sim/avr/interp.c

   1 /* Simulator for Atmel's AVR core.
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3    Written by Tristan Gingold, AdaCore.
   4
   5    This file is part of GDB, the GNU debugger.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* This must come before any other includes.  */
  21 #include "defs.h"
  22
  23 #include <string.h>
  24
  25 #include "bfd.h"
  26 #include "libiberty.h"
  27 #include "sim/sim.h"
  28
  29 #include "sim-main.h"
  30 #include "sim-base.h"
  31 #include "sim-options.h"
  32 #include "sim-signal.h"
  33
  34 /* As AVR is a 8/16 bits processor, define handy types.  */
  35 typedef unsigned short int word;
  36 typedef signed short int sword;
  37 typedef unsigned char byte;
  38 typedef signed char sbyte;
  39
  40 /* Max size of I space (which is always flash on avr).  */
  41 #define MAX_AVR_FLASH (128 * 1024)
  42 #define PC_MASK (MAX_AVR_FLASH - 1)
  43
  44 /* Mac size of D space.  */
  45 #define MAX_AVR_SRAM (64 * 1024)
  46 #define SRAM_MASK (MAX_AVR_SRAM - 1)
  47
  48 /* D space offset in ELF file.  */
  49 #define SRAM_VADDR 0x800000
  50
  51 /* Simulator specific ports.  */
  52 #define STDIO_PORT      0x52
  53 #define EXIT_PORT       0x4F
  54 #define ABORT_PORT      0x49
  55
  56 /* GDB defined register numbers.  */
  57 #define AVR_SREG_REGNUM  32
  58 #define AVR_SP_REGNUM    33
  59 #define AVR_PC_REGNUM    34
  60
  61 /* Memory mapped registers.  */
  62 #define SREG    0x5F
  63 #define REG_SP  0x5D
  64 #define EIND    0x5C
  65 #define RAMPZ   0x5B
  66
  67 #define REGX 0x1a
  68 #define REGY 0x1c
  69 #define REGZ 0x1e
  70 #define REGZ_LO 0x1e
  71 #define REGZ_HI 0x1f
  72
  73 /* Sreg (status) bits.  */
  74 #define SREG_I 0x80
  75 #define SREG_T 0x40
  76 #define SREG_H 0x20
  77 #define SREG_S 0x10
  78 #define SREG_V 0x08
  79 #define SREG_N 0x04
  80 #define SREG_Z 0x02
  81 #define SREG_C 0x01
  82
  83 /* In order to speed up emulation we use a simple approach:
  84    a code is associated with each instruction.  The pre-decoding occurs
  85    usually once when the instruction is first seen.
  86    This works well because I&D spaces are separated.
  87
  88    Missing opcodes: sleep, spm, wdr (as they are mmcu dependent).
  89 */
  90 enum avr_opcode
  91   {
  92     /* Opcode not yet decoded.  */
  93     OP_unknown,
  94     OP_bad,
  95
  96     OP_nop,
  97
  98     OP_rjmp,
  99     OP_rcall,
 100     OP_ret,
 101     OP_reti,
 102
 103     OP_break,
 104
 105     OP_brbs,
 106     OP_brbc,
 107
 108     OP_bset,
 109     OP_bclr,
 110
 111     OP_bld,
 112     OP_bst,
 113
 114     OP_sbrc,
 115     OP_sbrs,
 116
 117     OP_eor,
 118     OP_and,
 119     OP_andi,
 120     OP_or,
 121     OP_ori,
 122     OP_com,
 123     OP_swap,
 124     OP_neg,
 125
 126     OP_out,
 127     OP_in,
 128     OP_cbi,
 129     OP_sbi,
 130
 131     OP_sbic,
 132     OP_sbis,
 133
 134     OP_ldi,
 135     OP_cpse,
 136     OP_cp,
 137     OP_cpi,
 138     OP_cpc,
 139     OP_sub,
 140     OP_sbc,
 141     OP_sbiw,
 142     OP_adiw,
 143     OP_add,
 144     OP_adc,
 145     OP_subi,
 146     OP_sbci,
 147     OP_inc,
 148     OP_dec,
 149     OP_lsr,
 150     OP_ror,
 151     OP_asr,
 152
 153     OP_mul,
 154     OP_muls,
 155     OP_mulsu,
 156     OP_fmul,
 157     OP_fmuls,
 158     OP_fmulsu,
 159
 160     OP_mov,
 161     OP_movw,
 162
 163     OP_push,
 164     OP_pop,
 165
 166     OP_st_X,
 167     OP_st_dec_X,
 168     OP_st_X_inc,
 169     OP_st_Y_inc,
 170     OP_st_dec_Y,
 171     OP_st_Z_inc,
 172     OP_st_dec_Z,
 173     OP_std_Y,
 174     OP_std_Z,
 175     OP_ldd_Y,
 176     OP_ldd_Z,
 177     OP_ld_Z_inc,
 178     OP_ld_dec_Z,
 179     OP_ld_Y_inc,
 180     OP_ld_dec_Y,
 181     OP_ld_X,
 182     OP_ld_X_inc,
 183     OP_ld_dec_X,
 184
 185     OP_lpm,
 186     OP_lpm_Z,
 187     OP_lpm_inc_Z,
 188     OP_elpm,
 189     OP_elpm_Z,
 190     OP_elpm_inc_Z,
 191
 192     OP_ijmp,
 193     OP_icall,
 194
 195     OP_eijmp,
 196     OP_eicall,
 197
 198     /* 2 words opcodes.  */
 199 #define OP_2words OP_jmp
 200     OP_jmp,
 201     OP_call,
 202     OP_sts,
 203     OP_lds
 204   };
 205
 206 struct avr_insn_cell
 207 {
 208   /* The insn (16 bits).  */
 209   word op;
 210
 211   /* Pre-decoding code.  */
 212   enum avr_opcode code : 8;
 213   /* One byte of additional information.  */
 214   byte r;
 215 };
 216
 217 /* I&D memories.  */
 218 /* TODO: Should be moved to SIM_CPU.  */
 219 static struct avr_insn_cell flash[MAX_AVR_FLASH];
 220 static byte sram[MAX_AVR_SRAM];
 221
 222 /* Sign extend a value.  */
 223 static int sign_ext (word val, int nb_bits)
 224 {
 225   if (val & (1 << (nb_bits - 1)))
 226     return val | -(1 << nb_bits);
 227   return val;
 228 }
 229
 230 /* Insn field extractors.  */
 231
 232 /* Extract xxxx_xxxRx_xxxx_RRRR.  */
 233 static inline byte get_r (word op)
 234 {
 235   return (op & 0xf) | ((op >> 5) & 0x10);
 236 }
 237
 238 /* Extract xxxx_xxxxx_xxxx_RRRR.  */
 239 static inline byte get_r16 (word op)
 240 {
 241   return 16 + (op & 0xf);
 242 }
 243
 244 /* Extract xxxx_xxxxx_xxxx_xRRR.  */
 245 static inline byte get_r16_23 (word op)
 246 {
 247   return 16 + (op & 0x7);
 248 }
 249
 250 /* Extract xxxx_xxxD_DDDD_xxxx.  */
 251 static inline byte get_d (word op)
 252 {
 253   return (op >> 4) & 0x1f;
 254 }
 255
 256 /* Extract xxxx_xxxx_DDDD_xxxx.  */
 257 static inline byte get_d16 (word op)
 258 {
 259   return 16 + ((op >> 4) & 0x0f);
 260 }
 261
 262 /* Extract xxxx_xxxx_xDDD_xxxx.  */
 263 static inline byte get_d16_23 (word op)
 264 {
 265   return 16 + ((op >> 4) & 0x07);
 266 }
 267
 268 /* Extract xxxx_xAAx_xxxx_AAAA.  */
 269 static inline byte get_A (word op)
 270 {
 271   return (op & 0x0f) | ((op & 0x600) >> 5);
 272 }
 273
 274 /* Extract xxxx_xxxx_AAAA_Axxx.  */
 275 static inline byte get_biA (word op)
 276 {
 277   return (op >> 3) & 0x1f;
 278 }
 279
 280 /* Extract xxxx_KKKK_xxxx_KKKK.  */
 281 static inline byte get_K (word op)
 282 {
 283   return (op & 0xf) | ((op & 0xf00) >> 4);
 284 }
 285
 286 /* Extract xxxx_xxKK_KKKK_Kxxx.  */
