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cc68a136 1\r
2// Dave's Disa 68000 Disassembler\r
3#ifndef __GNUC__\r
4#pragma warning(disable:4115)\r
5#endif\r
6#include <stdio.h>\r
7#include <string.h>\r
8#include "Disa.h"\r
9\r
10unsigned int DisaPc=0;\r
11char *DisaText=NULL; // Text buffer to write in\r
12static char Tasm[]="bwl?";\r
13static char Comment[64]="";\r
8ab3e3c1 14unsigned short (*DisaWord)(unsigned int a)=NULL;\r
cc68a136 15\r
16static unsigned int DisaLong(unsigned int a)\r
17{\r
18 unsigned int d=0;\r
19 if (DisaWord==NULL) return d;\r
20\r
21 d= DisaWord(a)<<16;\r
22 d|=DisaWord(a+2)&0xffff;\r
23 return d;\r
24}\r
25\r
26// Get text version of the effective address\r
27int DisaGetEa(char *t,int ea,int size)\r
28{\r
29 ea&=0x3f; t[0]=0;\r
30 if ((ea&0x38)==0x00) { sprintf(t,"d%d",ea ); return 0; } // 000rrr\r
31 if ((ea&0x38)==0x08) { sprintf(t,"a%d",ea&7); return 0; } // 001rrr\r
32 if ((ea&0x38)==0x10) { sprintf(t,"(a%d)",ea&7); return 0; } // 010rrr\r
33 if ((ea&0x38)==0x18) { sprintf(t,"(a%d)+",ea&7); return 0; } // 011rrr\r
34 if ((ea&0x38)==0x20) { sprintf(t,"-(a%d)",ea&7); return 0; } // 100rrr\r
35 if ((ea&0x38)==0x28) { sprintf(t,"($%x,a%d)",DisaWord(DisaPc)&0xffff,ea&7); DisaPc+=2; return 0; } // 101rrr\r
36\r
37 if ((ea&0x38)==0x30)\r
38 {\r
39 // 110nnn - An + Disp + D/An\r
40 int areg=0,ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
41 ext=DisaWord(DisaPc)&0xffff;\r
85a36a57 42\r
cc68a136 43 areg=ea&7;\r
44 off=ext&0xff; da =ext&0x8000?'a':'d';\r
45 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
46 scale=1<<((ext>>9)&3);\r
47\r
48 if (scale<2) sprintf(t,"($%x,a%d,%c%d.%c)", off,areg,da,reg,wol);\r
49 else sprintf(t,"($%x,a%d,%c%d.%c*%d)",off,areg,da,reg,wol,scale); // 68020\r
50\r
51 DisaPc+=2;\r
52 return 0;\r
53 }\r
54\r
55 if (ea==0x38) { sprintf(t,"$%x.w",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0; } // 111000 - Absolute short\r
56 if (ea==0x39) { sprintf(t,"$%x.l",DisaLong(DisaPc)); DisaPc+=4; return 0; } // 111001 - Absolute long\r
57\r
58 if (ea==0x3a)\r
59 {\r
60 // 111010 - PC Relative\r
61 int ext=DisaWord(DisaPc)&0xffff;\r
62 sprintf(t,"($%x,pc)",ext);\r
63 sprintf(Comment,"; =%x",DisaPc+(short)ext); // Comment where pc+ext is\r
64 DisaPc+=2;\r
65 return 0;\r
66 }\r
67\r
68 if (ea==0x3b)\r
69 {\r
70 // 111011 - PC Relative + D/An\r
71 int ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
72 ext=DisaWord(DisaPc)&0xffff;\r
85a36a57 73\r
cc68a136 74 off=ext&0xff; da =ext&0x8000?'a':'d';\r
75 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
76 scale=1<<((ext>>9)&3);\r
77\r
78 if (scale<2) sprintf(t,"($%x,pc,%c%d.%c)", off,da,reg,wol);\r
79 else sprintf(t,"($%x,pc,%c%d.%c*%d)",off,da,reg,wol,scale); // 68020\r
80\r
81 sprintf(Comment,"; =%x",DisaPc+(char)off); // Comment where pc+ext is\r
82 DisaPc+=2;\r
83 return 0;\r
84 }\r
85\r
86 if (ea==0x3c)\r
87 {\r
88 // 111100 - Immediate\r
89 switch (size)\r
90 {\r
91 case 0: sprintf(t,"#$%x",DisaWord(DisaPc)&0x00ff); DisaPc+=2; return 0;\r
92 case 1: sprintf(t,"#$%x",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0;\r
93 case 2: sprintf(t,"#$%x",DisaLong(DisaPc) ); DisaPc+=4; return 0;\r
94 }\r
95 return 1;\r
