2 * QEMU MC146818 RTC emulation
4 * Copyright (c) 2003-2004 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
25 #include "qemu-timer.h"
29 #include "hpet_emul.h"
34 #define RTC_SECONDS_ALARM 1
36 #define RTC_MINUTES_ALARM 3
38 #define RTC_HOURS_ALARM 5
39 #define RTC_ALARM_DONT_CARE 0xC0
41 #define RTC_DAY_OF_WEEK 6
42 #define RTC_DAY_OF_MONTH 7
51 #define REG_A_UIP 0x80
53 #define REG_B_SET 0x80
54 #define REG_B_PIE 0x40
55 #define REG_B_AIE 0x20
56 #define REG_B_UIE 0x10
59 uint8_t cmos_data[128];
65 QEMUTimer *periodic_timer;
66 int64_t next_periodic_time;
68 int64_t next_second_time;
69 QEMUTimer *second_timer;
70 QEMUTimer *second_timer2;
73 static void rtc_irq_raise(qemu_irq irq) {
74 /* When HPET is operating in legacy mode, RTC interrupts are disabled
75 * We block qemu_irq_raise, but not qemu_irq_lower, in case legacy
76 * mode is established while interrupt is raised. We want it to
77 * be lowered in any case
79 #if defined TARGET_I386 || defined TARGET_X86_64
80 if (!hpet_in_legacy_mode())
85 static void rtc_set_time(RTCState *s);
86 static void rtc_copy_date(RTCState *s);
88 static void rtc_timer_update(RTCState *s, int64_t current_time)
90 int period_code, period;
91 int64_t cur_clock, next_irq_clock;
93 period_code = s->cmos_data[RTC_REG_A] & 0x0f;
94 #if defined TARGET_I386 || defined TARGET_X86_64
95 /* disable periodic timer if hpet is in legacy mode, since interrupts are
98 if (period_code != 0 && (s->cmos_data[RTC_REG_B] & REG_B_PIE) && !hpet_in_legacy_mode()) {
100 if (period_code != 0 && (s->cmos_data[RTC_REG_B] & REG_B_PIE)) {
102 if (period_code <= 2)
104 /* period in 32 Khz cycles */
105 period = 1 << (period_code - 1);
106 /* compute 32 khz clock */
107 cur_clock = muldiv64(current_time, 32768, ticks_per_sec);
108 next_irq_clock = (cur_clock & ~(period - 1)) + period;
109 s->next_periodic_time = muldiv64(next_irq_clock, ticks_per_sec, 32768) + 1;
110 qemu_mod_timer(s->periodic_timer, s->next_periodic_time);
112 qemu_del_timer(s->periodic_timer);
116 static void rtc_periodic_timer(void *opaque)
118 RTCState *s = opaque;
120 rtc_timer_update(s, s->next_periodic_time);
121 s->cmos_data[RTC_REG_C] |= 0xc0;
122 rtc_irq_raise(s->irq);
125 static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data)
127 RTCState *s = opaque;
129 if ((addr & 1) == 0) {
130 s->cmos_index = data & 0x7f;
133 printf("cmos: write index=0x%02x val=0x%02x\n",
134 s->cmos_index, data);
136 switch(s->cmos_index) {
137 case RTC_SECONDS_ALARM:
138 case RTC_MINUTES_ALARM:
139 case RTC_HOURS_ALARM:
140 /* XXX: not supported */
141 s->cmos_data[s->cmos_index] = data;
146 case RTC_DAY_OF_WEEK:
147 case RTC_DAY_OF_MONTH:
150 s->cmos_data[s->cmos_index] = data;
151 /* if in set mode, do not update the time */
152 if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
157 /* UIP bit is read only */
158 s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) |
159 (s->cmos_data[RTC_REG_A] & REG_A_UIP);
160 rtc_timer_update(s, qemu_get_clock(vm_clock));
163 if (data & REG_B_SET) {
164 /* set mode: reset UIP mode */
165 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
168 /* if disabling set mode, update the time */