 287 static inline int get_k (word op)
 288 {
 289   return sign_ext ((op & 0x3f8) >> 3, 7);
 290 }
 291
 292 /* Extract xxxx_xxxx_xxDD_xxxx.  */
 293 static inline byte get_d24 (word op)
 294 {
 295   return 24 + ((op >> 3) & 6);
 296 }
 297
 298 /* Extract xxxx_xxxx_KKxx_KKKK.  */
 299 static inline byte get_k6 (word op)
 300 {
 301   return (op & 0xf) | ((op >> 2) & 0x30);
 302 }
 303
 304 /* Extract xxQx_QQxx_xxxx_xQQQ.  */
 305 static inline byte get_q (word op)
 306 {
 307   return (op & 7) | ((op >> 7) & 0x18)| ((op >> 8) & 0x20);
 308 }
 309
 310 /* Extract xxxx_xxxx_xxxx_xBBB.  */
 311 static inline byte get_b (word op)
 312 {
 313   return (op & 7);
 314 }
 315
 316 /* AVR is little endian.  */
 317 static inline word
 318 read_word (unsigned int addr)
 319 {
 320   return sram[addr] | (sram[addr + 1] << 8);
 321 }
 322
 323 static inline void
 324 write_word (unsigned int addr, word w)
 325 {
 326   sram[addr] = w;
 327   sram[addr + 1] = w >> 8;
 328 }
 329
 330 static inline word
 331 read_word_post_inc (unsigned int addr)
 332 {
 333   word v = read_word (addr);
 334   write_word (addr, v + 1);
 335   return v;
 336 }
 337
 338 static inline word
 339 read_word_pre_dec (unsigned int addr)
 340 {
 341   word v = read_word (addr) - 1;
 342   write_word (addr, v);
 343   return v;
 344 }
 345
 346 static void
 347 update_flags_logic (byte res)
 348 {
 349   sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z);
 350   if (res == 0)
 351     sram[SREG] |= SREG_Z;
 352   if (res & 0x80)
 353     sram[SREG] |= SREG_N | SREG_S;
 354 }
 355
 356 static void
 357 update_flags_add (byte r, byte a, byte b)
 358 {
 359   byte carry;
 360
 361   sram[SREG] &= ~(SREG_H | SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
 362   if (r & 0x80)
 363     sram[SREG] |= SREG_N;
 364   carry = (a & b) | (a & ~r) | (b & ~r);
 365   if (carry & 0x08)
 366     sram[SREG] |= SREG_H;
 367   if (carry & 0x80)
 368     sram[SREG] |= SREG_C;
 369   if (((a & b & ~r) | (~a & ~b & r)) & 0x80)
 370     sram[SREG] |= SREG_V;
 371   if (!(sram[SREG] & SREG_N) ^ !(sram[SREG] & SREG_V))
 372     sram[SREG] |= SREG_S;
 373   if (r == 0)
 374     sram[SREG] |= SREG_Z;
 375 }
 376
 377 static void update_flags_sub (byte r, byte a, byte b)
 378 {
 379   byte carry;
 380
 381   sram[SREG] &= ~(SREG_H | SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
 382   if (r & 0x80)
 383     sram[SREG] |= SREG_N;
 384   carry = (~a & b) | (b & r) | (r & ~a);
 385   if (carry & 0x08)
 386     sram[SREG] |= SREG_H;
 387   if (carry & 0x80)
 388     sram[SREG] |= SREG_C;
 389   if (((a & ~b & ~r) | (~a & b & r)) & 0x80)
 390     sram[SREG] |= SREG_V;
 391   if (!(sram[SREG] & SREG_N) ^ !(sram[SREG] & SREG_V))
 392     sram[SREG] |= SREG_S;
 393   /* Note: Z is not set.  */
 394 }
 395
 396 static enum avr_opcode
 397 decode (unsigned int pc)
 398 {
 399   word op1 = flash[pc].op;
 400
 401   switch ((op1 >> 12) & 0x0f)
 402     {
 403     case 0x0:
 404       switch ((op1 >> 10) & 0x3)
 405         {
 406         case 0x0:
 407           switch ((op1 >> 8) & 0x3)
 408             {
 409             case 0x0:
 410               if (op1 == 0)
 411                 return OP_nop;
 412               break;
 413             case 0x1:
 414               return OP_movw;
 415             case 0x2:
 416               return OP_muls;
 417             case 0x3:
 418               if (op1 & 0x80)
 419                 {
 420                   if (op1 & 0x08)
 421                     return OP_fmulsu;
 422                   else
 423                     return OP_fmuls;
 424                 }
 425               else
 426                 {
 427                   if (op1 & 0x08)
 428                     return OP_fmul;
 429                   else
 430                     return OP_mulsu;
 431                 }
 432             }
 433           break;
 434         case 0x1:
 435           return OP_cpc;
 436         case 0x2:
 437           flash[pc].r = SREG_C;
 438           return OP_sbc;
 439         case 0x3:
 440           flash[pc].r = 0;
 441           return OP_add;
 442         }
 443       break;
 444     case 0x1:
 445       switch ((op1 >> 10) & 0x3)
 446         {
 447         case 0x0:
 448           return OP_cpse;
 449         case 0x1:
 450           return OP_cp;
 451         case 0x2:
 452           flash[pc].r = 0;
 453           return OP_sub;
 454         case 0x3:
 455           flash[pc].r = SREG_C;
 456           return OP_adc;
 457         }
 458       break;
 459     case 0x2:
 460       switch ((op1 >> 10) & 0x3)
 461         {
 462         case 0x0:
 463           return OP_and;
 464         case 0x1:
 465           return OP_eor;
 466         case 0x2:
 467           return OP_or;
 468         case 0x3:
 469           return OP_mov;
 470         }
 471       break;
 472     case 0x3:
 473       return OP_cpi;
 474     case 0x4:
 475       return OP_sbci;
 476     case 0x5:
 477       return OP_subi;
 478     case 0x6:
 479       return OP_ori;
 480     case 0x7:
 481       return OP_andi;
 482     case 0x8:
 483     case 0xa:
 484       if (op1 & 0x0200)
 485         {
 486           if (op1 & 0x0008)
 487             {
 488               flash[pc].r = get_q (op1);
 489               return OP_std_Y;
 490             }
 491           else
 492             {
 493               flash[pc].r = get_q (op1);
 494               return OP_std_Z;
 495             }
 496         }
 497       else
 498         {
 499           if (op1 & 0x0008)
 500             {
 501               flash[pc].r = get_q (op1);
 502               return OP_ldd_Y;
 503             }
 504           else
 505             {
 506               flash[pc].r = get_q (op1);
 507               return OP_ldd_Z;
 508             }
 509         }
 510       break;
 511     case 0x9: /* 9xxx */
 512       switch ((op1 >> 8) & 0xf)
 513         {
 514         case 0x0:
 515         case 0x1:
 516           switch ((op1 >> 0) & 0xf)
 517             {
 518             case 0x0:
 519               return OP_lds;
