| 1 | \r |
| 2 | // This file is part of the Cyclone 68000 Emulator\r |
| 3 | \r |
| 4 | // This code is licensed under the GNU General Public License version 2.0 and the MAME License.\r |
| 5 | // You can choose the license that has the most advantages for you.\r |
| 6 | \r |
| 7 | // SVN repository can be found at http://code.google.com/p/cyclone68000/\r |
| 8 | \r |
| 9 | #include "app.h"\r |
| 10 | \r |
| 11 | // --------------------- Opcodes 0x1000+ ---------------------\r |
| 12 | // Emit a Move opcode, 00xxdddd ddssssss\r |
| 13 | int OpMove(int op)\r |
| 14 | {\r |
| 15 | int sea=0,tea=0;\r |
| 16 | int size=0,use=0;\r |
| 17 | int movea=0;\r |
| 18 | \r |
| 19 | // Get source and target EA\r |
| 20 | sea = op&0x003f;\r |
| 21 | tea =(op&0x01c0)>>3;\r |
| 22 | tea|=(op&0x0e00)>>9;\r |
| 23 | \r |
| 24 | if (tea>=8 && tea<0x10) movea=1;\r |
| 25 | \r |
| 26 | // Find size extension\r |
| 27 | switch (op&0x3000)\r |
| 28 | {\r |
| 29 | default: return 1;\r |
| 30 | case 0x1000: size=0; break;\r |
| 31 | case 0x3000: size=1; break;\r |
| 32 | case 0x2000: size=2; break;\r |
| 33 | }\r |
| 34 | \r |
| 35 | if (movea && size<1) return 1; // movea.b is invalid\r |
| 36 | \r |
| 37 | // See if we can do this opcode:\r |
| 38 | if (EaCanRead (sea,size)==0) return 1;\r |
| 39 | if (EaCanWrite(tea )==0) return 1;\r |
| 40 | \r |
| 41 | use=OpBase(op);\r |
| 42 | if (tea<0x38) use&=~0x0e00; // Use same handler for register ?0-7\r |
| 43 | \r |
| 44 | if (tea>=0x18 && tea<0x28 && (tea&7)==7) use|=0x0e00; // Specific handler for (a7)+ and -(a7)\r |
| 45 | \r |
| 46 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 47 | \r |
| 48 | OpStart(op); Cycles=4;\r |
| 49 | \r |
| 50 | EaCalc(0,0x003f,sea,size);\r |
| 51 | EaRead(0, 0,sea,size);\r |
| 52 | \r |
| 53 | ot(" adds r1,r0,#0 ;@ Defines NZ, clears CV\n");\r |
| 54 | \r |
| 55 | if (movea==0) ot(" mrs r9,cpsr ;@ r9=NZCV flags\n");\r |
| 56 | ot("\n");\r |
| 57 | \r |
| 58 | if (movea) size=2; // movea always expands to 32-bits\r |
| 59 | \r |
| 60 | EaCalc (0,0x0e00,tea,size);\r |
| 61 | EaWrite(0, 1,tea,size);\r |
| 62 | \r |
| 63 | OpEnd();\r |
| 64 | return 0;\r |
| 65 | }\r |
| 66 | \r |
| 67 | // --------------------- Opcodes 0x41c0+ ---------------------\r |
| 68 | // Emit an Lea opcode, 0100nnn1 11aaaaaa\r |
| 69 | int OpLea(int op)\r |
| 70 | {\r |
| 71 | int use=0;\r |
| 72 | int sea=0,tea=0;\r |
| 73 | \r |
| 74 | sea= op&0x003f;\r |
| 75 | tea=(op&0x0e00)>>9; tea|=8;\r |
| 76 | \r |
