| 1 | \r |
| 2 | #include "app.h"\r |
| 3 | \r |
| 4 | static void CheckPc(int reg)\r |
| 5 | {\r |
| 6 | #if USE_CHECKPC_CALLBACK\r |
| 7 | ot(";@ Check Memory Base+pc (r4)\n");\r |
| 8 | if (reg != 0)\r |
| 9 | ot(" mov r0,r%i\n", reg);\r |
| 10 | ot(" mov lr,pc\n");\r |
| 11 | ot(" ldr pc,[r7,#0x64] ;@ Call checkpc()\n");\r |
| 12 | ot(" mov r4,r0\n");\r |
| 13 | #else\r |
| 14 | if (reg != 4)\r |
| 15 | ot(" mov r4,r%i\n", reg);\r |
| 16 | #endif\r |
| 17 | ot("\n");\r |
| 18 | }\r |
| 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 |
| 63 | ot(" add r0,r0,r10 ;@ Memory Base+PC\n");\r |
| 64 | ot("\n");\r |
| 65 | CheckPc(0);\r |
| 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 |
| 75 | OpStart(op,0x10);\r |
| 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 |
| 82 | Cycles=38; OpEnd(0x10);\r |
| 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 |
| 97 | OpStart(op,0x10);\r |
| 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 |
| 127 | OpEnd(0x10);\r |
| 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 |
| 139 | OpStart(op,0x10);\r |
| 140 | \r |
| 141 | ot(";@ Get An\n");\r |
| 142 | EaCalc(10, 7, 8, 2, 1);\r |
| 143 | EaRead(10, 0, 8, 2, 7, 1);\r |
| 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 |
| 154 | \r |
| 155 | Cycles=12;\r |
| 156 | OpEnd(0x10);\r |
| 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 |
| 175 | case 3: // rte\r |
| 176 | OpStart(op,0x10); Cycles=20;\r |
| 177 | SuperCheck(op);\r |
| 178 | PopSr(1);\r |
| 179 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
| 180 | PopPc();\r |
| 181 | SuperChange(op);\r |
| 182 | CheckInterrupt(op);\r |
| 183 | OpEnd(0x10);\r |
| 184 | SuperEnd(op);\r |
| 185 | return 0;\r |
| 186 | \r |
| 187 | case 5: // rts\r |
| 188 | OpStart(op,0x10); Cycles=16;\r |
| 189 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
| 190 | PopPc();\r |
| 191 | OpEnd(0x10);\r |
| 192 | return 0;\r |
| 193 | \r |
| 194 | case 6: // trapv\r |
| 195 | OpStart(op,0x10); Cycles=4;\r |
| 196 | ot(" tst r9,#0x10000000\n");\r |
| 197 | ot(" subne r5,r5,#%i\n",30);\r |
| 198 | ot(" movne r0,#0x1c ;@ TRAPV exception\n");\r |
| 199 | ot(" blne Exception\n");\r |
| 200 | OpEnd(0x10);\r |
| 201 | return 0;\r |
| 202 | \r |
| 203 | case 7: // rtr\r |
| 204 | OpStart(op,0x10); Cycles=20;\r |
| 205 | PopSr(0);\r |
| 206 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
| 207 | PopPc();\r |
| 208 | OpEnd(0x10);\r |
| 209 | return 0;\r |
| 210 | \r |
| 211 | default:\r |
| 212 | return 1;\r |
| 213 | }\r |
| 214 | }\r |
| 215 | \r |
| 216 | // --------------------- Opcodes 0x4e80+ ---------------------\r |
| 217 | // Emit a Jsr/Jmp opcode, 01001110 1meeeeee\r |
| 218 | int OpJsr(int op)\r |
| 219 | {\r |
| 220 | int use=0;\r |
| 221 | int sea=0;\r |
| 222 | \r |
| 223 | sea=op&0x003f;\r |
| 224 | \r |
| 225 | // See if we can do this opcode:\r |
| 226 | if (EaCanRead(sea,-1)==0) return 1;\r |
| 227 | \r |
| 228 | use=OpBase(op);\r |
| 229 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 230 | \r |
