hw/m48t59.c

   1 /*
   2  * QEMU M48T59 and M48T08 NVRAM emulation for PPC PREP and Sparc platforms
   3  *
   4  * Copyright (c) 2003-2005, 2007 Jocelyn Mayer
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "hw.h"
  25 #include "nvram.h"
  26 #include "isa.h"
  27 #include "qemu-timer.h"
  28 #include "sysemu.h"
  29
  30 //#define DEBUG_NVRAM
  31
  32 #if defined(DEBUG_NVRAM)
  33 #define NVRAM_PRINTF(fmt, ...) do { printf(fmt , ## __VA_ARGS__); } while (0)
  34 #else
  35 #define NVRAM_PRINTF(fmt, ...) do { } while (0)
  36 #endif
  37
  38 /*
  39  * The M48T02, M48T08 and M48T59 chips are very similar. The newer '59 has
  40  * alarm and a watchdog timer and related control registers. In the
  41  * PPC platform there is also a nvram lock function.
  42  */
  43 struct m48t59_t {
  44     /* Model parameters */
  45     int type; // 2 = m48t02, 8 = m48t08, 59 = m48t59
  46     /* Hardware parameters */
  47     qemu_irq IRQ;
  48     int mem_index;
  49     uint32_t io_base;
  50     uint16_t size;
  51     /* RTC management */
  52     time_t   time_offset;
  53     time_t   stop_time;
  54     /* Alarm & watchdog */
  55     struct tm alarm;
  56     struct QEMUTimer *alrm_timer;
  57     struct QEMUTimer *wd_timer;
  58     /* NVRAM storage */
  59     uint8_t  lock;
  60     uint16_t addr;
  61     uint8_t *buffer;
  62 };
  63
  64 /* Fake timer functions */
  65 /* Generic helpers for BCD */
  66 static inline uint8_t toBCD (uint8_t value)
  67 {
  68     return (((value / 10) % 10) << 4) | (value % 10);
  69 }
  70
  71 static inline uint8_t fromBCD (uint8_t BCD)
  72 {
  73     return ((BCD >> 4) * 10) + (BCD & 0x0F);
  74 }
  75
  76 /* Alarm management */
  77 static void alarm_cb (void *opaque)
  78 {
  79     struct tm tm;
  80     uint64_t next_time;
  81     m48t59_t *NVRAM = opaque;
  82
  83     qemu_set_irq(NVRAM->IRQ, 1);
  84     if ((NVRAM->buffer[0x1FF5] & 0x80) == 0 &&
  85         (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
  86         (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
  87         (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
  88         /* Repeat once a month */
  89         qemu_get_timedate(&tm, NVRAM->time_offset);
  90         tm.tm_mon++;
  91         if (tm.tm_mon == 13) {
  92             tm.tm_mon = 1;
  93             tm.tm_year++;
  94         }
  95         next_time = qemu_timedate_diff(&tm) - NVRAM->time_offset;
  96     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
  97                (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
  98                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
  99                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 100         /* Repeat once a day */
 101         next_time = 24 * 60 * 60;
 102     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
 103                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
 104                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
 105                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 106         /* Repeat once an hour */
 107         next_time = 60 * 60;
 108     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
 109                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
 110                (NVRAM->buffer[0x1FF3] & 0x80) != 0 &&
 111                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 112         /* Repeat once a minute */
 113         next_time = 60;
 114     } else {
 115         /* Repeat once a second */
 116         next_time = 1;
 117     }
 118     qemu_mod_timer(NVRAM->alrm_timer, qemu_get_clock(vm_clock) +
 119                     next_time * 1000);
 120     qemu_set_irq(NVRAM->IRQ, 0);
 121 }
 122
 123 static void set_alarm (m48t59_t *NVRAM)
 124 {
 125     int diff;
 126     if (NVRAM->alrm_timer != NULL) {
 127         qemu_del_timer(NVRAM->alrm_timer);
