tests/rtc-test.c

   1 /*
   2  * QTest testcase for the MC146818 real-time clock
   3  *
   4  * Copyright IBM, Corp. 2012
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu/osdep.h"
  15
  16 #include "libqtest-single.h"
  17 #include "qemu/timer.h"
  18 #include "hw/timer/mc146818rtc_regs.h"
  19
  20 #define UIP_HOLD_LENGTH           (8 * NANOSECONDS_PER_SECOND / 32768)
  21
  22 static uint8_t base = 0x70;
  23
  24 static int bcd2dec(int value)
  25 {
  26     return (((value >> 4) & 0x0F) * 10) + (value & 0x0F);
  27 }
  28
  29 static uint8_t cmos_read(uint8_t reg)
  30 {
  31     outb(base + 0, reg);
  32     return inb(base + 1);
  33 }
  34
  35 static void cmos_write(uint8_t reg, uint8_t val)
  36 {
  37     outb(base + 0, reg);
  38     outb(base + 1, val);
  39 }
  40
  41 static int tm_cmp(struct tm *lhs, struct tm *rhs)
  42 {
  43     time_t a, b;
  44     struct tm d1, d2;
  45
  46     memcpy(&d1, lhs, sizeof(d1));
  47     memcpy(&d2, rhs, sizeof(d2));
  48
  49     a = mktime(&d1);
  50     b = mktime(&d2);
  51
  52     if (a < b) {
  53         return -1;
  54     } else if (a > b) {
  55         return 1;
  56     }
  57
  58     return 0;
  59 }
  60
  61 #if 0
  62 static void print_tm(struct tm *tm)
  63 {
  64     printf("%04d-%02d-%02d %02d:%02d:%02d\n",
  65            tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
  66            tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_gmtoff);
  67 }
  68 #endif
  69
  70 static void cmos_get_date_time(struct tm *date)
  71 {
  72     int base_year = 2000, hour_offset;
  73     int sec, min, hour, mday, mon, year;
  74     time_t ts;
  75     struct tm dummy;
  76
  77     sec = cmos_read(RTC_SECONDS);
  78     min = cmos_read(RTC_MINUTES);
  79     hour = cmos_read(RTC_HOURS);
  80     mday = cmos_read(RTC_DAY_OF_MONTH);
  81     mon = cmos_read(RTC_MONTH);
  82     year = cmos_read(RTC_YEAR);
  83
  84     if ((cmos_read(RTC_REG_B) & REG_B_DM) == 0) {
  85         sec = bcd2dec(sec);
  86         min = bcd2dec(min);
  87         hour = bcd2dec(hour);
  88         mday = bcd2dec(mday);
  89         mon = bcd2dec(mon);
  90         year = bcd2dec(year);
  91         hour_offset = 80;
  92     } else {
  93         hour_offset = 0x80;
  94     }
  95
  96     if ((cmos_read(0x0B) & REG_B_24H) == 0) {
  97         if (hour >= hour_offset) {
  98             hour -= hour_offset;
  99             hour += 12;
 100         }
 101     }
 102
 103     ts = time(NULL);
 104     localtime_r(&ts, &dummy);
 105
 106     date->tm_isdst = dummy.tm_isdst;
 107     date->tm_sec = sec;
 108     date->tm_min = min;
 109     date->tm_hour = hour;
 110     date->tm_mday = mday;
 111     date->tm_mon = mon - 1;
 112     date->tm_year = base_year + year - 1900;
 113 #ifndef __sun__
 114     date->tm_gmtoff = 0;
 115 #endif
 116
 117     ts = mktime(date);
 118 }
 119
 120 static void check_time(int wiggle)
 121 {
 122     struct tm start, date[4], end;
 123     struct tm *datep;
 124     time_t ts;
 125
 126     /*
 127      * This check assumes a few things.  First, we cannot guarantee that we get
 128      * a consistent reading from the wall clock because we may hit an edge of
 129      * the clock while reading.  To work around this, we read four clock readings
 130      * such that at least two of them should match.  We need to assume that one
 131      * reading is corrupt so we need four readings to ensure that we have at
 132      * least two consecutive identical readings
 133      *
 134      * It's also possible that we'll cross an edge reading the host clock so
 135      * simply check to make sure that the clock reading is within the period of
 136      * when we expect it to be.
