emu-rv32i.c 51.3 KB
Newer Older
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1
/* Modified by Shaos <me@shaos.net>
2
   26-NOV-2018 - Some changes in processing of CSRR* commands
3
   22-NOV-2018 - Added saving HEX file with copy of the code in DEBUG_OUTPUT mode
Alexander Shabarshin's avatar
Alexander Shabarshin committed
4
   21-NOV-2018 - Some statistics added in DEBUG_EXTRA mode
Alexander Shabarshin's avatar
Alexander Shabarshin committed
5 6 7 8
   20-NOV-2018 - By default RV32M and RV32A extensions are disabled (STRICT_RV32I)
   18-NOV-2018 - Slghtly modified for pure C
   Source code taken from https://gist.github.com/FrankBuss/c974e59826d33e21d7cad54491ab50e8
*/
9

Alexander Shabarshin's avatar
Alexander Shabarshin committed
10 11 12 13 14 15 16 17 18 19 20 21 22
/*
RISCV emulator for the RV32I architecture
based on TinyEMU by Fabrice Bellard, see https://bellard.org/tinyemu/
stripped down for RV32I only, all "gotos" removed, and fixed some bugs for the compliance test
by Frank Buss, 2018

Requires libelf-dev:

sudo apt-get install libelf-dev


Compile it like this:

23
gcc -O3 -Wall -lelf emu-rv32i.c -o emu-rv32i
Alexander Shabarshin's avatar
Alexander Shabarshin committed
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42


It is compatible to Spike for the command line arguments, which means you can run
the compliance test from https://github.com/riscv/riscv-compliance like this:

make RISCV_TARGET=spike RISCV_DEVICE=rv32i TARGET_SIM=/full/path/emulator variant

It is also compatible with qemu32, as it is used for Zephyr. You can compile the
Zephyr examples for qemu like this:

cd zephyr
source zephyr-env.sh
cd samples/synchronization
mkdir build && cd build
cmake -GNinja -DBOARD=qemu_riscv32 ..
ninja

After this you can run it with the emulator like this:

43
emu-rv32i zephyr/zephyr.elf
Alexander Shabarshin's avatar
Alexander Shabarshin committed
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87


original copyright:
*/

/*
 * RISCV emulator
 *
 * Copyright (c) 2016 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#define XLEN 32

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <libelf.h>
#include <gelf.h>

Alexander Shabarshin's avatar
Alexander Shabarshin committed
88 89 90 91
/* uncomment this for an instruction trace and other debug outputs */
#if 0
#define DEBUG_OUTPUT
#endif
92 93 94
#if 0
#define DEBUG_EXTRA
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
95

Alexander Shabarshin's avatar
Alexander Shabarshin committed
96
/* added by Shaos: */
97
#define STRICT_RV32I
98 99 100
#define FALSE (0)
#define TRUE (-1)

Alexander Shabarshin's avatar
Alexander Shabarshin committed
101
#ifdef DEBUG_EXTRA
Alexander Shabarshin's avatar
Alexander Shabarshin committed
102 103
uint32_t minmemr,maxmemr,minmemw,maxmemw;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
104 105 106 107 108
int stats[64];

void init_stats(void)
{
  for(int i=0;i<64;i++) stats[i]=0;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
109 110
  minmemr = minmemw = ~0;
  maxmemr = maxmemw = 0;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
111 112 113 114 115
}

void print_stats(void)
{
  for(int i=0;i<64;i++) if(stats[i]) printf("stats[%i] = %i\n",i,stats[i]);
Alexander Shabarshin's avatar
Alexander Shabarshin committed
116
  printf("Memory Reading Area %x...%x\n",minmemr,maxmemr);
117 118
  if(minmemw+1) printf("Memory Writing Area %x...%x\n",minmemw,maxmemw);
  else printf("Memory Writing Area NONE\n");
Alexander Shabarshin's avatar
Alexander Shabarshin committed
119 120 121 122 123 124 125 126 127
}
#endif

#ifdef DEBUG_OUTPUT
#define dprintf(s) printf(s)
#else
#define dprintf(s)
#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
128
/* memory mapped registers */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
129 130 131 132
#define MTIME_ADDR 0x40000000
#define MTIMECMP_ADDR 0x40000008
#define UART_TX_ADDR 0x40002000

Alexander Shabarshin's avatar
Alexander Shabarshin committed
133
/* emulate RAM */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
134 135 136
#define RAM_SIZE 0x10000
uint8_t ram[RAM_SIZE];

Alexander Shabarshin's avatar
Alexander Shabarshin committed
137
/* special memory mapped registers */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
138 139 140
uint64_t mtime;
uint64_t mtimecmp;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
141
/* virtual start address for index 0 in the ram array */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
142 143
uint32_t ram_start;

144 145 146 147
/* last byte of the memory initialized and temporary value */
uint32_t ram_last = 0;
uint32_t ram_curr = 0;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
148
/* used when called from the compliance tests */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
149 150 151
uint32_t begin_signature = 0;
uint32_t end_signature = 0;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
152
/* is set to false to exit the emulator */
153
int machine_running = TRUE;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
154

Alexander Shabarshin's avatar
Alexander Shabarshin committed
155
/* privilege levels */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
156 157 158 159 160
#define PRV_U 0
#define PRV_S 1
#define PRV_H 2
#define PRV_M 3

Alexander Shabarshin's avatar
Alexander Shabarshin committed
161
/* CPU state */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198
uint32_t pc;
uint32_t next_pc;
uint32_t insn;
uint32_t reg[32];

uint8_t priv = PRV_M; /* see PRV_x */
uint8_t fs; /* MSTATUS_FS value */
uint8_t mxl; /* MXL field in MISA register */

uint64_t insn_counter;
int pending_exception; /* used during MMU exception handling */
uint32_t pending_tval;

/* CSRs */
uint32_t mstatus;
uint32_t mtvec;
uint32_t mscratch;
uint32_t mepc;
uint32_t mcause;
uint32_t mtval;
uint32_t mhartid; /* ro */
uint32_t misa;
uint32_t mie;
uint32_t mip;
uint32_t medeleg;
uint32_t mideleg;
uint32_t mcounteren;

uint32_t stvec;
uint32_t sscratch;
uint32_t sepc;
uint32_t scause;
uint32_t stval;
uint32_t satp;
uint32_t scounteren;
uint32_t load_res; /* for atomic LR/SC */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
199
/* exception causes */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301
#define CAUSE_MISALIGNED_FETCH    0x0
#define CAUSE_FAULT_FETCH         0x1
#define CAUSE_ILLEGAL_INSTRUCTION 0x2
#define CAUSE_BREAKPOINT          0x3
#define CAUSE_MISALIGNED_LOAD     0x4
#define CAUSE_FAULT_LOAD          0x5
#define CAUSE_MISALIGNED_STORE    0x6
#define CAUSE_FAULT_STORE         0x7
#define CAUSE_USER_ECALL          0x8
#define CAUSE_SUPERVISOR_ECALL    0x9
#define CAUSE_HYPERVISOR_ECALL    0xa
#define CAUSE_MACHINE_ECALL       0xb
#define CAUSE_FETCH_PAGE_FAULT    0xc
#define CAUSE_LOAD_PAGE_FAULT     0xd
#define CAUSE_STORE_PAGE_FAULT    0xf
#define CAUSE_INTERRUPT  ((uint32_t)1 << 31)

/* misa CSR */
#define MCPUID_SUPER   (1 << ('S' - 'A'))
#define MCPUID_USER    (1 << ('U' - 'A'))
#define MCPUID_I       (1 << ('I' - 'A'))
#define MCPUID_M       (1 << ('M' - 'A'))
#define MCPUID_A       (1 << ('A' - 'A'))
#define MCPUID_F       (1 << ('F' - 'A'))
#define MCPUID_D       (1 << ('D' - 'A'))
#define MCPUID_Q       (1 << ('Q' - 'A'))
#define MCPUID_C       (1 << ('C' - 'A'))