 128         diff = qemu_timedate_diff(&NVRAM->alarm) - NVRAM->time_offset;
 129         if (diff > 0)
 130             qemu_mod_timer(NVRAM->alrm_timer, diff * 1000);
 131     }
 132 }
 133
 134 /* RTC management helpers */
 135 static inline void get_time (m48t59_t *NVRAM, struct tm *tm)
 136 {
 137     qemu_get_timedate(tm, NVRAM->time_offset);
 138 }
 139
 140 static void set_time (m48t59_t *NVRAM, struct tm *tm)
 141 {
 142     NVRAM->time_offset = qemu_timedate_diff(tm);
 143     set_alarm(NVRAM);
 144 }
 145
 146 /* Watchdog management */
 147 static void watchdog_cb (void *opaque)
 148 {
 149     m48t59_t *NVRAM = opaque;
 150
 151     NVRAM->buffer[0x1FF0] |= 0x80;
 152     if (NVRAM->buffer[0x1FF7] & 0x80) {
 153         NVRAM->buffer[0x1FF7] = 0x00;
 154         NVRAM->buffer[0x1FFC] &= ~0x40;
 155         /* May it be a hw CPU Reset instead ? */
 156         qemu_system_reset_request();
 157     } else {
 158         qemu_set_irq(NVRAM->IRQ, 1);
 159         qemu_set_irq(NVRAM->IRQ, 0);
 160     }
 161 }
 162
 163 static void set_up_watchdog (m48t59_t *NVRAM, uint8_t value)
 164 {
 165     uint64_t interval; /* in 1/16 seconds */
 166
 167     NVRAM->buffer[0x1FF0] &= ~0x80;
 168     if (NVRAM->wd_timer != NULL) {
 169         qemu_del_timer(NVRAM->wd_timer);
 170         if (value != 0) {
 171             interval = (1 << (2 * (value & 0x03))) * ((value >> 2) & 0x1F);
 172             qemu_mod_timer(NVRAM->wd_timer, ((uint64_t)time(NULL) * 1000) +
 173                            ((interval * 1000) >> 4));
 174         }
 175     }
 176 }
 177
 178 /* Direct access to NVRAM */
 179 void m48t59_write (void *opaque, uint32_t addr, uint32_t val)
 180 {
 181     m48t59_t *NVRAM = opaque;
 182     struct tm tm;
 183     int tmp;
 184
 185     if (addr > 0x1FF8 && addr < 0x2000)
 186         NVRAM_PRINTF("%s: 0x%08x => 0x%08x\n", __func__, addr, val);
 187
 188     /* check for NVRAM access */
 189     if ((NVRAM->type == 2 && addr < 0x7f8) ||
 190         (NVRAM->type == 8 && addr < 0x1ff8) ||
 191         (NVRAM->type == 59 && addr < 0x1ff0))
 192         goto do_write;
 193
 194     /* TOD access */
 195     switch (addr) {
 196     case 0x1FF0:
 197         /* flags register : read-only */
 198         break;
 199     case 0x1FF1:
 200         /* unused */
 201         break;
 202     case 0x1FF2:
 203         /* alarm seconds */
 204         tmp = fromBCD(val & 0x7F);
 205         if (tmp >= 0 && tmp <= 59) {
 206             NVRAM->alarm.tm_sec = tmp;
 207             NVRAM->buffer[0x1FF2] = val;
 208             set_alarm(NVRAM);
 209         }
 210         break;
 211     case 0x1FF3:
 212         /* alarm minutes */
 213         tmp = fromBCD(val & 0x7F);
 214         if (tmp >= 0 && tmp <= 59) {
 215             NVRAM->alarm.tm_min = tmp;
 216             NVRAM->buffer[0x1FF3] = val;
 217             set_alarm(NVRAM);
 218         }
 219         break;
 220     case 0x1FF4:
 221         /* alarm hours */
 222         tmp = fromBCD(val & 0x3F);
 223         if (tmp >= 0 && tmp <= 23) {
 224             NVRAM->alarm.tm_hour = tmp;
 225             NVRAM->buffer[0x1FF4] = val;
 226             set_alarm(NVRAM);
 227         }
 228         break;
 229     case 0x1FF5:
 230         /* alarm date */
 231         tmp = fromBCD(val & 0x1F);
 232         if (tmp != 0) {
 233             NVRAM->alarm.tm_mday = tmp;
 234             NVRAM->buffer[0x1FF5] = val;
 235             set_alarm(NVRAM);
 236         }
 237         break;
 238     case 0x1FF6:
 239         /* interrupts */
 240         NVRAM->buffer[0x1FF6] = val;
 241         break;
 242     case 0x1FF7:
 243         /* watchdog */
 244         NVRAM->buffer[0x1FF7] = val;
 245         set_up_watchdog(NVRAM, val);
 246         break;
 247     case 0x1FF8:
 248     case 0x07F8:
 249         /* control */
 250        NVRAM->buffer[addr] = (val & ~0xA0) | 0x90;
 251         break;
 252     case 0x1FF9:
 253     case 0x07F9:
 254         /* seconds (BCD) */
 255         tmp = fromBCD(val & 0x7F);
 256         if (tmp >= 0 && tmp <= 59) {
 257             get_time(NVRAM, &tm);
 258             tm.tm_sec = tmp;
 259             set_time(NVRAM, &tm);
 260         }
 261         if ((val & 0x80) ^ (NVRAM->buffer[addr] & 0x80)) {
 262             if (val & 0x80) {
 263                 NVRAM->stop_time = time(NULL);
 264             } else {
 265                 NVRAM->time_offset += NVRAM->stop_time - time(NULL);
 266                 NVRAM->stop_time = 0;
 267             }
 268         }
 269         NVRAM->buffer[addr] = val & 0x80;
 270         break;
 271     case 0x1FFA:
 272     case 0x07FA:
 273         /* minutes (BCD) */
 274         tmp = fromBCD(val & 0x7F);
 275         if (tmp >= 0 && tmp <= 59) {
 276             get_time(NVRAM, &tm);
 277             tm.tm_min = tmp;
 278             set_time(NVRAM, &tm);
 279         }
 280         break;
 281     case 0x1FFB:
 282     case 0x07FB:
 283         /* hours (BCD) */
 284         tmp = fromBCD(val & 0x3F);
 285         if (tmp >= 0 && tmp <= 23) {
 286             get_time(NVRAM, &tm);
 287             tm.tm_hour = tmp;
 288             set_time(NVRAM, &tm);
 289         }
 290         break;
 291     case 0x1FFC:
 292     case 0x07FC:
 293         /* day of the week / century */
 294         tmp = fromBCD(val & 0x07);
 295         get_time(NVRAM, &tm);
 296         tm.tm_wday = tmp;
 297         set_time(NVRAM, &tm);
 298         NVRAM->buffer[addr] = val & 0x40;
 299         break;
 300     case 0x1FFD:
 301     case 0x07FD:
 302         /* date */
 303         tmp = fromBCD(val & 0x1F);
 304         if (tmp != 0) {
 305             get_time(NVRAM, &tm);
 306             tm.tm_mday = tmp;
 307             set_time(NVRAM, &tm);
 308         }
 309         break;
 310     case 0x1FFE:
 311     case 0x07FE:
 312         /* month */
 313         tmp = fromBCD(val & 0x1F);
 314         if (tmp >= 1 && tmp <= 12) {
 315             get_time(NVRAM, &tm);
 316             tm.tm_mon = tmp - 1;
 317             set_time(NVRAM, &tm);
 318         }
 319         break;
 320     case 0x1FFF:
 321     case 0x07FF:
 322         /* year */
 323         tmp = fromBCD(val);
 324         if (tmp >= 0 && tmp <= 99) {
 325             get_time(NVRAM, &tm);
 326             if (NVRAM->type == 8)
 327                 tm.tm_year = fromBCD(val) + 68; // Base year is 1968
 328             else
 329                 tm.tm_year = fromBCD(val);
 330             set_time(NVRAM, &tm);
 331         }
 332         break;
 333     default:
 334         /* Check lock registers state */
 335         if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
 336             break;
 337         if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
 338             break;
 339     do_write:
 340         if (addr < NVRAM->size) {
 341             NVRAM->buffer[addr] = val & 0xFF;
 342         }
 343         break;
 344     }
 345 }
 346
 347 uint32_t m48t59_read (void *opaque, uint32_t addr)
 348 {
 349     m48t59_t *NVRAM = opaque;
 350     struct tm tm;
 351     uint32_t retval = 0xFF;
 352
 353     /* check for NVRAM access */
 354     if ((NVRAM->type == 2 && addr < 0x078f) ||
 355         (NVRAM->type == 8 && addr < 0x1ff8) ||
 356         (NVRAM->type == 59 && addr < 0x1ff0))
 357         goto do_read;
 358
 359     /* TOD access */
 360     switch (addr) {
 361     case 0x1FF0:
 362         /* flags register */
 363         goto do_read;
 364     case 0x1FF1:
 365         /* unused */
 366         retval = 0;
 367         break;
 368     case 0x1FF2:
 369         /* alarm seconds */
 370         goto do_read;
 371     case 0x1FF3:
 372         /* alarm minutes */
 373         goto do_read;
 374     case 0x1FF4:
 375         /* alarm hours */
 376         goto do_read;
 377     case 0x1FF5:
 378         /* alarm date */