96 }\r
97\r
98// Unknown effective address\r
99 sprintf(t,"ea=(%d%d%d %d%d%d)",\r
100 (ea>>5)&1,(ea>>4)&1,(ea>>3)&1,\r
101 (ea>>2)&1,(ea>>1)&1, ea &1);\r
102 return 1;\r
103}\r
104\r
105static void GetOffset(char *text)\r
106{\r
107 int off=(short)DisaWord(DisaPc); DisaPc+=2;\r
108\r
109 if (off<0) sprintf(text,"-$%x",-off);\r
110 else sprintf(text,"$%x", off);\r
111}\r
112\r
113// ================ Opcodes 0x0000+ ================\r
114static int DisaArithImm(int op)\r
115{\r
116 // Or/And/Sub/Add/Eor/Cmp Immediate 0000ttt0 xxDDDddd (tt=type, xx=size extension, DDDddd=Dest ea)\r
117 int dea=0;\r
118 char seat[64]="",deat[64]="";\r
119 int type=0,size=0;\r
120 char *arith[8]={"or","and","sub","add","?","eor","cmp","?"};\r
121\r
122 type=(op>>9)&7; if (type==4 || type>=7) return 1;\r
123 size=(op>>6)&3; if (size>=3) return 1;\r
124 dea=op&0x3f; if (dea==0x3c) return 1;\r
125\r
126 DisaGetEa(seat,0x3c,size);\r
127 DisaGetEa(deat,dea, size);\r
128\r
129 sprintf(DisaText,"%si.%c %s, %s",arith[type],Tasm[size],seat,deat);\r
130 return 0;\r
131}\r
132\r
133// ================ Opcodes 0x0108+ ================\r
134static int DisaMovep(int op)\r
135{\r
136 // movep.x (Aa),Dn - 0000nnn1 dx001aaa nn\r
137 int dn=0,dir=0,size=0,an=0;\r
138 char offset[32]="";\r
139\r
140 dn =(op>>9)&7;\r
141 dir =(op>>7)&1;\r
142 size=(op>>6)&1; size++;\r
143 an = op &7;\r
144\r
145 GetOffset(offset);\r
146 if (dir) sprintf(DisaText,"movep.%c d%d, (%s,a%d)",Tasm[size],dn,offset,an);\r
147 else sprintf(DisaText,"movep.%c (%s,a%d), d%d",Tasm[size],offset,an,dn);\r
148\r
149 return 0;\r
150}\r
151\r
152// ================ Opcodes 0x007c+ ================\r
153static int DisaArithSr(int op)\r
154{\r
155 // Ori/Andi/Eori $nnnn,sr 0000t0tx 0s111100\r
156 char *opcode[6]={"ori","andi","","","","eori"};\r
157 char seat[64]="";\r
158 int type=0,size=0;\r
159\r
160 type=(op>>9)&5;\r
161 size=(op>>6)&1;\r
162\r
163 DisaGetEa(seat,0x3c,size);\r
164 sprintf(DisaText,"%s.%c %s, %s", opcode[type], Tasm[size], seat, size?"sr":"ccr");\r
165\r
166 return 0;\r
167}\r
168\r
169// ================ Opcodes 0x0100+ ================\r
170static int DisaBtstReg(int op)\r
171{\r
172 // Btst/Bchg/Bclr/Bset 0000nnn1 tteeeeee (nn=reg number, eeeeee=Dest ea)\r
173 int type=0;\r
174 int sea=0,dea=0;\r
175 char seat[64]="",deat[64]="";\r
176 char *opcode[4]={"btst","bchg","bclr","bset"};\r
177\r
178 sea =(op>>9)&7;\r
179 type=(op>>6)&3;\r
180 dea= op&0x3f;\r
181\r
182 if ((dea&0x38)==0x08) return 1; // movep\r
183 DisaGetEa(seat,sea,0);\r
184 DisaGetEa(deat,dea,0);\r
185\r
186 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
187 return 0;\r
188}\r
189\r
190// ================ Opcodes 0x0800+ ================\r
191static int DisaBtstImm(int op)\r
192{\r
193 // Btst/Bchg/Bclr/Bset 00001000 tteeeeee 00 nn (eeeeee=ea, nn=bit number)\r
194 int type=0;\r
195 char seat[64]="",deat[64]="";\r
196 char *opcode[4]={"btst","bchg","bclr","bset"};\r
197\r
198 type=(op>>6)&3;\r
199 DisaGetEa(seat, 0x3c,0);\r
200 DisaGetEa(deat,op&0x3f,0);\r
201\r
202 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
203 return 0;\r
204}\r
205\r
206// ================ Opcodes 0x1000+ ================\r
207static int DisaMove(int op)\r
