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1 | \r |
2 | #include "app.h"\r |
3 | \r |
4 | #if USE_CHECKPC_CALLBACK\r |
5 | static void CheckPc()\r |
6 | {\r |
7 | ot(";@ Check Memory Base+pc (r4)\n");\r |
8 | ot(" add lr,pc,#4\n");\r |
9 | ot(" mov r0,r4\n");\r |
10 | ot(" ldr pc,[r7,#0x64] ;@ Call checkpc()\n");\r |
11 | ot(" mov r4,r0\n");\r |
12 | ot("\n");\r |
13 | }\r |
14 | #endif\r |
15 | \r |
16 | // Push 32-bit value in r1 - trashes r0-r3,r12,lr\r |
17 | void OpPush32()\r |
18 | {\r |
19 | ot(";@ Push r1 onto stack\n");\r |
20 | ot(" ldr r0,[r7,#0x3c]\n");\r |
21 | ot(" sub r0,r0,#4 ;@ Predecrement A7\n");\r |
22 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
23 | MemHandler(1,2);\r |
24 | ot("\n");\r |
25 | }\r |
26 | \r |
27 | // Push SR - trashes r0-r3,r12,lr\r |
28 | void OpPushSr(int high)\r |
29 | {\r |
30 | ot(";@ Push SR:\n");\r |
31 | OpFlagsToReg(high);\r |
32 | ot(" ldr r0,[r7,#0x3c]\n");\r |
33 | ot(" sub r0,r0,#2 ;@ Predecrement A7\n");\r |
34 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
35 | MemHandler(1,1);\r |
36 | ot("\n");\r |
37 | }\r |
38 | \r |
39 | // Pop SR - trashes r0-r3\r |
40 | static void PopSr(int high)\r |
41 | {\r |
42 | ot(";@ Pop SR:\n");\r |
43 | ot(" ldr r0,[r7,#0x3c]\n");\r |
44 | ot(" add r1,r0,#2 ;@ Postincrement A7\n");\r |
45 | ot(" str r1,[r7,#0x3c] ;@ Save A7\n");\r |
46 | MemHandler(0,1);\r |
47 | ot("\n");\r |
48 | OpRegToFlags(high);\r |
49 | }\r |
50 | \r |
51 | // Pop PC - assumes r10=Memory Base - trashes r0-r3\r |
52 | static void PopPc()\r |
53 | {\r |
54 | ot(";@ Pop PC:\n");\r |
55 | ot(" ldr r0,[r7,#0x3c]\n");\r |
56 | ot(" add r1,r0,#4 ;@ Postincrement A7\n");\r |
57 | ot(" str r1,[r7,#0x3c] ;@ Save A7\n");\r |
58 | MemHandler(0,2);\r |
59 | ot(" add r4,r0,r10 ;@ r4=Memory Base+PC\n");\r |
60 | ot("\n");\r |
a6785576 |
61 | #if USE_CHECKPC_CALLBACK\r |
cc68a136 |
62 | CheckPc();\r |
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63 | #endif\r |
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64 | }\r |
65 | \r |
66 | int OpTrap(int op)\r |
67 | {\r |
68 | int use=0;\r |
69 | \r |
70 | use=op&~0xf;\r |
71 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
72 | \r |
a6785576 |
73 | OpStart(op,0x10);\r |
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74 | ot(" and r0,r8,#0xf ;@ Get trap number\n");\r |
75 | ot(" orr r0,r0,#0x20\n");\r |
76 | ot(" mov r0,r0,asl #2\n");\r |
77 | ot(" bl Exception\n");\r |
78 | ot("\n");\r |
79 | \r |
80 | Cycles=38; OpEnd();\r |
81 | \r |
82 | return 0;\r |
83 | }\r |
84 | \r |
85 | // --------------------- Opcodes 0x4e50+ ---------------------\r |
86 | int OpLink(int op)\r |
87 | {\r |
88 | int use=0,reg;\r |
89 | \r |
90 | use=op&~7;\r |
91 | reg=op&7;\r |
92 | if (reg==7) use=op;\r |
93 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
94 | \r |
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95 | OpStart(op,0x10);\r |
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96 | \r |
97 | if(reg!=7) {\r |
98 | ot(";@ Get An\n");\r |
99 | EaCalc(10, 7, 8, 2, 1);\r |
100 | EaRead(10, 1, 8, 2, 7, 1);\r |
101 | }\r |
102 | \r |
103 | ot(" ldr r0,[r7,#0x3c] ;@ Get A7\n");\r |
104 | ot(" sub r0,r0,#4 ;@ A7-=4\n");\r |
105 | ot(" mov r11,r0\n");\r |
106 | if(reg==7) ot(" mov r1,r0\n");\r |
107 | ot("\n");\r |
108 | \r |
109 | ot(";@ Write An to Stack\n");\r |
110 | MemHandler(1,2);\r |
