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make Ea* functions easier to work with
[cyclone68000.git] / Disa / Disa.c
CommitLineData
7441f043 1\r
2// This file is part of the PicoDrive Megadrive Emulator\r
3\r
4// Copyright (c) 2011 FinalDave (emudave (at) gmail.com)\r
5\r
6// This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r
7// You can choose the license that has the most advantages for you.\r
8\r
9// SVN repository can be found at http://code.google.com/p/cyclone68000/\r
10\r
11// Disa 68000 Disassembler\r
12#ifndef __GNUC__\r
13#pragma warning(disable:4115)\r
14#endif\r
15\r
16#define _CRT_SECURE_NO_WARNINGS\r
17#include <stdio.h>\r
18#include <string.h>\r
19#include "Disa.h"\r
20\r
21unsigned int DisaPc=0;\r
22char *DisaText=NULL; // Text buffer to write in\r
23static char Tasm[]="bwl?";\r
24static char Comment[64]="";\r
25unsigned short (CPU_CALL *DisaWord)(unsigned int a)=NULL;\r
26\r
27static unsigned int DisaLong(unsigned int a)\r
28{\r
29 unsigned int d=0;\r
30 if (DisaWord==NULL) return d;\r
31\r
32 d= DisaWord(a)<<16;\r
33 d|=DisaWord(a+2)&0xffff;\r
34 return d;\r
35}\r
36\r
37// Get text version of the effective address\r
38int DisaGetEa(char *t,int ea,int size)\r
39{\r
40 ea&=0x3f; t[0]=0;\r
41 if ((ea&0x38)==0x00) { sprintf(t,"d%d",ea ); return 0; } // 000rrr\r
42 if ((ea&0x38)==0x08) { sprintf(t,"a%d",ea&7); return 0; } // 001rrr\r
43 if ((ea&0x38)==0x10) { sprintf(t,"(a%d)",ea&7); return 0; } // 010rrr\r
44 if ((ea&0x38)==0x18) { sprintf(t,"(a%d)+",ea&7); return 0; } // 011rrr\r
45 if ((ea&0x38)==0x20) { sprintf(t,"-(a%d)",ea&7); return 0; } // 100rrr\r
46 if ((ea&0x38)==0x28) { sprintf(t,"($%x,a%d)",DisaWord(DisaPc)&0xffff,ea&7); DisaPc+=2; return 0; } // 101rrr\r
47\r
48 if ((ea&0x38)==0x30)\r
49 {\r
50 // 110nnn - An + Disp + D/An\r
51 int areg=0,ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
52 ext=DisaWord(DisaPc)&0xffff;\r
53 \r
54 areg=ea&7;\r
55 off=ext&0xff; da =ext&0x8000?'a':'d';\r
56 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
57 scale=1<<((ext>>9)&3);\r
58\r
59 if (scale<2) sprintf(t,"($%x,a%d,%c%d.%c)", off,areg,da,reg,wol);\r
60 else sprintf(t,"($%x,a%d,%c%d.%c*%d)",off,areg,da,reg,wol,scale); // 68020\r
61\r
62 DisaPc+=2;\r
63 return 0;\r
64 }\r
65\r
66 if (ea==0x38) { sprintf(t,"$%x.w",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0; } // 111000 - Absolute short\r
67 if (ea==0x39) { sprintf(t,"$%x.l",DisaLong(DisaPc)); DisaPc+=4; return 0; } // 111001 - Absolute long\r
68\r
69 if (ea==0x3a)\r
70 {\r
71 // 111010 - PC Relative\r
72 int ext=DisaWord(DisaPc)&0xffff;\r
73 sprintf(t,"($%x,pc)",ext);\r
74 sprintf(Comment,"; =%x",DisaPc+(short)ext); // Comment where pc+ext is\r
75 DisaPc+=2;\r
76 return 0;\r
77 }\r
78\r
79 if (ea==0x3b)\r
80 {\r
81 // 111011 - PC Relative + D/An\r
82 int ext=0,off=0,da=0,reg=0,wol=0,scale=0;\r
83 ext=DisaWord(DisaPc)&0xffff;\r
84 \r
85 off=ext&0xff; da =ext&0x8000?'a':'d';\r
86 reg=(ext>>12)&7; wol=ext&0x0800?'l':'w';\r
87 scale=1<<((ext>>9)&3);\r
88\r
89 if (scale<2) sprintf(t,"($%x,pc,%c%d.%c)", off,da,reg,wol);\r
90 else sprintf(t,"($%x,pc,%c%d.%c*%d)",off,da,reg,wol,scale); // 68020\r
91\r
92 sprintf(Comment,"; =%x",DisaPc+(char)off); // Comment where pc+ext is\r
93 DisaPc+=2;\r
94 return 0;\r