 137      */
 138
 139     ts = time(NULL);
 140     gmtime_r(&ts, &start);
 141
 142     cmos_get_date_time(&date[0]);
 143     cmos_get_date_time(&date[1]);
 144     cmos_get_date_time(&date[2]);
 145     cmos_get_date_time(&date[3]);
 146
 147     ts = time(NULL);
 148     gmtime_r(&ts, &end);
 149
 150     if (tm_cmp(&date[0], &date[1]) == 0) {
 151         datep = &date[0];
 152     } else if (tm_cmp(&date[1], &date[2]) == 0) {
 153         datep = &date[1];
 154     } else if (tm_cmp(&date[2], &date[3]) == 0) {
 155         datep = &date[2];
 156     } else {
 157         g_assert_not_reached();
 158     }
 159
 160     if (!(tm_cmp(&start, datep) <= 0 && tm_cmp(datep, &end) <= 0)) {
 161         long t, s;
 162
 163         start.tm_isdst = datep->tm_isdst;
 164
 165         t = (long)mktime(datep);
 166         s = (long)mktime(&start);
 167         if (t < s) {
 168             g_test_message("RTC is %ld second(s) behind wall-clock", (s - t));
 169         } else {
 170             g_test_message("RTC is %ld second(s) ahead of wall-clock", (t - s));
 171         }
 172
 173         g_assert_cmpint(ABS(t - s), <=, wiggle);
 174     }
 175 }
 176
 177 static int wiggle = 2;
 178
 179 static void set_year_20xx(void)
 180 {
 181     /* Set BCD mode */
 182     cmos_write(RTC_REG_B, REG_B_24H);
 183     cmos_write(RTC_REG_A, 0x76);
 184     cmos_write(RTC_YEAR, 0x11);
 185     cmos_write(RTC_CENTURY, 0x20);
 186     cmos_write(RTC_MONTH, 0x02);
 187     cmos_write(RTC_DAY_OF_MONTH, 0x02);
 188     cmos_write(RTC_HOURS, 0x02);
 189     cmos_write(RTC_MINUTES, 0x04);
 190     cmos_write(RTC_SECONDS, 0x58);
 191     cmos_write(RTC_REG_A, 0x26);
 192
 193     g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02);
 194     g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04);
 195     g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58);
 196     g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02);
 197     g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02);
 198     g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11);
 199     g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20);
 200
 201     if (sizeof(time_t) == 4) {
 202         return;
 203     }
 204
 205     /* Set a date in 2080 to ensure there is no year-2038 overflow.  */
 206     cmos_write(RTC_REG_A, 0x76);
 207     cmos_write(RTC_YEAR, 0x80);
 208     cmos_write(RTC_REG_A, 0x26);
 209
 210     g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02);
 211     g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04);
 212     g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58);
 213     g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02);
 214     g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02);
 215     g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x80);
 216     g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20);
 217
 218     cmos_write(RTC_REG_A, 0x76);
 219     cmos_write(RTC_YEAR, 0x11);
 220     cmos_write(RTC_REG_A, 0x26);
 221
 222     g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02);