111 | \r |
112 | ot(";@ Save to An\n");\r |
113 | if(reg!=7)\r |
114 | EaWrite(10,11, 8, 2, 7, 1);\r |
115 | \r |
116 | ot(";@ Get offset:\n");\r |
117 | EaCalc(0,0,0x3c,1);\r |
118 | EaRead(0,0,0x3c,1,0);\r |
119 | \r |
120 | ot(" add r11,r11,r0 ;@ Add offset to A7\n");\r |
121 | ot(" str r11,[r7,#0x3c]\n");\r |
122 | ot("\n");\r |
123 | \r |
124 | Cycles=16;\r |
125 | OpEnd();\r |
126 | return 0;\r |
127 | }\r |
128 | \r |
129 | // --------------------- Opcodes 0x4e58+ ---------------------\r |
130 | int OpUnlk(int op)\r |
131 | {\r |
132 | int use=0;\r |
133 | \r |
134 | use=op&~7;\r |
135 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
136 | \r |
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137 | OpStart(op,0x10);\r |
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138 | \r |
139 | ot(";@ Get An\n");\r |
140 | EaCalc(10, 7, 8, 2, 1);\r |
141 | EaRead(10, 0, 8, 2, 7, 1);\r |
142 | \r |
143 | ot(" add r11,r0,#4 ;@ A7+=4\n");\r |
144 | ot("\n");\r |
145 | ot(";@ Pop An from stack:\n");\r |
146 | MemHandler(0,2);\r |
147 | ot("\n");\r |
148 | ot(" str r11,[r7,#0x3c] ;@ Save A7\n");\r |
149 | ot("\n");\r |
150 | ot(";@ An = value from stack:\n");\r |
151 | EaWrite(10, 0, 8, 2, 7, 1);\r |
152 | \r |
153 | Cycles=12;\r |
154 | OpEnd();\r |
155 | return 0;\r |
156 | }\r |
157 | \r |
158 | // --------------------- Opcodes 0x4e70+ ---------------------\r |
159 | int Op4E70(int op)\r |
160 | {\r |
161 | int type=0;\r |
162 | \r |
163 | type=op&7; // 01001110 01110ttt, reset/nop/stop/rte/rtd/rts/trapv/rtr\r |
164 | \r |
165 | switch (type)\r |
166 | {\r |
167 | case 1: // nop\r |
168 | OpStart(op);\r |
169 | Cycles=4;\r |
170 | OpEnd();\r |
171 | return 0;\r |
172 | \r |
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173 | case 3: // rte\r |
174 | OpStart(op,0x10); Cycles=20;\r |
175 | SuperCheck(op);\r |
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176 | PopSr(1);\r |
177 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
178 | PopPc();\r |
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179 | SuperChange(op);\r |
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180 | CheckInterrupt(op);\r |
181 | OpEnd();\r |
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182 | SuperEnd(op);\r |
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183 | return 0;\r |
184 | \r |
185 | case 5: // rts\r |
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186 | OpStart(op,0x10); Cycles=16;\r |
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187 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
188 | PopPc();\r |
189 | OpEnd();\r |
190 | return 0;\r |
191 | \r |
192 | case 6: // trapv\r |
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193 | OpStart(op,0x10); Cycles=4;\r |
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194 | ot(" tst r9,#0x10000000\n");\r |
195 | ot(" subne r5,r5,#%i\n",30);\r |
196 | ot(" movne r0,#0x1c ;@ TRAPV exception\n");\r |
197 | ot(" blne Exception\n");\r |
198 | OpEnd();\r |
199 | return 0;\r |
200 | \r |
201 | case 7: // rtr\r |
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202 | OpStart(op,0x10); Cycles=20;\r |
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203 | PopSr(0);\r |
204 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
205 | PopPc();\r |
206 | OpEnd();\r |
207 | return 0;\r |
208 | \r |
209 | default:\r |
210 | return 1;\r |