95 }\r
96\r
97 if (ea==0x3c)\r
98 {\r
99 // 111100 - Immediate\r
100 switch (size)\r
101 {\r
102 case 0: sprintf(t,"#$%x",DisaWord(DisaPc)&0x00ff); DisaPc+=2; return 0;\r
103 case 1: sprintf(t,"#$%x",DisaWord(DisaPc)&0xffff); DisaPc+=2; return 0;\r
104 case 2: sprintf(t,"#$%x",DisaLong(DisaPc) ); DisaPc+=4; return 0;\r
105 }\r
106 return 1;\r
107 }\r
108\r
109// Unknown effective address\r
110 sprintf(t,"ea=(%d%d%d %d%d%d)",\r
111 (ea>>5)&1,(ea>>4)&1,(ea>>3)&1,\r
112 (ea>>2)&1,(ea>>1)&1, ea &1);\r
113 return 1;\r
114}\r
115\r
116static void GetOffset(char *text)\r
117{\r
118 int off=(short)DisaWord(DisaPc); DisaPc+=2;\r
119\r
120 if (off<0) sprintf(text,"-$%x",-off);\r
121 else sprintf(text,"$%x", off);\r
122}\r
123\r
124// ================ Opcodes 0x0000+ ================\r
125static int DisaArithImm(int op)\r
126{\r
127 // Or/And/Sub/Add/Eor/Cmp Immediate 0000ttt0 xxDDDddd (tt=type, xx=size extension, DDDddd=Dest ea)\r
128 int dea=0;\r
129 char seat[64]="",deat[64]="";\r
130 int type=0,size=0;\r
131 char *arith[8]={"or","and","sub","add","?","eor","cmp","?"};\r
132\r
133 type=(op>>9)&7; if (type==4 || type>=7) return 1;\r
134 size=(op>>6)&3; if (size>=3) return 1;\r
135 dea=op&0x3f; if (dea==0x3c) return 1;\r
136\r
137 DisaGetEa(seat,0x3c,size);\r
138 DisaGetEa(deat,dea, size);\r
139\r
140 sprintf(DisaText,"%si.%c %s, %s",arith[type],Tasm[size],seat,deat);\r
141 return 0;\r
142}\r
143\r
144// ================ Opcodes 0x0108+ ================\r
145static int DisaMovep(int op)\r
146{\r
147 // movep.x (Aa),Dn - 0000nnn1 dx001aaa nn\r
148 int dn=0,dir=0,size=0,an=0;\r
149 char offset[32]="";\r
150\r
151 dn =(op>>9)&7;\r
152 dir =(op>>7)&1;\r
153 size=(op>>6)&1; size++;\r
154 an = op &7;\r
155\r
156 GetOffset(offset);\r
157 if (dir) sprintf(DisaText,"movep.%c d%d, (%s,a%d)",Tasm[size],dn,offset,an);\r
158 else sprintf(DisaText,"movep.%c (%s,a%d), d%d",Tasm[size],offset,an,dn);\r
159\r
160 return 0;\r
161}\r
162\r
163// ================ Opcodes 0x007c+ ================\r
164static int DisaArithSr(int op)\r
165{\r
166 // Ori/Andi/Eori $nnnn,sr 0000t0tx 0s111100\r
167 char *opcode[6]={"ori","andi","","","","eori"};\r
168 char seat[64]="";\r
169 int type=0,size=0;\r
170\r
171 type=(op>>9)&5;\r
172 size=(op>>6)&1;\r
173\r
174 DisaGetEa(seat,0x3c,size);\r
175 sprintf(DisaText,"%s.%c %s, %s", opcode[type], Tasm[size], seat, size?"sr":"ccr");\r
176\r
177 return 0;\r
178}\r
179\r
180// ================ Opcodes 0x0100+ ================\r
181static int DisaBtstReg(int op)\r
182{\r
183 // Btst/Bchg/Bclr/Bset 0000nnn1 tteeeeee (nn=reg number, eeeeee=Dest ea)\r
184 int type=0;\r
185 int sea=0,dea=0;\r
186 char seat[64]="",deat[64]="";\r
187 char *opcode[4]={"btst","bchg","bclr","bset"};\r
188\r
189 sea =(op>>9)&7;\r
190 type=(op>>6)&3;\r
191 dea= op&0x3f;\r
192\r
193 if ((dea&0x38)==0x08) return 1; // movep\r
194 DisaGetEa(seat,sea,0);\r
195 DisaGetEa(deat,dea,0);\r
196\r
197 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
198 return 0;\r
199}\r
200\r
201// ================ Opcodes 0x0800+ ================\r
202static int DisaBtstImm(int op)\r
203{\r
204 // Btst/Bchg/Bclr/Bset 00001000 tteeeeee 00 nn (eeeeee=ea, nn=bit number)\r
205 int type=0;\r
206 char seat[64]="",deat[64]="";\r