 379         goto do_read;
 380     case 0x1FF6:
 381         /* interrupts */
 382         goto do_read;
 383     case 0x1FF7:
 384         /* A read resets the watchdog */
 385         set_up_watchdog(NVRAM, NVRAM->buffer[0x1FF7]);
 386         goto do_read;
 387     case 0x1FF8:
 388     case 0x07F8:
 389         /* control */
 390         goto do_read;
 391     case 0x1FF9:
 392     case 0x07F9:
 393         /* seconds (BCD) */
 394         get_time(NVRAM, &tm);
 395         retval = (NVRAM->buffer[addr] & 0x80) | toBCD(tm.tm_sec);
 396         break;
 397     case 0x1FFA:
 398     case 0x07FA:
 399         /* minutes (BCD) */
 400         get_time(NVRAM, &tm);
 401         retval = toBCD(tm.tm_min);
 402         break;
 403     case 0x1FFB:
 404     case 0x07FB:
 405         /* hours (BCD) */
 406         get_time(NVRAM, &tm);
 407         retval = toBCD(tm.tm_hour);
 408         break;
 409     case 0x1FFC:
 410     case 0x07FC:
 411         /* day of the week / century */
 412         get_time(NVRAM, &tm);
 413         retval = NVRAM->buffer[addr] | tm.tm_wday;
 414         break;
 415     case 0x1FFD:
 416     case 0x07FD:
 417         /* date */
 418         get_time(NVRAM, &tm);
 419         retval = toBCD(tm.tm_mday);
 420         break;
 421     case 0x1FFE:
 422     case 0x07FE:
 423         /* month */
 424         get_time(NVRAM, &tm);
 425         retval = toBCD(tm.tm_mon + 1);
 426         break;
 427     case 0x1FFF:
 428     case 0x07FF:
 429         /* year */
 430         get_time(NVRAM, &tm);
 431         if (NVRAM->type == 8)
 432             retval = toBCD(tm.tm_year - 68); // Base year is 1968
 433         else
 434             retval = toBCD(tm.tm_year);
 435         break;
 436     default:
 437         /* Check lock registers state */
 438         if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
 439             break;
 440         if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
 441             break;
 442     do_read:
 443         if (addr < NVRAM->size) {
 444             retval = NVRAM->buffer[addr];
 445         }
 446         break;
 447     }
 448     if (addr > 0x1FF9 && addr < 0x2000)
 449        NVRAM_PRINTF("%s: 0x%08x <= 0x%08x\n", __func__, addr, retval);
 450
 451     return retval;
 452 }
 453
 454 void m48t59_set_addr (void *opaque, uint32_t addr)
 455 {
 456     m48t59_t *NVRAM = opaque;
 457
 458     NVRAM->addr = addr;
 459 }
 460
 461 void m48t59_toggle_lock (void *opaque, int lock)
 462 {
 463     m48t59_t *NVRAM = opaque;
 464
 465     NVRAM->lock ^= 1 << lock;
 466 }
 467
 468 /* IO access to NVRAM */
 469 static void NVRAM_writeb (void *opaque, uint32_t addr, uint32_t val)
 470 {
 471     m48t59_t *NVRAM = opaque;
 472
 473     addr -= NVRAM->io_base;
 474     NVRAM_PRINTF("%s: 0x%08x => 0x%08x\n", __func__, addr, val);
 475     switch (addr) {
 476     case 0:
 477         NVRAM->addr &= ~0x00FF;
 478         NVRAM->addr |= val;
 479         break;
 480     case 1:
 481         NVRAM->addr &= ~0xFF00;
 482         NVRAM->addr |= val << 8;
 483         break;
 484     case 3:
 485         m48t59_write(NVRAM, val, NVRAM->addr);
 486         NVRAM->addr = 0x0000;
 487         break;
 488     default:
 489         break;
 490     }
 491 }
 492
 493 static uint32_t NVRAM_readb (void *opaque, uint32_t addr)
 494 {
 495     m48t59_t *NVRAM = opaque;
 496     uint32_t retval;
 497
 498     addr -= NVRAM->io_base;
 499     switch (addr) {
 500     case 3:
 501         retval = m48t59_read(NVRAM, NVRAM->addr);
 502         break;
 503     default:
 504         retval = -1;
 505         break;
 506     }
 507     NVRAM_PRINTF("%s: 0x%08x <= 0x%08x\n", __func__, addr, retval);
 508
 509     return retval;
 510 }
 511
 512 static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
 513 {
 514     m48t59_t *NVRAM = opaque;
 515
 516     m48t59_write(NVRAM, addr, value & 0xff);
 517 }
 518