211 | }\r |
212 | }\r |
213 | \r |
214 | // --------------------- Opcodes 0x4e80+ ---------------------\r |
215 | // Emit a Jsr/Jmp opcode, 01001110 1meeeeee\r |
216 | int OpJsr(int op)\r |
217 | {\r |
218 | int use=0;\r |
219 | int sea=0;\r |
220 | \r |
221 | sea=op&0x003f;\r |
222 | \r |
223 | // See if we can do this opcode:\r |
224 | if (EaCanRead(sea,-1)==0) return 1;\r |
225 | \r |
226 | use=OpBase(op);\r |
227 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
228 | \r |
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229 | OpStart(op,0x10);\r |
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230 | \r |
231 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
232 | ot("\n");\r |
233 | EaCalc(0,0x003f,sea,0);\r |
234 | \r |
235 | ot(";@ Jump - Get new PC from r0\n");\r |
236 | if (op&0x40)\r |
237 | {\r |
238 | // Jmp - Get new PC from r0\r |
239 | ot(" add r4,r0,r10 ;@ r4 = Memory Base + New PC\n");\r |
240 | ot("\n");\r |
241 | }\r |
242 | else\r |
243 | {\r |
244 | ot(";@ Jsr - Push old PC first\n");\r |
245 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
246 | ot(" add r4,r0,r10 ;@ r4 = Memory Base + New PC\n");\r |
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 |
254 | ot("\n");\r |
255 | }\r |
256 | \r |
257 | #if USE_CHECKPC_CALLBACK\r |
258 | CheckPc();\r |
259 | #endif\r |
260 | \r |
261 | Cycles=(op&0x40) ? 4 : 12;\r |
262 | Cycles+=Ea_add_ns((op&0x40) ? g_jmp_cycle_table : g_jsr_cycle_table, sea);\r |
263 | \r |
264 | OpEnd();\r |
265 | \r |
266 | return 0;\r |
267 | }\r |
268 | \r |
269 | // --------------------- Opcodes 0x50c8+ ---------------------\r |
270 | \r |
271 | // ARM version of 68000 condition codes:\r |
272 | static char *Cond[16]=\r |
273 | {\r |
274 | "", "", "hi","ls","cc","cs","ne","eq",\r |
275 | "vc","vs","pl","mi","ge","lt","gt","le"\r |
276 | };\r |
277 | \r |
278 | // Emit a Dbra opcode, 0101cccc 11001nnn vv\r |
279 | int OpDbra(int op)\r |
280 | {\r |
281 | int use=0;\r |
282 | int cc=0;\r |
283 | \r |
284 | use=op&~7; // Use same handler\r |
285 | cc=(op>>8)&15;\r |
286 | \r |
287 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
288 | OpStart(op);\r |
289 | \r |
290 | if (cc>=2)\r |
291 | {\r |
292 | ot(";@ Is the condition true?\n");\r |
293 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");\r |
294 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
295 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000\n");\r |
296 | ot(";@ If so, don't dbra\n");\r |
297 | ot(" b%s DbraTrue%.4x\n",Cond[cc],op);\r |
298 | ot("\n");\r |
299 | }\r |
300 | \r |
301 | ot(";@ Decrement Dn.w\n");\r |
302 | ot(" and r1,r8,#0x0007\n");\r |
303 | ot(" mov r1,r1,lsl #2\n");\r |
304 | ot(" ldrsh r0,[r7,r1]\n");\r |
305 | ot(" sub r0,r0,#1\n");\r |
306 | ot(" strh r0,[r7,r1]\n");\r |
307 | ot("\n");\r |
308 | \r |
309 | ot(";@ Check if Dn.w is -1\n");\r |
310 | ot(" cmps r0,#-1\n");\r |
311 | ot(" beq DbraMin1%.4x\n",op);\r |
312 | ot("\n");\r |
313 | \r |
314 | ot(";@ Get Branch offset:\n");\r |
315 | ot(" ldrsh r0,[r4]\n");\r |
316 | ot(" add r4,r4,r0 ;@ r4 = New PC\n");\r |
317 | ot("\n");\r |
318 | Cycles=12-2;\r |
319 | OpEnd();\r |
320 | \r |
321 | ot(";@ Dn.w is -1:\n");\r |
322 | ot("DbraMin1%.4x%s\n", op, ms?"":":");\r |
323 | ot(" add r4,r4,#2 ;@ Skip branch offset\n");\r |
324 | ot("\n");\r |
325 | Cycles=12+2;\r |
326 | OpEnd();\r |
327 | \r |