207 char *opcode[4]={"btst","bchg","bclr","bset"};\r
208\r
209 type=(op>>6)&3;\r
210 DisaGetEa(seat, 0x3c,0);\r
211 DisaGetEa(deat,op&0x3f,0);\r
212\r
213 sprintf(DisaText,"%s %s, %s",opcode[type],seat,deat);\r
214 return 0;\r
215}\r
216\r
217// ================ Opcodes 0x1000+ ================\r
218static int DisaMove(int op)\r
219{\r
220 // Move 00xxdddD DDssssss (xx=size extension, ssssss=Source EA, DDDddd=Dest ea)\r
221 int sea=0,dea=0;\r
222 char inst[64]="",seat[64]="",deat[64]="";\r
223 char *movea="";\r
224 int size=0;\r
225\r
226 if ((op&0x01c0)==0x0040) movea="a"; // See if it's a movea opcode\r
227\r
228 // Find size extension\r
229 switch (op&0x3000)\r
230 {\r
231 case 0x1000: size=0; break;\r
232 case 0x3000: size=1; break;\r
233 case 0x2000: size=2; break;\r
234 default: return 1;\r
235 }\r
236\r
237 sea = op&0x003f;\r
238 DisaGetEa(seat,sea,size);\r
239 \r
240 dea =(op&0x01c0)>>3;\r
241 dea|=(op&0x0e00)>>9;\r
242 DisaGetEa(deat,dea,size);\r
243\r
244 sprintf(inst,"move%s.%c",movea,Tasm[size]);\r
245 sprintf(DisaText,"%s %s, %s",inst,seat,deat);\r
246 return 0;\r
247}\r
248\r
249// ================ Opcodes 0x4000+ ================\r
250static int DisaNeg(int op)\r
251{\r
252 // 01000tt0 xxeeeeee (tt=negx/clr/neg/not, xx=size, eeeeee=EA)\r
253 char eat[64]="";\r
254 int type=0,size=0;\r
255 char *opcode[4]={"negx","clr","neg","not"};\r
256\r
257 type=(op>>9)&3;\r
258 size=(op>>6)&3; if (size>=3) return 1;\r
259 DisaGetEa(eat,op&0x3f,size);\r
260\r
261 sprintf(DisaText,"%s.%c %s",opcode[type],Tasm[size],eat);\r
262 return 0;\r
263}\r
264\r
265// ================ Opcodes 0x40c0+ ================\r
266static int DisaMoveSr(int op)\r
267{\r
268 // 01000tt0 11eeeeee (tt=type, xx=size, eeeeee=EA)\r
269 int type=0,ea=0;\r
270 char eat[64]="";\r
271\r
272 type=(op>>9)&3;\r
273 ea=op&0x3f;\r
274 DisaGetEa(eat,ea,1);\r
275\r
276 switch (type)\r
277 {\r
278 default: sprintf(DisaText,"move sr, %s", eat); break;\r
279 case 1: sprintf(DisaText,"move ccr, %s",eat); break;\r
280 case 2: sprintf(DisaText,"move %s, ccr",eat); break;\r
281 case 3: sprintf(DisaText,"move %s, sr", eat); break;\r
282 }\r
283 return 0;\r
284}\r
285\r
8b9d2144 286static int OpChk(int op)\r
287{\r
288 int sea=0,dea=0;\r
289 char seat[64]="",deat[64]="";\r
290\r
291 sea=op&0x003f;\r
292 DisaGetEa(seat,sea,0);\r
293\r
294 dea=(op>>9)&7; dea|=8;\r
295 DisaGetEa(deat,dea,2);\r
296\r
297 sprintf(DisaText,"chk %s, %s",seat,deat);\r
298 return 0;\r
299}\r
300\r
7441f043 301// ================ Opcodes 0x41c0+ ================\r
302static int DisaLea(int op)\r
303{\r
304 // Lea 0100nnn1 11eeeeee (eeeeee=ea)\r
305 int sea=0,dea=0;\r
306 char seat[64]="",deat[64]="";\r
307\r
308 sea=op&0x003f;\r
309 DisaGetEa(seat,sea,0);\r
310\r
311 dea=(op>>9)&7; dea|=8;\r
312 DisaGetEa(deat,dea,2);\r
313\r
314 sprintf(DisaText,"lea %s, %s",seat,deat);\r
315 return 0;\r
316}\r
317\r
318static int MakeRegList(char *list,int mask,int ea)\r
319{\r
320 int reverse=0,i=0,low=0,len=0;\r
321\r
322 if ((ea&0x38)==0x20) reverse=1; // -(An), bitfield is reversed\r
323\r
324 mask&=0xffff; list[0]=0;\r
325\r
326 for (i=0;i<17;i++)\r
327 {\r
328 int bit=0;\r
329 \r
330 // Mask off bit i:\r
331 if (reverse) bit=0x8000>>i; else bit=1<<i;\r
332 bit&=mask;\r
333\r
334 if (bit==0 || i==8)\r