 519 static void nvram_writew (void *opaque, target_phys_addr_t addr, uint32_t value)
 520 {
 521     m48t59_t *NVRAM = opaque;
 522
 523     m48t59_write(NVRAM, addr, (value >> 8) & 0xff);
 524     m48t59_write(NVRAM, addr + 1, value & 0xff);
 525 }
 526
 527 static void nvram_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 528 {
 529     m48t59_t *NVRAM = opaque;
 530
 531     m48t59_write(NVRAM, addr, (value >> 24) & 0xff);
 532     m48t59_write(NVRAM, addr + 1, (value >> 16) & 0xff);
 533     m48t59_write(NVRAM, addr + 2, (value >> 8) & 0xff);
 534     m48t59_write(NVRAM, addr + 3, value & 0xff);
 535 }
 536
 537 static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
 538 {
 539     m48t59_t *NVRAM = opaque;
 540     uint32_t retval;
 541
 542     retval = m48t59_read(NVRAM, addr);
 543     return retval;
 544 }
 545
 546 static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)
 547 {
 548     m48t59_t *NVRAM = opaque;
 549     uint32_t retval;
 550
 551     retval = m48t59_read(NVRAM, addr) << 8;
 552     retval |= m48t59_read(NVRAM, addr + 1);
 553     return retval;
 554 }
 555
 556 static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)
 557 {
 558     m48t59_t *NVRAM = opaque;
 559     uint32_t retval;
 560
 561     retval = m48t59_read(NVRAM, addr) << 24;
 562     retval |= m48t59_read(NVRAM, addr + 1) << 16;
 563     retval |= m48t59_read(NVRAM, addr + 2) << 8;
 564     retval |= m48t59_read(NVRAM, addr + 3);
 565     return retval;
 566 }
 567
 568 static CPUWriteMemoryFunc *nvram_write[] = {
 569     &nvram_writeb,
 570     &nvram_writew,
 571     &nvram_writel,
 572 };
 573
 574 static CPUReadMemoryFunc *nvram_read[] = {
 575     &nvram_readb,
 576     &nvram_readw,
 577     &nvram_readl,
 578 };
 579
 580 static void m48t59_save(QEMUFile *f, void *opaque)
 581 {
 582     m48t59_t *s = opaque;
 583
 584     qemu_put_8s(f, &s->lock);
 585     qemu_put_be16s(f, &s->addr);
 586     qemu_put_buffer(f, s->buffer, s->size);
 587 }
 588
 589 static int m48t59_load(QEMUFile *f, void *opaque, int version_id)
 590 {
 591     m48t59_t *s = opaque;
 592
 593     if (version_id != 1)
 594         return -EINVAL;
 595
 596     qemu_get_8s(f, &s->lock);
 597     qemu_get_be16s(f, &s->addr);
 598     qemu_get_buffer(f, s->buffer, s->size);
 599
 600     return 0;
 601 }
 602
 603 static void m48t59_reset(void *opaque)
 604 {
 605     m48t59_t *NVRAM = opaque;
 606
 607     NVRAM->addr = 0;
 608     NVRAM->lock = 0;
 609     if (NVRAM->alrm_timer != NULL)
 610         qemu_del_timer(NVRAM->alrm_timer);
 611
 612     if (NVRAM->wd_timer != NULL)
 613         qemu_del_timer(NVRAM->wd_timer);
 614 }
 615
 616 /* Initialisation routine */
 617 m48t59_t *m48t59_init (qemu_irq IRQ, target_phys_addr_t mem_base,
 618                        uint32_t io_base, uint16_t size,
 619                        int type)
 620 {
 621     m48t59_t *s;
 622     target_phys_addr_t save_base;
 623
 624     s = qemu_mallocz(sizeof(m48t59_t));
 625     s->buffer = qemu_mallocz(size);
 626     s->IRQ = IRQ;
 627     s->size = size;
 628     s->io_base = io_base;
 629     s->type = type;
 630     if (io_base != 0) {
 631         register_ioport_read(io_base, 0x04, 1, NVRAM_readb, s);
 632         register_ioport_write(io_base, 0x04, 1, NVRAM_writeb, s);
 633     }
 634     if (mem_base != 0) {
 635         s->mem_index = cpu_register_io_memory(0, nvram_read, nvram_write, s);
 636         cpu_register_physical_memory(mem_base, size, s->mem_index);
 637     }
 638     if (type == 59) {
 639         s->alrm_timer = qemu_new_timer(vm_clock, &alarm_cb, s);
 640         s->wd_timer = qemu_new_timer(vm_clock, &watchdog_cb, s);
 641     }
 642     qemu_get_timedate(&s->alarm, 0);
 643
 644     qemu_register_reset(m48t59_reset, s);
 645     save_base = mem_base ? mem_base : io_base;
 646     register_savevm("m48t59", save_base, 1, m48t59_save, m48t59_load, s);
 647
 648     return s;
 649 }