#define MIP_USIP (1 << 0)
#define MIP_SSIP (1 << 1)
#define MIP_HSIP (1 << 2)
#define MIP_MSIP (1 << 3)
#define MIP_UTIP (1 << 4)
#define MIP_STIP (1 << 5)
#define MIP_HTIP (1 << 6)
#define MIP_MTIP (1 << 7)
#define MIP_UEIP (1 << 8)
#define MIP_SEIP (1 << 9)
#define MIP_HEIP (1 << 10)
#define MIP_MEIP (1 << 11)

/* mstatus CSR */
#define MSTATUS_SPIE_SHIFT 5
#define MSTATUS_MPIE_SHIFT 7
#define MSTATUS_SPP_SHIFT 8
#define MSTATUS_MPP_SHIFT 11
#define MSTATUS_FS_SHIFT 13
#define MSTATUS_UXL_SHIFT 32
#define MSTATUS_SXL_SHIFT 34

#define MSTATUS_UIE (1 << 0)
#define MSTATUS_SIE (1 << 1)
#define MSTATUS_HIE (1 << 2)
#define MSTATUS_MIE (1 << 3)
#define MSTATUS_UPIE (1 << 4)
#define MSTATUS_SPIE (1 << MSTATUS_SPIE_SHIFT)
#define MSTATUS_HPIE (1 << 6)
#define MSTATUS_MPIE (1 << MSTATUS_MPIE_SHIFT)
#define MSTATUS_SPP (1 << MSTATUS_SPP_SHIFT)
#define MSTATUS_HPP (3 << 9)
#define MSTATUS_MPP (3 << MSTATUS_MPP_SHIFT)
#define MSTATUS_FS (3 << MSTATUS_FS_SHIFT)
#define MSTATUS_XS (3 << 15)
#define MSTATUS_MPRV (1 << 17)
#define MSTATUS_SUM (1 << 18)
#define MSTATUS_MXR (1 << 19)
#define MSTATUS_UXL_MASK ((uint64_t)3 << MSTATUS_UXL_SHIFT)
#define MSTATUS_SXL_MASK ((uint64_t)3 << MSTATUS_SXL_SHIFT)

int ctz32(uint32_t a)
{
    int i;
    if (a == 0)
        return 32;
    for(i = 0; i < 32; i++) {
        if ((a >> i) & 1)
            return i;
    }
    return 32;
}

#define SSTATUS_MASK0 (MSTATUS_UIE | MSTATUS_SIE |       \
                      MSTATUS_UPIE | MSTATUS_SPIE |     \
                      MSTATUS_SPP | \
                      MSTATUS_FS | MSTATUS_XS | \
                      MSTATUS_SUM | MSTATUS_MXR)
#define SSTATUS_MASK SSTATUS_MASK0


#define MSTATUS_MASK (MSTATUS_UIE | MSTATUS_SIE | MSTATUS_MIE |      \
                      MSTATUS_UPIE | MSTATUS_SPIE | MSTATUS_MPIE |    \
                      MSTATUS_SPP | MSTATUS_MPP | \
                      MSTATUS_FS | \
                      MSTATUS_MPRV | MSTATUS_SUM | MSTATUS_MXR)

/* cycle and insn counters */
#define COUNTEREN_MASK ((1 << 0) | (1 << 2))

/* return the complete mstatus with the SD bit */
uint32_t get_mstatus(uint32_t mask)
{
    uint32_t val;
302
    int sd;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
    val = mstatus | (fs << MSTATUS_FS_SHIFT);
    val &= mask;
    sd = ((val & MSTATUS_FS) == MSTATUS_FS) |
         ((val & MSTATUS_XS) == MSTATUS_XS);
    if (sd)
        val |= (uint32_t)1 << (XLEN - 1);
    return val;
}

void set_mstatus(uint32_t val)
{
    fs = (val >> MSTATUS_FS_SHIFT) & 3;

    uint32_t mask = MSTATUS_MASK & ~MSTATUS_FS;
    mstatus = (mstatus & ~mask) | (val & mask);
}

void invalid_csr(uint32_t *pval, uint32_t csr)
{
    /* the 'time' counter is usually emulated */
    if (csr != 0xc01 && csr != 0xc81) {
#ifdef DEBUG_OUTPUT
        printf("csr_read: invalid CSR=0x%x\n", csr);
#endif
    }
    *pval = 0;
}

/* return -1 if invalid CSR. 0 if OK. 'will_write' indicate that the
   csr will be written after (used for CSR access check) */
int csr_read(uint32_t *pval, uint32_t csr,
334
             int will_write)
Alexander Shabarshin's avatar
Alexander Shabarshin committed
335 336 337
{
    uint32_t val;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
338 339 340 341
#ifdef DEBUG_EXTRA
    printf("csr_read: csr=0x%03x %i\n", csr, will_write);
#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
342 343 344 345 346 347
    if (((csr & 0xc00) == 0xc00) && will_write)
        return -1; /* read-only CSR */
    if (priv < ((csr >> 8) & 3))
        return -1; /* not enough priviledge */

    switch(csr) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
348 349
    case 0xc00: /* cycle */
    case 0xc02: /* instret */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
350 351 352 353 354 355 356 357 358 359 360 361 362 363 364
    {
        uint32_t counteren;
        if (priv < PRV_M) {
            if (priv < PRV_S)
                counteren = scounteren;
            else
                counteren = mcounteren;
            if (((counteren >> (csr & 0x1f)) & 1) == 0) {
                invalid_csr(pval, csr);
                return -1;
            }
        }
    }
    val = (int64_t)insn_counter;
    break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
365 366
    case 0xc80: /* cycleh */
    case 0xc82: /* instreth */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462
    {
        uint32_t counteren;
        if (priv < PRV_M) {
            if (priv < PRV_S)
                counteren = scounteren;
            else
                counteren = mcounteren;
            if (((counteren >> (csr & 0x1f)) & 1) == 0) {
                invalid_csr(pval, csr);
                return -1;
            }
        }
    }
    val = insn_counter >> 32;
    break;

    case 0x100:
        val = get_mstatus(SSTATUS_MASK);
        break;
    case 0x104: /* sie */
        val = mie & mideleg;
        break;
    case 0x105:
        val = stvec;
        break;
    case 0x106:
        val = scounteren;
        break;
    case 0x140:
        val = sscratch;
        break;
    case 0x141:
        val = sepc;
        break;
    case 0x142:
        val = scause;
        break;
    case 0x143:
        val = stval;
        break;
    case 0x144: /* sip */
        val = mip & mideleg;
        break;
    case 0x180:
        val = satp;
        break;
    case 0x300:
        val = get_mstatus((uint32_t)-1);
        break;
    case 0x301:
        val = misa;
        val |= (uint32_t)mxl << (XLEN - 2);
        break;
    case 0x302:
        val = medeleg;
        break;
    case 0x303:
        val = mideleg;
        break;
    case 0x304:
        val = mie;
        break;
    case 0x305:
        val = mtvec;
        break;
    case 0x306:
        val = mcounteren;
        break;
    case 0x340:
        val = mscratch;
        break;
    case 0x341:
        val = mepc;
        break;
    case 0x342:
        val = mcause;
        break;
    case 0x343:
        val = mtval;
        break;
    case 0x344:
        val = mip;
        break;
    case 0xb00: /* mcycle */
    case 0xb02: /* minstret */
        val = (int64_t)insn_counter;
        break;
    case 0xb80: /* mcycleh */
    case 0xb82: /* minstreth */
        val = insn_counter >> 32;
        break;
    case 0xf14:
        val = mhartid;
        break;
    default:
        invalid_csr(pval, csr);
Alexander Shabarshin's avatar
Alexander Shabarshin committed
463
        /* return -1; */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
464 465
        return 0;
    }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
466 467 468 469 470