 223     g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04);
 224     g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58);
 225     g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02);
 226     g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02);
 227     g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11);
 228     g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20);
 229 }
 230
 231 static void set_year_1980(void)
 232 {
 233     /* Set BCD mode */
 234     cmos_write(RTC_REG_B, REG_B_24H);
 235     cmos_write(RTC_REG_A, 0x76);
 236     cmos_write(RTC_YEAR, 0x80);
 237     cmos_write(RTC_CENTURY, 0x19);
 238     cmos_write(RTC_MONTH, 0x02);
 239     cmos_write(RTC_DAY_OF_MONTH, 0x02);
 240     cmos_write(RTC_HOURS, 0x02);
 241     cmos_write(RTC_MINUTES, 0x04);
 242     cmos_write(RTC_SECONDS, 0x58);
 243     cmos_write(RTC_REG_A, 0x26);
 244
 245     g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02);
 246     g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04);
 247     g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58);
 248     g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02);
 249     g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02);
 250     g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x80);
 251     g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x19);
 252 }
 253
 254 static void bcd_check_time(void)
 255 {
 256     /* Set BCD mode */
 257     cmos_write(RTC_REG_B, REG_B_24H);
 258     check_time(wiggle);
 259 }
 260
 261 static void dec_check_time(void)
 262 {
 263     /* Set DEC mode */
 264     cmos_write(RTC_REG_B, REG_B_24H | REG_B_DM);
 265     check_time(wiggle);
 266 }
 267
 268 static void alarm_time(void)
 269 {
 270     struct tm now;
 271     time_t ts;
 272     int i;
 273
 274     ts = time(NULL);
 275     gmtime_r(&ts, &now);
 276
 277     /* set DEC mode */
 278     cmos_write(RTC_REG_B, REG_B_24H | REG_B_DM);
 279
 280     g_assert(!get_irq(RTC_ISA_IRQ));
 281     cmos_read(RTC_REG_C);
 282
 283     now.tm_sec = (now.tm_sec + 2) % 60;
 284     cmos_write(RTC_SECONDS_ALARM, now.tm_sec);
 285     cmos_write(RTC_MINUTES_ALARM, RTC_ALARM_DONT_CARE);
 286     cmos_write(RTC_HOURS_ALARM, RTC_ALARM_DONT_CARE);
 287     cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) | REG_B_AIE);
 288
 289     for (i = 0; i < 2 + wiggle; i++) {
 290         if (get_irq(RTC_ISA_IRQ)) {
 291             break;
 292         }
 293
 294         clock_step(1000000000);
 295     }
 296
 297     g_assert(get_irq(RTC_ISA_IRQ));
 298     g_assert((cmos_read(RTC_REG_C) & REG_C_AF) != 0);
 299     g_assert(cmos_read(RTC_REG_C) == 0);
 300 }
 301
 302 static void set_time_regs(int h, int m, int s)
 303 {
 304     cmos_write(RTC_HOURS, h);
 305     cmos_write(RTC_MINUTES, m);
 306     cmos_write(RTC_SECONDS, s);
 307 }
 308
 309 static void set_time(int mode, int h, int m, int s)
 310 {
 311     cmos_write(RTC_REG_B, mode);
 312     cmos_write(RTC_REG_A, 0x76);
 313     set_time_regs(h, m, s);
 314     cmos_write(RTC_REG_A, 0x26);
 315 }
 316