| 77 | if (EaCanRead(sea,-1)==0) return 1; // See if we can do this opcode:\r |
| 78 | \r |
| 79 | use=OpBase(op);\r |
| 80 | use&=~0x0e00; // Also use 1 handler for target ?0-7\r |
| 81 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 82 | \r |
| 83 | OpStart(op); Cycles=4;\r |
| 84 | \r |
| 85 | EaCalc (1,0x003f,sea,0); // Lea\r |
| 86 | EaCalc (0,0x0e00,tea,2);\r |
| 87 | EaWrite(0, 1,tea,2);\r |
| 88 | \r |
| 89 | if (Amatch)\r |
| 90 | {\r |
| 91 | // Correct?\r |
| 92 | if (sea< 0x18) Cycles+=4;\r |
| 93 | else if (sea==0x30) Cycles+=12;\r |
| 94 | else Cycles+=8;\r |
| 95 | }\r |
| 96 | \r |
| 97 | OpEnd();\r |
| 98 | \r |
| 99 | return 0;\r |
| 100 | }\r |
| 101 | \r |
| 102 | // --------------------- Opcodes 0x40c0+ ---------------------\r |
| 103 | \r |
| 104 | // Pack our flags into r1, in SR/CCR register format\r |
| 105 | // trashes r0,r2\r |
| 106 | void OpFlagsToReg(int high)\r |
| 107 | {\r |
| 108 | ot(" mov r1,r9,lsr #28 ;@ ____NZCV\n");\r |
| 109 | ot(" eor r0,r1,r1,ror #1 ;@ Bit 0=C^V\n");\r |
| 110 | ot(" tst r0,#1 ;@ 1 if C!=V\n");\r |
| 111 | ot(" eorne r1,r1,#3 ;@ ____NZVC\n");\r |
| 112 | ot("\n");\r |
| 113 | ot(" ldrb r0,[r7,#0x45] ;@ X bit\n");\r |
| 114 | if (high) ot(" ldrb r2,[r7,#0x44] ;@ Include SR high\n");\r |
| 115 | ot(" and r0,r0,#0x02\n");\r |
| 116 | if (high) ot(" orr r1,r1,r2,lsl #8\n");\r |
| 117 | ot(" orr r1,r1,r0,lsl #3 ;@ ___XNZVC\n");\r |
| 118 | ot("\n");\r |
| 119 | }\r |
| 120 | \r |
| 121 | // Convert SR/CRR register in r0 to our flags\r |
| 122 | // trashes r0,r1\r |
| 123 | void OpRegToFlags(int high)\r |
| 124 | {\r |
| 125 | ot(" eor r1,r0,r0,ror #1 ;@ Bit 0=C^V\n");\r |
| 126 | ot(" mov r2,r0,lsr #3 ;@ r2=___XN\n");\r |
| 127 | ot(" tst r1,#1 ;@ 1 if C!=V\n");\r |
| 128 | ot(" eorne r0,r0,#3 ;@ ___XNZCV\n");\r |
| 129 | ot(" strb r2,[r7,#0x45] ;@ Store X bit\n");\r |
| 130 | ot(" mov r9,r0,lsl #28 ;@ r9=NZCV...\n");\r |
| 131 | \r |
| 132 | if (high)\r |
| 133 | {\r |
| 134 | ot(" mov r0,r0,ror #8\n");\r |
| 135 | ot(" strb r0,[r7,#0x44] ;@ Store SR high\n");\r |
| 136 | }\r |
| 137 | ot("\n");\r |
| 138 | }\r |
| 139 | \r |
| 140 | static void SuperCheck(int op)\r |
| 141 | {\r |
| 142 | ot(" ldrb r0,[r7,#0x44] ;@ Get SR high\n");\r |
| 143 | ot(" tst r0,#0x20 ;@ Check we are in supervisor mode\n");\r |
| 144 | ot(" beq WrongMode%.4x ;@ No\n",op);\r |
| 145 | ot("\n");\r |
| 146 | }\r |
| 147 | \r |
| 148 | static void SuperEnd(int op)\r |
| 149 | {\r |
| 150 | ot("WrongMode%.4x%s\n",op,ms?"":":");\r |