#ifdef DEBUG_EXTRA
    printf("csr_read: csr=0x%03x --> 0x%08x\n", csr, val);
#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
471 472 473 474 475 476 477 478 479
    *pval = val;
    return 0;
}

/* return -1 if invalid CSR, 0 if OK, 1 if the interpreter loop must be
   exited (e.g. XLEN was modified), 2 if TLBs have been flushed. */
int csr_write(uint32_t csr, uint32_t val)
{
    uint32_t mask;
480
#ifdef DEBUG_EXTRA
Alexander Shabarshin's avatar
Alexander Shabarshin committed
481
    printf("csr_write: csr=0x%03x val=0x%08x\n", csr, val);
Alexander Shabarshin's avatar
Alexander Shabarshin committed
482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512
#endif
    switch(csr) {
    case 0x100: /* sstatus */
        set_mstatus((mstatus & ~SSTATUS_MASK) | (val & SSTATUS_MASK));
        break;
    case 0x104: /* sie */
        mask = mideleg;
        mie = (mie & ~mask) | (val & mask);
        break;
    case 0x105:
        stvec = val & ~3;
        break;
    case 0x106:
        scounteren = val & COUNTEREN_MASK;
        break;
    case 0x140:
        sscratch = val;
        break;
    case 0x141:
        sepc = val & ~1;
        break;
    case 0x142:
        scause = val;
        break;
    case 0x143:
        stval = val;
        break;
    case 0x144: /* sip */
        mask = mideleg;
        mip = (mip & ~mask) | (val & mask);
        break;
513 514 515 516 517 518 519 520
    case 0x180: /* no ASID implemented */
        {
            int new_mode;
            new_mode = (val >> 31) & 1;
            satp = (val & (((uint32_t)1 << 22) - 1)) |
                   (new_mode << 31);
        }
        return 2;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562

    case 0x300:
        set_mstatus(val);
        break;
    case 0x301: /* misa */
        break;
    case 0x302:
        mask = (1 << (CAUSE_STORE_PAGE_FAULT + 1)) - 1;
        medeleg = (medeleg & ~mask) | (val & mask);
        break;
    case 0x303:
        mask = MIP_SSIP | MIP_STIP | MIP_SEIP;
        mideleg = (mideleg & ~mask) | (val & mask);
        break;
    case 0x304:
        mask = MIP_MSIP | MIP_MTIP | MIP_SSIP | MIP_STIP | MIP_SEIP;
        mie = (mie & ~mask) | (val & mask);
        break;
    case 0x305:
        mtvec = val & ~3;
        break;
    case 0x306:
        mcounteren = val & COUNTEREN_MASK;
        break;
    case 0x340:
        mscratch = val;
        break;
    case 0x341:
        mepc = val & ~1;
        break;
    case 0x342:
        mcause = val;
        break;
    case 0x343:
        mtval = val;
        break;
    case 0x344:
        mask = MIP_SSIP | MIP_STIP;
        mip = (mip & ~mask) | (val & mask);
        break;
    default:
        return 0;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
563
        /* return -1; */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599
    }
    return 0;
}

void handle_sret()
{
    int spp, spie;
    spp = (mstatus >> MSTATUS_SPP_SHIFT) & 1;
    /* set the IE state to previous IE state */
    spie = (mstatus >> MSTATUS_SPIE_SHIFT) & 1;
    mstatus = (mstatus & ~(1 << spp)) |
              (spie << spp);
    /* set SPIE to 1 */
    mstatus |= MSTATUS_SPIE;
    /* set SPP to U */
    mstatus &= ~MSTATUS_SPP;
    priv = spp;
    next_pc = sepc;
}

void handle_mret()
{
    int mpp, mpie;
    mpp = (mstatus >> MSTATUS_MPP_SHIFT) & 3;
    /* set the IE state to previous IE state */
    mpie = (mstatus >> MSTATUS_MPIE_SHIFT) & 1;
    mstatus = (mstatus & ~(1 << mpp)) |
              (mpie << mpp);
    /* set MPIE to 1 */
    mstatus |= MSTATUS_MPIE;
    /* set MPP to U */
    mstatus &= ~MSTATUS_MPP;
    priv = mpp;
    next_pc = mepc;
}

Alexander Shabarshin's avatar
Alexander Shabarshin committed
600
void raise_exception(uint32_t cause, uint32_t tval)
Alexander Shabarshin's avatar
Alexander Shabarshin committed
601
{
602
    int deleg;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
603

Alexander Shabarshin's avatar
Alexander Shabarshin committed
604
    /* exit for Zephyr applications */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
605
    if (cause == CAUSE_ILLEGAL_INSTRUCTION) {
606 607 608
#ifdef DEBUG_OUTPUT
        printf("raise_exception: illegal instruction 0x%x 0x%x\n", cause, tval);
#endif
609
        machine_running = FALSE;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687
        return;
    }

    if (priv <= PRV_S) {
        /* delegate the exception to the supervisor priviledge */
        if (cause & CAUSE_INTERRUPT)
            deleg = (mideleg >> (cause & (XLEN - 1))) & 1;
        else
            deleg = (medeleg >> cause) & 1;
    } else {
        deleg = 0;
    }

    if (deleg) {
        scause = cause;
        sepc = pc;
        stval = tval;
        mstatus = (mstatus & ~MSTATUS_SPIE) |
                  (((mstatus >> priv) & 1) << MSTATUS_SPIE_SHIFT);
        mstatus = (mstatus & ~MSTATUS_SPP) |
                  (priv << MSTATUS_SPP_SHIFT);
        mstatus &= ~MSTATUS_SIE;
        priv = PRV_S;
        next_pc = stvec;
    } else {
        mcause = cause;
        mepc = pc;
        mtval = tval;
        mstatus = (mstatus & ~MSTATUS_MPIE) |
                  (((mstatus >> priv) & 1) << MSTATUS_MPIE_SHIFT);
        mstatus = (mstatus & ~MSTATUS_MPP) |
                  (priv << MSTATUS_MPP_SHIFT);
        mstatus &= ~MSTATUS_MIE;
        priv = PRV_M;
        next_pc = mtvec;
    }
}

uint32_t get_pending_irq_mask()
{
    uint32_t pending_ints, enabled_ints;

    pending_ints = mip & mie;
    if (pending_ints == 0)
        return 0;

    enabled_ints = 0;
    switch(priv) {
    case PRV_M:
        if (mstatus & MSTATUS_MIE)
            enabled_ints = ~mideleg;
        break;
    case PRV_S:
        enabled_ints = ~mideleg;
        if (mstatus & MSTATUS_SIE)
            enabled_ints |= mideleg;
        break;
    default:
    case PRV_U:
        enabled_ints = -1;
        break;
    }
    return pending_ints & enabled_ints;
}

int raise_interrupt()
{
    uint32_t mask;
    int irq_num;

    mask = get_pending_irq_mask();
    if (mask == 0)
        return 0;
    irq_num = ctz32(mask);
    raise_exception(irq_num | CAUSE_INTERRUPT, 0);
    return -1;
}

688 689
/* read 32-bit instruction from memory by PC */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
690 691
uint32_t get_insn32(uint32_t pc)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
692 693 694 695
#ifdef DEBUG_EXTRA
    if(pc && pc < minmemr) minmemr = pc;
    if(pc+3 > maxmemr) maxmemr = pc+3;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
696 697 698 699 700 701
    uint32_t ptr = pc - ram_start;
    if (ptr > RAM_SIZE) return 1;
    uint8_t* p = ram + ptr;
    return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
}