 317 static void set_datetime_bcd(int h, int min, int s, int d, int m, int y)
 318 {
 319     cmos_write(RTC_HOURS, h);
 320     cmos_write(RTC_MINUTES, min);
 321     cmos_write(RTC_SECONDS, s);
 322     cmos_write(RTC_YEAR, y & 0xFF);
 323     cmos_write(RTC_CENTURY, y >> 8);
 324     cmos_write(RTC_MONTH, m);
 325     cmos_write(RTC_DAY_OF_MONTH, d);
 326 }
 327
 328 static void set_datetime_dec(int h, int min, int s, int d, int m, int y)
 329 {
 330     cmos_write(RTC_HOURS, h);
 331     cmos_write(RTC_MINUTES, min);
 332     cmos_write(RTC_SECONDS, s);
 333     cmos_write(RTC_YEAR, y % 100);
 334     cmos_write(RTC_CENTURY, y / 100);
 335     cmos_write(RTC_MONTH, m);
 336     cmos_write(RTC_DAY_OF_MONTH, d);
 337 }
 338
 339 static void set_datetime(int mode, int h, int min, int s, int d, int m, int y)
 340 {
 341     cmos_write(RTC_REG_B, mode);
 342
 343     cmos_write(RTC_REG_A, 0x76);
 344     if (mode & REG_B_DM) {
 345         set_datetime_dec(h, min, s, d, m, y);
 346     } else {
 347         set_datetime_bcd(h, min, s, d, m, y);
 348     }
 349     cmos_write(RTC_REG_A, 0x26);
 350 }
 351
 352 #define assert_time(h, m, s) \
 353     do { \
 354         g_assert_cmpint(cmos_read(RTC_HOURS), ==, h); \
 355         g_assert_cmpint(cmos_read(RTC_MINUTES), ==, m); \
 356         g_assert_cmpint(cmos_read(RTC_SECONDS), ==, s); \
 357     } while(0)
 358
 359 #define assert_datetime_bcd(h, min, s, d, m, y) \
 360     do { \
 361         g_assert_cmpint(cmos_read(RTC_HOURS), ==, h); \
 362         g_assert_cmpint(cmos_read(RTC_MINUTES), ==, min); \
 363         g_assert_cmpint(cmos_read(RTC_SECONDS), ==, s); \
 364         g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, d); \
 365         g_assert_cmpint(cmos_read(RTC_MONTH), ==, m); \
 366         g_assert_cmpint(cmos_read(RTC_YEAR), ==, (y & 0xFF)); \
 367         g_assert_cmpint(cmos_read(RTC_CENTURY), ==, (y >> 8)); \
 368     } while(0)
 369
 370 static void basic_12h_bcd(void)
 371 {
 372     /* set BCD 12 hour mode */
 373     set_time(0, 0x81, 0x59, 0x00);
 374     clock_step(1000000000LL);
 375     assert_time(0x81, 0x59, 0x01);
 376     clock_step(59000000000LL);
 377     assert_time(0x82, 0x00, 0x00);
 378
 379     /* test BCD wraparound */
 380     set_time(0, 0x09, 0x59, 0x59);
 381     clock_step(60000000000LL);
 382     assert_time(0x10, 0x00, 0x59);
 383
 384     /* 12 AM -> 1 AM */
 385     set_time(0, 0x12, 0x59, 0x59);
 386     clock_step(1000000000LL);
 387     assert_time(0x01, 0x00, 0x00);
 388
 389     /* 12 PM -> 1 PM */
 390     set_time(0, 0x92, 0x59, 0x59);
 391     clock_step(1000000000LL);
 392     assert_time(0x81, 0x00, 0x00);
 393
 394     /* 11 AM -> 12 PM */
 395     set_time(0, 0x11, 0x59, 0x59);
 396     clock_step(1000000000LL);
 397     assert_time(0x92, 0x00, 0x00);
 398     /* TODO: test day wraparound */
 399
 400     /* 11 PM -> 12 AM */
 401     set_time(0, 0x91, 0x59, 0x59);
 402     clock_step(1000000000LL);
 403     assert_time(0x12, 0x00, 0x00);
 404     /* TODO: test day wraparound */
 405 }
 406
 407 static void basic_12h_dec(void)
 408 {
