cc68a136 |
1 | \r |
2 | #include "app.h"\r |
3 | \r |
cfb3dfa0 |
4 | static void CheckPc(int reg)\r |
cc68a136 |
5 | {\r |
cfb3dfa0 |
6 | #if USE_CHECKPC_CALLBACK\r |
cc68a136 |
7 | ot(";@ Check Memory Base+pc (r4)\n");\r |
cfb3dfa0 |
8 | if (reg != 0)\r |
9 | ot(" mov r0,r%i\n", reg);\r |
10 | ot(" mov lr,pc\n");\r |
cc68a136 |
11 | ot(" ldr pc,[r7,#0x64] ;@ Call checkpc()\n");\r |
12 | ot(" mov r4,r0\n");\r |
cfb3dfa0 |
13 | #else\r |
14 | if (reg != 4)\r |
15 | ot(" mov r4,r%i\n", reg);\r |
16 | #endif\r |
cc68a136 |
17 | ot("\n");\r |
18 | }\r |
cc68a136 |
19 | \r |
20 | // Push 32-bit value in r1 - trashes r0-r3,r12,lr\r |
21 | void OpPush32()\r |
22 | {\r |
23 | ot(";@ Push r1 onto stack\n");\r |
24 | ot(" ldr r0,[r7,#0x3c]\n");\r |
25 | ot(" sub r0,r0,#4 ;@ Predecrement A7\n");\r |
26 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
27 | MemHandler(1,2);\r |
28 | ot("\n");\r |
29 | }\r |
30 | \r |
31 | // Push SR - trashes r0-r3,r12,lr\r |
32 | void OpPushSr(int high)\r |
33 | {\r |
34 | ot(";@ Push SR:\n");\r |
35 | OpFlagsToReg(high);\r |
36 | ot(" ldr r0,[r7,#0x3c]\n");\r |
37 | ot(" sub r0,r0,#2 ;@ Predecrement A7\n");\r |
38 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
39 | MemHandler(1,1);\r |
40 | ot("\n");\r |
41 | }\r |
42 | \r |
43 | // Pop SR - trashes r0-r3\r |
44 | static void PopSr(int high)\r |
45 | {\r |
46 | ot(";@ Pop SR:\n");\r |
47 | ot(" ldr r0,[r7,#0x3c]\n");\r |
48 | ot(" add r1,r0,#2 ;@ Postincrement A7\n");\r |
49 | ot(" str r1,[r7,#0x3c] ;@ Save A7\n");\r |
50 | MemHandler(0,1);\r |
51 | ot("\n");\r |
52 | OpRegToFlags(high);\r |
53 | }\r |
54 | \r |
55 | // Pop PC - assumes r10=Memory Base - trashes r0-r3\r |
56 | static void PopPc()\r |
57 | {\r |
58 | ot(";@ Pop PC:\n");\r |
59 | ot(" ldr r0,[r7,#0x3c]\n");\r |
60 | ot(" add r1,r0,#4 ;@ Postincrement A7\n");\r |
61 | ot(" str r1,[r7,#0x3c] ;@ Save A7\n");\r |
62 | MemHandler(0,2);\r |
cfb3dfa0 |
63 | ot(" add r0,r0,r10 ;@ Memory Base+PC\n");\r |
cc68a136 |
64 | ot("\n");\r |
cfb3dfa0 |
65 | CheckPc(0);\r |
cc68a136 |
66 | }\r |
67 | \r |
68 | int OpTrap(int op)\r |
69 | {\r |
70 | int use=0;\r |
71 | \r |
72 | use=op&~0xf;\r |
73 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
74 | \r |
a6785576 |
75 | OpStart(op,0x10);\r |
cc68a136 |
76 | ot(" and r0,r8,#0xf ;@ Get trap number\n");\r |
77 | ot(" orr r0,r0,#0x20\n");\r |
78 | ot(" mov r0,r0,asl #2\n");\r |
79 | ot(" bl Exception\n");\r |
80 | ot("\n");\r |
81 | \r |
cfb3dfa0 |
82 | Cycles=38; OpEnd(0x10);\r |
cc68a136 |
83 | \r |
84 | return 0;\r |
85 | }\r |
86 | \r |
87 | // --------------------- Opcodes 0x4e50+ ---------------------\r |
88 | int OpLink(int op)\r |
89 | {\r |
90 | int use=0,reg;\r |
91 | \r |
92 | use=op&~7;\r |
93 | reg=op&7;\r |
94 | if (reg==7) use=op;\r |
95 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
96 | \r |
a6785576 |
97 | OpStart(op,0x10);\r |
cc68a136 |
98 | \r |
99 | if(reg!=7) {\r |