335 {\r
336 // low to i-1 are a continuous section, add it:\r
337 char add[16]="";\r
338 int ad=low&8?'a':'d';\r
339 if (low==i-1) sprintf(add,"%c%d/", ad,low&7);\r
340 if (low< i-1) sprintf(add,"%c%d-%c%d/",ad,low&7, ad,(i-1)&7);\r
341 strcat(list,add);\r
342\r
343 low=i; // Next section\r
344 }\r
345\r
346 if (bit==0) low=i+1;\r
347 }\r
348\r
349 // Knock off trailing '/'\r
350 len=strlen(list);\r
351 if (len>0) if (list[len-1]=='/') list[len-1]=0; \r
352 return 0;\r
353}\r
354\r
8b9d2144 355// ================ Opcodes 0x4800+ ================\r
356static int DisaNbcd(int op)\r
357{\r
358 // Nbcd 01001000 00eeeeee (eeeeee=ea)\r
359 int ea=0;\r
360 char eat[64]="";\r
361\r
362 ea=op&0x003f;\r
363 DisaGetEa(eat,ea,0);\r
364\r
365 sprintf(DisaText,"nbcd %s",eat);\r
366 return 0;\r
367}\r
368\r
7441f043 369// ================ Opcodes 0x4840+ ================\r
370static int DisaSwap(int op)\r
371{\r
372 // Swap, 01001000 01000nnn swap Dn\r
373 sprintf(DisaText,"swap d%d",op&7);\r
374 return 0;\r
375}\r
376\r
377// ================ Opcodes 0x4850+ ================\r
378static int DisaPea(int op)\r
379{\r
380 // Pea 01001000 01eeeeee (eeeeee=ea) pea \r
381 int ea=0;\r
382 char eat[64]="";\r
383\r
384 ea=op&0x003f; if (ea<0x10) return 1; // swap opcode\r
385 DisaGetEa(eat,ea,2);\r
386\r
387 sprintf(DisaText,"pea %s",eat);\r
388 return 0;\r
389}\r
390\r
391// ================ Opcodes 0x4880+ ================\r
392static int DisaExt(int op)\r
393{\r
394 // Ext 01001000 1x000nnn (x=size, eeeeee=EA)\r
395 char eat[64]="";\r
396 int size=0;\r
397\r
398 size=(op>>6)&1; size++;\r
399 DisaGetEa(eat,op&0x3f,size);\r
400\r
401 sprintf(DisaText,"ext.%c %s",Tasm[size],eat);\r
402 return 0;\r
403}\r
404\r
405// ================ Opcodes 0x4890+ ================\r
406static int DisaMovem(int op)\r
407{\r
408 // Movem 01001d00 1xeeeeee regmask d=direction, x=size, eeeeee=EA\r
409 int dir=0,size=0;\r
410 int ea=0,mask=0;\r
411 char list[64]="",eat[64]="";\r
412\r
413 dir=(op>>10)&1;\r
414 size=((op>>6)&1)+1;\r
415 ea=op&0x3f; if (ea<0x10) return 1; // ext opcode\r
416\r
417 mask=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
418\r
419 MakeRegList(list,mask,ea); // Turn register mask into text\r
420 DisaGetEa(eat,ea,size);\r
421\r
422 if (dir) sprintf(DisaText,"movem.%c %s, %s",Tasm[size],eat,list);\r
423 else sprintf(DisaText,"movem.%c %s, %s",Tasm[size],list,eat);\r
424 return 0;\r
425}\r
426\r
427// ================ Opcodes 0x4e40+ ================\r
428static int DisaTrap(int op)\r
429{\r
430 sprintf(DisaText,"trap #%d",op&0xf);\r
431 return 0;\r
432}\r
433\r
434// ================ Opcodes 0x4e50+ ================\r
435static int DisaLink(int op)\r
436{\r
437 // Link opcode, 01001110 01010nnn dd link An,#offset\r
438 char eat[64]="";\r
439 char offset[32]="";\r
440\r
441 DisaGetEa(eat,(op&7)|8,0);\r
442 GetOffset(offset);\r
443\r
444 sprintf(DisaText,"link %s,#%s",eat,offset);\r
445\r
446 return 0;\r
447}\r
448\r
449// ================ Opcodes 0x4e58+ ================\r
450static int DisaUnlk(int op)\r
451{\r
452 // Link opcode, 01001110 01011nnn dd unlk An\r
453 char eat[64]="";\r
454\r
455 DisaGetEa(eat,(op&7)|8,0);\r
456 sprintf(DisaText,"unlk %s",eat);\r
457\r
458 return 0;\r
459}\r
460\r