| 151 | ot(";@ todo - cause an exception\n");\r |
| 152 | OpEnd();\r |
| 153 | }\r |
| 154 | \r |
| 155 | // Move SR opcode, 01000tt0 11aaaaaa move to SR\r |
| 156 | int OpMoveSr(int op)\r |
| 157 | {\r |
| 158 | int type=0,ea=0;\r |
| 159 | int use=0,size=1;\r |
| 160 | \r |
| 161 | type=(op>>9)&3;\r |
| 162 | ea=op&0x3f;\r |
| 163 | \r |
| 164 | switch(type)\r |
| 165 | {\r |
| 166 | case 0: case 1:\r |
| 167 | if (EaCanWrite(ea)==0) return 1; // See if we can do this opcode:\r |
| 168 | break;\r |
| 169 | \r |
| 170 | default: return 1; // todo\r |
| 171 | \r |
| 172 | case 2: case 3:\r |
| 173 | if (EaCanRead(ea,size)==0) return 1; // See if we can do this opcode:\r |
| 174 | break;\r |
| 175 | }\r |
| 176 | \r |
| 177 | use=OpBase(op);\r |
| 178 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 179 | \r |
| 180 | OpStart(op);\r |
| 181 | if (type==0) Cycles=8;\r |
| 182 | else if (type==1) Cycles=6;\r |
| 183 | else Cycles=12;\r |
| 184 | \r |
| 185 | if (Amatch && ea==0x3c) Cycles-=4; // Correct?\r |
| 186 | \r |
| 187 | if (type==0 || type==3) SuperCheck(op);\r |
| 188 | \r |
| 189 | if (type==0 || type==1)\r |
| 190 | {\r |
| 191 | OpFlagsToReg(type==0);\r |
| 192 | EaCalc (0,0x003f,ea,size);\r |
| 193 | EaWrite(0, 1,ea,size);\r |
| 194 | }\r |
| 195 | \r |
| 196 | if (type==2 || type==3)\r |
| 197 | {\r |
| 198 | EaCalc(0,0x003f,ea,size);\r |
| 199 | EaRead(0, 0,ea,size);\r |
| 200 | OpRegToFlags(type==3);\r |
| 201 | if (type==3) CheckInterrupt();\r |
| 202 | }\r |
| 203 | \r |
| 204 | OpEnd();\r |
| 205 | \r |
| 206 | if (type==0 || type==3) SuperEnd(op);\r |
| 207 | \r |
| 208 | return 0;\r |
| 209 | }\r |
| 210 | \r |
| 211 | \r |
| 212 | // Ori/Andi/Eori $nnnn,sr 0000t0t0 01111100\r |
| 213 | int OpArithSr(int op)\r |
| 214 | {\r |
| 215 | int type=0,ea=0;\r |
| 216 | int use=0,size=0;\r |
| 217 | \r |
| 218 | type=(op>>9)&5; if (type==4) return 1;\r |
| 219 | size=(op>>6)&1;\r |
| 220 | ea=0x3c;\r |
| 221 | \r |
| 222 | use=OpBase(op);\r |
| 223 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 224 | \r |
| 225 | OpStart(op); Cycles=16;\r |
| 226 | \r |
| 227 | SuperCheck(op);\r |
| 228 | \r |
| 229 | EaCalc(0,0x003f,ea,size);\r |
| 230 | EaRead(0, 10,ea,size);\r |
| 231 | \r |
| 232 | OpFlagsToReg(size);\r |
| 233 | if (type==0) ot(" orr r0,r1,r10\n");\r |
| 234 | if (type==1) ot(" and r0,r1,r10\n");\r |
| 235 | if (type==5) ot(" eor r0,r1,r10\n");\r |
| 236 | OpRegToFlags(size);\r |
| 237 | if (size) CheckInterrupt();\r |
| 238 | \r |