208{\r
209 // Move 00xxdddD DDssssss (xx=size extension, ssssss=Source EA, DDDddd=Dest ea)\r
210 int sea=0,dea=0;\r
211 char inst[64]="",seat[64]="",deat[64]="";\r
212 char *movea="";\r
213 int size=0;\r
214\r
215 if ((op&0x01c0)==0x0040) movea="a"; // See if it's a movea opcode\r
216\r
217 // Find size extension\r
218 switch (op&0x3000)\r
219 {\r
220 case 0x1000: size=0; break;\r
221 case 0x3000: size=1; break;\r
222 case 0x2000: size=2; break;\r
223 default: return 1;\r
224 }\r
225\r
226 sea = op&0x003f;\r
227 DisaGetEa(seat,sea,size);\r
85a36a57 228\r
cc68a136 229 dea =(op&0x01c0)>>3;\r
230 dea|=(op&0x0e00)>>9;\r
231 DisaGetEa(deat,dea,size);\r
232\r
233 sprintf(inst,"move%s.%c",movea,Tasm[size]);\r
234 sprintf(DisaText,"%s %s, %s",inst,seat,deat);\r
235 return 0;\r
236}\r
237\r
238// ================ Opcodes 0x4000+ ================\r
239static int DisaNeg(int op)\r
240{\r
241 // 01000tt0 xxeeeeee (tt=negx/clr/neg/not, xx=size, eeeeee=EA)\r
242 char eat[64]="";\r
243 int type=0,size=0;\r
244 char *opcode[4]={"negx","clr","neg","not"};\r
245\r
246 type=(op>>9)&3;\r
247 size=(op>>6)&3; if (size>=3) return 1;\r
248 DisaGetEa(eat,op&0x3f,size);\r
249\r
250 sprintf(DisaText,"%s.%c %s",opcode[type],Tasm[size],eat);\r
251 return 0;\r
252}\r
253\r
254// ================ Opcodes 0x40c0+ ================\r
255static int DisaMoveSr(int op)\r
256{\r
257 // 01000tt0 11eeeeee (tt=type, xx=size, eeeeee=EA)\r
258 int type=0,ea=0;\r
259 char eat[64]="";\r
260\r
261 type=(op>>9)&3;\r
262 ea=op&0x3f;\r
263 DisaGetEa(eat,ea,1);\r
264\r
265 switch (type)\r
266 {\r
267 default: sprintf(DisaText,"move sr, %s", eat); break;\r
268 case 1: sprintf(DisaText,"move ccr, %s",eat); break;\r
269 case 2: sprintf(DisaText,"move %s, ccr",eat); break;\r
270 case 3: sprintf(DisaText,"move %s, sr", eat); break;\r
271 }\r
272 return 0;\r
273}\r
274\r
0e11c502 275static int OpChk(int op)\r
85a36a57 276{\r
277 int sea=0,dea=0;\r
278 char seat[64]="",deat[64]="";\r
279\r
280 sea=op&0x003f;\r
281 DisaGetEa(seat,sea,0);\r
282\r
283 dea=(op>>9)&7; dea|=8;\r
284 DisaGetEa(deat,dea,2);\r
285\r
286 sprintf(DisaText,"chk %s, %s",seat,deat);\r
287 return 0;\r
288}\r
289\r
cc68a136 290// ================ Opcodes 0x41c0+ ================\r
291static int DisaLea(int op)\r
292{\r
293 // Lea 0100nnn1 11eeeeee (eeeeee=ea)\r
294 int sea=0,dea=0;\r
295 char seat[64]="",deat[64]="";\r
296\r
297 sea=op&0x003f;\r
298 DisaGetEa(seat,sea,0);\r
299\r
300 dea=(op>>9)&7; dea|=8;\r
301 DisaGetEa(deat,dea,2);\r
302\r
303 sprintf(DisaText,"lea %s, %s",seat,deat);\r
304 return 0;\r
305}\r
306\r
307static int MakeRegList(char *list,int mask,int ea)\r
308{\r
309 int reverse=0,i=0,low=0,len=0;\r
310\r
311 if ((ea&0x38)==0x20) reverse=1; // -(An), bitfield is reversed\r
312\r
313 mask&=0xffff; list[0]=0;\r
314\r
315 for (i=0;i<17;i++)\r
316 {\r
317 int bit=0;\r
85a36a57 318\r
cc68a136 319 // Mask off bit i:\r
320 if (reverse) bit=0x8000>>i; else bit=1<<i;\r
321 bit&=mask;\r
322\r
323 if (bit==0 || i==8)\r
324 {\r
325 // low to i-1 are a continuous section, add it:\r
326 char add[16]="";\r
327 int ad=low&8?'a':'d';\r
328 if (low==i-1) sprintf(add,"%c%d/", ad,low&7);\r