100 | ot(";@ Get An\n");\r |
101 | EaCalc(10, 7, 8, 2, 1);\r |
102 | EaRead(10, 1, 8, 2, 7, 1);\r |
103 | }\r |
104 | \r |
105 | ot(" ldr r0,[r7,#0x3c] ;@ Get A7\n");\r |
106 | ot(" sub r0,r0,#4 ;@ A7-=4\n");\r |
107 | ot(" mov r11,r0\n");\r |
108 | if(reg==7) ot(" mov r1,r0\n");\r |
109 | ot("\n");\r |
110 | \r |
111 | ot(";@ Write An to Stack\n");\r |
112 | MemHandler(1,2);\r |
113 | \r |
114 | ot(";@ Save to An\n");\r |
115 | if(reg!=7)\r |
116 | EaWrite(10,11, 8, 2, 7, 1);\r |
117 | \r |
118 | ot(";@ Get offset:\n");\r |
119 | EaCalc(0,0,0x3c,1);\r |
120 | EaRead(0,0,0x3c,1,0);\r |
121 | \r |
122 | ot(" add r11,r11,r0 ;@ Add offset to A7\n");\r |
123 | ot(" str r11,[r7,#0x3c]\n");\r |
124 | ot("\n");\r |
125 | \r |
126 | Cycles=16;\r |
cfb3dfa0 |
127 | OpEnd(0x10);\r |
cc68a136 |
128 | return 0;\r |
129 | }\r |
130 | \r |
131 | // --------------------- Opcodes 0x4e58+ ---------------------\r |
132 | int OpUnlk(int op)\r |
133 | {\r |
134 | int use=0;\r |
135 | \r |
136 | use=op&~7;\r |
137 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
138 | \r |
a6785576 |
139 | OpStart(op,0x10);\r |
cc68a136 |
140 | \r |
141 | ot(";@ Get An\n");\r |
85a36a57 |
142 | EaCalc(10, 0xf, 8, 2, 1);\r |
143 | EaRead(10, 0, 8, 2, 0xf, 1);\r |
cc68a136 |
144 | \r |
145 | ot(" add r11,r0,#4 ;@ A7+=4\n");\r |
146 | ot("\n");\r |
147 | ot(";@ Pop An from stack:\n");\r |
148 | MemHandler(0,2);\r |
149 | ot("\n");\r |
150 | ot(" str r11,[r7,#0x3c] ;@ Save A7\n");\r |
151 | ot("\n");\r |
152 | ot(";@ An = value from stack:\n");\r |
153 | EaWrite(10, 0, 8, 2, 7, 1);\r |
85a36a57 |
154 | \r |
cc68a136 |
155 | Cycles=12;\r |
cfb3dfa0 |
156 | OpEnd(0x10);\r |
cc68a136 |
157 | return 0;\r |
158 | }\r |
159 | \r |
160 | // --------------------- Opcodes 0x4e70+ ---------------------\r |
161 | int Op4E70(int op)\r |
162 | {\r |
163 | int type=0;\r |
164 | \r |
165 | type=op&7; // 01001110 01110ttt, reset/nop/stop/rte/rtd/rts/trapv/rtr\r |
166 | \r |
167 | switch (type)\r |
168 | {\r |
169 | case 1: // nop\r |
170 | OpStart(op);\r |
171 | Cycles=4;\r |
172 | OpEnd();\r |
173 | return 0;\r |
174 | \r |
a6785576 |
175 | case 3: // rte\r |
176 | OpStart(op,0x10); Cycles=20;\r |
177 | SuperCheck(op);\r |
cc68a136 |
178 | PopSr(1);\r |
179 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
180 | PopPc();\r |
a6785576 |
181 | SuperChange(op);\r |
cc68a136 |
182 | CheckInterrupt(op);\r |
cfb3dfa0 |
183 | OpEnd(0x10);\r |
cc68a136 |
184 | return 0;\r |
185 | \r |
186 | case 5: // rts\r |
a6785576 |
187 | OpStart(op,0x10); Cycles=16;\r |
cc68a136 |
188 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
189 | PopPc();\r |
cfb3dfa0 |
190 | OpEnd(0x10);\r |
cc68a136 |
191 | return 0;\r |
192 | \r |
193 | case 6: // trapv\r |
a6785576 |
194 | OpStart(op,0x10); Cycles=4;\r |
cc68a136 |
195 | ot(" tst r9,#0x10000000\n");\r |
196 | ot(" subne r5,r5,#%i\n",30);\r |
197 | ot(" movne r0,#0x1c ;@ TRAPV exception\n");\r |
198 | ot(" blne Exception\n");\r |