 520             case 0x1:
 521               return OP_ld_Z_inc;
 522             case 0x2:
 523               return OP_ld_dec_Z;
 524             case 0x4:
 525               return OP_lpm_Z;
 526             case 0x5:
 527               return OP_lpm_inc_Z;
 528             case 0x6:
 529               return OP_elpm_Z;
 530             case 0x7:
 531               return OP_elpm_inc_Z;
 532             case 0x9:
 533               return OP_ld_Y_inc;
 534             case 0xa:
 535               return OP_ld_dec_Y;
 536             case 0xc:
 537               return OP_ld_X;
 538             case 0xd:
 539               return OP_ld_X_inc;
 540             case 0xe:
 541               return OP_ld_dec_X;
 542             case 0xf:
 543               return OP_pop;
 544             }
 545           break;
 546         case 0x2:
 547         case 0x3:
 548           switch ((op1 >> 0) & 0xf)
 549             {
 550             case 0x0:
 551               return OP_sts;
 552             case 0x1:
 553               return OP_st_Z_inc;
 554             case 0x2:
 555               return OP_st_dec_Z;
 556             case 0x9:
 557               return OP_st_Y_inc;
 558             case 0xa:
 559               return OP_st_dec_Y;
 560             case 0xc:
 561               return OP_st_X;
 562             case 0xd:
 563               return OP_st_X_inc;
 564             case 0xe:
 565               return OP_st_dec_X;
 566             case 0xf:
 567               return OP_push;
 568             }
 569           break;
 570         case 0x4:
 571         case 0x5:
 572           switch (op1 & 0xf)
 573             {
 574             case 0x0:
 575               return OP_com;
 576             case 0x1:
 577               return OP_neg;
 578             case 0x2:
 579               return OP_swap;
 580             case 0x3:
 581               return OP_inc;
 582             case 0x5:
 583               flash[pc].r = 0x80;
 584               return OP_asr;
 585             case 0x6:
 586               flash[pc].r = 0;
 587               return OP_lsr;
 588             case 0x7:
 589               return OP_ror;
 590             case 0x8: /* 9[45]x8 */
 591               switch ((op1 >> 4) & 0x1f)
 592                 {
 593                 case 0x00:
 594                 case 0x01:
 595                 case 0x02:
 596                 case 0x03:
 597                 case 0x04:
 598                 case 0x05:
 599                 case 0x06:
 600                 case 0x07:
 601                   return OP_bset;
 602                 case 0x08:
 603                 case 0x09:
 604                 case 0x0a:
 605                 case 0x0b:
 606                 case 0x0c:
 607                 case 0x0d:
 608                 case 0x0e:
 609                 case 0x0f:
 610                   return OP_bclr;
 611                 case 0x10:
 612                   return OP_ret;
 613                 case 0x11:
 614                   return OP_reti;
 615                 case 0x19:
 616                   return OP_break;
 617                 case 0x1c:
 618                   return OP_lpm;
 619                 case 0x1d:
 620                   return OP_elpm;
 621                 default:
 622                   break;
 623                 }
 624               break;
 625             case 0x9: /* 9[45]x9 */
 626               switch ((op1 >> 4) & 0x1f)
 627                 {
 628                 case 0x00:
 629                   return OP_ijmp;
 630                 case 0x01:
 631                   return OP_eijmp;
 632                 case 0x10:
 633                   return OP_icall;
 634                 case 0x11:
 635                   return OP_eicall;
 636                 default:
 637                   break;
 638                 }
 639               break;
 640             case 0xa:
 641               return OP_dec;
 642             case 0xc:
 643             case 0xd:
 644               flash[pc].r = ((op1 & 0x1f0) >> 3) | (op1 & 1);
 645               return OP_jmp;
 646             case 0xe:
 647             case 0xf:
 648               flash[pc].r = ((op1 & 0x1f0) >> 3) | (op1 & 1);
 649               return OP_call;
 650             }
 651           break;
 652         case 0x6:
 653           return OP_adiw;
 654         case 0x7:
 655           return OP_sbiw;
 656         case 0x8:
 657           return OP_cbi;
 658         case 0x9:
 659           return OP_sbic;
 660         case 0xa:
 661           return OP_sbi;
 662         case 0xb:
 663           return OP_sbis;
 664         case 0xc:
 665         case 0xd:
 666         case 0xe:
 667         case 0xf:
 668           return OP_mul;
 669         }
 670       break;
 671     case 0xb:
 672       flash[pc].r = get_A (op1);
 673       if (((op1 >> 11) & 1) == 0)
 674         return OP_in;
 675       else
 676         return OP_out;
 677     case 0xc:
 678       return OP_rjmp;
 679     case 0xd:
 680       return OP_rcall;
 681     case 0xe:
 682       return OP_ldi;
 683     case 0xf:
 684       switch ((op1 >> 9) & 7)
 685         {
 686         case 0:
 687         case 1:
 688           flash[pc].r = 1 << (op1 & 7);
 689           return OP_brbs;
 690         case 2:
 691         case 3:
 692           flash[pc].r = 1 << (op1 & 7);
 693           return OP_brbc;
 694         case 4:
 695           if ((op1 & 8) == 0)
 696             {
 697               flash[pc].r = 1 << (op1 & 7);
 698               return OP_bld;
 699             }
 700           break;
 701         case 5:
 702           if ((op1 & 8) == 0)
 703             {
 704               flash[pc].r = 1 << (op1 & 7);
 705               return OP_bst;
 706             }
 707           break;
 708         case 6:
 709           if ((op1 & 8) == 0)
 710             {
 711               flash[pc].r = 1 << (op1 & 7);
 712               return OP_sbrc;
 713             }
 714           break;
 715         case 7:
 716           if ((op1 & 8) == 0)
 717             {
 718               flash[pc].r = 1 << (op1 & 7);
 719               return OP_sbrs;
 720             }