329 if (low< i-1) sprintf(add,"%c%d-%c%d/",ad,low&7, ad,(i-1)&7);\r
330 strcat(list,add);\r
331\r
332 low=i; // Next section\r
333 }\r
334\r
335 if (bit==0) low=i+1;\r
336 }\r
337\r
338 // Knock off trailing '/'\r
339 len=strlen(list);\r
85a36a57 340 if (len>0) if (list[len-1]=='/') list[len-1]=0;\r
341 return 0;\r
342}\r
343\r
344// ================ Opcodes 0x4800+ ================\r
345static int DisaNbcd(int op)\r
346{\r
347 // Nbcd 01001000 00eeeeee (eeeeee=ea)\r
348 int ea=0;\r
349 char eat[64]="";\r
350\r
351 ea=op&0x003f;\r
352 DisaGetEa(eat,ea,0);\r
353\r
354 sprintf(DisaText,"nbcd %s",eat);\r
cc68a136 355 return 0;\r
356}\r
357\r
358// ================ Opcodes 0x4840+ ================\r
359static int DisaSwap(int op)\r
360{\r
361 // Swap, 01001000 01000nnn swap Dn\r
362 sprintf(DisaText,"swap d%d",op&7);\r
363 return 0;\r
364}\r
365\r
366// ================ Opcodes 0x4850+ ================\r
367static int DisaPea(int op)\r
368{\r
85a36a57 369 // Pea 01001000 01eeeeee (eeeeee=ea) pea\r
cc68a136 370 int ea=0;\r
371 char eat[64]="";\r
372\r
373 ea=op&0x003f; if (ea<0x10) return 1; // swap opcode\r
374 DisaGetEa(eat,ea,2);\r
375\r
376 sprintf(DisaText,"pea %s",eat);\r
377 return 0;\r
378}\r
379\r
380// ================ Opcodes 0x4880+ ================\r
381static int DisaExt(int op)\r
382{\r
383 // Ext 01001000 1x000nnn (x=size, eeeeee=EA)\r
384 char eat[64]="";\r
385 int size=0;\r
386\r
387 size=(op>>6)&1; size++;\r
388 DisaGetEa(eat,op&0x3f,size);\r
389\r
390 sprintf(DisaText,"ext.%c %s",Tasm[size],eat);\r
391 return 0;\r
392}\r
393\r
394// ================ Opcodes 0x4890+ ================\r
395static int DisaMovem(int op)\r
396{\r
397 // Movem 01001d00 1xeeeeee regmask d=direction, x=size, eeeeee=EA\r
398 int dir=0,size=0;\r
399 int ea=0,mask=0;\r
400 char list[64]="",eat[64]="";\r
401\r
402 dir=(op>>10)&1;\r
403 size=((op>>6)&1)+1;\r
404 ea=op&0x3f; if (ea<0x10) return 1; // ext opcode\r
405\r
406 mask=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
407\r
408 MakeRegList(list,mask,ea); // Turn register mask into text\r
409 DisaGetEa(eat,ea,size);\r
410\r
411 if (dir) sprintf(DisaText,"movem.%c %s, %s",Tasm[size],eat,list);\r
412 else sprintf(DisaText,"movem.%c %s, %s",Tasm[size],list,eat);\r
413 return 0;\r
414}\r
415\r
416// ================ Opcodes 0x4e40+ ================\r
417static int DisaTrap(int op)\r
418{\r
419 sprintf(DisaText,"trap #%d",op&0xf);\r
420 return 0;\r
421}\r
422\r
423// ================ Opcodes 0x4e50+ ================\r
424static int DisaLink(int op)\r
425{\r
426 // Link opcode, 01001110 01010nnn dd link An,#offset\r
427 char eat[64]="";\r
428 char offset[32]="";\r
429\r
430 DisaGetEa(eat,(op&7)|8,0);\r
431 GetOffset(offset);\r
432\r
433 sprintf(DisaText,"link %s,#%s",eat,offset);\r
434\r
435 return 0;\r
436}\r
437\r
438// ================ Opcodes 0x4e58+ ================\r
439static int DisaUnlk(int op)\r
440{\r
441 // Link opcode, 01001110 01011nnn dd unlk An\r
442 char eat[64]="";\r
443\r
444 DisaGetEa(eat,(op&7)|8,0);\r
445 sprintf(DisaText,"unlk %s",eat);\r
446\r
447 return 0;\r
448}\r
449\r
450// ================ Opcodes 0x4e60+ ================\r
451static int DisaMoveUsp(int op)\r
452{\r