| 239 | OpEnd();\r |
| 240 | SuperEnd(op);\r |
| 241 | \r |
| 242 | return 0;\r |
| 243 | }\r |
| 244 | \r |
| 245 | // --------------------- Opcodes 0x4850+ ---------------------\r |
| 246 | // Emit an Pea opcode, 01001000 01aaaaaa\r |
| 247 | int OpPea(int op)\r |
| 248 | {\r |
| 249 | int use=0;\r |
| 250 | int ea=0;\r |
| 251 | \r |
| 252 | ea=op&0x003f; if (ea<0x10) return 1; // Swap opcode\r |
| 253 | if (EaCanRead(ea,-1)==0) return 1; // See if we can do this opcode:\r |
| 254 | \r |
| 255 | use=OpBase(op);\r |
| 256 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 257 | \r |
| 258 | OpStart(op); Cycles=20;\r |
| 259 | \r |
| 260 | EaCalc (1,0x003f, ea,0);\r |
| 261 | ot("\n");\r |
| 262 | ot(" ldr r0,[r7,#0x3c]\n");\r |
| 263 | ot(" sub r0,r0,#4 ;@ Predecrement A7\n");\r |
| 264 | ot(" str r0,[r7,#0x3c] ;@ Save A7\n");\r |
| 265 | ot("\n");\r |
| 266 | MemHandler(1,2); // Write 32-bit\r |
| 267 | ot("\n");\r |
| 268 | \r |
| 269 | OpEnd();\r |
| 270 | \r |
| 271 | return 0;\r |
| 272 | }\r |
| 273 | \r |
| 274 | // --------------------- Opcodes 0x4880+ ---------------------\r |
| 275 | // Emit a Movem opcode, 01001d00 1xeeeeee regmask\r |
| 276 | int OpMovem(int op)\r |
| 277 | {\r |
| 278 | int size=0,ea=0,cea=0,dir=0;\r |
| 279 | int use=0,decr=0,change=0;\r |
| 280 | \r |
| 281 | size=((op>>6)&1)+1;\r |
| 282 | ea=op&0x003f;\r |
| 283 | dir=(op>>10)&1; // Direction\r |
| 284 | \r |
| 285 | if (ea<0x10 || ea>0x39) return 1; // Invalid EA\r |
| 286 | if ((ea&0x38)==0x18 || (ea&0x38)==0x20) change=1;\r |
| 287 | if ((ea&0x38)==0x20) decr=1; // -(An), bitfield is decr\r |
| 288 | \r |
| 289 | // See if we can do this opcode:\r |
| 290 | if (EaCanWrite(ea)==0) return 1;\r |
| 291 | \r |
| 292 | cea=ea; if (change) cea=0x10;\r |
| 293 | \r |
| 294 | use=OpBase(op);\r |
| 295 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 296 | \r |
| 297 | OpStart(op);\r |
| 298 | \r |
| 299 | ot(" stmdb sp!,{r9} ;@ Push r9\n");\r |
| 300 | ot(" ldrh r11,[r4],#2 ;@ r11=register mask\n");\r |
| 301 | \r |
| 302 | ot("\n");\r |
| 303 | ot(";@ Get the address into r9:\n");\r |
| 304 | EaCalc(9,0x003f,cea,size);\r |
| 305 | \r |
| 306 | ot(";@ r10=Register Index*4:\n");\r |
| 307 | if (decr) ot(" mov r10,#0x3c ;@ order reversed for -(An)\n");\r |
| 308 | else ot(" mov r10,#0\n");\r |
| 309 | \r |
| 310 | ot("\n");\r |
| 311 | ot("MoreReg%.4x%s\n",op, ms?"":":");\r |
| 312 | \r |
| 313 | ot(" tst r11,#1\n");\r |
| 314 | ot(" beq SkipReg%.4x\n",op);\r |