cfb3dfa0 |
199 | OpEnd(0x10);\r |
cc68a136 |
200 | return 0;\r |
201 | \r |
202 | case 7: // rtr\r |
a6785576 |
203 | OpStart(op,0x10); Cycles=20;\r |
cc68a136 |
204 | PopSr(0);\r |
205 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
206 | PopPc();\r |
cfb3dfa0 |
207 | OpEnd(0x10);\r |
cc68a136 |
208 | return 0;\r |
209 | \r |
210 | default:\r |
211 | return 1;\r |
212 | }\r |
213 | }\r |
214 | \r |
215 | // --------------------- Opcodes 0x4e80+ ---------------------\r |
216 | // Emit a Jsr/Jmp opcode, 01001110 1meeeeee\r |
217 | int OpJsr(int op)\r |
218 | {\r |
219 | int use=0;\r |
220 | int sea=0;\r |
221 | \r |
222 | sea=op&0x003f;\r |
223 | \r |
224 | // See if we can do this opcode:\r |
225 | if (EaCanRead(sea,-1)==0) return 1;\r |
226 | \r |
85a36a57 |
227 | use=OpBase(op,0);\r |
cc68a136 |
228 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
229 | \r |
cfb3dfa0 |
230 | OpStart(op,(op&0x40)?0:0x10);\r |
cc68a136 |
231 | \r |
232 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
233 | ot("\n");\r |
cfb3dfa0 |
234 | EaCalc(11,0x003f,sea,0);\r |
cc68a136 |
235 | \r |
236 | ot(";@ Jump - Get new PC from r0\n");\r |
237 | if (op&0x40)\r |
238 | {\r |
239 | // Jmp - Get new PC from r0\r |
cfb3dfa0 |
240 | ot(" add r0,r11,r10 ;@ Memory Base + New PC\n");\r |
cc68a136 |
241 | ot("\n");\r |
242 | }\r |
243 | else\r |
244 | {\r |
245 | ot(";@ Jsr - Push old PC first\n");\r |
246 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
cc68a136 |
247 | ot(" mov r1,r1,lsl #8\n");\r |
248 | ot(" ldr r0,[r7,#0x3c]\n");\r |
249 | ot(" mov r1,r1,asr #8\n");\r |
250 | ot(";@ Push r1 onto stack\n");\r |
251 | ot(" sub r0,r0,#4 ;@ Predecrement A7\n");\r |
252 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
253 | MemHandler(1,2);\r |
cfb3dfa0 |
254 | ot(" add r0,r11,r10 ;@ Memory Base + New PC\n");\r |
cc68a136 |
255 | ot("\n");\r |
256 | }\r |
257 | \r |
cfb3dfa0 |
258 | CheckPc(0);\r |
cc68a136 |
259 | \r |
260 | Cycles=(op&0x40) ? 4 : 12;\r |
261 | Cycles+=Ea_add_ns((op&0x40) ? g_jmp_cycle_table : g_jsr_cycle_table, sea);\r |
262 | \r |
cfb3dfa0 |
263 | OpEnd((op&0x40)?0:0x10);\r |
cc68a136 |
264 | \r |
265 | return 0;\r |
266 | }\r |
267 | \r |
268 | // --------------------- Opcodes 0x50c8+ ---------------------\r |
269 | \r |
270 | // ARM version of 68000 condition codes:\r |
271 | static char *Cond[16]=\r |
272 | {\r |
273 | "", "", "hi","ls","cc","cs","ne","eq",\r |
274 | "vc","vs","pl","mi","ge","lt","gt","le"\r |
275 | };\r |
276 | \r |
277 | // Emit a Dbra opcode, 0101cccc 11001nnn vv\r |
278 | int OpDbra(int op)\r |
279 | {\r |
280 | int use=0;\r |
281 | int cc=0;\r |
282 | \r |
283 | use=op&~7; // Use same handler\r |
284 | cc=(op>>8)&15;\r |
285 | \r |
286 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
287 | OpStart(op);\r |
288 | \r |
3a5e6cf8 |
289 | switch (cc)\r |
cc68a136 |
290 | {\r |
3a5e6cf8 |
291 | case 0: // T\r |
292 | case 1: // F\r |