453 // Move USP opcode, 01001110 0110dnnn move An to/from USP (d=direction)\r
454 int ea=0,dir=0;\r
455 char eat[64]="";\r
456\r
457 dir=(op>>3)&1;\r
458 ea=(op&7)|8;\r
459 DisaGetEa(eat,ea,0);\r
460\r
461 if (dir) sprintf(DisaText,"move usp, %s",eat);\r
462 else sprintf(DisaText,"move %s, usp",eat);\r
463 return 0;\r
464}\r
465\r
466// ================ Opcodes 0x4e70+ ================\r
467static int Disa4E70(int op)\r
468{\r
469 char *inst[8]={"reset","nop","stop","rte","rtd","rts","trapv","rtr"};\r
470 int n=0;\r
471\r
472 n=op&7;\r
473\r
474 sprintf(DisaText,"%s",inst[n]);\r
475\r
476 //todo - 'stop' with 16 bit data\r
85a36a57 477\r
cc68a136 478 return 0;\r
479}\r
480\r
481// ================ Opcodes 0x4a00+ ================\r
482static int DisaTst(int op)\r
483{\r
484 // Tst 01001010 xxeeeeee (eeeeee=ea)\r
485 int ea=0;\r
486 char eat[64]="";\r
487 int size=0;\r
488\r
489 ea=op&0x003f;\r
490 DisaGetEa(eat,ea,0);\r
491 size=(op>>6)&3; if (size>=3) return 1;\r
492\r
493 sprintf(DisaText,"tst.%c %s",Tasm[size],eat);\r
494 return 0;\r
495}\r
496\r
85a36a57 497static int DisaTas(int op)\r
498{\r
499 // Tas 01001010 11eeeeee (eeeeee=ea)\r
500 int ea=0;\r
501 char eat[64]="";\r
502\r
503 ea=op&0x003f;\r
504 DisaGetEa(eat,ea,0);\r
505\r
506 sprintf(DisaText,"tas %s",eat);\r
507 return 0;\r
508}\r
509\r
cc68a136 510// ================ Opcodes 0x4e80+ ================\r
511static int DisaJsr(int op)\r
512{\r
513 // Jsr/Jmp 0100 1110 1mEE Eeee (eeeeee=ea m=1=jmp)\r
514 int sea=0;\r
515 char seat[64]="";\r
516\r
517 sea=op&0x003f;\r
518 DisaGetEa(seat,sea,0);\r
519\r
520 sprintf(DisaText,"j%s %s", op&0x40?"mp":"sr", seat);\r
521 return 0;\r
522}\r
523\r
524// ================ Opcodes 0x5000+ ================\r
525static int DisaAddq(int op)\r
526{\r
527 // 0101nnnt xxeeeeee (nnn=#8,1-7 t=addq/subq xx=size, eeeeee=EA)\r
528 int num=0,type=0,size=0,ea=0;\r
529 char eat[64]="";\r
530\r
531 num =(op>>9)&7; if (num==0) num=8;\r
532 type=(op>>8)&1;\r
533 size=(op>>6)&3; if (size>=3) return 1;\r
534 ea = op&0x3f;\r
535\r
536 DisaGetEa(eat,ea,size);\r
537\r
538 sprintf(DisaText,"%s.%c #%d, %s",type?"subq":"addq",Tasm[size],num,eat);\r
539 return 0;\r
540}\r
541\r
542// ================ Opcodes 0x50c0+ ================\r
543static int DisaSet(int op)\r
544{\r
545 // 0101cccc 11eeeeee (sxx ea)\r
546 static char *cond[16]=\r
547 {"t" ,"f", "hi","ls","cc","cs","ne","eq",\r
548 "vc","vs","pl","mi","ge","lt","gt","le"};\r
549 char *cc="";\r
550 int ea=0;\r
551 char eat[64]="";\r
552\r
553 cc=cond[(op>>8)&0xf]; // Get condition code\r
554 ea=op&0x3f;\r
555 if ((ea&0x38)==0x08) return 1; // dbra, not scc\r
556\r
557 DisaGetEa(eat,ea,0);\r
558 sprintf(DisaText,"s%s %s",cc,eat);\r
559 return 0;\r
560}\r
561\r
562// ================ Opcodes 0x50c8+ ================\r
563static int DisaDbra(int op)\r
564{\r
565 // 0101cccc 11001nnn offset (dbra/dbxx Rn,offset)\r
566 int dea=0; char deat[64]="";\r
567 int pc=0,Offset=0;\r
568\r
569 static char *BraCode[16]=\r
570 {"bt" ,"bra","bhi","bls","bcc","bcs","bne","beq",\r
571 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
572 char *Bra="";\r
573\r
574 dea=op&7;\r
575 DisaGetEa(deat,dea,2);\r
576\r
577 // Get condition code\r
578 Bra=BraCode[(op>>8)&0xf];\r