| 231 | OpStart(op,(op&0x40)?0:0x10);\r |
| 232 | \r |
| 233 | ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
| 234 | ot("\n");\r |
| 235 | EaCalc(11,0x003f,sea,0);\r |
| 236 | \r |
| 237 | ot(";@ Jump - Get new PC from r0\n");\r |
| 238 | if (op&0x40)\r |
| 239 | {\r |
| 240 | // Jmp - Get new PC from r0\r |
| 241 | ot(" add r0,r11,r10 ;@ Memory Base + New PC\n");\r |
| 242 | ot("\n");\r |
| 243 | }\r |
| 244 | else\r |
| 245 | {\r |
| 246 | ot(";@ Jsr - Push old PC first\n");\r |
| 247 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
| 248 | ot(" mov r1,r1,lsl #8\n");\r |
| 249 | ot(" ldr r0,[r7,#0x3c]\n");\r |
| 250 | ot(" mov r1,r1,asr #8\n");\r |
| 251 | ot(";@ Push r1 onto stack\n");\r |
| 252 | ot(" sub r0,r0,#4 ;@ Predecrement A7\n");\r |
| 253 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
| 254 | MemHandler(1,2);\r |
| 255 | ot(" add r0,r11,r10 ;@ Memory Base + New PC\n");\r |
| 256 | ot("\n");\r |
| 257 | }\r |
| 258 | \r |
| 259 | CheckPc(0);\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((op&0x40)?0:0x10);\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 | switch (cc)\r |
| 291 | {\r |
| 292 | case 0: // T\r |
| 293 | case 1: // F\r |
| 294 | break;\r |
| 295 | case 2: // hi\r |
| 296 | ot(" tst r9,#0x60000000 ;@ hi: !C && !Z\n");\r |
| 297 | ot(" beq DbraTrue%.4x\n\n",op);\r |
| 298 | break;\r |
| 299 | case 3: // ls\r |
| 300 | ot(" tst r9,#0x60000000 ;@ ls: C || Z\n");\r |
| 301 | ot(" bne DbraTrue%.4x\n\n",op);\r |
| 302 | break;\r |
| 303 | default:\r |
| 304 | ot(";@ Is the condition true?\n");\r |
| 305 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
| 306 | ot(";@ If so, don't dbra\n");\r |
| 307 | ot(" b%s DbraTrue%.4x\n\n",Cond[cc],op);\r |
| 308 | break;\r |
| 309 | }\r |
| 310 | \r |
| 311 | if (cc!=0)\r |
| 312 | {\r |
| 313 | ot(";@ Decrement Dn.w\n");\r |
| 314 | ot(" and r1,r8,#0x0007\n");\r |
| 315 | ot(" mov r1,r1,lsl #2\n");\r |
| 316 | ot(" ldrsh r0,[r7,r1]\n");\r |
| 317 | ot(" sub r0,r0,#1\n");\r |
| 318 | ot(" strh r0,[r7,r1]\n");\r |
| 319 | ot("\n");\r |
| 320 | \r |
| 321 | ot(";@ Check if Dn.w is -1\n");\r |
| 322 | ot(" cmn r0,#1\n");\r |
| 323 | ot("\n");\r |
| 324 | \r |
| 325 | ot(";@ Get Branch offset:\n");\r |
| 326 | ot(" ldrnesh r0,[r4]\n");\r |
| 327 | ot(" addeq r4,r4,#2 ;@ Skip branch offset\n");\r |
| 328 | ot(" subeq r5,r5,#4 ;@ additional cycles\n");\r |
| 329 | ot(" addne r4,r4,r0 ;@ r4 = New PC\n");\r |
| 330 | ot("\n");\r |
| 331 | Cycles=12-2;\r |
| 332 | OpEnd();\r |
| 333 | }\r |
| 334 | \r |
| 335 | if (cc==0||cc>=2)\r |
| 336 | {\r |
| 337 | ot(";@ condition true:\n");\r |
| 338 | ot("DbraTrue%.4x%s\n", op, ms?"":":");\r |
| 339 | ot(" add r4,r4,#2 ;@ Skip branch offset\n");\r |
| 340 | ot("\n");\r |
| 341 | Cycles=12;\r |
| 342 | OpEnd();\r |
| 343 | }\r |
| 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 |
| 355 | \r |
| 356 | offset=(char)(op&0xff);\r |
| 357 | cc=(op>>8)&15;\r |
| 358 | \r |
| 359 | // Special offsets:\r |
