332 unsigned int rt; \
333 uint8 tmp; \
334 tmp=RdMem(_PC++); \
335 rt=RdRAM(tmp++); \
336 rt|=RdRAM(tmp)<<8; \
337 target=rt; \
338 target+=_Y; \
339 DummyRdMem((target&0x00FF)|(rt&0xFF00)); \
340}
341
342/* Now come the macros to wrap up all of the above stuff addressing mode functions
343 and operation macros. Note that operation macros will always operate(redundant
344 redundant) on the variable "x".
345*/
346
347#define RMW_A(op) {uint8 x=_A; op; _A=x; break; } /* Meh... */
348#define RMW_AB(op) {unsigned int A; uint8 x; GetAB(A); x=RdMem(A); WrMem(A,x); op; WrMem(A,x); break; }
349#define RMW_ABI(reg,op) {unsigned int A; uint8 x; GetABIWR(A,reg); x=RdMem(A); WrMem(A,x); op; WrMem(A,x); break; }
350#define RMW_ABX(op) RMW_ABI(_X,op)
351#define RMW_ABY(op) RMW_ABI(_Y,op)
352#define RMW_IX(op) {unsigned int A; uint8 x; GetIX(A); x=RdMem(A); WrMem(A,x); op; WrMem(A,x); break; }
353#define RMW_IY(op) {unsigned int A; uint8 x; GetIYWR(A); x=RdMem(A); WrMem(A,x); op; WrMem(A,x); break; }
354#define RMW_ZP(op) {uint8 A; uint8 x; GetZP(A); x=RdRAM(A); op; WrRAM(A,x); break; }
355#define RMW_ZPX(op) {uint8 A; uint8 x; GetZPI(A,_X); x=RdRAM(A); op; WrRAM(A,x); break;}
356
357#define LD_IM(op) {uint8 x; x=RdMem(_PC++); op; break;}
358#define LD_ZP(op) {uint8 A; uint8 x; GetZP(A); x=RdRAM(A); op; break;}
359#define LD_ZPX(op) {uint8 A; uint8 x; GetZPI(A,_X); x=RdRAM(A); op; break;}
360#define LD_ZPY(op) {uint8 A; uint8 x; GetZPI(A,_Y); x=RdRAM(A); op; break;}
361#define LD_AB(op) {unsigned int A; uint8 x; GetAB(A); x=RdMem(A); op; break; }
362#define LD_ABI(reg,op) {unsigned int A; uint8 x; GetABIRD(A,reg); x=RdMem(A); op; break;}
363#define LD_ABX(op) LD_ABI(_X,op)
364#define LD_ABY(op) LD_ABI(_Y,op)
365#define LD_IX(op) {unsigned int A; uint8 x; GetIX(A); x=RdMem(A); op; break;}
366#define LD_IY(op) {unsigned int A; uint8 x; GetIYRD(A); x=RdMem(A); op; break;}
367
368#define ST_ZP(r) {uint8 A; GetZP(A); WrRAM(A,r); break;}
369#define ST_ZPX(r) {uint8 A; GetZPI(A,_X); WrRAM(A,r); break;}
370#define ST_ZPY(r) {uint8 A; GetZPI(A,_Y); WrRAM(A,r); break;}
371#define ST_AB(r) {unsigned int A; GetAB(A); WrMem(A,r); break;}
372#define ST_ABI(reg,r) {unsigned int A; GetABIWR(A,reg); WrMem(A,r); break; }
373#define ST_ABX(r) ST_ABI(_X,r)
374#define ST_ABY(r) ST_ABI(_Y,r)
375#define ST_IX(r) {unsigned int A; GetIX(A); WrMem(A,r); break; }
376#define ST_IY(r) {unsigned int A; GetIYWR(A); WrMem(A,r); break; }
377
378static uint8 CycTable[256] =
379{
380/*0x00*/ 7,6,2,8,3,3,5,5,3,2,2,2,4,4,6,6,
381/*0x10*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
382/*0x20*/ 6,6,2,8,3,3,5,5,4,2,2,2,4,4,6,6,
383/*0x30*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
384/*0x40*/ 6,6,2,8,3,3,5,5,3,2,2,2,3,4,6,6,
385/*0x50*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
386/*0x60*/ 6,6,2,8,3,3,5,5,4,2,2,2,5,4,6,6,
387/*0x70*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
388/*0x80*/ 2,6,2,6,3,3,3,3,2,2,2,2,4,4,4,4,
389/*0x90*/ 2,6,2,6,4,4,4,4,2,5,2,5,5,5,5,5,
390/*0xA0*/ 2,6,2,6,3,3,3,3,2,2,2,2,4,4,4,4,
391/*0xB0*/ 2,5,2,5,4,4,4,4,2,4,2,4,4,4,4,4,
392/*0xC0*/ 2,6,2,8,3,3,5,5,2,2,2,2,4,4,6,6,