579\r
580 // Get offset\r
581 pc=DisaPc;\r
582 Offset=(short)DisaWord(DisaPc); DisaPc+=2;\r
583\r
584 sprintf(DisaText,"d%s %s, %x",Bra,deat,pc+Offset);\r
585 return 0;\r
586}\r
587\r
588// ================ Opcodes 0x6000+ ================\r
589static int DisaBranch(int op)\r
590{\r
591 // Branch 0110cccc nn (cccc=condition)\r
592 int pc=0,Offset=0;\r
593\r
594 static char *BraCode[16]=\r
595 {"bra","bsr","bhi","bls","bcc","bcs","bne","beq",\r
596 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
597 char *Bra="";\r
598\r
599 // Get condition code\r
600 Bra=BraCode[(op>>8)&0x0f];\r
601\r
602 // Get offset\r
603 pc=DisaPc;\r
604 Offset=(char)(op&0xff);\r
605 if (Offset== 0) { Offset=(short)DisaWord(DisaPc); DisaPc+=2; }\r
606 else if (Offset==-1) { Offset= DisaLong(DisaPc); DisaPc+=4; }\r
607\r
608 sprintf(DisaText,"%s %x",Bra,pc+Offset);\r
609 return 0;\r
610}\r
611\r
612// ================ Opcodes 0x7000+ ================\r
613static int DisaMoveq(int op)\r
614{\r
615 // Moveq 0111rrr0 nn (rrr=Dest register, nn=data)\r
616\r
617 int dea=0; char deat[64]="";\r
618 char *inst="moveq";\r
619 int val=0;\r
620\r
621 dea=(op>>9)&7;\r
622 DisaGetEa(deat,dea,2);\r
623\r
624 val=(char)(op&0xff);\r
625 sprintf(DisaText,"%s #$%x, %s",inst,val,deat);\r
626 return 0;\r
627}\r
628\r
629// ================ Opcodes 0x8000+ ================\r
630static int DisaArithReg(int op)\r
631{\r
632 // 1t0tnnnd xxeeeeee (tt=type:or/sub/and/add xx=size, eeeeee=EA)\r
633 int type=0,size=0,dir=0,rea=0,ea=0;\r
634 char reat[64]="",eat[64]="";\r
635 char *opcode[]={"or","sub","","","and","add"};\r
636\r
637 type=(op>>12)&5;\r
638 rea =(op>> 9)&7;\r
639 dir =(op>> 8)&1;\r
640 size=(op>> 6)&3; if (size>=3) return 1;\r
641 ea = op&0x3f;\r
642\r
643 if (dir && ea<0x10) return 1; // addx opcode\r
644\r
645 DisaGetEa(reat,rea,size);\r
646 DisaGetEa( eat, ea,size);\r
647\r
648 if (dir) sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],reat,eat);\r
649 else sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],eat,reat);\r
650 return 0;\r
651}\r
652\r
653// ================ Opcodes 0x8100+ ================\r
654static int DisaAbcd(int op)\r
655{\r
656 // 1t00ddd1 0000asss - sbcd/abcd Ds,Dd or -(As),-(Ad)\r
657 int type=0;\r
658 int dn=0,addr=0,sn=0;\r
659 char *opcode[]={"sbcd","abcd"};\r
660\r
661 type=(op>>14)&1;\r
662 dn =(op>> 9)&7;\r
663 addr=(op>> 3)&1;\r
664 sn = op &7;\r
665\r
666 if (addr) sprintf(DisaText,"%s -(a%d), -(a%d)",opcode[type],sn,dn);\r
667 else sprintf(DisaText,"%s d%d, d%d", opcode[type],sn,dn);\r
668\r
669 return 0;\r
670}\r
671\r
672// ================ Opcodes 0x80c0+ ================\r
673static int DisaMul(int op)\r
674{\r
675 // Div/Mul: 1m00nnns 11eeeeee (m=Mul, nnn=Register Dn, s=signed, eeeeee=EA)\r
676 int type=0,rea=0,sign=0,ea=0,size=1;\r
677 char reat[64]="",eat[64]="";\r
678 char *opcode[2]={"div","mul"};\r
679\r
680 type=(op>>14)&1; // div/mul\r
681 rea =(op>> 9)&7;\r
682 sign=(op>> 8)&1;\r
683 ea = op&0x3f;\r
684\r
685 DisaGetEa(reat,rea,size);\r
686 DisaGetEa( eat, ea,size);\r
687\r
688 sprintf(DisaText,"%s%c.%c %s, %s",opcode[type],sign?'s':'u',Tasm[size],eat,reat);\r
689 return 0;\r
690}\r
691\r