702 703
/* read 8-bit data from memory */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
704 705
int target_read_u8(uint8_t *pval, uint32_t addr)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
706 707 708 709
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemr) minmemr = addr;
    if(addr > maxmemr) maxmemr = addr;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
710 711 712 713 714 715 716 717 718 719 720 721
    addr -= ram_start;
    if (addr > RAM_SIZE) {
        *pval = 0;
        printf("illegal read 8, PC: 0x%08x, address: 0x%08x\n", pc, addr + ram_start);
        return 1;
    } else {
        uint8_t* p = ram + addr;
        *pval = p[0];
    }
    return 0;
}

722 723
/* read 16-bit data from memory */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
724 725
int target_read_u16(uint16_t *pval, uint32_t addr)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
726 727 728 729
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemr) minmemr = addr;
    if(addr+1 > maxmemr) maxmemr = addr+1;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746
    if (addr & 1) {
        pending_exception = CAUSE_MISALIGNED_LOAD;
        pending_tval = addr;
        return 1;
    }
    addr -= ram_start;
    if (addr > RAM_SIZE)  {
        *pval = 0;
        printf("illegal read 16, PC: 0x%08x, address: 0x%08x\n", pc, addr + ram_start);
        return 1;
    } else {
        uint8_t* p = ram + addr;
        *pval = p[0] | (p[1] << 8);
    }
    return 0;
}

747 748
/* read 32-bit data from memory */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
749 750
int target_read_u32(uint32_t *pval, uint32_t addr)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
751 752 753 754
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemr) minmemr = addr;
    if(addr+3 > maxmemr) maxmemr = addr+3;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781
    if (addr & 3) {
        pending_exception = CAUSE_MISALIGNED_LOAD;
        pending_tval = addr;
        return 1;
    }
    if (addr == MTIMECMP_ADDR) {
        *pval = (uint32_t) mtimecmp;
    } else if (addr == MTIMECMP_ADDR + 4) {
        *pval = (uint32_t) (mtimecmp >> 32);
    } else if (addr == MTIME_ADDR) {
        *pval = (uint32_t) mtime;
    } else if (addr == MTIME_ADDR + 4) {
        *pval = (uint32_t) (mtime >> 32);
    } else {
        addr -= ram_start;
        if (addr > RAM_SIZE) {
            *pval = 0;
            printf("illegal read 32, PC: 0x%08x, address: 0x%08x\n", pc, addr + ram_start);
            return 1;
        } else {
            uint8_t* p = ram + addr;
            *pval = p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
        }
    }
    return 0;
}

782 783
/* write 8-bit data to memory */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
784 785
int target_write_u8(uint32_t addr, uint8_t val)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
786 787 788 789
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemw) minmemw = addr;
    if(addr > maxmemw) maxmemw = addr;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
790
    if (addr == UART_TX_ADDR) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
791
        /* test for UART output, compatible with QEMU */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
792 793 794 795 796 797 798 799 800 801 802 803 804 805
        printf("%c", val);
    } else {
        addr -= ram_start;
        if (addr > RAM_SIZE - 1) {
            printf("illegal write 8, PC: 0x%08x, address: 0x%08x\n", pc, addr + ram_start);
            return 1;
        } else {
            uint8_t* p = ram + addr;
            p[0] = val & 0xff;
        }
    }
    return 0;
}

806 807
/* write 16-bit data to memory */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
808 809
int target_write_u16(uint32_t addr, uint16_t val)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
810 811 812 813
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemw) minmemw = addr;
    if(addr+1 > maxmemw) maxmemw = addr+1;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830
    if (addr & 1) {
        pending_exception = CAUSE_MISALIGNED_STORE;
        pending_tval = addr;
        return 1;
    }
    addr -= ram_start;
    if (addr > RAM_SIZE - 2) {
        printf("illegal write 16, PC: 0x%08x, address: 0x%08x\n", pc, addr + ram_start);
        return 1;
    } else {
        uint8_t* p = ram + addr;
        p[0] = val & 0xff;
        p[1] = (val >> 8) & 0xff;
    }
    return 0;
}

831
/* write 32-bit data to memory */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
832 833 834

int target_write_u32(uint32_t addr, uint32_t val)
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
835 836 837 838
#ifdef DEBUG_EXTRA
    if((addr>>28)!=4 && addr < minmemw) minmemw = addr;
    if(addr+3 > maxmemw) maxmemw = addr+3;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
839 840 841 842 843 844
    if (addr & 3) {
        pending_exception = CAUSE_MISALIGNED_STORE;
        pending_tval = addr;
        return 1;
    }
    if (addr == MTIMECMP_ADDR) {
845 846
        mtimecmp = (mtimecmp & 0xffffffff00000000ll) | val;
        mip &= ~MIP_MTIP;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
847
    } else if (addr == MTIMECMP_ADDR + 4) {
848 849
        mtimecmp = (mtimecmp & 0xffffffffll) | (((uint64_t)val) << 32);
        mip &= ~MIP_MTIP;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
    } else {
        addr -= ram_start;
        if (addr > RAM_SIZE - 4)  {
            return 1;
        } else {
            uint8_t* p = ram + addr;
            p[0] = val & 0xff;
            p[1] = (val >> 8) & 0xff;
            p[2] = (val >> 16) & 0xff;
            p[3] = (val >> 24) & 0xff;
        }
    }
    return 0;
}

865 866
#ifndef STRICT_RV32I

Alexander Shabarshin's avatar
Alexander Shabarshin committed
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921
int32_t div32(int32_t a, int32_t b)
{
    if (b == 0) {
        return -1;
    } else if (a == ((int32_t)1 << (XLEN - 1)) && b == -1) {
        return a;
    } else {
        return a / b;
    }
}

uint32_t divu32(uint32_t a, uint32_t b)
{
    if (b == 0) {
        return -1;
    } else {
        return a / b;
    }
}

int32_t rem32(int32_t a, int32_t b)
{
    if (b == 0) {
        return a;
    } else if (a == ((int32_t)1 << (XLEN - 1)) && b == -1) {
        return 0;
    } else {
        return a % b;
    }
}

uint32_t remu32(uint32_t a, uint32_t b)
{
    if (b == 0) {
        return a;
    } else {
        return a % b;
    }
}

static uint32_t mulh32(int32_t a, int32_t b)
{
    return ((int64_t)a * (int64_t)b) >> 32;
}

static uint32_t mulhsu32(int32_t a, uint32_t b)
{
    return ((int64_t)a * (int64_t)b) >> 32;
}

static uint32_t mulhu32(uint32_t a, uint32_t b)
{
    return ((int64_t)a * (int64_t)b) >> 32;
}

922 923
#endif

924 925
#ifdef DEBUG_EXTRA

Alexander Shabarshin's avatar
Alexander Shabarshin committed
926
/* dumps all registers, useful for in-depth debugging */
927

Alexander Shabarshin's avatar
Alexander Shabarshin committed
928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962
static void dump_regs()
{
    printf("x0 zero: %08x\n", reg[0]);
    printf("x1 ra:   %08x\n", reg[1]);
    printf("x2 sp:   %08x\n", reg[2]);
    printf("x3 gp:   %08x\n", reg[3]);
    printf("x4 tp:   %08x\n", reg[4]);
    printf("x5 t0:   %08x\n", reg[5]);
    printf("x6 t1:   %08x\n", reg[6]);
    printf("x7 t2:   %08x\n", reg[7]);
    printf("x8 s0:   %08x\n", reg[8]);
    printf("x9 s1:   %08x\n", reg[9]);
    printf("x10 a0:  %08x\n", reg[10]);
    printf("x11 a1:  %08x\n", reg[11]);
    printf("x12 a2:  %08x\n", reg[12]);
    printf("x13 a3:  %08x\n", reg[13]);
    printf("x14 a4:  %08x\n", reg[14]);
    printf("x15 a5:  %08x\n", reg[15]);
    printf("x16 a6:  %08x\n", reg[16]);
    printf("x17 a7:  %08x\n", reg[17]);
    printf("x18 s2:  %08x\n", reg[18]);
    printf("x19 s3:  %08x\n", reg[19]);
    printf("x20 s4:  %08x\n", reg[20]);
    printf("x21 s5:  %08x\n", reg[21]);
    printf("x22 s6:  %08x\n", reg[22]);
    printf("x23 s7:  %08x\n", reg[23]);
    printf("x24 s8:  %08x\n", reg[24]);
    printf("x25 s9:  %08x\n", reg[25]);
    printf("x26 s10: %08x\n", reg[26]);
    printf("x27 s11: %08x\n", reg[27]);
    printf("x28 t3:  %08x\n", reg[28]);
    printf("x29 t4:  %08x\n", reg[29]);
    printf("x30 t5:  %08x\n", reg[30]);
    printf("x31 t6:  %08x\n", reg[31]);
}
963