461// ================ Opcodes 0x4e60+ ================\r
462static int DisaMoveUsp(int op)\r
463{\r
464 // Move USP opcode, 01001110 0110dnnn move An to/from USP (d=direction)\r
465 int ea=0,dir=0;\r
466 char eat[64]="";\r
467\r
468 dir=(op>>3)&1;\r
469 ea=(op&7)|8;\r
470 DisaGetEa(eat,ea,0);\r
471\r
472 if (dir) sprintf(DisaText,"move usp, %s",eat);\r
473 else sprintf(DisaText,"move %s, usp",eat);\r
474 return 0;\r
475}\r
476\r
477// ================ Opcodes 0x4e70+ ================\r
478static int Disa4E70(int op)\r
479{\r
480 char *inst[8]={"reset","nop","stop","rte","rtd","rts","trapv","rtr"};\r
481 int n=0;\r
482\r
483 n=op&7;\r
484\r
485 sprintf(DisaText,"%s",inst[n]);\r
486\r
487 //todo - 'stop' with 16 bit data\r
488 \r
489 return 0;\r
490}\r
491\r
492// ================ Opcodes 0x4a00+ ================\r
493static int DisaTst(int op)\r
494{\r
495 // Tst 01001010 xxeeeeee (eeeeee=ea)\r
496 int ea=0;\r
497 char eat[64]="";\r
498 int size=0;\r
499\r
500 ea=op&0x003f;\r
501 DisaGetEa(eat,ea,0);\r
502 size=(op>>6)&3; if (size>=3) return 1;\r
503\r
504 sprintf(DisaText,"tst.%c %s",Tasm[size],eat);\r
505 return 0;\r
506}\r
507\r
8b9d2144 508static int DisaTas(int op)\r
509{\r
510 // Tas 01001010 11eeeeee (eeeeee=ea)\r
511 int ea=0;\r
512 char eat[64]="";\r
513\r
514 ea=op&0x003f;\r
515 DisaGetEa(eat,ea,0);\r
516\r
517 sprintf(DisaText,"tas %s",eat);\r
518 return 0;\r
519}\r
520\r
7441f043 521// ================ Opcodes 0x4e80+ ================\r
522static int DisaJsr(int op)\r
523{\r
524 // Jsr/Jmp 0100 1110 1mEE Eeee (eeeeee=ea m=1=jmp)\r
525 int sea=0;\r
526 char seat[64]="";\r
527\r
528 sea=op&0x003f;\r
529 DisaGetEa(seat,sea,0);\r
530\r
531 sprintf(DisaText,"j%s %s", op&0x40?"mp":"sr", seat);\r
532 return 0;\r
533}\r
534\r
535// ================ Opcodes 0x5000+ ================\r
536static int DisaAddq(int op)\r
537{\r
538 // 0101nnnt xxeeeeee (nnn=#8,1-7 t=addq/subq xx=size, eeeeee=EA)\r
539 int num=0,type=0,size=0,ea=0;\r
540 char eat[64]="";\r
541\r
542 num =(op>>9)&7; if (num==0) num=8;\r
543 type=(op>>8)&1;\r
544 size=(op>>6)&3; if (size>=3) return 1;\r
545 ea = op&0x3f;\r
546\r
547 DisaGetEa(eat,ea,size);\r
548\r
549 sprintf(DisaText,"%s.%c #%d, %s",type?"subq":"addq",Tasm[size],num,eat);\r
550 return 0;\r
551}\r
552\r
553// ================ Opcodes 0x50c0+ ================\r
554static int DisaSet(int op)\r
555{\r
556 // 0101cccc 11eeeeee (sxx ea)\r
557 static char *cond[16]=\r
558 {"t" ,"f", "hi","ls","cc","cs","ne","eq",\r
559 "vc","vs","pl","mi","ge","lt","gt","le"};\r
560 char *cc="";\r
561 int ea=0;\r
562 char eat[64]="";\r
563\r
564 cc=cond[(op>>8)&0xf]; // Get condition code\r
565 ea=op&0x3f;\r
566 if ((ea&0x38)==0x08) return 1; // dbra, not scc\r
567\r
568 DisaGetEa(eat,ea,0);\r
569 sprintf(DisaText,"s%s %s",cc,eat);\r
570 return 0;\r
571}\r
572\r
573// ================ Opcodes 0x50c8+ ================\r
574static int DisaDbra(int op)\r
575{\r
576 // 0101cccc 11001nnn offset (dbra/dbxx Rn,offset)\r
577 int dea=0; char deat[64]="";\r
578 int pc=0,Offset=0;\r
579\r
580 static char *BraCode[16]=\r
581 {"bt" ,"bra","bhi","bls","bcc","bcs","bne","beq",\r
582 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
583 char *Bra="";\r
584\r
585 dea=op&7;\r
586 DisaGetEa(deat,dea,2);\r
587\r