692// ================ Opcodes 0x90c0+ ================\r
693static int DisaAritha(int op)\r
694{\r
695 // Suba/Cmpa/Adda 1tt1nnnx 11eeeeee (tt=type, x=size, eeeeee=Source EA)\r
696 int type=0,size=0,sea=0,dea=0;\r
697 char seat[64]="",deat[64]="";\r
698 char *aritha[4]={"suba","cmpa","adda",""};\r
699\r
700 type=(op>>13)&3; if (type>=3) return 1;\r
701 size=(op>>8)&1; size++;\r
702 dea =(op>>9)&7; dea|=8; // Dest=An\r
703 sea = op&0x003f; // Source\r
704\r
705 DisaGetEa(seat,sea,size);\r
706 DisaGetEa(deat,dea,size);\r
707\r
708 sprintf(DisaText,"%s.%c %s, %s",aritha[type],Tasm[size],seat,deat);\r
709 return 0;\r
710}\r
711\r
712// ================ Opcodes 0xb000+ ================\r
713static int DisaCmpEor(int op)\r
714{\r
715 // Cmp/Eor 1011rrrt xxeeeeee (rrr=Dn, t=cmp/eor, xx=size extension, eeeeee=ea)\r
716 char reat[64]="",eat[64]="";\r
717 int type=0,size=0;\r
718\r
719 type=(op>>8)&1;\r
720 size=(op>>6)&3; if (size>=3) return 1;\r
721 DisaGetEa(reat,(op>>9)&7,size);\r
722 DisaGetEa(eat, op&0x3f, size);\r
723\r
724 if (type) sprintf(DisaText,"eor.%c %s, %s",Tasm[size],reat,eat);\r
725 else sprintf(DisaText,"cmp.%c %s, %s",Tasm[size],eat,reat);\r
726 return 0;\r
727}\r
728\r
85a36a57 729static int DisaCmpm(int op)\r
730{\r
731 char seat[64]="",deat[64]="";\r
732 int type=0,size=0,sea,dea;\r
733\r
734 type=(op>>8)&1;\r
735 size=(op>>6)&3; if (size>=3) return 1;\r
736 sea=(op&7)|0x18;\r
737 dea=(op>>9)&0x3f;\r
738 DisaGetEa(seat,sea,size);\r
739 DisaGetEa(deat,dea,size);\r
740\r
741 sprintf(DisaText,"cmpm.%c %s, %s",Tasm[size],seat,deat);\r
742 return 0;\r
743}\r
744\r
745\r
cc68a136 746// ================ Opcodes 0xc140+ ================\r
747// 1100ttt1 01000sss exg ds,dt\r
748// 1100ttt1 01001sss exg as,at\r
749// 1100ttt1 10001sss exg as,dt\r
750static int DisaExg(int op)\r
751{\r
752 int tr=0,type=0,sr=0;\r
753\r
754 tr =(op>>9)&7;\r
755 type= op&0xf8;\r
756 sr = op&7;\r
757\r
758 if (type==0x40) sprintf(DisaText,"exg d%d, d%d",sr,tr);\r
759 else if (type==0x48) sprintf(DisaText,"exg a%d, a%d",sr,tr);\r
760 else if (type==0x88) sprintf(DisaText,"exg a%d, d%d",sr,tr);\r
761 else return 1;\r
762\r
763 return 0;\r
764}\r
765\r
766// ================ Opcodes 0xd100+ ================\r
767static int DisaAddx(int op)\r
768{\r
769 // 1t01ddd1 xx000sss addx\r
85a36a57 770 int type=0,size=0,dea=0,sea=0,mem;\r
cc68a136 771 char deat[64]="",seat[64]="";\r
772 char *opcode[6]={"","subx","","","","addx"};\r
773\r
774 type=(op>>12)&5;\r
775 dea =(op>> 9)&7;\r
776 size=(op>> 6)&3; if (size>=3) return 1;\r
85a36a57 777 sea = op&7;\r
778 mem = op&8;\r
779 if(mem) { sea+=0x20; dea+=0x20; }\r
cc68a136 780\r
781 DisaGetEa(deat,dea,size);\r
782 DisaGetEa(seat,sea,size);\r
783\r
784 sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],seat,deat);\r
785 return 0;\r
786}\r
787\r
788// ================ Opcodes 0xe000+ ================\r
789static char *AsrName[4]={"as","ls","rox","ro"};\r
790static int DisaAsr(int op)\r
791{\r
792 // Asr/l/Ror/l etc - 1110cccd xxuttnnn\r
793 // (ccc=count, d=direction xx=size extension, u=use reg for count, tt=type, nnn=register Dn)\r
794 int count=0,dir=0,size=0,usereg=0,type=0,num=0;\r
795\r
796 count =(op>>9)&7;\r
797 dir =(op>>8)&1;\r