Alexander Shabarshin's avatar
Alexander Shabarshin committed
964
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
965 966 967 968 969

void execute_instruction()
{
    uint32_t opcode, rd, rs1, rs2, funct3;
    int32_t imm, cond, err;
970
    uint32_t addr, val=0, val2;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
971 972 973 974 975 976 977

    opcode = insn & 0x7f;
    rd = (insn >> 7) & 0x1f;
    rs1 = (insn >> 15) & 0x1f;
    rs2 = (insn >> 20) & 0x1f;

    switch(opcode) {
978

Alexander Shabarshin's avatar
Alexander Shabarshin committed
979
    case 0x37: /* lui */
980

Alexander Shabarshin's avatar
Alexander Shabarshin committed
981 982 983 984
#ifdef DEBUG_EXTRA
        dprintf(">>> LUI\n");
        stats[0]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
985 986 987
        if (rd != 0)
            reg[rd] = (int32_t)(insn & 0xfffff000);
        break;
988

Alexander Shabarshin's avatar
Alexander Shabarshin committed
989
    case 0x17: /* auipc */
990

Alexander Shabarshin's avatar
Alexander Shabarshin committed
991 992 993 994
#ifdef DEBUG_EXTRA
        dprintf(">>> AUIPC\n");
        stats[1]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
995 996 997
        if (rd != 0)
            reg[rd] = (int32_t)(pc + (int32_t)(insn & 0xfffff000));
        break;
998

Alexander Shabarshin's avatar
Alexander Shabarshin committed
999
    case 0x6f: /* jal */
1000

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1001 1002 1003 1004
#ifdef DEBUG_EXTRA
        dprintf(">>> JAL\n");
        stats[2]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1005 1006 1007 1008 1009 1010 1011 1012 1013
        imm = ((insn >> (31 - 20)) & (1 << 20)) |
              ((insn >> (21 - 1)) & 0x7fe) |
              ((insn >> (20 - 11)) & (1 << 11)) |
              (insn & 0xff000);
        imm = (imm << 11) >> 11;
        if (rd != 0)
            reg[rd] = pc + 4;
        next_pc = (int32_t)(pc + imm);
        break;
1014

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1015
    case 0x67: /* jalr */
1016

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1017 1018 1019 1020
#ifdef DEBUG_EXTRA
        dprintf(">>> JALR\n");
        stats[3]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1021 1022 1023 1024 1025 1026
        imm = (int32_t)insn >> 20;
        val = pc + 4;
        next_pc = (int32_t)(reg[rs1] + imm) & ~1;
        if (rd != 0)
            reg[rd] = val;
        break;
1027 1028 1029

    case 0x63: /* BRANCH */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1030 1031 1032
        funct3 = (insn >> 12) & 7;
        switch(funct3 >> 1) {
        case 0: /* beq/bne */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1033 1034 1035 1036 1037 1038 1039 1040 1041
#ifdef DEBUG_EXTRA
            if(!(funct3 & 1)) {
              dprintf(">>> BEQ\n");
              stats[4]++;
            } else  {
              dprintf(">>> BNE\n");
              stats[5]++;
            }
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1042 1043 1044
            cond = (reg[rs1] == reg[rs2]);
            break;
        case 2: /* blt/bge */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1045 1046 1047 1048 1049 1050 1051 1052 1053
#ifdef DEBUG_EXTRA
            if(!(funct3 & 1)) {
              dprintf(">>> BLT\n");
              stats[6]++;
            } else  {
              dprintf(">>> BGE\n");
              stats[7]++;
            }
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1054 1055 1056
            cond = ((int32_t)reg[rs1] < (int32_t)reg[rs2]);
            break;
        case 3: /* bltu/bgeu */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1057 1058 1059 1060 1061 1062 1063 1064 1065
#ifdef DEBUG_EXTRA
            if(!(funct3 & 1)) {
              dprintf(">>> BLTU\n");
              stats[8]++;
            } else  {
              dprintf(">>> BGEU\n");
              stats[9]++;
            }
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
            cond = (reg[rs1] < reg[rs2]);
            break;
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        cond ^= (funct3 & 1);
        if (cond) {
            imm = ((insn >> (31 - 12)) & (1 << 12)) |
                  ((insn >> (25 - 5)) & 0x7e0) |
                  ((insn >> (8 - 1)) & 0x1e) |
                  ((insn << (11 - 7)) & (1 << 11));
            imm = (imm << 19) >> 19;
            next_pc = (int32_t)(pc + imm);
            break;
        }
        break;
1083 1084 1085

    case 0x03: /* LOAD */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1086 1087 1088 1089
        funct3 = (insn >> 12) & 7;
        imm = (int32_t)insn >> 20;
        addr = reg[rs1] + imm;
        switch(funct3) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1090

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1091 1092
        case 0: /* lb */
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1093 1094 1095 1096
#ifdef DEBUG_EXTRA
            dprintf(">>> LB\n");
            stats[10]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1097 1098 1099 1100 1101 1102 1103 1104
            uint8_t rval;
            if (target_read_u8(&rval, addr)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            val = (int8_t)rval;
        }
        break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1105

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1106 1107
        case 1: /* lh */
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1108 1109 1110 1111
#ifdef DEBUG_EXTRA
            dprintf(">>> LH\n");
            stats[11]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1112 1113 1114 1115 1116 1117 1118 1119
            uint16_t rval;
            if (target_read_u16(&rval, addr)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            val = (int16_t)rval;
        }
        break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1120

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1121 1122
        case 2: /* lw */
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1123 1124 1125 1126
#ifdef DEBUG_EXTRA
            dprintf(">>> LW\n");
            stats[12]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1127 1128 1129 1130 1131 1132 1133 1134
            uint32_t rval;
            if (target_read_u32(&rval, addr)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            val = (int32_t)rval;
        }
        break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1135

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1136 1137
        case 4: /* lbu */
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1138 1139 1140 1141
#ifdef DEBUG_EXTRA
            dprintf(">>> LBU\n");
            stats[13]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1142 1143 1144 1145 1146 1147 1148 1149
            uint8_t rval;
            if (target_read_u8(&rval, addr)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            val = rval;
        }
        break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1150

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1151 1152
        case 5: /* lhu */
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1153 1154 1155 1156
#ifdef DEBUG_EXTRA
            dprintf(">>> LHU\n");
            stats[14]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1157 1158 1159 1160 1161 1162 1163 1164
            uint16_t rval;
            if (target_read_u16(&rval, addr)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            val = rval;
        }
        break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1165

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1166 1167 1168 1169 1170 1171 1172
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        if (rd != 0)
            reg[rd] = val;
        break;
1173 1174 1175

    case 0x23: /* STORE */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1176 1177 1178 1179 1180 1181
        funct3 = (insn >> 12) & 7;
        imm = rd | ((insn >> (25 - 5)) & 0xfe0);
        imm = (imm << 20) >> 20;
        addr = reg[rs1] + imm;
        val = reg[rs2];
        switch(funct3) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1182