| 315 | ot("\n");\r |
| 316 | \r |
| 317 | if (decr) ot(" sub r9,r9,#%d ;@ Pre-decrement address\n",1<<size);\r |
| 318 | \r |
| 319 | if (dir)\r |
| 320 | {\r |
| 321 | ot(" ;@ Copy memory to register:\n",1<<size);\r |
| 322 | EaRead (9,0,ea,size);\r |
| 323 | ot(" str r0,[r7,r10] ;@ Save value into Dn/An\n");\r |
| 324 | }\r |
| 325 | else\r |
| 326 | {\r |
| 327 | ot(" ;@ Copy register to memory:\n",1<<size);\r |
| 328 | ot(" ldr r1,[r7,r10] ;@ Load value from Dn/An\n");\r |
| 329 | EaWrite(9,1,ea,size);\r |
| 330 | }\r |
| 331 | \r |
| 332 | if (decr==0) ot(" add r9,r9,#%d ;@ Post-increment address\n",1<<size);\r |
| 333 | \r |
| 334 | ot(" sub r5,r5,#%d ;@ Take some cycles\n",2<<size);\r |
| 335 | ot("\n");\r |
| 336 | ot("SkipReg%.4x%s\n",op, ms?"":":");\r |
| 337 | ot(" movs r11,r11,lsr #1;@ Shift mask:\n");\r |
| 338 | ot(" add r10,r10,#%d ;@ r10=Next Register\n",decr?-4:4);\r |
| 339 | ot(" bne MoreReg%.4x\n",op);\r |
| 340 | ot("\n");\r |
| 341 | \r |
| 342 | if (change)\r |
| 343 | {\r |
| 344 | ot(";@ Write back address:\n");\r |
| 345 | EaCalc (0,0x0007,8|(ea&7),2);\r |
| 346 | EaWrite(0, 9,8|(ea&7),2);\r |
| 347 | }\r |
| 348 | \r |
| 349 | ot(" ldmia sp!,{r9} ;@ Pop r9\n");\r |
| 350 | ot("\n");\r |
| 351 | \r |
| 352 | if (ea<0x10) { }\r |
| 353 | else if (ea<0x18) Cycles=16; // (a0)\r |
| 354 | else if (ea<0x20) Cycles= 0; // (a0)+ ?\r |
| 355 | else if (ea<0x28) Cycles= 8; //-(a0)\r |
| 356 | else if (ea<0x30) Cycles=24; // ($3333,a0)\r |
| 357 | else if (ea<0x38) Cycles=28; // ($33,a0,d3.w*2)\r |
| 358 | else if (ea<0x39) Cycles=24; // $3333.w\r |
| 359 | else if (ea<0x3a) Cycles=28; // $33333333.l\r |
| 360 | \r |
| 361 | OpEnd();\r |
| 362 | \r |
| 363 | return 0;\r |
| 364 | }\r |
| 365 | \r |
| 366 | // --------------------- Opcodes 0x4e60+ ---------------------\r |
| 367 | // Emit a Move USP opcode, 01001110 0110dnnn move An to/from USP\r |
| 368 | int OpMoveUsp(int op)\r |
| 369 | {\r |
| 370 | int use=0,dir=0;\r |
| 371 | \r |
| 372 | dir=(op>>3)&1; // Direction\r |
| 373 | use=op&~0x0007; // Use same opcode for all An\r |
| 374 | \r |
| 375 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 376 | \r |
| 377 | OpStart(op); Cycles=4;\r |
| 378 | \r |
| 379 | ot(" ldrb r0,[r7,#0x44] ;@ Get SR\n");\r |
| 380 | ot(" tst r0,#0x20 ;@ Check we are in supervisor mode\n");\r |
| 381 | ot(" beq WrongMode%.4x ;@ No\n",op);\r |
| 382 | ot("\n");\r |
| 383 | \r |
| 384 | if (dir)\r |
| 385 | {\r |
| 386 | EaCalc (0,0x0007,8,2);\r |