293 | break;\r |
294 | case 2: // hi\r |
295 | ot(" tst r9,#0x60000000 ;@ hi: !C && !Z\n");\r |
85a36a57 |
296 | ot(" beq DbraTrue\n\n");\r |
3a5e6cf8 |
297 | break;\r |
298 | case 3: // ls\r |
299 | ot(" tst r9,#0x60000000 ;@ ls: C || Z\n");\r |
85a36a57 |
300 | ot(" bne DbraTrue\n\n");\r |
3a5e6cf8 |
301 | break;\r |
302 | default:\r |
303 | ot(";@ Is the condition true?\n");\r |
304 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
305 | ot(";@ If so, don't dbra\n");\r |
85a36a57 |
306 | ot(" b%s DbraTrue\n\n",Cond[cc]);\r |
3a5e6cf8 |
307 | break;\r |
cc68a136 |
308 | }\r |
309 | \r |
3a5e6cf8 |
310 | if (cc!=0)\r |
311 | {\r |
312 | ot(";@ Decrement Dn.w\n");\r |
313 | ot(" and r1,r8,#0x0007\n");\r |
314 | ot(" mov r1,r1,lsl #2\n");\r |
315 | ot(" ldrsh r0,[r7,r1]\n");\r |
316 | ot(" sub r0,r0,#1\n");\r |
317 | ot(" strh r0,[r7,r1]\n");\r |
318 | ot("\n");\r |
cc68a136 |
319 | \r |
3a5e6cf8 |
320 | ot(";@ Check if Dn.w is -1\n");\r |
321 | ot(" cmn r0,#1\n");\r |
322 | ot("\n");\r |
cc68a136 |
323 | \r |
3a5e6cf8 |
324 | ot(";@ Get Branch offset:\n");\r |
325 | ot(" ldrnesh r0,[r4]\n");\r |
326 | ot(" addeq r4,r4,#2 ;@ Skip branch offset\n");\r |
327 | ot(" subeq r5,r5,#4 ;@ additional cycles\n");\r |
328 | ot(" addne r4,r4,r0 ;@ r4 = New PC\n");\r |
329 | ot("\n");\r |
330 | Cycles=12-2;\r |
331 | OpEnd();\r |
332 | }\r |
cc68a136 |
333 | \r |
85a36a57 |
334 | //if (cc==0||cc>=2)\r |
335 | if (op==0x50c8)\r |
3a5e6cf8 |
336 | {\r |
337 | ot(";@ condition true:\n");\r |
85a36a57 |
338 | ot("DbraTrue%s\n", ms?"":":");\r |
3a5e6cf8 |
339 | ot(" add r4,r4,#2 ;@ Skip branch offset\n");\r |
340 | ot("\n");\r |
341 | Cycles=12;\r |
342 | OpEnd();\r |
343 | }\r |
cc68a136 |
344 | \r |
345 | return 0;\r |
346 | }\r |
347 | \r |
348 | // --------------------- Opcodes 0x6000+ ---------------------\r |
349 | // Emit a Branch opcode 0110cccc nn (cccc=condition)\r |
350 | int OpBranch(int op)\r |
351 | {\r |
352 | int size=0,use=0;\r |
353 | int offset=0;\r |
354 | int cc=0;\r |
85a36a57 |
355 | char *asr_r11="";\r |
cc68a136 |
356 | \r |
357 | offset=(char)(op&0xff);\r |
358 | cc=(op>>8)&15;\r |
359 | \r |
360 | // Special offsets:\r |
361 | if (offset==0) size=1;\r |
362 | if (offset==-1) size=2;\r |
363 | \r |
364 | if (size) use=op; // 16-bit or 32-bit\r |
365 | else use=(op&0xff00)+1; // Use same opcode for all 8-bit branches\r |
366 | \r |
367 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
a6785576 |
368 | OpStart(op,size?0x10:0);\r |
cc68a136 |
369 | Cycles=10; // Assume branch taken\r |
370 | \r |
cc68a136 |
371 | if (cc==1) ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
372 | \r |
85a36a57 |
373 | switch (cc)\r |
cc68a136 |
374 | {\r |
85a36a57 |
375 | case 0: // T\r |
376 | case 1: // F\r |
377 | break;\r |
378 | case 2: // hi\r |
379 | ot(" tst r9,#0x60000000 ;@ hi: !C && !Z\n");\r |
380 | ot(" bne BccDontBranch%i\n\n",8<<size);\r |
381 | break;\r |
382 | case 3: // ls\r |