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1183
        case 0: /* sb */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1184 1185 1186 1187
#ifdef DEBUG_EXTRA
            dprintf(">>> SB\n");
            stats[15]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1188 1189 1190 1191 1192
            if (target_write_u8(addr, val)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1193

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1194
        case 1: /* sh */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1195 1196 1197 1198
#ifdef DEBUG_EXTRA
            dprintf(">>> SH\n");
            stats[16]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1199 1200 1201 1202 1203
            if (target_write_u16(addr, val)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1204

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1205
        case 2: /* sw */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1206 1207 1208 1209
#ifdef DEBUG_EXTRA
            dprintf(">>> SW\n");
            stats[17]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1210 1211 1212 1213 1214
            if (target_write_u32(addr, val)) {
                raise_exception(pending_exception, pending_tval);
                return;
            }
            break;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1215

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1216 1217 1218 1219 1220
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        break;
1221 1222 1223

    case 0x13: /* OP-IMM */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1224 1225 1226 1227
        funct3 = (insn >> 12) & 7;
        imm = (int32_t)insn >> 20;
        switch(funct3) {
        case 0: /* addi */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1228 1229 1230 1231
#ifdef DEBUG_EXTRA
            dprintf(">>> ADDI\n");
            stats[18]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1232 1233 1234
            val = (int32_t)(reg[rs1] + imm);
            break;
        case 1: /* slli */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1235 1236 1237 1238
#ifdef DEBUG_EXTRA
            dprintf(">>> SLLI\n");
            stats[24]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1239 1240 1241 1242 1243 1244 1245
            if ((imm & ~(XLEN - 1)) != 0) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            val = (int32_t)(reg[rs1] << (imm & (XLEN - 1)));
            break;
        case 2: /* slti */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1246 1247 1248 1249
#ifdef DEBUG_EXTRA
            dprintf(">>> SLTI\n");
            stats[19]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1250 1251 1252
            val = (int32_t)reg[rs1] < (int32_t)imm;
            break;
        case 3: /* sltiu */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1253 1254 1255 1256
#ifdef DEBUG_EXTRA
            dprintf(">>> SLTIU\n");
            stats[20]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1257 1258 1259
            val = reg[rs1] < (uint32_t)imm;
            break;
        case 4: /* xori */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1260 1261 1262 1263
#ifdef DEBUG_EXTRA
            dprintf(">>> XORI\n");
            stats[21]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1264 1265 1266 1267 1268 1269 1270 1271
            val = reg[rs1] ^ imm;
            break;
        case 5: /* srli/srai */
            if ((imm & ~((XLEN - 1) | 0x400)) != 0) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            if (imm & 0x400)
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1272 1273 1274 1275 1276
            {
#ifdef DEBUG_EXTRA
                dprintf(">>> SRAI\n");
                stats[26]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1277
                val = (int32_t)reg[rs1] >> (imm & (XLEN - 1));
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1278
            }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1279
            else
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1280 1281 1282 1283 1284
            {
#ifdef DEBUG_EXTRA
                dprintf(">>> SRLI\n");
                stats[25]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1285
                val = (int32_t)((uint32_t)reg[rs1] >> (imm & (XLEN - 1)));
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1286
            }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1287 1288
            break;
        case 6: /* ori */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1289 1290 1291 1292
#ifdef DEBUG_EXTRA
            dprintf(">>> ORI\n");
            stats[22]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1293 1294 1295
            val = reg[rs1] | imm;
            break;
        case 7: /* andi */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1296 1297 1298 1299
#ifdef DEBUG_EXTRA
            dprintf(">>> ANDI\n");
            stats[23]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1300 1301 1302 1303 1304 1305
            val = reg[rs1] & imm;
            break;
        }
        if (rd != 0)
            reg[rd] = val;
        break;
1306 1307 1308

    case 0x33: /* OP */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1309 1310 1311
        imm = insn >> 25;
        val = reg[rs1];
        val2 = reg[rs2];
1312
#ifndef STRICT_RV32I
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
        if (imm == 1) {
            funct3 = (insn >> 12) & 7;
            switch(funct3) {
            case 0: /* mul */
                val = (int32_t)((int32_t)val * (int32_t)val2);
                break;
            case 1: /* mulh */
                val = (int32_t)mulh32(val, val2);
                break;
            case 2:/* mulhsu */
                val = (int32_t)mulhsu32(val, val2);
                break;
            case 3:/* mulhu */
                val = (int32_t)mulhu32(val, val2);
                break;
            case 4:/* div */
                val = div32(val, val2);
                break;
            case 5:/* divu */
                val = (int32_t)divu32(val, val2);
                break;
            case 6:/* rem */
                val = rem32(val, val2);
                break;
            case 7:/* remu */
                val = (int32_t)remu32(val, val2);
                break;
            default:
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
1344 1345 1346 1347
        }
        else
#endif
        {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1348 1349 1350 1351 1352 1353 1354
            if (imm & ~0x20) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            funct3 = ((insn >> 12) & 7) | ((insn >> (30 - 3)) & (1 << 3));
            switch(funct3) {
            case 0: /* add */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1355 1356 1357 1358
#ifdef DEBUG_EXTRA
                dprintf(">>> ADD\n");
                stats[27]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1359 1360 1361
                val = (int32_t)(val + val2);
                break;
            case 0 | 8: /* sub */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1362 1363 1364 1365
#ifdef DEBUG_EXTRA
                dprintf(">>> SUB\n");
                stats[28]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1366 1367 1368
                val = (int32_t)(val - val2);
                break;
            case 1: /* sll */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1369 1370 1371 1372
#ifdef DEBUG_EXTRA
                dprintf(">>> SLL\n");
                stats[29]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1373 1374 1375
                val = (int32_t)(val << (val2 & (XLEN - 1)));
                break;
            case 2: /* slt */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1376 1377 1378 1379
#ifdef DEBUG_EXTRA
                dprintf(">>> SLT\n");
                stats[30]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1380 1381 1382
                val = (int32_t)val < (int32_t)val2;
                break;
            case 3: /* sltu */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1383 1384 1385 1386
#ifdef DEBUG_EXTRA
                dprintf(">>> SLTU\n");
                stats[31]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1387 1388 1389
                val = val < val2;
                break;
            case 4: /* xor */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1390 1391 1392 1393
#ifdef DEBUG_EXTRA
                dprintf(">>> XOR\n");
                stats[32]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1394 1395 1396
                val = val ^ val2;
                break;
            case 5: /* srl */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1397 1398 1399 1400
#ifdef DEBUG_EXTRA
                dprintf(">>> SRL\n");
                stats[33]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1401 1402 1403
                val = (int32_t)((uint32_t)val >> (val2 & (XLEN - 1)));
                break;
            case 5 | 8: /* sra */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1404 1405 1406 1407
#ifdef DEBUG_EXTRA
                dprintf(">>> SRA\n");
                stats[34]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1408 1409 1410
                val = (int32_t)val >> (val2 & (XLEN - 1));
                break;
            case 6: /* or */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1411 1412 1413 1414
#ifdef DEBUG_EXTRA
                dprintf(">>> OR\n");
                stats[35]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1415 1416 1417
                val = val | val2;
                break;
            case 7: /* and */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1418 1419 1420 1421
#ifdef DEBUG_EXTRA
                dprintf(">>> AND\n");
                stats[36]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1422 1423 1424 1425 1426 1427 1428 1429 1430 1431
                val = val & val2;
                break;
            default:
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
        }
        if (rd != 0)
            reg[rd] = val;
        break;
1432 1433 1434

    case 0x73: /* SYSTEM */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1435 1436 1437 1438 1439 1440 1441 1442
        funct3 = (insn >> 12) & 7;
        imm = insn >> 20;
        if (funct3 & 4)
            val = rs1;
        else
            val = reg[rs1];
        funct3 &= 3;
        switch(funct3) {
1443