 409     /* set decimal 12 hour mode */
 410     set_time(REG_B_DM, 0x81, 59, 0);
 411     clock_step(1000000000LL);
 412     assert_time(0x81, 59, 1);
 413     clock_step(59000000000LL);
 414     assert_time(0x82, 0, 0);
 415
 416     /* 12 PM -> 1 PM */
 417     set_time(REG_B_DM, 0x8c, 59, 59);
 418     clock_step(1000000000LL);
 419     assert_time(0x81, 0, 0);
 420
 421     /* 12 AM -> 1 AM */
 422     set_time(REG_B_DM, 0x0c, 59, 59);
 423     clock_step(1000000000LL);
 424     assert_time(0x01, 0, 0);
 425
 426     /* 11 AM -> 12 PM */
 427     set_time(REG_B_DM, 0x0b, 59, 59);
 428     clock_step(1000000000LL);
 429     assert_time(0x8c, 0, 0);
 430
 431     /* 11 PM -> 12 AM */
 432     set_time(REG_B_DM, 0x8b, 59, 59);
 433     clock_step(1000000000LL);
 434     assert_time(0x0c, 0, 0);
 435     /* TODO: test day wraparound */
 436 }
 437
 438 static void basic_24h_bcd(void)
 439 {
 440     /* set BCD 24 hour mode */
 441     set_time(REG_B_24H, 0x09, 0x59, 0x00);
 442     clock_step(1000000000LL);
 443     assert_time(0x09, 0x59, 0x01);
 444     clock_step(59000000000LL);
 445     assert_time(0x10, 0x00, 0x00);
 446
 447     /* test BCD wraparound */
 448     set_time(REG_B_24H, 0x09, 0x59, 0x00);
 449     clock_step(60000000000LL);
 450     assert_time(0x10, 0x00, 0x00);
 451
 452     /* TODO: test day wraparound */
 453     set_time(REG_B_24H, 0x23, 0x59, 0x00);
 454     clock_step(60000000000LL);
 455     assert_time(0x00, 0x00, 0x00);
 456 }
 457
 458 static void basic_24h_dec(void)
 459 {
 460     /* set decimal 24 hour mode */
 461     set_time(REG_B_24H | REG_B_DM, 9, 59, 0);
 462     clock_step(1000000000LL);
 463     assert_time(9, 59, 1);
 464     clock_step(59000000000LL);
 465     assert_time(10, 0, 0);
 466
 467     /* test BCD wraparound */
 468     set_time(REG_B_24H | REG_B_DM, 9, 59, 0);
 469     clock_step(60000000000LL);
 470     assert_time(10, 0, 0);
 471
 472     /* TODO: test day wraparound */
 473     set_time(REG_B_24H | REG_B_DM, 23, 59, 0);
 474     clock_step(60000000000LL);
 475     assert_time(0, 0, 0);
 476 }
 477
 478 static void am_pm_alarm(void)
 479 {
 480     cmos_write(RTC_MINUTES_ALARM, 0xC0);
 481     cmos_write(RTC_SECONDS_ALARM, 0xC0);
 482
 483     /* set BCD 12 hour mode */
 484     cmos_write(RTC_REG_B, 0);
 485
 486     /* Set time and alarm hour.  */
 487     cmos_write(RTC_REG_A, 0x76);
 488     cmos_write(RTC_HOURS_ALARM, 0x82);
 489     cmos_write(RTC_HOURS, 0x81);
 490     cmos_write(RTC_MINUTES, 0x59);
 491     cmos_write(RTC_SECONDS, 0x00);
 492     cmos_read(RTC_REG_C);
 493     cmos_write(RTC_REG_A, 0x26);
 494
 495     /* Check that alarm triggers when AM/PM is set.  */
 496     clock_step(60000000000LL);
 497     g_assert(cmos_read(RTC_HOURS) == 0x82);
 498     g_assert((cmos_read(RTC_REG_C) & REG_C_AF) != 0);
 499
 500     /*
 501      * Each of the following two tests takes over 60 seconds due to the time
 502      * needed to report the PIT interrupts.  Unfortunately, our PIT device
 503      * model keeps counting even when GATE=0, so we cannot simply disable
 504      * it in main().