328 | ot(";@ condition true:\n");\r |
329 | ot("DbraTrue%.4x%s\n", op, ms?"":":");\r |
330 | ot(" add r4,r4,#2 ;@ Skip branch offset\n");\r |
331 | ot("\n");\r |
332 | Cycles=12;\r |
333 | OpEnd();\r |
334 | \r |
335 | return 0;\r |
336 | }\r |
337 | \r |
338 | // --------------------- Opcodes 0x6000+ ---------------------\r |
339 | // Emit a Branch opcode 0110cccc nn (cccc=condition)\r |
340 | int OpBranch(int op)\r |
341 | {\r |
342 | int size=0,use=0;\r |
343 | int offset=0;\r |
344 | int cc=0;\r |
345 | \r |
346 | offset=(char)(op&0xff);\r |
347 | cc=(op>>8)&15;\r |
348 | \r |
349 | // Special offsets:\r |
350 | if (offset==0) size=1;\r |
351 | if (offset==-1) size=2;\r |
352 | \r |
353 | if (size) use=op; // 16-bit or 32-bit\r |
354 | else use=(op&0xff00)+1; // Use same opcode for all 8-bit branches\r |
355 | \r |
356 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
a6785576 |
357 | OpStart(op,size?0x10:0);\r |
cc68a136 |
358 | \r |
359 | ot(";@ Get Branch offset:\n");\r |
360 | if (size) \r |
361 | {\r |
362 | EaCalc(0,0,0x3c,size);\r |
363 | EaRead(0,0,0x3c,size,0);\r |
364 | }\r |
365 | \r |
366 | // above code messes cycles\r |
367 | Cycles=10; // Assume branch taken\r |
368 | \r |
369 | if (size==0) ot(" mov r0,r8,asl #24 ;@ Shift 8-bit signed offset up...\n\n");\r |
370 | \r |
371 | if (cc==1) ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
372 | \r |
373 | if (cc>=2)\r |
374 | {\r |
375 | ot(";@ Is the condition true?\n");\r |
376 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");\r |
377 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
378 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000\n");\r |
379 | \r |
380 | if (size==0) ot(" mov r0,r0,asr #24 ;@ ...shift down\n\n");\r |
381 | \r |
382 | ot(" b%s DontBranch%.4x\n",Cond[cc^1],op);\r |
383 | \r |
384 | ot("\n");\r |
385 | }\r |
386 | else\r |
387 | {\r |
388 | if (size==0) ot(" mov r0,r0,asr #24 ;@ ...shift down\n\n");\r |
389 | }\r |
390 | \r |
391 | ot(";@ Branch taken - Add on r0 to PC\n");\r |
392 | \r |
393 | if (cc==1)\r |
394 | {\r |
395 | ot(";@ Bsr - remember old PC\n");\r |
396 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
397 | ot(" mov r1,r1, lsl #8\n");\r |
398 | ot(" mov r1,r1, asr #8\n");\r |
399 | ot("\n");\r |
400 | if (size) ot(" sub r4,r4,#%d ;@ (Branch is relative to Opcode+2)\n",1<<size);\r |
401 | ot(" ldr r2,[r7,#0x3c]\n");\r |
402 | ot(" add r4,r4,r0 ;@ r4 = New PC\n");\r |
403 | ot(";@ Push r1 onto stack\n");\r |
404 | ot(" sub r0,r2,#4 ;@ Predecrement A7\n");\r |
405 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
406 | MemHandler(1,2);\r |
407 | ot("\n");\r |
408 | Cycles=18; // always 18\r |
409 | }\r |
410 | else\r |
411 | {\r |
412 | if (size) ot(" sub r4,r4,#%d ;@ (Branch is relative to Opcode+2)\n",1<<size);\r |
413 | ot(" add r4,r4,r0 ;@ r4 = New PC\n");\r |
414 | ot("\n");\r |
415 | }\r |
416 | \r |
417 | #if USE_CHECKPC_CALLBACK\r |
418 | if (offset==0 || offset==-1)\r |
419 | {\r |
420 | ot(";@ Branch is quite far, so may be a good idea to check Memory Base+pc\n");\r |
421 | CheckPc();\r |
422 | }\r |
423 | #endif\r |
424 | \r |
425 | OpEnd();\r |
426 | \r |
427 | if (cc>=2)\r |
428 | {\r |
429 | ot("DontBranch%.4x%s\n", op, ms?"":":");\r |
430 | Cycles+=(size==1)? 2 : -2; // Branch not taken\r |
431 | OpEnd();\r |
432 | }\r |
433 | \r |
434 | return 0;\r |
435 | }\r |
436 | \r |