 721           break;
 722         }
 723     }
 724
 725   return OP_bad;
 726 }
 727
 728 static void
 729 do_call (SIM_CPU *cpu, unsigned int npc)
 730 {
 731   const struct avr_sim_state *state = AVR_SIM_STATE (CPU_STATE (cpu));
 732   unsigned int sp = read_word (REG_SP);
 733
 734   /* Big endian!  */
 735   sram[sp--] = cpu->pc;
 736   sram[sp--] = cpu->pc >> 8;
 737   if (state->avr_pc22)
 738     {
 739       sram[sp--] = cpu->pc >> 16;
 740       cpu->cycles++;
 741     }
 742   write_word (REG_SP, sp);
 743   cpu->pc = npc & PC_MASK;
 744   cpu->cycles += 3;
 745 }
 746
 747 static int
 748 get_insn_length (unsigned int p)
 749 {
 750   if (flash[p].code == OP_unknown)
 751     flash[p].code = decode(p);
 752   if (flash[p].code >= OP_2words)
 753     return 2;
 754   else
 755     return 1;
 756 }
 757
 758 static unsigned int
 759 get_z (void)
 760 {
 761   return (sram[RAMPZ] << 16) | (sram[REGZ_HI] << 8) | sram[REGZ_LO];
 762 }
 763
 764 static unsigned char
 765 get_lpm (unsigned int addr)
 766 {
 767   word w;
 768
 769   w = flash[(addr >> 1) & PC_MASK].op;
 770   if (addr & 1)
 771     w >>= 8;
 772   return w;
 773 }
 774
 775 static void
 776 gen_mul (SIM_CPU *cpu, unsigned int res)
 777 {
 778   write_word (0, res);
 779   sram[SREG] &= ~(SREG_Z | SREG_C);
 780   if (res == 0)
 781     sram[SREG] |= SREG_Z;
 782   if (res & 0x8000)
 783     sram[SREG] |= SREG_C;
 784   cpu->cycles++;
 785 }
 786
 787 static void
 788 step_once (SIM_CPU *cpu)
 789 {
 790   unsigned int ipc;
 791
 792   int code;
 793   word op;
 794   byte res;
 795   byte r, d, vd;
 796
 797  again:
 798   code = flash[cpu->pc].code;
 799   op = flash[cpu->pc].op;
 800
 801 #if 0
 802       if (tracing && code != OP_unknown)
 803         {
 804           if (verbose > 0) {
 805             int flags;
 806             int i;
 807
 808             sim_cb_eprintf (callback, "R00-07:");
 809             for (i = 0; i < 8; i++)
 810               sim_cb_eprintf (callback, " %02x", sram[i]);
 811             sim_cb_eprintf (callback, " -");
 812             for (i = 8; i < 16; i++)
 813               sim_cb_eprintf (callback, " %02x", sram[i]);
 814             sim_cb_eprintf (callback, "  SP: %02x %02x",
 815                             sram[REG_SP + 1], sram[REG_SP]);
 816             sim_cb_eprintf (callback, "\n");
 817             sim_cb_eprintf (callback, "R16-31:");
 818             for (i = 16; i < 24; i++)
 819               sim_cb_eprintf (callback, " %02x", sram[i]);
 820             sim_cb_eprintf (callback, " -");
 821             for (i = 24; i < 32; i++)
 822               sim_cb_eprintf (callback, " %02x", sram[i]);
 823             sim_cb_eprintf (callback, "  ");
 824             flags = sram[SREG];
 825             for (i = 0; i < 8; i++)
 826               sim_cb_eprintf (callback, "%c",
 827                               flags & (0x80 >> i) ? "ITHSVNZC"[i] : '-');
 828             sim_cb_eprintf (callback, "\n");
 829           }
 830
 831           if (!tracing)
 832             sim_cb_eprintf (callback, "%06x: %04x\n", 2 * cpu->pc, flash[cpu->pc].op);
 833           else
 834             {
 835               sim_cb_eprintf (callback, "pc=0x%06x insn=0x%04x code=%d r=%d\n",
 836                               2 * cpu->pc, flash[cpu->pc].op, code, flash[cpu->pc].r);
 837               disassemble_insn (CPU_STATE (cpu), cpu->pc);
 838               sim_cb_eprintf (callback, "\n");
 839             }
 840         }
 841 #endif
 842
 843   ipc = cpu->pc;
 844   cpu->pc = (cpu->pc + 1) & PC_MASK;
 845   cpu->cycles++;
 846
 847   switch (code)
 848     {
 849       case OP_unknown:
 850         flash[ipc].code = decode(ipc);
 851         cpu->pc = ipc;
 852         cpu->cycles--;
 853         goto again;
 854
 855       case OP_nop:
 856         break;
 857
 858       case OP_jmp:
 859         /* 2 words instruction, but we don't care about the pc.  */
 860         cpu->pc = ((flash[ipc].r << 16) | flash[ipc + 1].op) & PC_MASK;
 861         cpu->cycles += 2;
 862         break;
 863
 864       case OP_eijmp:
 865         cpu->pc = ((sram[EIND] << 16) | read_word (REGZ)) & PC_MASK;
 866         cpu->cycles += 2;
 867         break;
 868
 869       case OP_ijmp:
 870         cpu->pc = read_word (REGZ) & PC_MASK;
 871         cpu->cycles += 1;
 872         break;
 873
 874       case OP_call:
 875         /* 2 words instruction.  */
 876         cpu->pc++;
 877         do_call (cpu, (flash[ipc].r << 16) | flash[ipc + 1].op);
 878         break;
 879
 880       case OP_eicall:
 881         do_call (cpu, (sram[EIND] << 16) | read_word (REGZ));
 882         break;
 883
 884       case OP_icall:
 885         do_call (cpu, read_word (REGZ));
 886         break;
 887
 888       case OP_rcall:
 889         do_call (cpu, cpu->pc + sign_ext (op & 0xfff, 12));
 890         break;
 891
 892       case OP_reti:
 893         sram[SREG] |= SREG_I;
 894         /* Fall through */
 895       case OP_ret:
 896         {
 897           const struct avr_sim_state *state = AVR_SIM_STATE (CPU_STATE (cpu));
 898           unsigned int sp = read_word (REG_SP);
 899           if (state->avr_pc22)
 900             {
 901               cpu->pc = sram[++sp] << 16;
 902               cpu->cycles++;
 903             }
 904           else
 905             cpu->pc = 0;
 906           cpu->pc |= sram[++sp] << 8;
 907           cpu->pc |= sram[++sp];
 908           write_word (REG_SP, sp);
 909         }
 910         cpu->cycles += 3;
 911         break;
 912
 913       case OP_break:
 914         /* Stop on this address.  */
 915         sim_engine_halt (CPU_STATE (cpu), cpu, NULL, ipc, sim_stopped, SIM_SIGTRAP);
 916         break;
 917
 918       case OP_bld:
 919         d = get_d (op);
 920         r = flash[ipc].r;
 921         if (sram[SREG] & SREG_T)
 922           sram[d] |= r;
 923         else
 924           sram[d] &= ~r;
 925         break;
 926
 927       case OP_bst:
 928         if (sram[get_d (op)] & flash[ipc].r)
 929           sram[SREG] |= SREG_T;
 930         else
 931           sram[SREG] &= ~SREG_T;