 505      */
 506     if (g_test_quick()) {
 507         return;
 508     }
 509
 510     /* set DEC 12 hour mode */
 511     cmos_write(RTC_REG_B, REG_B_DM);
 512
 513     /* Set time and alarm hour.  */
 514     cmos_write(RTC_REG_A, 0x76);
 515     cmos_write(RTC_HOURS_ALARM, 0x82);
 516     cmos_write(RTC_HOURS, 3);
 517     cmos_write(RTC_MINUTES, 0);
 518     cmos_write(RTC_SECONDS, 0);
 519     cmos_read(RTC_REG_C);
 520     cmos_write(RTC_REG_A, 0x26);
 521
 522     /* Check that alarm triggers.  */
 523     clock_step(3600 * 11 * 1000000000LL);
 524     g_assert(cmos_read(RTC_HOURS) == 0x82);
 525     g_assert((cmos_read(RTC_REG_C) & REG_C_AF) != 0);
 526
 527     /* Same as above, with inverted HOURS and HOURS_ALARM.  */
 528     cmos_write(RTC_REG_A, 0x76);
 529     cmos_write(RTC_HOURS_ALARM, 2);
 530     cmos_write(RTC_HOURS, 3);
 531     cmos_write(RTC_MINUTES, 0);
 532     cmos_write(RTC_SECONDS, 0);
 533     cmos_read(RTC_REG_C);
 534     cmos_write(RTC_REG_A, 0x26);
 535
 536     /* Check that alarm does not trigger if hours differ only by AM/PM.  */
 537     clock_step(3600 * 11 * 1000000000LL);
 538     g_assert(cmos_read(RTC_HOURS) == 0x82);
 539     g_assert((cmos_read(RTC_REG_C) & REG_C_AF) == 0);
 540 }
 541
 542 /* success if no crash or abort */
 543 static void fuzz_registers(void)
 544 {
 545     unsigned int i;
 546
 547     for (i = 0; i < 1000; i++) {
 548         uint8_t reg, val;
 549
 550         reg = (uint8_t)g_test_rand_int_range(0, 16);
 551         val = (uint8_t)g_test_rand_int_range(0, 256);
 552
 553         cmos_write(reg, val);
 554         cmos_read(reg);
 555     }
 556 }
 557
 558 static void register_b_set_flag(void)
 559 {
 560     if (cmos_read(RTC_REG_A) & REG_A_UIP) {
 561         clock_step(UIP_HOLD_LENGTH + NANOSECONDS_PER_SECOND / 5);
 562     }
 563     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, ==, 0);
 564
 565     /* Enable binary-coded decimal (BCD) mode and SET flag in Register B*/
 566     cmos_write(RTC_REG_B, REG_B_24H | REG_B_SET);
 567
 568     set_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 569
 570     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 571
 572     /* Since SET flag is still enabled, time does not advance. */
 573     clock_step(1000000000LL);
 574     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 575
 576     /* Disable SET flag in Register B */
 577     cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) & ~REG_B_SET);
 578
 579     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 580
 581     /* Since SET flag is disabled, the clock now advances.  */
 582     clock_step(1000000000LL);
 583     assert_datetime_bcd(0x02, 0x04, 0x59, 0x02, 0x02, 0x2011);
 584 }
 585
 586 static void divider_reset(void)
 587 {
 588     /* Enable binary-coded decimal (BCD) mode in Register B*/
 589     cmos_write(RTC_REG_B, REG_B_24H);
 590
 591     /* Enter divider reset */
 592     cmos_write(RTC_REG_A, 0x76);
 593     set_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 594
 595     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 596
 597     /* Since divider reset flag is still enabled, these are equality checks. */
 598     clock_step(1000000000LL);
 599     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 600
 601     /* The first update ends 500 ms after divider reset */
 602     cmos_write(RTC_REG_A, 0x26);
 603     clock_step(500000000LL - UIP_HOLD_LENGTH - 1);
 604     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, ==, 0);
 605     assert_datetime_bcd(0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 606
 607     clock_step(1);
 608     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, !=, 0);
 609     clock_step(UIP_HOLD_LENGTH);
 610     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, ==, 0);
 611
 612     assert_datetime_bcd(0x02, 0x04, 0x59, 0x02, 0x02, 0x2011);
 613 }
 614
 615 static void uip_stuck(void)
 616 {
 617     set_datetime(REG_B_24H, 0x02, 0x04, 0x58, 0x02, 0x02, 0x2011);