1444
        case 1: /* csrrw & csrrwi */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1445
#ifdef DEBUG_EXTRA
1446 1447 1448 1449 1450 1451 1452 1453 1454 1455
            if ((insn >> 12) & 4)
            {
               dprintf(">>> CSRRWI\n");
               stats[44]++;
            }
            else
            {
               dprintf(">>> CSRRW\n");
               stats[41]++;
            }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1456
#endif
1457
            if (csr_read(&val2, imm, /*TRUE*/ (rd != 0))) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            val2 = (int32_t)val2;
            err = csr_write(imm, val);
            if (err < 0) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            if (rd != 0)
                reg[rd] = val2;
            if (err > 0) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1470
                /* pc = pc + 4; */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1471 1472
            }
            break;
1473

1474 1475
        case 2: /* csrrs & csrrsi */
        case 3: /* csrrc & csrrci */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1476 1477 1478 1479 1480
            if (csr_read(&val2, imm, (rs1 != 0))) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            val2 = (int32_t)val2;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1481
#ifdef DEBUG_EXTRA
1482 1483 1484 1485 1486 1487 1488
            switch((insn >> 12) & 7)
            {
               case 2: dprintf(">>> CSRRS\n"); stats[42]++; break;
               case 3: dprintf(">>> CSRRC\n"); stats[43]++; break;
               case 6: dprintf(">>> CSRRSI\n"); stats[45]++; break;
               case 7: dprintf(">>> CSRRCI\n"); stats[46]++; break;
            }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1489
#endif
1490 1491 1492 1493
            if (rs1 != 0)
            {
                if (funct3 == 2)
                {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1494
                    val = val2 | val;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1495
                }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1496
                else
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1497
                {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1498
                    val = val2 & ~val;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1499
                }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1500 1501 1502 1503 1504
                err = csr_write(imm, val);
                if (err < 0) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
1505
            }
1506 1507
            else
            {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1508 1509 1510 1511 1512
                err = 0;
            }
            if (rd != 0)
                reg[rd] = val2;
            break;
1513

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1514 1515 1516
        case 0:
            switch(imm) {
            case 0x000: /* ecall */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1517 1518 1519 1520
#ifdef DEBUG_EXTRA
                dprintf(">>> ECALL\n");
                stats[39]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1521 1522 1523 1524
                if (insn & 0x000fff80) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1525 1526 1527 1528
                /*
                    compliance test specific: if bit 0 of gp (x3) is 0, it is a syscall,
                    otherwise it is the program end, with the exit code in the bits 31:1
                */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1529 1530 1531 1532 1533
                if (begin_signature) {
                    if (reg[3] & 1) {
#ifdef DEBUG_OUTPUT
                        printf("program end, result: %04x\n", reg[3] >> 1);
#endif
1534
                        machine_running = FALSE;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1535
                        return;
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1536

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1537 1538 1539 1540 1541 1542 1543
                    } else {
#ifdef DEBUG_OUTPUT
                        printf("syscall: %04x\n", reg[3]);
#endif
                        raise_exception(CAUSE_USER_ECALL + priv, 0);
                    }
                } else {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1544
                    /* on real hardware, an exception is raised, the I-ECALL-01 compliance test tests this as well */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1545 1546 1547 1548 1549 1550
                    raise_exception(CAUSE_USER_ECALL + priv, 0);
                    return;
                }
                break;

            case 0x001: /* ebreak */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1551 1552 1553 1554
#ifdef DEBUG_EXTRA
                dprintf(">>> EBREAK\n");
                stats[40]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1555 1556 1557 1558 1559 1560
                if (insn & 0x000fff80) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                raise_exception(CAUSE_BREAKPOINT, 0);
                return;
1561

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1562 1563
            case 0x102: /* sret */
            {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1564 1565 1566 1567
#ifdef DEBUG_EXTRA
                dprintf(">>> SRET\n");
                stats[47]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1568 1569 1570 1571 1572 1573 1574 1575
                if ((insn & 0x000fff80) || (priv < PRV_S)) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                handle_sret();
                return;
            }
            break;
1576

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1577
            case 0x105: /* wfi */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1578 1579 1580 1581
#ifdef DEBUG_EXTRA
                dprintf(">>> WFI\n");
                stats[48]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1582
                /* wait for interrupt: it is allowed to execute it as nop */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1583
                break;
1584

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1585 1586
            case 0x302: /* mret */
            {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1587 1588 1589 1590
#ifdef DEBUG_EXTRA
                dprintf(">>> MRET\n");
                stats[49]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1591 1592 1593 1594 1595 1596 1597 1598
                if ((insn & 0x000fff80) || (priv < PRV_M)) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                handle_mret();
                return;
            }
            break;
1599

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1600 1601
            default:
                if ((imm >> 5) == 0x09) {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1602 1603 1604 1605
#ifdef DEBUG_EXTRA
                    dprintf(">>> SFENCE.VMA\n");
                    stats[50]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617
                    /* sfence.vma */
                    if ((insn & 0x00007f80) || (priv == PRV_U)) {
                        raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                        return;
                    }
                } else {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                break;
            }
            break;
1618

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1619 1620 1621 1622 1623
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        break;
1624 1625 1626

    case 0x0f: /* MISC-MEM */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1627 1628
        funct3 = (insn >> 12) & 7;
        switch(funct3) {
1629

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1630
        case 0: /* fence */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1631 1632 1633 1634
#ifdef DEBUG_EXTRA
            dprintf(">>> FENCE\n");
            stats[37]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1635 1636 1637 1638 1639
            if (insn & 0xf00fff80) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            break;
1640

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1641
        case 1: /* fence.i */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1642 1643 1644 1645
#ifdef DEBUG_EXTRA
            dprintf(">>> FENCE.I\n");
            stats[38]++;
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1646 1647 1648 1649 1650
            if (insn != 0x0000100f) {
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
            break;
1651

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1652 1653 1654 1655 1656
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        break;
1657 1658 1659 1660 1661

#ifndef STRICT_RV32I

    case 0x2f: /* AMO */

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1662 1663 1664 1665 1666 1667 1668 1669 1670
        funct3 = (insn >> 12) & 7;
        switch(funct3) {
        case 2:
        {
            uint32_t rval;

            addr = reg[rs1];
            funct3 = insn >> 27;
            switch(funct3) {
1671

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
            case 2: /* lr.w */
                if (rs2 != 0) {
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                if (target_read_u32(&rval, addr)) {
                    raise_exception(pending_exception, pending_tval);
                    return;
                }
                val = (int32_t)rval;
                load_res = addr;
                break;
1684

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695
            case 3: /* sc.w */
                if (load_res == addr) {
                    if (target_write_u32(addr, reg[rs2])) {
                        raise_exception(pending_exception, pending_tval);
                        return;
                    }
                    val = 0;
                } else {
                    val = 1;
                }
                break;
1696

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1697 1698 1699 1700 1701 1702 1703 1704 1705
            case 1: /* amiswap.w */
            case 0: /* amoadd.w */
            case 4: /* amoxor.w */
            case 0xc: /* amoand.w */
            case 0x8: /* amoor.w */
            case 0x10: /* amomin.w */
            case 0x14: /* amomax.w */
            case 0x18: /* amominu.w */
            case 0x1c: /* amomaxu.w */
1706