 932         break;
 933
 934       case OP_sbrc:
 935       case OP_sbrs:
 936         if (((sram[get_d (op)] & flash[ipc].r) == 0) ^ ((op & 0x0200) != 0))
 937           {
 938             int l = get_insn_length (cpu->pc);
 939             cpu->pc += l;
 940             cpu->cycles += l;
 941           }
 942         break;
 943
 944       case OP_push:
 945         {
 946           unsigned int sp = read_word (REG_SP);
 947           sram[sp--] = sram[get_d (op)];
 948           write_word (REG_SP, sp);
 949         }
 950         cpu->cycles++;
 951         break;
 952
 953       case OP_pop:
 954         {
 955           unsigned int sp = read_word (REG_SP);
 956           sram[get_d (op)] = sram[++sp];
 957           write_word (REG_SP, sp);
 958         }
 959         cpu->cycles++;
 960         break;
 961
 962       case OP_bclr:
 963         sram[SREG] &= ~(1 << ((op >> 4) & 0x7));
 964         break;
 965
 966       case OP_bset:
 967         sram[SREG] |= 1 << ((op >> 4) & 0x7);
 968         break;
 969
 970       case OP_rjmp:
 971         cpu->pc = (cpu->pc + sign_ext (op & 0xfff, 12)) & PC_MASK;
 972         cpu->cycles++;
 973         break;
 974
 975       case OP_eor:
 976         d = get_d (op);
 977         res = sram[d] ^ sram[get_r (op)];
 978         sram[d] = res;
 979         update_flags_logic (res);
 980         break;
 981
 982       case OP_and:
 983         d = get_d (op);
 984         res = sram[d] & sram[get_r (op)];
 985         sram[d] = res;
 986         update_flags_logic (res);
 987         break;
 988
 989       case OP_andi:
 990         d = get_d16 (op);
 991         res = sram[d] & get_K (op);
 992         sram[d] = res;
 993         update_flags_logic (res);
 994         break;
 995
 996       case OP_or:
 997         d = get_d (op);
 998         res = sram[d] | sram[get_r (op)];
 999         sram[d] = res;
1000         update_flags_logic (res);
1001         break;
1002
1003       case OP_ori:
1004         d = get_d16 (op);
1005         res = sram[d] | get_K (op);
1006         sram[d] = res;
1007         update_flags_logic (res);
1008         break;
1009
1010       case OP_com:
1011         d = get_d (op);
1012         res = ~sram[d];
1013         sram[d] = res;
1014         update_flags_logic (res);
1015         sram[SREG] |= SREG_C;
1016         break;
1017
1018       case OP_swap:
1019         d = get_d (op);
1020         vd = sram[d];
1021         sram[d] = (vd >> 4) | (vd << 4);
1022         break;
1023
1024       case OP_neg:
1025         d = get_d (op);
1026         vd = sram[d];
1027         res = -vd;
1028         sram[d] = res;
1029         sram[SREG] &= ~(SREG_H | SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
1030         if (res == 0)
1031           sram[SREG] |= SREG_Z;
1032         else
1033           sram[SREG] |= SREG_C;
1034         if (res == 0x80)
1035           sram[SREG] |= SREG_V | SREG_N;
1036         else if (res & 0x80)
1037           sram[SREG] |= SREG_N | SREG_S;
1038         if ((res | vd) & 0x08)
1039           sram[SREG] |= SREG_H;
1040         break;
1041
1042       case OP_inc:
1043         d = get_d (op);
1044         res = sram[d] + 1;
1045         sram[d] = res;
1046         sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z);
1047         if (res == 0x80)
1048           sram[SREG] |= SREG_V | SREG_N;
1049         else if (res & 0x80)
1050           sram[SREG] |= SREG_N | SREG_S;
1051         else if (res == 0)
1052           sram[SREG] |= SREG_Z;
1053         break;
1054
1055       case OP_dec:
1056         d = get_d (op);
1057         res = sram[d] - 1;
1058         sram[d] = res;
1059         sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z);
1060         if (res == 0x7f)
1061           sram[SREG] |= SREG_V | SREG_S;
1062         else if (res & 0x80)
1063           sram[SREG] |= SREG_N | SREG_S;
1064         else if (res == 0)
1065           sram[SREG] |= SREG_Z;
1066         break;
1067
1068       case OP_lsr:
1069       case OP_asr:
1070         d = get_d (op);
1071         vd = sram[d];
1072         res = (vd >> 1) | (vd & flash[ipc].r);
1073         sram[d] = res;
1074         sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
1075         if (vd & 1)
1076           sram[SREG] |= SREG_C | SREG_S;
1077         if (res & 0x80)
1078           sram[SREG] |= SREG_N;
1079         if (!(sram[SREG] & SREG_N) ^ !(sram[SREG] & SREG_C))
1080           sram[SREG] |= SREG_V;
1081         if (res == 0)
1082           sram[SREG] |= SREG_Z;
1083         break;
1084
1085       case OP_ror:
1086         d = get_d (op);
1087         vd = sram[d];
1088         res = vd >> 1 | (sram[SREG] << 7);
1089         sram[d] = res;
1090         sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
1091         if (vd & 1)
1092           sram[SREG] |= SREG_C | SREG_S;
1093         if (res & 0x80)
1094           sram[SREG] |= SREG_N;
1095         if (!(sram[SREG] & SREG_N) ^ !(sram[SREG] & SREG_C))
1096           sram[SREG] |= SREG_V;
1097         if (res == 0)
1098           sram[SREG] |= SREG_Z;
1099         break;
1100
1101       case OP_mul:
1102         gen_mul (cpu, (word)sram[get_r (op)] * (word)sram[get_d (op)]);
1103         break;
1104
1105       case OP_muls:
1106         gen_mul (cpu, (sword)(sbyte)sram[get_r16 (op)]
1107                       * (sword)(sbyte)sram[get_d16 (op)]);
1108         break;
1109
1110       case OP_mulsu:
1111         gen_mul (cpu, (sword)(word)sram[get_r16_23 (op)]
1112                       * (sword)(sbyte)sram[get_d16_23 (op)]);
1113         break;
1114
1115       case OP_fmul:
1116         gen_mul (cpu, ((word)sram[get_r16_23 (op)]
1117                        * (word)sram[get_d16_23 (op)]) << 1);
1118         break;
1119
1120       case OP_fmuls:
1121         gen_mul (cpu, ((sword)(sbyte)sram[get_r16_23 (op)]
1122                        * (sword)(sbyte)sram[get_d16_23 (op)]) << 1);
1123         break;
1124
1125       case OP_fmulsu:
1126         gen_mul (cpu, ((sword)(word)sram[get_r16_23 (op)]
1127                        * (sword)(sbyte)sram[get_d16_23 (op)]) << 1);