 618
 619     /* The first update ends 500 ms after divider reset */
 620     (void)cmos_read(RTC_REG_C);
 621     clock_step(500000000LL);
 622     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, ==, 0);
 623     assert_datetime_bcd(0x02, 0x04, 0x59, 0x02, 0x02, 0x2011);
 624
 625     /* UF is now set.  */
 626     cmos_write(RTC_HOURS_ALARM, 0x02);
 627     cmos_write(RTC_MINUTES_ALARM, 0xC0);
 628     cmos_write(RTC_SECONDS_ALARM, 0xC0);
 629
 630     /* Because the alarm will fire soon, reading register A will latch UIP.  */
 631     clock_step(1000000000LL - UIP_HOLD_LENGTH / 2);
 632     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, !=, 0);
 633
 634     /* Move the alarm far away.  This must not cause UIP to remain stuck!  */
 635     cmos_write(RTC_HOURS_ALARM, 0x03);
 636     clock_step(UIP_HOLD_LENGTH);
 637     g_assert_cmpint(cmos_read(RTC_REG_A) & REG_A_UIP, ==, 0);
 638 }
 639
 640 #define RTC_PERIOD_CODE1    13   /* 8 Hz */
 641 #define RTC_PERIOD_CODE2    15   /* 2 Hz */
 642
 643 #define RTC_PERIOD_TEST_NR  50
 644
 645 static uint64_t wait_periodic_interrupt(uint64_t real_time)
 646 {
 647     while (!get_irq(RTC_ISA_IRQ)) {
 648         real_time = clock_step_next();
 649     }
 650
 651     g_assert((cmos_read(RTC_REG_C) & REG_C_PF) != 0);
 652     return real_time;
 653 }
 654
 655 static void periodic_timer(void)
 656 {
 657     int i;
 658     uint64_t period_clocks, period_time, start_time, real_time;
 659
 660     /* disable all interrupts. */
 661     cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) &
 662                                    ~(REG_B_PIE | REG_B_AIE | REG_B_UIE));
 663     cmos_write(RTC_REG_A, RTC_PERIOD_CODE1);
 664     /* enable periodic interrupt after properly configure the period. */
 665     cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) | REG_B_PIE);
 666
 667     start_time = real_time = clock_step_next();
 668
 669     for (i = 0; i < RTC_PERIOD_TEST_NR; i++) {
 670         cmos_write(RTC_REG_A, RTC_PERIOD_CODE1);
 671         real_time = wait_periodic_interrupt(real_time);
 672         cmos_write(RTC_REG_A, RTC_PERIOD_CODE2);
 673         real_time = wait_periodic_interrupt(real_time);
 674     }
 675
 676     period_clocks = periodic_period_to_clock(RTC_PERIOD_CODE1) +
 677                        periodic_period_to_clock(RTC_PERIOD_CODE2);
 678     period_clocks *= RTC_PERIOD_TEST_NR;
 679     period_time = periodic_clock_to_ns(period_clocks);
 680
 681     real_time -= start_time;
 682     g_assert_cmpint(ABS((int64_t)(real_time - period_time)), <=,
 683                     NANOSECONDS_PER_SECOND * 0.5);
 684 }
 685
 686 int main(int argc, char **argv)
 687 {
 688     QTestState *s = NULL;
 689     int ret;
 690
 691     g_test_init(&argc, &argv, NULL);
 692
 693     s = qtest_start("-rtc clock=vm");
 694     qtest_irq_intercept_in(s, "ioapic");
 695
 696     qtest_add_func("/rtc/check-time/bcd", bcd_check_time);
 697     qtest_add_func("/rtc/check-time/dec", dec_check_time);
 698     qtest_add_func("/rtc/alarm/interrupt", alarm_time);
 699     qtest_add_func("/rtc/alarm/am-pm", am_pm_alarm);
 700     qtest_add_func("/rtc/basic/dec-24h", basic_24h_dec);
 701     qtest_add_func("/rtc/basic/bcd-24h", basic_24h_bcd);
 702     qtest_add_func("/rtc/basic/dec-12h", basic_12h_dec);
 703     qtest_add_func("/rtc/basic/bcd-12h", basic_12h_bcd);
 704     qtest_add_func("/rtc/set-year/20xx", set_year_20xx);
 705     qtest_add_func("/rtc/set-year/1980", set_year_1980);
 706     qtest_add_func("/rtc/update/register_b_set_flag", register_b_set_flag);
 707     qtest_add_func("/rtc/update/divider-reset", divider_reset);
 708     qtest_add_func("/rtc/update/uip-stuck", uip_stuck);
 709     qtest_add_func("/rtc/misc/fuzz-registers", fuzz_registers);
 710     qtest_add_func("/rtc/periodic/interrupt", periodic_timer);
 711
 712     ret = g_test_run();
 713
 714     if (s) {
 715         qtest_quit(s);
 716     }
 717
 718     return ret;
 719 }