393/*0xD0*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
394/*0xE0*/ 2,6,3,8,3,3,5,5,2,2,2,2,4,4,6,6,
395/*0xF0*/ 2,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,
396};
397
398void FASTAPASS(1) X6502_IRQBegin_c(int w)
399{
400 _IRQlow|=w;
401}
402
403void FASTAPASS(1) X6502_IRQEnd_c(int w)
404{
405 _IRQlow&=~w;
406}
407
408void TriggerIRQ_c(void) /* This function should probably be phased out. */
409{
410 _IRQlow|=FCEU_IQTEMP;
411}
412
413void TriggerNMINSF_c(void)
414{
415 ADDCYC(7);
416 PUSH(_PC>>8);
417 PUSH(_PC);
418 PUSH((_P&~B_FLAG)|(U_FLAG));
419 _PC=0x3800;
420}
421
422void TriggerNMI_c(void)
423{
424 _IRQlow|=FCEU_IQNMI;
425}
426
427static void TriggerNMIReal(void)
428{
429 if(!_jammed)
430 {
431 dprintf("NMI");
432 ADDCYC(7);
433 PUSH(_PC>>8);
434 PUSH(_PC);
435 _P&=~B_FLAG;
436 PUSH(_P|U_FLAG);
437 _PC=RdMem(0xFFFA);
438 _PC|=RdMem(0xFFFB)<<8;
439#ifdef DEBUG_ASM_6502
440 PC_prev = _PC;
441 OP_prev = 0x100;
442#endif
443 }
444}
445
446void TriggerIRQReal(void)
447{
448 if(!(_PI&I_FLAG) && !_jammed)
449 {
450 dprintf("IRQ");
451 ADDCYC(7);
452 PUSH(_PC>>8);
453 PUSH(_PC);
454 _P&=~B_FLAG;
455 PUSH(_P|U_FLAG);
456 _P|=I_FLAG;
457 _PC=RdMem(0xFFFE);
458 _PC|=RdMem(0xFFFF)<<8;
459#ifdef DEBUG_ASM_6502
460 PC_prev = _PC;
461 OP_prev = 0x101;
462#endif
463 }
464}
465
466void X6502_Reset_c(void)
467{
468 _PC=RdMem(0xFFFC);
469 _PC|=RdMem(0xFFFD)<<8;
470 if(FCEUGameInfo.type==GIT_NSF) _PC=0x3830;
471 _jammed=0;
472 _PI=_P=I_FLAG;
473}
474
475void X6502_Power_c(void)
476{
477 memset((void *)&X,0,sizeof(X));
478 timestamp=0;
479 X6502_Reset_c();
480}
481
482
483//int asdc = 0;
484void X6502_Run_c(void/*int32 cycles*/)
485{
486/*
487 if(PAL)
488 cycles*=15; // 15*4=60
489 else
490 cycles*=16; // 16*4=64
491
492 _count+=cycles;
493*/
494// if (_count <= 0) asdc++;
495
496 while(_count>0)
497 {
498 int32 temp;
499 uint8 b1;
500
501 if(_IRQlow)
502 {
503 if(_IRQlow&FCEU_IQNMI)
504 TriggerNMIReal();
505 else
506 TriggerIRQReal();
507
508 _IRQlow&=~(FCEU_IQTEMP|FCEU_IQNMI);
509 if(_count<=0)
510 {
511#ifdef DEBUG_ASM_6502
512 if(MapIRQHook) mapirq_cyc_c = _tcount;
513 _tcount=0;
514#endif
515 _PI=_P;
516 return; /* Should increase accuracy without a major speed hit. */
517 }
518 }
519 _PI=_P;
520 b1=RdMem(_PC);
521 ADDCYC(CycTable[b1]);
522 temp=_tcount;
523
524 temp*=48;
525
526 fhcnt-=temp;
527 if(fhcnt<=0)
528 {
529 FrameSoundUpdate();
530 fhcnt+=fhinc;
531 }
532
533 if(PCMIRQCount>0)
534 {
535 PCMIRQCount-=temp;
536 if(PCMIRQCount<=0)
537 {
538 vdis=1;
539 if((PSG[0x10]&0x80) && !(PSG[0x10]&0x40))
540 {
541 extern uint8 SIRQStat;
542 SIRQStat|=0x80;
543 X6502_IRQBegin_c(FCEU_IQDPCM);
544 }
545 }
546 }
547
548#ifdef DEBUG_ASM_6502
549 PC_prev = _PC;
550 OP_prev = b1;
551#endif
552 //printf("$%04x:$%02x\n",_PC,b1);
553 //_PC++;
554 //printf("$%02x\n",b1);
555 _PC++;
556 switch(b1)
557 {
558 #include "ops.h"
559 }
560
561 temp=_tcount; /* Gradius II (J) glitches if _tcount is not used */
562 _tcount=0;
563
564 if(MapIRQHook) {
565#ifdef DEBUG_ASM_6502
566 mapirq_cyc_c = temp;
567#endif
568 MapIRQHook(temp);
569 }
570
571#ifdef DEBUG_ASM_6502
572 _PI=_P;
573#endif
574 }
575}
576
577
ARM optimized FCE Ultra port