798 size =(op>>6)&3; if (size>=3) return 1; // todo Asr EA\r
799 usereg=(op>>5)&1;\r
800 type =(op>>3)&3;\r
801 num = op &7; // Register number\r
802\r
803 if (usereg==0) count=((count-1)&7)+1; // because ccc=000 means 8\r
804\r
805 sprintf(DisaText,"%s%c.%c %c%d, d%d",\r
806 AsrName[type], dir?'l':'r', Tasm[size],\r
807 usereg?'d':'#', count, num);\r
808 return 0;\r
809}\r
810\r
811static int DisaAsrEa(int op)\r
812{\r
85a36a57 813 // Asr/l/Ror/l etc EA - 11100ttd 11eeeeee\r
cc68a136 814 int type=0,dir=0,size=1;\r
815 char eat[64]="";\r
816\r
817 type=(op>>9)&3;\r
818 dir =(op>>8)&1;\r
819 DisaGetEa(eat,op&0x3f,size);\r
820\r
821 sprintf(DisaText,"%s%c.w %s", AsrName[type], dir?'l':'r', eat);\r
822 return 0;\r
823}\r
824\r
825// =================================================================\r
826\r
827static int TryOp(int op)\r
828{\r
829 if ((op&0xf100)==0x0000) DisaArithImm(op); // Ori/And/Sub/Add/Eor/Cmp Immediate\r
830 if ((op&0xf5bf)==0x003c) DisaArithSr(op); // Ori/Andi/Eori $nnnn,sr\r
831 if ((op&0xf100)==0x0100) DisaBtstReg(op);\r
832 if ((op&0xf138)==0x0108) DisaMovep(op);\r
833 if ((op&0xff00)==0x0800) DisaBtstImm(op); // Btst/Bchg/Bclr/Bset\r
834 if ((op&0xc000)==0x0000) DisaMove(op);\r
835 if ((op&0xf900)==0x4000) DisaNeg(op); // Negx/Clr/Neg/Not\r
85a36a57 836 if ((op&0xf140)==0x4100) OpChk(op);\r
cc68a136 837 if ((op&0xf1c0)==0x41c0) DisaLea(op);\r
838 if ((op&0xf9c0)==0x40c0) DisaMoveSr(op);\r
85a36a57 839 if ((op&0xffc0)==0x4800) DisaNbcd(op);\r
cc68a136 840 if ((op&0xfff8)==0x4840) DisaSwap(op);\r
841 if ((op&0xffc0)==0x4840) DisaPea(op);\r
842 if ((op&0xffb8)==0x4880) DisaExt(op);\r
843 if ((op&0xfb80)==0x4880) DisaMovem(op);\r
844 if ((op&0xff00)==0x4a00) DisaTst(op);\r
85a36a57 845 if ((op&0xffc0)==0x4ac0) DisaTas(op);\r
cc68a136 846 if ((op&0xfff0)==0x4e40) DisaTrap(op);\r
847 if ((op&0xfff8)==0x4e50) DisaLink(op);\r
848 if ((op&0xfff8)==0x4e58) DisaUnlk(op);\r
849 if ((op&0xfff0)==0x4e60) DisaMoveUsp(op);\r
850 if ((op&0xfff8)==0x4e70) Disa4E70(op);\r
851 if ((op&0xff80)==0x4e80) DisaJsr(op);\r
852 if ((op&0xf000)==0x5000) DisaAddq(op);\r
853 if ((op&0xf0c0)==0x50c0) DisaSet(op);\r
854 if ((op&0xf0f8)==0x50c8) DisaDbra(op);\r
855 if ((op&0xf000)==0x6000) DisaBranch(op);\r
856 if ((op&0xa000)==0x8000) DisaArithReg(op); // Or/Sub/And/Add\r
857 if ((op&0xb1f0)==0x8100) DisaAbcd(op);\r
858 if ((op&0xb130)==0x9100) DisaAddx(op);\r
859 if ((op&0xb0c0)==0x80c0) DisaMul(op);\r
860 if ((op&0xf100)==0x7000) DisaMoveq(op);\r
861 if ((op&0x90c0)==0x90c0) DisaAritha(op);\r
862 if ((op&0xf000)==0xb000) DisaCmpEor(op);\r
85a36a57 863 if ((op&0xf138)==0xb108) DisaCmpm(op);\r
cc68a136 864 if ((op&0xf130)==0xc100) DisaExg(op);\r
865 if ((op&0xf000)==0xe000) DisaAsr(op);\r
866 if ((op&0xf8c0)==0xe0c0) DisaAsrEa(op);\r
867\r
868 // Unknown opcoode\r
869 return 0;\r
870}\r
871\r
872int DisaGet()\r
873{\r
874 int op=0;\r
875 if (DisaWord==NULL) return 1;\r
876\r
877 Comment[0]=0;\r
878 DisaText[0]=0; // Assume opcode unknown\r
879\r
880 op=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
881 TryOp(op);\r
882 strcat(DisaText,Comment);\r
883\r
884 // Unknown opcoode\r
885 return 0;\r
886}\r
fast MegaDrive/MegaCD/32X emulator