1128         break;
1129
1130       case OP_adc:
1131       case OP_add:
1132         r = sram[get_r (op)];
1133         d = get_d (op);
1134         vd = sram[d];
1135         res = r + vd + (sram[SREG] & flash[ipc].r);
1136         sram[d] = res;
1137         update_flags_add (res, vd, r);
1138         break;
1139
1140       case OP_sub:
1141         d = get_d (op);
1142         vd = sram[d];
1143         r = sram[get_r (op)];
1144         res = vd - r;
1145         sram[d] = res;
1146         update_flags_sub (res, vd, r);
1147         if (res == 0)
1148           sram[SREG] |= SREG_Z;
1149         break;
1150
1151       case OP_sbc:
1152         {
1153           byte old = sram[SREG];
1154           d = get_d (op);
1155           vd = sram[d];
1156           r = sram[get_r (op)];
1157           res = vd - r - (old & SREG_C);
1158           sram[d] = res;
1159           update_flags_sub (res, vd, r);
1160           if (res == 0 && (old & SREG_Z))
1161             sram[SREG] |= SREG_Z;
1162         }
1163         break;
1164
1165       case OP_subi:
1166         d = get_d16 (op);
1167         vd = sram[d];
1168         r = get_K (op);
1169         res = vd - r;
1170         sram[d] = res;
1171         update_flags_sub (res, vd, r);
1172         if (res == 0)
1173           sram[SREG] |= SREG_Z;
1174         break;
1175
1176       case OP_sbci:
1177         {
1178           byte old = sram[SREG];
1179
1180           d = get_d16 (op);
1181           vd = sram[d];
1182           r = get_K (op);
1183           res = vd - r - (old & SREG_C);
1184           sram[d] = res;
1185           update_flags_sub (res, vd, r);
1186           if (res == 0 && (old & SREG_Z))
1187             sram[SREG] |= SREG_Z;
1188         }
1189         break;
1190
1191       case OP_mov:
1192         sram[get_d (op)] = sram[get_r (op)];
1193         break;
1194
1195       case OP_movw:
1196         d = (op & 0xf0) >> 3;
1197         r = (op & 0x0f) << 1;
1198         sram[d] = sram[r];
1199         sram[d + 1] = sram[r + 1];
1200         break;
1201
1202       case OP_out:
1203         d = get_A (op) + 0x20;
1204         res = sram[get_d (op)];
1205         sram[d] = res;
1206         if (d == STDIO_PORT)
1207           putchar (res);
1208         else if (d == EXIT_PORT)
1209           sim_engine_halt (CPU_STATE (cpu), cpu, NULL, cpu->pc, sim_exited, 0);
1210         else if (d == ABORT_PORT)
1211           sim_engine_halt (CPU_STATE (cpu), cpu, NULL, cpu->pc, sim_exited, 1);
1212         break;
1213
1214       case OP_in:
1215         d = get_A (op) + 0x20;
1216         sram[get_d (op)] = sram[d];
1217         break;
1218
1219       case OP_cbi:
1220         d = get_biA (op) + 0x20;
1221         sram[d] &= ~(1 << get_b(op));
1222         break;
1223
1224       case OP_sbi:
1225         d = get_biA (op) + 0x20;
1226         sram[d] |= 1 << get_b(op);
1227         break;
1228
1229       case OP_sbic:
1230         if (!(sram[get_biA (op) + 0x20] & 1 << get_b(op)))
1231           {
1232             int l = get_insn_length (cpu->pc);
1233             cpu->pc += l;
1234             cpu->cycles += l;
1235           }
1236         break;
1237
1238       case OP_sbis:
1239         if (sram[get_biA (op) + 0x20] & 1 << get_b(op))
1240           {
1241             int l = get_insn_length (cpu->pc);
1242             cpu->pc += l;
1243             cpu->cycles += l;
1244           }
1245         break;
1246
1247       case OP_ldi:
1248         res = get_K (op);
1249         d = get_d16 (op);
1250         sram[d] = res;
1251         break;
1252
1253       case OP_lds:
1254         sram[get_d (op)] = sram[flash[cpu->pc].op];
1255         cpu->pc++;
1256         cpu->cycles++;
1257         break;
1258
1259       case OP_sts:
1260         sram[flash[cpu->pc].op] = sram[get_d (op)];
1261         cpu->pc++;
1262         cpu->cycles++;
1263         break;
1264
1265       case OP_cpse:
1266         if (sram[get_r (op)] == sram[get_d (op)])
1267           {
1268             int l = get_insn_length (cpu->pc);
1269             cpu->pc += l;
1270             cpu->cycles += l;
1271           }
1272         break;
1273
1274       case OP_cp:
1275         r = sram[get_r (op)];
1276         d = sram[get_d (op)];
1277         res = d - r;
1278         update_flags_sub (res, d, r);
1279         if (res == 0)
1280           sram[SREG] |= SREG_Z;
1281         break;
1282
1283       case OP_cpi:
1284         r = get_K (op);
1285         d = sram[get_d16 (op)];
1286         res = d - r;
1287         update_flags_sub (res, d, r);
1288         if (res == 0)
1289           sram[SREG] |= SREG_Z;
1290         break;
1291
1292       case OP_cpc:
1293         {
1294           byte old = sram[SREG];
1295           d = sram[get_d (op)];
1296           r = sram[get_r (op)];
1297           res = d - r - (old & SREG_C);
1298           update_flags_sub (res, d, r);
1299           if (res == 0 && (old & SREG_Z))
1300             sram[SREG] |= SREG_Z;
1301         }
1302         break;
1303
1304       case OP_brbc:
1305         if (!(sram[SREG] & flash[ipc].r))
1306           {
1307             cpu->pc = (cpu->pc + get_k (op)) & PC_MASK;
1308             cpu->cycles++;
1309           }
1310         break;
1311
1312       case OP_brbs:
1313         if (sram[SREG] & flash[ipc].r)
1314           {
1315             cpu->pc = (cpu->pc + get_k (op)) & PC_MASK;
1316             cpu->cycles++;
1317           }
1318         break;
1319
1320       case OP_lpm:
1321         sram[0] = get_lpm (read_word (REGZ));
1322         cpu->cycles += 2;
1323         break;
1324
1325       case OP_lpm_Z:
1326         sram[get_d (op)] = get_lpm (read_word (REGZ));
1327         cpu->cycles += 2;
1328         break;
1329
1330       case OP_lpm_inc_Z:
1331         sram[get_d (op)] = get_lpm (read_word_post_inc (REGZ));
1332         cpu->cycles += 2;
1333         break;
1334
1335       case OP_elpm:
1336         sram[0] = get_lpm (get_z ());
1337         cpu->cycles += 2;
1338         break;
1339
1340       case OP_elpm_Z:
1341         sram[get_d (op)] = get_lpm (get_z ());