588 // Get condition code\r
589 Bra=BraCode[(op>>8)&0xf];\r
590\r
591 // Get offset\r
592 pc=DisaPc;\r
593 Offset=(short)DisaWord(DisaPc); DisaPc+=2;\r
594\r
595 sprintf(DisaText,"d%s %s, %x",Bra,deat,pc+Offset);\r
596 return 0;\r
597}\r
598\r
599// ================ Opcodes 0x6000+ ================\r
600static int DisaBranch(int op)\r
601{\r
602 // Branch 0110cccc nn (cccc=condition)\r
603 int pc=0,Offset=0;\r
604\r
605 static char *BraCode[16]=\r
606 {"bra","bsr","bhi","bls","bcc","bcs","bne","beq",\r
607 "bvc","bvs","bpl","bmi","bge","blt","bgt","ble"};\r
608 char *Bra="";\r
609\r
610 // Get condition code\r
611 Bra=BraCode[(op>>8)&0x0f];\r
612\r
613 // Get offset\r
614 pc=DisaPc;\r
615 Offset=(char)(op&0xff);\r
616 if (Offset== 0) { Offset=(short)DisaWord(DisaPc); DisaPc+=2; }\r
617 else if (Offset==-1) { Offset= DisaLong(DisaPc); DisaPc+=4; }\r
618\r
619 sprintf(DisaText,"%s %x",Bra,pc+Offset);\r
620 return 0;\r
621}\r
622\r
623// ================ Opcodes 0x7000+ ================\r
624static int DisaMoveq(int op)\r
625{\r
626 // Moveq 0111rrr0 nn (rrr=Dest register, nn=data)\r
627\r
628 int dea=0; char deat[64]="";\r
629 char *inst="moveq";\r
630 int val=0;\r
631\r
632 dea=(op>>9)&7;\r
633 DisaGetEa(deat,dea,2);\r
634\r
635 val=(char)(op&0xff);\r
636 sprintf(DisaText,"%s #$%x, %s",inst,val,deat);\r
637 return 0;\r
638}\r
639\r
640// ================ Opcodes 0x8000+ ================\r
641static int DisaArithReg(int op)\r
642{\r
643 // 1t0tnnnd xxeeeeee (tt=type:or/sub/and/add xx=size, eeeeee=EA)\r
644 int type=0,size=0,dir=0,rea=0,ea=0;\r
645 char reat[64]="",eat[64]="";\r
646 char *opcode[]={"or","sub","","","and","add"};\r
647\r
648 type=(op>>12)&5;\r
649 rea =(op>> 9)&7;\r
650 dir =(op>> 8)&1;\r
651 size=(op>> 6)&3; if (size>=3) return 1;\r
652 ea = op&0x3f;\r
653\r
654 if (dir && ea<0x10) return 1; // addx opcode\r
655\r
656 DisaGetEa(reat,rea,size);\r
657 DisaGetEa( eat, ea,size);\r
658\r
659 if (dir) sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],reat,eat);\r
660 else sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],eat,reat);\r
661 return 0;\r
662}\r
663\r
664// ================ Opcodes 0x8100+ ================\r
665static int DisaAbcd(int op)\r
666{\r
667 // 1t00ddd1 0000asss - sbcd/abcd Ds,Dd or -(As),-(Ad)\r
668 int type=0;\r
669 int dn=0,addr=0,sn=0;\r
670 char *opcode[]={"sbcd","abcd"};\r
671\r
672 type=(op>>14)&1;\r
673 dn =(op>> 9)&7;\r
674 addr=(op>> 3)&1;\r
675 sn = op &7;\r
676\r
677 if (addr) sprintf(DisaText,"%s -(a%d), -(a%d)",opcode[type],sn,dn);\r
678 else sprintf(DisaText,"%s d%d, d%d", opcode[type],sn,dn);\r
679\r
680 return 0;\r
681}\r
682\r
683// ================ Opcodes 0x80c0+ ================\r
684static int DisaMul(int op)\r
685{\r
686 // Div/Mul: 1m00nnns 11eeeeee (m=Mul, nnn=Register Dn, s=signed, eeeeee=EA)\r
687 int type=0,rea=0,sign=0,ea=0,size=1;\r
688 char reat[64]="",eat[64]="";\r
689 char *opcode[2]={"div","mul"};\r
690\r
691 type=(op>>14)&1; // div/mul\r
692 rea =(op>> 9)&7;\r
693 sign=(op>> 8)&1;\r
694 ea = op&0x3f;\r
695\r
696 DisaGetEa(reat,rea,size);\r
697 DisaGetEa( eat, ea,size);\r
698\r
699 sprintf(DisaText,"%s%c.%c %s, %s",opcode[type],sign?'s':'u',Tasm[size],eat,reat);\r
700 return 0;\r
701}\r
702\r