383 | ot(" tst r9,#0x60000000 ;@ ls: C || Z\n");\r |
384 | ot(" beq BccDontBranch%i\n\n",8<<size);\r |
385 | break;\r |
386 | default:\r |
387 | ot(";@ Is the condition true?\n");\r |
388 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
389 | ot(" b%s BccDontBranch%i\n\n",Cond[cc^1],8<<size);\r |
390 | break;\r |
cc68a136 |
391 | }\r |
cfb3dfa0 |
392 | \r |
85a36a57 |
393 | if (size) \r |
394 | {\r |
395 | if (size<2)\r |
396 | {\r |
397 | ot(" ldrsh r11,[r4] ;@ Fetch Branch offset\n");\r |
398 | }\r |
399 | else\r |
400 | {\r |
401 | ot(" ldrh r2,[r4] ;@ Fetch Branch offset\n");\r |
402 | ot(" ldrh r11,[r4,#2]\n");\r |
403 | ot(" orr r11,r11,r2,lsl #16\n");\r |
404 | }\r |
405 | }\r |
406 | else\r |
407 | {\r |
408 | ot(" mov r11,r8,asl #24 ;@ Shift 8-bit signed offset up...\n\n");\r |
409 | asr_r11=",asr #24";\r |
410 | }\r |
cc68a136 |
411 | \r |
412 | ot(";@ Branch taken - Add on r0 to PC\n");\r |
413 | \r |
414 | if (cc==1)\r |
415 | {\r |
416 | ot(";@ Bsr - remember old PC\n");\r |
417 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
85a36a57 |
418 | if (size) ot(" add r1,r1,#%d\n",1<<size);\r |
cc68a136 |
419 | ot(" mov r1,r1, lsl #8\n");\r |
85a36a57 |
420 | ot(" ldr r2,[r7,#0x3c]\n");\r |
cc68a136 |
421 | ot(" mov r1,r1, asr #8\n");\r |
422 | ot("\n");\r |
cc68a136 |
423 | ot(";@ Push r1 onto stack\n");\r |
424 | ot(" sub r0,r2,#4 ;@ Predecrement A7\n");\r |
425 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
426 | MemHandler(1,2);\r |
427 | ot("\n");\r |
428 | Cycles=18; // always 18\r |
cfb3dfa0 |
429 | if (offset==0 || offset==-1)\r |
430 | {\r |
431 | ot(";@ Branch is quite far, so may be a good idea to check Memory Base+pc\n");\r |
85a36a57 |
432 | ot(" add r0,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r |
433 | CheckPc(0);\r |
cfb3dfa0 |
434 | }\r |
85a36a57 |
435 | else\r |
436 | ot(" add r4,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r |
cc68a136 |
437 | }\r |
438 | else\r |
439 | {\r |
cfb3dfa0 |
440 | if (offset==0 || offset==-1)\r |
441 | {\r |
85a36a57 |
442 | ot(" add r0,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r |
cfb3dfa0 |
443 | ot(";@ Branch is quite far, so may be a good idea to check Memory Base+pc\n");\r |
444 | CheckPc(0);\r |
445 | }\r |
446 | else\r |
447 | {\r |
85a36a57 |
448 | ot(" add r4,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r |
cfb3dfa0 |
449 | ot("\n");\r |
450 | }\r |
cc68a136 |
451 | }\r |
452 | \r |
cfb3dfa0 |
453 | OpEnd(size?0x10:0);\r |
cc68a136 |
454 | \r |
85a36a57 |
455 | // since all "DontBranch" code is same for every size, output only once\r |
456 | if (cc>=2&&(op&0xff00)==0x6200)\r |
cc68a136 |
457 | {\r |
85a36a57 |
458 | ot("BccDontBranch%i%s\n", 8<<size, ms?"":":");\r |
459 | if (size) ot(" add r4,r4,#%d\n",8<<size);\r |
460 | Cycles+=(size==1) ? 2 : -2; // Branch not taken\r |
461 | OpEnd(0);\r |
cc68a136 |
462 | }\r |
463 | \r |
464 | return 0;\r |
465 | }\r |
466 | \r |