| 387 | ot(" ldr r1,[r7,#0x48] ;@ Get from USP\n\n");\r |
| 388 | EaWrite(0, 1,8,2);\r |
| 389 | }\r |
| 390 | else\r |
| 391 | {\r |
| 392 | EaCalc (0,0x0007,8,2);\r |
| 393 | EaRead (0, 0,8,2);\r |
| 394 | ot(" str r0,[r7,#0x48] ;@ Put in USP\n\n");\r |
| 395 | }\r |
| 396 | \r |
| 397 | OpEnd();\r |
| 398 | \r |
| 399 | ot("WrongMode%.4x%s\n",op,ms?"":":");\r |
| 400 | ot(";@ todo - cause an exception\n");\r |
| 401 | OpEnd();\r |
| 402 | \r |
| 403 | return 0;\r |
| 404 | }\r |
| 405 | \r |
| 406 | // --------------------- Opcodes 0x7000+ ---------------------\r |
| 407 | // Emit a Move Quick opcode, 0111nnn0 dddddddd moveq #dd,Dn\r |
| 408 | int OpMoveq(int op)\r |
| 409 | {\r |
| 410 | int use=0;\r |
| 411 | \r |
| 412 | use=op&0xf100; // Use same opcode for all values\r |
| 413 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 414 | \r |
| 415 | OpStart(op); Cycles=4;\r |
| 416 | \r |
| 417 | ot(" movs r0,r8,asl #24\n");\r |
| 418 | ot(" and r1,r8,#0x0e00\n");\r |
| 419 | ot(" mov r0,r0,asr #24 ;@ Sign extended Quick value\n");\r |
| 420 | ot(" mrs r9,cpsr ;@ r9=NZ flags\n");\r |
| 421 | ot(" str r0,[r7,r1,lsr #7] ;@ Store into Dn\n");\r |
| 422 | ot("\n");\r |
| 423 | \r |
| 424 | OpEnd();\r |
| 425 | \r |
| 426 | return 0;\r |
| 427 | }\r |
| 428 | \r |
| 429 | // --------------------- Opcodes 0xc140+ ---------------------\r |
| 430 | // Emit a Exchange opcode:\r |
| 431 | // 1100ttt1 01000sss exg ds,dt\r |
| 432 | // 1100ttt1 01001sss exg as,at\r |
| 433 | // 1100ttt1 10001sss exg as,dt\r |
| 434 | int OpExg(int op)\r |
| 435 | {\r |
| 436 | int use=0,type=0;\r |
| 437 | \r |
| 438 | type=op&0xf8;\r |
| 439 | \r |
| 440 | if (type!=0x40 && type!=0x48 && type!=0x88) return 1; // Not an exg opcode\r |
| 441 | \r |
| 442 | use=op&0xf1f8; // Use same opcode for all values\r |
| 443 | if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r |
| 444 | \r |
| 445 | OpStart(op); Cycles=6;\r |
| 446 | \r |
| 447 | ot(" and r10,r8,#0x0e00 ;@ Find T register\n");\r |
| 448 | ot(" and r11,r8,#0x000f ;@ Find S register\n");\r |
| 449 | if (type==0x48) ot(" orr r10,r10,#0x1000 ;@ T is an address register\n");\r |
| 450 | ot("\n");\r |
| 451 | ot(" ldr r0,[r7,r10,lsr #7] ;@ Get T\n");\r |
| 452 | ot(" ldr r1,[r7,r11,lsl #2] ;@ Get S\n");\r |
| 453 | ot("\n");\r |
| 454 | ot(" str r0,[r7,r11,lsl #2] ;@ T->S\n");\r |
| 455 | ot(" str r1,[r7,r10,lsr #7] ;@ S->T\n"); \r |
| 456 | ot("\n");\r |
| 457 | \r |
| 458 | OpEnd();\r |
| 459 | \r |
| 460 | return 0;\r |
| 461 | }\r |