1342         cpu->cycles += 2;
1343         break;
1344
1345       case OP_elpm_inc_Z:
1346         {
1347           unsigned int z = get_z ();
1348
1349           sram[get_d (op)] = get_lpm (z);
1350           z++;
1351           sram[REGZ_LO] = z;
1352           sram[REGZ_HI] = z >> 8;
1353           sram[RAMPZ] = z >> 16;
1354         }
1355         cpu->cycles += 2;
1356         break;
1357
1358       case OP_ld_Z_inc:
1359         sram[get_d (op)] = sram[read_word_post_inc (REGZ) & SRAM_MASK];
1360         cpu->cycles++;
1361         break;
1362
1363       case OP_ld_dec_Z:
1364         sram[get_d (op)] = sram[read_word_pre_dec (REGZ) & SRAM_MASK];
1365         cpu->cycles++;
1366         break;
1367
1368       case OP_ld_X_inc:
1369         sram[get_d (op)] = sram[read_word_post_inc (REGX) & SRAM_MASK];
1370         cpu->cycles++;
1371         break;
1372
1373       case OP_ld_dec_X:
1374         sram[get_d (op)] = sram[read_word_pre_dec (REGX) & SRAM_MASK];
1375         cpu->cycles++;
1376         break;
1377
1378       case OP_ld_Y_inc:
1379         sram[get_d (op)] = sram[read_word_post_inc (REGY) & SRAM_MASK];
1380         cpu->cycles++;
1381         break;
1382
1383       case OP_ld_dec_Y:
1384         sram[get_d (op)] = sram[read_word_pre_dec (REGY) & SRAM_MASK];
1385         cpu->cycles++;
1386         break;
1387
1388       case OP_st_X:
1389         sram[read_word (REGX) & SRAM_MASK] = sram[get_d (op)];
1390         cpu->cycles++;
1391         break;
1392
1393       case OP_st_X_inc:
1394         sram[read_word_post_inc (REGX) & SRAM_MASK] = sram[get_d (op)];
1395         cpu->cycles++;
1396         break;
1397
1398       case OP_st_dec_X:
1399         sram[read_word_pre_dec (REGX) & SRAM_MASK] = sram[get_d (op)];
1400         cpu->cycles++;
1401         break;
1402
1403       case OP_st_Z_inc:
1404         sram[read_word_post_inc (REGZ) & SRAM_MASK] = sram[get_d (op)];
1405         cpu->cycles++;
1406         break;
1407
1408       case OP_st_dec_Z:
1409         sram[read_word_pre_dec (REGZ) & SRAM_MASK] = sram[get_d (op)];
1410         cpu->cycles++;
1411         break;
1412
1413       case OP_st_Y_inc:
1414         sram[read_word_post_inc (REGY) & SRAM_MASK] = sram[get_d (op)];
1415         cpu->cycles++;
1416         break;
1417
1418       case OP_st_dec_Y:
1419         sram[read_word_pre_dec (REGY) & SRAM_MASK] = sram[get_d (op)];
1420         cpu->cycles++;
1421         break;
1422
1423       case OP_std_Y:
1424         sram[read_word (REGY) + flash[ipc].r] = sram[get_d (op)];
1425         cpu->cycles++;
1426         break;
1427
1428       case OP_std_Z:
1429         sram[read_word (REGZ) + flash[ipc].r] = sram[get_d (op)];
1430         cpu->cycles++;
1431         break;
1432
1433       case OP_ldd_Z:
1434         sram[get_d (op)] = sram[read_word (REGZ) + flash[ipc].r];
1435         cpu->cycles++;
1436         break;
1437
1438       case OP_ldd_Y:
1439         sram[get_d (op)] = sram[read_word (REGY) + flash[ipc].r];
1440         cpu->cycles++;
1441         break;
1442
1443       case OP_ld_X:
1444         sram[get_d (op)] = sram[read_word (REGX) & SRAM_MASK];
1445         cpu->cycles++;
1446         break;
1447
1448       case OP_sbiw:
1449         {
1450           word wk = get_k6 (op);
1451           word wres;
1452           word wr;
1453
1454           d = get_d24 (op);
1455           wr = read_word (d);
1456           wres = wr - wk;
1457
1458           sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
1459           if (wres == 0)
1460             sram[SREG] |= SREG_Z;
1461           if (wres & 0x8000)
1462             sram[SREG] |= SREG_N;
1463           if (wres & ~wr & 0x8000)
1464             sram[SREG] |= SREG_C;
1465           if (~wres & wr & 0x8000)
1466             sram[SREG] |= SREG_V;
1467           if (((~wres & wr) ^ wres) & 0x8000)
1468             sram[SREG] |= SREG_S;
1469           write_word (d, wres);
1470         }
1471         cpu->cycles++;
1472         break;
1473
1474       case OP_adiw:
1475         {
1476           word wk = get_k6 (op);
1477           word wres;
1478           word wr;
1479
1480           d = get_d24 (op);
1481           wr = read_word (d);
1482           wres = wr + wk;
1483
1484           sram[SREG] &= ~(SREG_S | SREG_V | SREG_N | SREG_Z | SREG_C);
1485           if (wres == 0)
1486             sram[SREG] |= SREG_Z;
1487           if (wres & 0x8000)
1488             sram[SREG] |= SREG_N;
1489           if (~wres & wr & 0x8000)
1490             sram[SREG] |= SREG_C;
1491           if (wres & ~wr & 0x8000)
1492             sram[SREG] |= SREG_V;
1493           if (((wres & ~wr) ^ wres) & 0x8000)
1494             sram[SREG] |= SREG_S;
1495           write_word (d, wres);
1496         }
1497         cpu->cycles++;
1498         break;
1499
1500       case OP_bad:
1501         sim_engine_halt (CPU_STATE (cpu), cpu, NULL, cpu->pc, sim_signalled, SIM_SIGILL);
1502
1503       default:
1504         sim_engine_halt (CPU_STATE (cpu), cpu, NULL, cpu->pc, sim_signalled, SIM_SIGILL);
1505       }
1506 }
1507
1508 void
1509 sim_engine_run (SIM_DESC sd,
1510                 int next_cpu_nr, /* ignore  */
1511                 int nr_cpus, /* ignore  */
1512                 int siggnal) /* ignore  */
1513 {
1514   SIM_CPU *cpu;
1515
1516   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
1517
1518   cpu = STATE_CPU (sd, 0);
1519
1520   while (1)
1521     {
1522       step_once (cpu);
1523       if (sim_events_tick (sd))
1524         sim_events_process (sd);
1525     }
1526 }
1527
1528 int
1529 sim_write (SIM_DESC sd, SIM_ADDR addr, const unsigned char *buffer, int size)
1530 {
1531   int osize = size;
1532
1533   if (addr >= 0 && addr < SRAM_VADDR)
1534     {
1535       while (size > 0 && addr < (MAX_AVR_FLASH << 1))
1536         {
1537           word val = flash[addr >> 1].op;
1538
1539           if (addr & 1)
1540             val = (val & 0xff) | (buffer[0] << 8);
1541           else
1542             val = (val & 0xff00) | buffer[0];
1543
1544           flash[addr >> 1].op = val;
1545           flash[addr >> 1].code = OP_unknown;