703// ================ Opcodes 0x90c0+ ================\r
704static int DisaAritha(int op)\r
705{\r
706 // Suba/Cmpa/Adda 1tt1nnnx 11eeeeee (tt=type, x=size, eeeeee=Source EA)\r
707 int type=0,size=0,sea=0,dea=0;\r
708 char seat[64]="",deat[64]="";\r
709 char *aritha[4]={"suba","cmpa","adda",""};\r
710\r
711 type=(op>>13)&3; if (type>=3) return 1;\r
712 size=(op>>8)&1; size++;\r
713 dea =(op>>9)&7; dea|=8; // Dest=An\r
714 sea = op&0x003f; // Source\r
715\r
716 DisaGetEa(seat,sea,size);\r
717 DisaGetEa(deat,dea,size);\r
718\r
719 sprintf(DisaText,"%s.%c %s, %s",aritha[type],Tasm[size],seat,deat);\r
720 return 0;\r
721}\r
722\r
723// ================ Opcodes 0xb000+ ================\r
724static int DisaCmpEor(int op)\r
725{\r
726 // Cmp/Eor 1011rrrt xxeeeeee (rrr=Dn, t=cmp/eor, xx=size extension, eeeeee=ea)\r
727 char reat[64]="",eat[64]="";\r
728 int type=0,size=0;\r
729\r
730 type=(op>>8)&1;\r
731 size=(op>>6)&3; if (size>=3) return 1; // cmpa opcode\r
732 if ((op&0xf138)==0xb108) return 1; // cmpm opcode\r
733\r
734 DisaGetEa(reat,(op>>9)&7,size);\r
735 DisaGetEa(eat, op&0x3f, size);\r
736\r
737 if (type) sprintf(DisaText,"eor.%c %s, %s",Tasm[size],reat,eat);\r
738 else sprintf(DisaText,"cmp.%c %s, %s",Tasm[size],eat,reat);\r
739 return 0;\r
740}\r
741\r
742// ================ Opcodes 0xb108+ ================\r
743static int DisaCmpm(int op)\r
744{\r
745 // Cmpm 1011ddd1 xx001sss\r
e5b2956d 746 int size=0,dea=0,sea=0;\r
7441f043 747 char deat[64]="",seat[64]="";\r
748\r
7441f043 749 dea =(op>> 9)&7; dea|=8;\r
750 size=(op>> 6)&3; if (size>=3) return 1;\r
751 sea = op&0x3f;\r
752\r
753 DisaGetEa(deat,dea,size);\r
754 DisaGetEa(seat,sea,size);\r
755\r
756 sprintf(DisaText,"cmpm.%c (%s)+, (%s)+",Tasm[size],seat,deat);\r
757\r
758 return 0;\r
759}\r
760\r
761// ================ Opcodes 0xc140+ ================\r
762// 1100ttt1 01000sss exg ds,dt\r
763// 1100ttt1 01001sss exg as,at\r
764// 1100ttt1 10001sss exg as,dt\r
765static int DisaExg(int op)\r
766{\r
767 int tr=0,type=0,sr=0;\r
768\r
769 tr =(op>>9)&7;\r
770 type= op&0xf8;\r
771 sr = op&7;\r
772\r
773 if (type==0x40) sprintf(DisaText,"exg d%d, d%d",sr,tr);\r
774 else if (type==0x48) sprintf(DisaText,"exg a%d, a%d",sr,tr);\r
775 else if (type==0x88) sprintf(DisaText,"exg a%d, d%d",sr,tr);\r
776 else return 1;\r
777\r
778 return 0;\r
779}\r
780\r
781// ================ Opcodes 0xd100+ ================\r
782static int DisaAddx(int op)\r
783{\r
784 // 1t01ddd1 xx000sss addx\r
8b9d2144 785 int type=0,size=0,dea=0,sea=0,mem;\r
7441f043 786 char deat[64]="",seat[64]="";\r
787 char *opcode[6]={"","subx","","","","addx"};\r
788\r
789 type=(op>>12)&5;\r
790 dea =(op>> 9)&7;\r
791 size=(op>> 6)&3; if (size>=3) return 1;\r
8b9d2144 792 sea = op&7;\r
793 mem = op&8;\r
794 if(mem) { sea+=0x20; dea+=0x20; }\r
7441f043 795\r
796 DisaGetEa(deat,dea,size);\r
797 DisaGetEa(seat,sea,size);\r
798\r
799 sprintf(DisaText,"%s.%c %s, %s",opcode[type],Tasm[size],seat,deat);\r
800 return 0;\r
801}\r
802\r
803// ================ Opcodes 0xe000+ ================\r
804static char *AsrName[4]={"as","ls","rox","ro"};\r
805static int DisaAsr(int op)\r
806{\r
807 // Asr/l/Ror/l etc - 1110cccd xxuttnnn\r
808 // (ccc=count, d=direction xx=size extension, u=use reg for count, tt=type, nnn=register Dn)\r