169 if (s->cmos_data[RTC_REG_B] & REG_B_SET) {
173 s->cmos_data[RTC_REG_B] = data;
174 rtc_timer_update(s, qemu_get_clock(vm_clock));
178 /* cannot write to them */
181 s->cmos_data[s->cmos_index] = data;
187 static inline int to_bcd(RTCState *s, int a)
189 if (s->cmos_data[RTC_REG_B] & 0x04) {
192 return ((a / 10) << 4) | (a % 10);
196 static inline int from_bcd(RTCState *s, int a)
198 if (s->cmos_data[RTC_REG_B] & 0x04) {
201 return ((a >> 4) * 10) + (a & 0x0f);
205 static void rtc_set_time(RTCState *s)
207 struct tm *tm = &s->current_tm;
209 tm->tm_sec = from_bcd(s, s->cmos_data[RTC_SECONDS]);
210 tm->tm_min = from_bcd(s, s->cmos_data[RTC_MINUTES]);
211 tm->tm_hour = from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
212 if (!(s->cmos_data[RTC_REG_B] & 0x02) &&
213 (s->cmos_data[RTC_HOURS] & 0x80)) {
216 tm->tm_wday = from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]);
217 tm->tm_mday = from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
218 tm->tm_mon = from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
219 tm->tm_year = from_bcd(s, s->cmos_data[RTC_YEAR]) + 100;
222 static void rtc_copy_date(RTCState *s)
224 const struct tm *tm = &s->current_tm;
226 s->cmos_data[RTC_SECONDS] = to_bcd(s, tm->tm_sec);
227 s->cmos_data[RTC_MINUTES] = to_bcd(s, tm->tm_min);
228 if (s->cmos_data[RTC_REG_B] & 0x02) {
230 s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour);
233 s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour % 12);
234 if (tm->tm_hour >= 12)
235 s->cmos_data[RTC_HOURS] |= 0x80;
237 s->cmos_data[RTC_DAY_OF_WEEK] = to_bcd(s, tm->tm_wday);
238 s->cmos_data[RTC_DAY_OF_MONTH] = to_bcd(s, tm->tm_mday);
239 s->cmos_data[RTC_MONTH] = to_bcd(s, tm->tm_mon + 1);
240 s->cmos_data[RTC_YEAR] = to_bcd(s, tm->tm_year % 100);
243 /* month is between 0 and 11. */
244 static int get_days_in_month(int month, int year)
246 static const int days_tab[12] = {
247 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
250 if ((unsigned )month >= 12)
254 if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0))
260 /* update 'tm' to the next second */
261 static void rtc_next_second(struct tm *tm)
266 if ((unsigned)tm->tm_sec >= 60) {
269 if ((unsigned)tm->tm_min >= 60) {
272 if ((unsigned)tm->tm_hour >= 24) {
276 if ((unsigned)tm->tm_wday >= 7)
278 days_in_month = get_days_in_month(tm->tm_mon,
281 if (tm->tm_mday < 1) {
283 } else if (tm->tm_mday > days_in_month) {
286 if (tm->tm_mon >= 12) {
297 static void rtc_update_second(void *opaque)
299 RTCState *s = opaque;
302 /* if the oscillator is not in normal operation, we do not update */
303 if ((s->cmos_data[RTC_REG_A] & 0x70) != 0x20) {
304 s->next_second_time += ticks_per_sec;
305 qemu_mod_timer(s->second_timer, s->next_second_time);
307 rtc_next_second(&s->current_tm);
309 if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
310 /* update in progress bit */
311 s->cmos_data[RTC_REG_A] |= REG_A_UIP;
313 /* should be 244 us = 8 / 32768 seconds, but currently the
314 timers do not have the necessary resolution. */
315 delay = (ticks_per_sec * 1) / 100;
318 qemu_mod_timer(s->second_timer2,
319 s->next_second_time + delay);
323 static void rtc_update_second2(void *opaque)