| 360 | if (offset==0) size=1;\r |
| 361 | if (offset==-1) size=2;\r |
| 362 | \r |
| 363 | if (size) use=op; // 16-bit or 32-bit\r |
| 364 | else use=(op&0xff00)+1; // Use same opcode for all 8-bit branches\r |
| 365 | \r |
| 366 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 367 | OpStart(op,size?0x10:0);\r |
| 368 | \r |
| 369 | ot(";@ Get Branch offset:\n");\r |
| 370 | if (size) \r |
| 371 | {\r |
| 372 | EaCalc(0,0,0x3c,size);\r |
| 373 | EaRead(0,0,0x3c,size,0);\r |
| 374 | }\r |
| 375 | else\r |
| 376 | ot(" mov r0,r8,asl #24 ;@ Shift 8-bit signed offset up...\n\n");\r |
| 377 | \r |
| 378 | // above code messes cycles\r |
| 379 | Cycles=10; // Assume branch taken\r |
| 380 | \r |
| 381 | if (cc==1) ot(" ldr r10,[r7,#0x60] ;@ Get Memory base\n");\r |
| 382 | \r |
| 383 | if (cc>=2)\r |
| 384 | {\r |
| 385 | ot(";@ Is the condition true?\n");\r |
| 386 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");\r |
| 387 | ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");\r |
| 388 | if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000\n");\r |
| 389 | \r |
| 390 | ot(" b%s DontBranch%.4x\n",Cond[cc^1],op);\r |
| 391 | ot("\n");\r |
| 392 | }\r |
| 393 | \r |
| 394 | if (size==0) ot(" mov r0,r0,asr #24 ;@ ...shift down\n\n");\r |
| 395 | \r |
| 396 | ot(";@ Branch taken - Add on r0 to PC\n");\r |
| 397 | \r |
| 398 | if (cc==1)\r |
| 399 | {\r |
| 400 | ot(";@ Bsr - remember old PC\n");\r |
| 401 | ot(" sub r1,r4,r10 ;@ r1 = Old PC\n");\r |
| 402 | ot(" mov r1,r1, lsl #8\n");\r |
| 403 | ot(" mov r1,r1, asr #8\n");\r |
| 404 | ot("\n");\r |
| 405 | if (size) ot(" sub r4,r4,#%d ;@ (Branch is relative to Opcode+2)\n",1<<size);\r |
| 406 | ot(" ldr r2,[r7,#0x3c]\n");\r |
| 407 | ot(" add r4,r4,r0 ;@ r4 = New PC\n");\r |
| 408 | ot(";@ Push r1 onto stack\n");\r |
| 409 | ot(" sub r0,r2,#4 ;@ Predecrement A7\n");\r |
| 410 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
| 411 | MemHandler(1,2);\r |
| 412 | ot("\n");\r |
| 413 | Cycles=18; // always 18\r |
| 414 | if (offset==0 || offset==-1)\r |
| 415 | {\r |
| 416 | ot(";@ Branch is quite far, so may be a good idea to check Memory Base+pc\n");\r |
| 417 | CheckPc(4);\r |
| 418 | }\r |
| 419 | }\r |
| 420 | else\r |
| 421 | {\r |
| 422 | if (size) ot(" sub r4,r4,#%d ;@ (Branch is relative to Opcode+2)\n",1<<size);\r |
| 423 | if (offset==0 || offset==-1)\r |
| 424 | {\r |
| 425 | ot(" add r0,r4,r0 ;@ r4 = New PC\n");\r |
| 426 | ot(";@ Branch is quite far, so may be a good idea to check Memory Base+pc\n");\r |
| 427 | CheckPc(0);\r |
| 428 | }\r |
| 429 | else\r |
| 430 | {\r |
| 431 | ot(" add r4,r4,r0 ;@ r4 = New PC\n");\r |
| 432 | ot("\n");\r |
| 433 | }\r |
| 434 | }\r |
| 435 | \r |
| 436 | \r |
| 437 | OpEnd(size?0x10:0);\r |
| 438 | \r |
| 439 | if (cc>=2)\r |
| 440 | {\r |
| 441 | ot("DontBranch%.4x%s\n", op, ms?"":":");\r |
| 442 | Cycles+=(size==1)? 2 : -2; // Branch not taken\r |
| 443 | OpEnd(size?0x10:0);\r |
| 444 | }\r |
| 445 | \r |
| 446 | return 0;\r |
| 447 | }\r |
| 448 | \r |