809 int count=0,dir=0,size=0,usereg=0,type=0,num=0;\r
810\r
811 count =(op>>9)&7;\r
812 dir =(op>>8)&1;\r
813 size =(op>>6)&3; if (size>=3) return 1; // todo Asr EA\r
814 usereg=(op>>5)&1;\r
815 type =(op>>3)&3;\r
816 num = op &7; // Register number\r
817\r
818 if (usereg==0) count=((count-1)&7)+1; // because ccc=000 means 8\r
819\r
820 sprintf(DisaText,"%s%c.%c %c%d, d%d",\r
821 AsrName[type], dir?'l':'r', Tasm[size],\r
822 usereg?'d':'#', count, num);\r
823 return 0;\r
824}\r
825\r
826static int DisaAsrEa(int op)\r
827{\r
828 // Asr/l/Ror/l etc EA - 11100ttd 11eeeeee \r
829 int type=0,dir=0,size=1;\r
830 char eat[64]="";\r
831\r
832 type=(op>>9)&3;\r
833 dir =(op>>8)&1;\r
834 DisaGetEa(eat,op&0x3f,size);\r
835\r
836 sprintf(DisaText,"%s%c.w %s", AsrName[type], dir?'l':'r', eat);\r
837 return 0;\r
838}\r
839\r
840// =================================================================\r
841\r
842static int TryOp(int op)\r
843{\r
844 if ((op&0xf100)==0x0000) DisaArithImm(op); // Ori/And/Sub/Add/Eor/Cmp Immediate\r
845 if ((op&0xf5bf)==0x003c) DisaArithSr(op); // Ori/Andi/Eori $nnnn,sr\r
846 if ((op&0xf100)==0x0100) DisaBtstReg(op);\r
847 if ((op&0xf138)==0x0108) DisaMovep(op);\r
848 if ((op&0xff00)==0x0800) DisaBtstImm(op); // Btst/Bchg/Bclr/Bset\r
849 if ((op&0xc000)==0x0000) DisaMove(op);\r
850 if ((op&0xf900)==0x4000) DisaNeg(op); // Negx/Clr/Neg/Not\r
8b9d2144 851 if ((op&0xf140)==0x4100) OpChk(op);\r
7441f043 852 if ((op&0xf1c0)==0x41c0) DisaLea(op);\r
853 if ((op&0xf9c0)==0x40c0) DisaMoveSr(op);\r
8b9d2144 854 if ((op&0xffc0)==0x4800) DisaNbcd(op);\r
7441f043 855 if ((op&0xfff8)==0x4840) DisaSwap(op);\r
856 if ((op&0xffc0)==0x4840) DisaPea(op);\r
857 if ((op&0xffb8)==0x4880) DisaExt(op);\r
858 if ((op&0xfb80)==0x4880) DisaMovem(op);\r
859 if ((op&0xff00)==0x4a00) DisaTst(op);\r
8b9d2144 860 if ((op&0xffc0)==0x4ac0) DisaTas(op);\r
7441f043 861 if ((op&0xfff0)==0x4e40) DisaTrap(op);\r
862 if ((op&0xfff8)==0x4e50) DisaLink(op);\r
863 if ((op&0xfff8)==0x4e58) DisaUnlk(op);\r
864 if ((op&0xfff0)==0x4e60) DisaMoveUsp(op);\r
865 if ((op&0xfff8)==0x4e70) Disa4E70(op);\r
866 if ((op&0xff80)==0x4e80) DisaJsr(op);\r
867 if ((op&0xf000)==0x5000) DisaAddq(op);\r
868 if ((op&0xf0c0)==0x50c0) DisaSet(op);\r
869 if ((op&0xf0f8)==0x50c8) DisaDbra(op);\r
870 if ((op&0xf000)==0x6000) DisaBranch(op);\r
871 if ((op&0xa000)==0x8000) DisaArithReg(op); // Or/Sub/And/Add\r
872 if ((op&0xb1f0)==0x8100) DisaAbcd(op);\r
873 if ((op&0xb130)==0x9100) DisaAddx(op);\r
874 if ((op&0xb0c0)==0x80c0) DisaMul(op);\r
875 if ((op&0xf100)==0x7000) DisaMoveq(op);\r
876 if ((op&0x90c0)==0x90c0) DisaAritha(op);\r
877 if ((op&0xf000)==0xb000) DisaCmpEor(op);\r
878 if ((op&0xf138)==0xb108) DisaCmpm(op);\r
879 if ((op&0xf130)==0xc100) DisaExg(op);\r
880 if ((op&0xf000)==0xe000) DisaAsr(op);\r
881 if ((op&0xf8c0)==0xe0c0) DisaAsrEa(op);\r
882\r
883 // Unknown opcoode\r
884 return 0;\r
885}\r
886\r
887int DisaGet()\r
888{\r
889 int op=0;\r
890 if (DisaWord==NULL) return 1;\r
891\r
892 Comment[0]=0;\r
893 DisaText[0]=0; // Assume opcode unknown\r
894\r
895 op=DisaWord(DisaPc)&0xffff; DisaPc+=2;\r
896 TryOp(op);\r
897 strcat(DisaText,Comment);\r
898\r
899 // Unknown opcoode\r
900 return 0;\r
901}\r
68000 emulator written in ARM 32-bit assembly