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765
                if (target_read_u32(&rval, addr)) {
                    raise_exception(pending_exception, pending_tval);
                    return;
                }
                val = (int32_t)rval;
                val2 = reg[rs2];
                switch(funct3) {
                case 1: /* amiswap.w */
                    break;
                case 0: /* amoadd.w */
                    val2 = (int32_t)(val + val2);
                    break;
                case 4: /* amoxor.w */
                    val2 = (int32_t)(val ^ val2);
                    break;
                case 0xc: /* amoand.w */
                    val2 = (int32_t)(val & val2);
                    break;
                case 0x8: /* amoor.w */
                    val2 = (int32_t)(val | val2);
                    break;
                case 0x10: /* amomin.w */
                    if ((int32_t)val < (int32_t)val2)
                        val2 = (int32_t)val;
                    break;
                case 0x14: /* amomax.w */
                    if ((int32_t)val > (int32_t)val2)
                        val2 = (int32_t)val;
                    break;
                case 0x18: /* amominu.w */
                    if ((uint32_t)val < (uint32_t)val2)
                        val2 = (int32_t)val;
                    break;
                case 0x1c: /* amomaxu.w */
                    if ((uint32_t)val > (uint32_t)val2)
                        val2 = (int32_t)val;
                    break;
                default:
                    raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                    return;
                }
                if (target_write_u32(addr, val2)) {
                    raise_exception(pending_exception, pending_tval);
                    return;
                }
                break;
            default:
                raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
                return;
            }
        }
        break;
        default:
            raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
            return;
        }
        if (rd != 0)
            reg[rd] = val;
        break;
1766 1767 1768

#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1769 1770 1771 1772 1773 1774
    default:
        raise_exception(CAUSE_ILLEGAL_INSTRUCTION, insn);
        return;
    }
}

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1775
/* returns realtime in nanoseconds */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1776 1777 1778 1779 1780 1781 1782 1783 1784 1785
int64_t get_clock()
{
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    return ts.tv_sec * 1000000000LL + ts.tv_nsec;
}


void riscv_cpu_interp_x32()
{
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1786
    /* we use a single execution loop to keep a simple control flow for emscripten */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1787
    while (machine_running) {
1788
#if 1
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1789
        /* update timer, assuming 10 MHz clock (100 ns period) for the mtime counter */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1790 1791
        mtime = get_clock() / 100ll;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1792
        /* for reproducible debug runs, you can use a fixed fixed increment per instruction */
1793
#else
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1794 1795 1796
        mtime += 10;
#endif
        /* default value for next PC is next instruction, can be changed by branches or exceptions */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1797 1798
        next_pc = pc + 4;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1799
        /* test for timer interrupt */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1800 1801 1802 1803 1804 1805
        if (mtimecmp <= mtime) {
            mip |= MIP_MTIP;
        }
        if ((mip & mie) != 0 && (mstatus & MSTATUS_MIE)) {
            raise_interrupt();
        } else {
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1806
            /* normal instruction execution */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1807 1808 1809 1810
            insn = get_insn32(pc);
            insn_counter++;

#ifdef DEBUG_OUTPUT
1811
            printf("[%08x]=%08x, mtime: %lx, mtimecmp: %lx\n", pc, insn, mtime, mtimecmp);
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1812 1813 1814 1815
#endif
            execute_instruction();
        }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1816
        /* test for misaligned fetches */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1817 1818 1819 1820
        if (next_pc & 3) {
            raise_exception(CAUSE_MISALIGNED_FETCH, next_pc);
        }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1821
        /* update current PC */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833
        pc = next_pc;
    }

#ifdef DEBUG_OUTPUT
    printf("done interp %lx int=%x mstatus=%lx prv=%d\n",
           (uint64_t)insn_counter, mip & mie, (uint64_t)mstatus,
           priv);
#endif
}

int main(int argc, char** argv)
{
1834 1835 1836 1837 1838
#ifdef DEBUG_OUTPUT
    FILE *fo;
    char *po,hex_file[100];
#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1839
    /* automatic STDOUT flushing, no fflush needed */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1840 1841
    setvbuf(stdout, NULL, _IONBF, 0);

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1842
    /* parse command line */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857
    const char* elf_file = NULL;
    const char* signature_file = NULL;
    for (int i = 1; i < argc; i++) {
        char* arg = argv[i];
        if (arg == strstr(arg, "+signature=")) {
            signature_file = arg + 11;
        } else if (arg[0] != '-') {
            elf_file = arg;
        }
    }
    if (elf_file == NULL) {
        printf("missing ELF file\n");
        return 1;
    }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1858 1859 1860 1861
#ifdef DEBUG_EXTRA
    init_stats();
#endif

1862 1863
    for(uint32_t u=0;u<RAM_SIZE;u++) ram[u]=0;

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1864
    /* open ELF file */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1865 1866 1867 1868 1869 1870 1871 1872
    elf_version(EV_CURRENT);
    int fd = open(elf_file, O_RDONLY);
    if (fd == -1) {
        printf("can't open file %s\n", elf_file);
        return 1;
    }
    Elf *elf = elf_begin(fd, ELF_C_READ, NULL);

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1873
    /* scan for symbol table */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
    Elf_Scn *scn = NULL;
    GElf_Shdr shdr;
    while ((scn = elf_nextscn(elf, scn)) != NULL) {
        gelf_getshdr(scn, &shdr);
        if (shdr.sh_type == SHT_SYMTAB) {
            Elf_Data *data = elf_getdata(scn, NULL);
            int count = shdr.sh_size / shdr.sh_entsize;
            for (int i = 0; i < count; i++) {
                GElf_Sym sym;
                gelf_getsym(data, i, &sym);
                char* name = elf_strptr(elf, shdr.sh_link, sym.st_name);
1885 1886 1887
#if 0
                if(*name) printf("sym '%s' %lx\n",name,sym.st_value);
#endif
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1888 1889 1890 1891 1892 1893 1894
                if (strcmp(name, "begin_signature") == 0) {
                    begin_signature = sym.st_value;
                }
                if (strcmp(name, "end_signature") == 0) {
                    end_signature = sym.st_value;
                }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1895
                /* for compliance test */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1896 1897 1898 1899
                if (strcmp(name, "_start") == 0) {
                    ram_start = sym.st_value;
                }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1900
                /* for zephyr */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915
                if (strcmp(name, "__reset") == 0) {
                    ram_start = sym.st_value;
                }
                if (strcmp(name, "__irq_wrapper") == 0) {
                    mtvec = sym.st_value;
                }
            }
        }
    }
#ifdef DEBUG_OUTPUT
    printf("begin_signature: 0x%08x\n", begin_signature);
    printf("end_signature: 0x%08x\n", end_signature);
    printf("start: 0x%08x\n", ram_start);
#endif

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1916
    /* scan for program */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1917 1918 1919 1920 1921 1922
    while ((scn = elf_nextscn(elf, scn)) != NULL) {
        gelf_getshdr(scn, &shdr);
        if (shdr.sh_type == SHT_PROGBITS) {
            Elf_Data *data = elf_getdata(scn, NULL);
            if (shdr.sh_addr >= ram_start) {
                for (size_t i = 0; i < shdr.sh_size; i++) {
1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
                    ram_curr = shdr.sh_addr + i - ram_start;
                    if(ram_curr >= RAM_SIZE)
                    {
#ifdef DEBUG_OUTPUT
                        printf("memory pointer outside of range 0x%08x (section at address 0x%08x)\n", ram_curr, (uint32_t) shdr.sh_addr);
#endif
                        /* break; */
                    }
                    else
                    {
                        ram[ram_curr] = ((uint8_t *)data->d_buf)[i];
                        if(ram_curr > ram_last) ram_last = ram_curr;
                    }
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1936 1937 1938 1939 1940 1941 1942 1943 1944
                }
            } else {
#ifdef DEBUG_OUTPUT
                printf("ignoring section at address 0x%08x\n", (uint32_t) shdr.sh_addr);
#endif
            }
        }
    }

Alexander Shabarshin's avatar
Alexander Shabarshin committed
1945
    /* close ELF file */
Alexander Shabarshin's avatar
Alexander Shabarshin committed
1946 1947 1948
    elf_end(elf);
    close(fd);

1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 196