1546           addr++;
1547           buffer++;
1548           size--;
1549         }
1550       return osize - size;
1551     }
1552   else if (addr >= SRAM_VADDR && addr < SRAM_VADDR + MAX_AVR_SRAM)
1553     {
1554       addr -= SRAM_VADDR;
1555       if (addr + size > MAX_AVR_SRAM)
1556         size = MAX_AVR_SRAM - addr;
1557       memcpy (sram + addr, buffer, size);
1558       return size;
1559     }
1560   else
1561     return 0;
1562 }
1563
1564 int
1565 sim_read (SIM_DESC sd, SIM_ADDR addr, unsigned char *buffer, int size)
1566 {
1567   int osize = size;
1568
1569   if (addr >= 0 && addr < SRAM_VADDR)
1570     {
1571       while (size > 0 && addr < (MAX_AVR_FLASH << 1))
1572         {
1573           word val = flash[addr >> 1].op;
1574
1575           if (addr & 1)
1576             val >>= 8;
1577
1578           *buffer++ = val;
1579           addr++;
1580           size--;
1581         }
1582       return osize - size;
1583     }
1584   else if (addr >= SRAM_VADDR && addr < SRAM_VADDR + MAX_AVR_SRAM)
1585     {
1586       addr -= SRAM_VADDR;
1587       if (addr + size > MAX_AVR_SRAM)
1588         size = MAX_AVR_SRAM - addr;
1589       memcpy (buffer, sram + addr, size);
1590       return size;
1591     }
1592   else
1593     {
1594       /* Avoid errors.  */
1595       memset (buffer, 0, size);
1596       return size;
1597     }
1598 }
1599
1600 static int
1601 avr_reg_store (SIM_CPU *cpu, int rn, unsigned char *memory, int length)
1602 {
1603   if (rn < 32 && length == 1)
1604     {
1605       sram[rn] = *memory;
1606       return 1;
1607     }
1608   if (rn == AVR_SREG_REGNUM && length == 1)
1609     {
1610       sram[SREG] = *memory;
1611       return 1;
1612     }
1613   if (rn == AVR_SP_REGNUM && length == 2)
1614     {
1615       sram[REG_SP] = memory[0];
1616       sram[REG_SP + 1] = memory[1];
1617       return 2;
1618     }
1619   if (rn == AVR_PC_REGNUM && length == 4)
1620     {
1621       cpu->pc = (memory[0] >> 1) | (memory[1] << 7)
1622                 | (memory[2] << 15) | (memory[3] << 23);
1623       cpu->pc &= PC_MASK;
1624       return 4;
1625     }
1626   return 0;
1627 }
1628
1629 static int
1630 avr_reg_fetch (SIM_CPU *cpu, int rn, unsigned char *memory, int length)
1631 {
1632   if (rn < 32 && length == 1)
1633     {
1634       *memory = sram[rn];
1635       return 1;
1636     }
1637   if (rn == AVR_SREG_REGNUM && length == 1)
1638     {
1639       *memory = sram[SREG];
1640       return 1;
1641     }
1642   if (rn == AVR_SP_REGNUM && length == 2)
1643     {
1644       memory[0] = sram[REG_SP];
1645       memory[1] = sram[REG_SP + 1];
1646       return 2;
1647     }
1648   if (rn == AVR_PC_REGNUM && length == 4)
1649     {
1650       memory[0] = cpu->pc << 1;
1651       memory[1] = cpu->pc >> 7;
1652       memory[2] = cpu->pc >> 15;
1653       memory[3] = cpu->pc >> 23;
1654       return 4;
1655     }
1656   return 0;
1657 }
1658
1659 static sim_cia
1660 avr_pc_get (sim_cpu *cpu)
1661 {
1662   return cpu->pc;
1663 }
1664
1665 static void
1666 avr_pc_set (sim_cpu *cpu, sim_cia pc)
1667 {
1668   cpu->pc = pc;
1669 }
1670
1671 static void
1672 free_state (SIM_DESC sd)
1673 {
1674   if (STATE_MODULES (sd) != NULL)
1675     sim_module_uninstall (sd);
1676   sim_cpu_free_all (sd);
1677   sim_state_free (sd);
1678 }
1679
1680 SIM_DESC
1681 sim_open (SIM_OPEN_KIND kind, host_callback *cb,
1682           struct bfd *abfd, char * const *argv)
1683 {
1684   int i;
1685   SIM_DESC sd = sim_state_alloc_extra (kind, cb, sizeof (struct avr_sim_state));
1686   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
1687
1688   /* Set default options before parsing user options.  */
1689   current_alignment = STRICT_ALIGNMENT;
1690   current_target_byte_order = BFD_ENDIAN_LITTLE;
1691
1692   /* The cpu data is kept in a separately allocated chunk of memory.  */
1693   if (sim_cpu_alloc_all (sd, 1) != SIM_RC_OK)
1694     {
1695       free_state (sd);
1696       return 0;
1697     }
1698
1699   if (sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK)
1700     {
1701       free_state (sd);
1702       return 0;
1703     }
1704
1705   /* The parser will print an error message for us, so we silently return.  */
1706   if (sim_parse_args (sd, argv) != SIM_RC_OK)
1707     {
1708       free_state (sd);
1709       return 0;
1710     }
1711
1712   /* Check for/establish the a reference program image.  */
1713   if (sim_analyze_program (sd, STATE_PROG_FILE (sd), abfd) != SIM_RC_OK)
1714     {
1715       free_state (sd);
1716       return 0;
1717     }
1718
1719   /* Configure/verify the target byte order and other runtime
1720      configuration options.  */
1721   if (sim_config (sd) != SIM_RC_OK)
1722     {
1723       sim_module_uninstall (sd);
1724       return 0;
1725     }
1726
1727   if (sim_post_argv_init (sd) != SIM_RC_OK)
1728     {
1729       /* Uninstall the modules to avoid memory leaks,
1730          file descriptor leaks, etc.  */
1731       sim_module_uninstall (sd);
1732       return 0;
1733     }
1734
1735   /* CPU specific initialization.  */
1736   for (i = 0; i < MAX_NR_PROCESSORS; ++i)
1737     {
1738       SIM_CPU *cpu = STATE_CPU (sd, i);
1739
1740       CPU_REG_FETCH (cpu) = avr_reg_fetch;
1741       CPU_REG_STORE (cpu) = avr_reg_store;
1742       CPU_PC_FETCH (cpu) = avr_pc_get;
1743       CPU_PC_STORE (cpu) = avr_pc_set;
1744     }
1745
1746   /* Clear all the memory.  */
1747   memset (sram, 0, sizeof (sram));
1748   memset (flash, 0, sizeof (flash));
1749
1750   return sd;
1751 }
1752
1753 SIM_RC
1754 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
1755                      char * const *argv, char * const *env)
1756 {
1757   struct avr_sim_state *state = AVR_SIM_STATE (sd);
1758   SIM_CPU *cpu = STATE_CPU (sd, 0);
1759   SIM_ADDR addr;
1760
1761   /* Set the PC.  */
1762   if (abfd != NULL)
1763     addr = bfd_get_start_address (abfd);
1764   else
1765     addr = 0;
1766   sim_pc_set (cpu, addr);
1767
1768   if (abfd != NULL)
1769     state->avr_pc22 = (bfd_get_mach (abfd) >= bfd_mach_avr6);
1770
1771   return SIM_RC_OK;
1772 }