325 RTCState *s = opaque;
327 if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
332 if (s->cmos_data[RTC_REG_B] & REG_B_AIE) {
333 if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 ||
334 s->cmos_data[RTC_SECONDS_ALARM] == s->current_tm.tm_sec) &&
335 ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 ||
336 s->cmos_data[RTC_MINUTES_ALARM] == s->current_tm.tm_mon) &&
337 ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 ||
338 s->cmos_data[RTC_HOURS_ALARM] == s->current_tm.tm_hour)) {
340 s->cmos_data[RTC_REG_C] |= 0xa0;
341 rtc_irq_raise(s->irq);
345 /* update ended interrupt */
346 if (s->cmos_data[RTC_REG_B] & REG_B_UIE) {
347 s->cmos_data[RTC_REG_C] |= 0x90;
348 rtc_irq_raise(s->irq);
351 /* clear update in progress bit */
352 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
354 s->next_second_time += ticks_per_sec;
355 qemu_mod_timer(s->second_timer, s->next_second_time);
358 static uint32_t cmos_ioport_read(void *opaque, uint32_t addr)
360 RTCState *s = opaque;
362 if ((addr & 1) == 0) {
365 switch(s->cmos_index) {
369 case RTC_DAY_OF_WEEK:
370 case RTC_DAY_OF_MONTH:
373 ret = s->cmos_data[s->cmos_index];
376 ret = s->cmos_data[s->cmos_index];
379 ret = s->cmos_data[s->cmos_index];
380 qemu_irq_lower(s->irq);
381 s->cmos_data[RTC_REG_C] = 0x00;
384 ret = s->cmos_data[s->cmos_index];
388 printf("cmos: read index=0x%02x val=0x%02x\n",
395 void rtc_set_memory(RTCState *s, int addr, int val)
397 if (addr >= 0 && addr <= 127)
398 s->cmos_data[addr] = val;
401 void rtc_set_date(RTCState *s, const struct tm *tm)
407 /* PC cmos mappings */
408 #define REG_IBM_CENTURY_BYTE 0x32
409 #define REG_IBM_PS2_CENTURY_BYTE 0x37
411 static void rtc_set_date_from_host(RTCState *s)
416 /* set the CMOS date */
417 qemu_get_timedate(&tm, 0);
418 rtc_set_date(s, &tm);
420 val = to_bcd(s, (tm.tm_year / 100) + 19);
421 rtc_set_memory(s, REG_IBM_CENTURY_BYTE, val);
422 rtc_set_memory(s, REG_IBM_PS2_CENTURY_BYTE, val);
425 static void rtc_save(QEMUFile *f, void *opaque)
427 RTCState *s = opaque;
429 qemu_put_buffer(f, s->cmos_data, 128);
430 qemu_put_8s(f, &s->cmos_index);
432 qemu_put_be32(f, s->current_tm.tm_sec);
433 qemu_put_be32(f, s->current_tm.tm_min);
434 qemu_put_be32(f, s->current_tm.tm_hour);
435 qemu_put_be32(f, s->current_tm.tm_wday);
436 qemu_put_be32(f, s->current_tm.tm_mday);
437 qemu_put_be32(f, s->current_tm.tm_mon);
438 qemu_put_be32(f, s->current_tm.tm_year);
440 qemu_put_timer(f, s->periodic_timer);
441 qemu_put_be64(f, s->next_periodic_time);
443 qemu_put_be64(f, s->next_second_time);
444 qemu_put_timer(f, s->second_timer);
445 qemu_put_timer(f, s->second_timer2);
448 static int rtc_load(QEMUFile *f, void *opaque, int version_id)
450 RTCState *s = opaque;
455 qemu_get_buffer(f, s->cmos_data, 128);
456 qemu_get_8s(f, &s->cmos_index);
458 s->current_tm.tm_sec=qemu_get_be32(f);
459 s->current_tm.tm_min=qemu_get_be32(f);
460 s->current_tm.tm_hour=qemu_get_be32(f);
461 s->current_tm.tm_wday=qemu_get_be32(f);
462 s->current_tm.tm_mday=qemu_get_be32(f);
463 s->current_tm.tm_mon=qemu_get_be32(f);
464 s->current_tm.tm_year=qemu_get_be32(f);
466 qemu_get_timer(f, s->periodic_timer);
467 s->next_periodic_time=qemu_get_be64(f);
469 s->next_second_time=qemu_get_be64(f);
470 qemu_get_timer(f, s->second_timer);
471 qemu_get_timer(f, s->second_timer2);
475 RTCState *rtc_init(int base, qemu_irq irq)
479 s = qemu_mallocz(sizeof(RTCState));
484 s->cmos_data[RTC_REG_A] = 0x26;
485 s->cmos_data[RTC_REG_B] = 0x02;
486 s->cmos_data[RTC_REG_C] = 0x00;
487 s->cmos_data[RTC_REG_D] = 0x80;
489 rtc_set_date_from_host(s);
491 s->periodic_timer = qemu_new_timer(vm_clock,
492 rtc_periodic_timer, s);
493 s->second_timer = qemu_new_timer(vm_clock,
494 rtc_update_second, s);
495 s->second_timer2 = qemu_new_timer(vm_clock,
496 rtc_update_second2, s);
498 s->next_second_time = qemu_get_clock(vm_clock) + (ticks_per_sec * 99) / 100;
499 qemu_mod_timer(s->second_timer2, s->next_second_time);
501 register_ioport_write(base, 2, 1, cmos_ioport_write, s);
502 register_ioport_read(base, 2, 1, cmos_ioport_read, s);
504 register_savevm("mc146818rtc", base, 1, rtc_save, rtc_load, s);
508 /* Memory mapped interface */
509 static uint32_t cmos_mm_readb (void *opaque, target_phys_addr_t addr)
511 RTCState *s = opaque;
513 return cmos_ioport_read(s, addr >> s->it_shift) & 0xFF;
516 static void cmos_mm_writeb (void *opaque,
517 target_phys_addr_t addr, uint32_t value)
519 RTCState *s = opaque;
521 cmos_ioport_write(s, addr >> s->it_shift, value & 0xFF);
524 static uint32_t cmos_mm_readw (void *opaque, target_phys_addr_t addr)
526 RTCState *s = opaque;
529 val = cmos_ioport_read(s, addr >> s->it_shift) & 0xFFFF;
530 #ifdef TARGET_WORDS_BIGENDIAN
536 static void cmos_mm_writew (void *opaque,
537 target_phys_addr_t addr, uint32_t value)
539 RTCState *s = opaque;
540 #ifdef TARGET_WORDS_BIGENDIAN
541 value = bswap16(value);
543 cmos_ioport_write(s, addr >> s->it_shift, value & 0xFFFF);
546 static uint32_t cmos_mm_readl (void *opaque, target_phys_addr_t addr)
548 RTCState *s = opaque;
551 val = cmos_ioport_read(s, addr >> s->it_shift);
552 #ifdef TARGET_WORDS_BIGENDIAN
558 static void cmos_mm_writel (void *opaque,
559 target_phys_addr_t addr, uint32_t value)
561 RTCState *s = opaque;
562 #ifdef TARGET_WORDS_BIGENDIAN
563 value = bswap32(value);
565 cmos_ioport_write(s, addr >> s->it_shift, value);
568 static CPUReadMemoryFunc *rtc_mm_read[] = {
574 static CPUWriteMemoryFunc *rtc_mm_write[] = {
580 RTCState *rtc_mm_init(target_phys_addr_t base, int it_shift, qemu_irq irq)
585 s = qemu_mallocz(sizeof(RTCState));
590 s->cmos_data[RTC_REG_A] = 0x26;
591 s->cmos_data[RTC_REG_B] = 0x02;
592 s->cmos_data[RTC_REG_C] = 0x00;
593 s->cmos_data[RTC_REG_D] = 0x80;
595 rtc_set_date_from_host(s);
597 s->periodic_timer = qemu_new_timer(vm_clock,
598 rtc_periodic_timer, s);
599 s->second_timer = qemu_new_timer(vm_clock,
600 rtc_update_second, s);
601 s->second_timer2 = qemu_new_timer(vm_clock,
602 rtc_update_second2, s);
604 s->next_second_time = qemu_get_clock(vm_clock) + (ticks_per_sec * 99) / 100;
605 qemu_mod_timer(s->second_timer2, s->next_second_time);
607 io_memory = cpu_register_io_memory(0, rtc_mm_read, rtc_mm_write, s);
608 cpu_register_physical_memory(base, 2 << it_shift, io_memory);
610 register_savevm("mc146818rtc", base, 1, rtc_save, rtc_load, s);