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authorUpstream <upstream-import@none>1970-01-12 13:46:40 +0000
committerUpstream <upstream-import@none>1970-01-12 13:46:40 +0000
commit413f05aaf54fa08c0ae7e997327a4f4a473c0a8d (patch)
tree642d637ab01ee6c54ca27d1fa96cf92a32df8053 /hw/mc146818rtc.c
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external/qemu 0.8.2
Diffstat (limited to 'hw/mc146818rtc.c')
-rw-r--r--hw/mc146818rtc.c463
1 files changed, 463 insertions, 0 deletions
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
new file mode 100644
index 0000000..9d4cbed
--- /dev/null
+++ b/hw/mc146818rtc.c
@@ -0,0 +1,463 @@
+/*
+ * QEMU MC146818 RTC emulation
+ *
+ * Copyright (c) 2003-2004 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.
+ */
+#include "vl.h"
+
+//#define DEBUG_CMOS
+
+#define RTC_SECONDS 0
+#define RTC_SECONDS_ALARM 1
+#define RTC_MINUTES 2
+#define RTC_MINUTES_ALARM 3
+#define RTC_HOURS 4
+#define RTC_HOURS_ALARM 5
+#define RTC_ALARM_DONT_CARE 0xC0
+
+#define RTC_DAY_OF_WEEK 6
+#define RTC_DAY_OF_MONTH 7
+#define RTC_MONTH 8
+#define RTC_YEAR 9
+
+#define RTC_REG_A 10
+#define RTC_REG_B 11
+#define RTC_REG_C 12
+#define RTC_REG_D 13
+
+#define REG_A_UIP 0x80
+
+#define REG_B_SET 0x80
+#define REG_B_PIE 0x40
+#define REG_B_AIE 0x20
+#define REG_B_UIE 0x10
+
+struct RTCState {
+ uint8_t cmos_data[128];
+ uint8_t cmos_index;
+ struct tm current_tm;
+ int irq;
+ /* periodic timer */
+ QEMUTimer *periodic_timer;
+ int64_t next_periodic_time;
+ /* second update */
+ int64_t next_second_time;
+ QEMUTimer *second_timer;
+ QEMUTimer *second_timer2;
+};
+
+static void rtc_set_time(RTCState *s);
+static void rtc_copy_date(RTCState *s);
+
+static void rtc_timer_update(RTCState *s, int64_t current_time)
+{
+ int period_code, period;
+ int64_t cur_clock, next_irq_clock;
+
+ period_code = s->cmos_data[RTC_REG_A] & 0x0f;
+ if (period_code != 0 &&
+ (s->cmos_data[RTC_REG_B] & REG_B_PIE)) {
+ if (period_code <= 2)
+ period_code += 7;
+ /* period in 32 Khz cycles */
+ period = 1 << (period_code - 1);
+ /* compute 32 khz clock */
+ cur_clock = muldiv64(current_time, 32768, ticks_per_sec);
+ next_irq_clock = (cur_clock & ~(period - 1)) + period;
+ s->next_periodic_time = muldiv64(next_irq_clock, ticks_per_sec, 32768) + 1;
+ qemu_mod_timer(s->periodic_timer, s->next_periodic_time);
+ } else {
+ qemu_del_timer(s->periodic_timer);
+ }
+}
+
+static void rtc_periodic_timer(void *opaque)
+{
+ RTCState *s = opaque;
+
+ rtc_timer_update(s, s->next_periodic_time);
+ s->cmos_data[RTC_REG_C] |= 0xc0;
+ pic_set_irq(s->irq, 1);
+}
+
+static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data)
+{
+ RTCState *s = opaque;
+
+ if ((addr & 1) == 0) {
+ s->cmos_index = data & 0x7f;
+ } else {
+#ifdef DEBUG_CMOS
+ printf("cmos: write index=0x%02x val=0x%02x\n",
+ s->cmos_index, data);
+#endif
+ switch(s->cmos_index) {
+ case RTC_SECONDS_ALARM:
+ case RTC_MINUTES_ALARM:
+ case RTC_HOURS_ALARM:
+ /* XXX: not supported */
+ s->cmos_data[s->cmos_index] = data;
+ break;
+ case RTC_SECONDS:
+ case RTC_MINUTES:
+ case RTC_HOURS:
+ case RTC_DAY_OF_WEEK:
+ case RTC_DAY_OF_MONTH:
+ case RTC_MONTH:
+ case RTC_YEAR:
+ s->cmos_data[s->cmos_index] = data;
+ /* if in set mode, do not update the time */
+ if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
+ rtc_set_time(s);
+ }
+ break;
+ case RTC_REG_A:
+ /* UIP bit is read only */
+ s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) |
+ (s->cmos_data[RTC_REG_A] & REG_A_UIP);
+ rtc_timer_update(s, qemu_get_clock(vm_clock));
+ break;
+ case RTC_REG_B:
+ if (data & REG_B_SET) {
+ /* set mode: reset UIP mode */
+ s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
+ data &= ~REG_B_UIE;
+ } else {
+ /* if disabling set mode, update the time */
+ if (s->cmos_data[RTC_REG_B] & REG_B_SET) {
+ rtc_set_time(s);
+ }
+ }
+ s->cmos_data[RTC_REG_B] = data;
+ rtc_timer_update(s, qemu_get_clock(vm_clock));
+ break;
+ case RTC_REG_C:
+ case RTC_REG_D:
+ /* cannot write to them */
+ break;
+ default:
+ s->cmos_data[s->cmos_index] = data;
+ break;
+ }
+ }
+}
+
+static inline int to_bcd(RTCState *s, int a)
+{
+ if (s->cmos_data[RTC_REG_B] & 0x04) {
+ return a;
+ } else {
+ return ((a / 10) << 4) | (a % 10);
+ }
+}
+
+static inline int from_bcd(RTCState *s, int a)
+{
+ if (s->cmos_data[RTC_REG_B] & 0x04) {
+ return a;
+ } else {
+ return ((a >> 4) * 10) + (a & 0x0f);
+ }
+}
+
+static void rtc_set_time(RTCState *s)
+{
+ struct tm *tm = &s->current_tm;
+
+ tm->tm_sec = from_bcd(s, s->cmos_data[RTC_SECONDS]);
+ tm->tm_min = from_bcd(s, s->cmos_data[RTC_MINUTES]);
+ tm->tm_hour = from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
+ if (!(s->cmos_data[RTC_REG_B] & 0x02) &&
+ (s->cmos_data[RTC_HOURS] & 0x80)) {
+ tm->tm_hour += 12;
+ }
+ tm->tm_wday = from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]);
+ tm->tm_mday = from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
+ tm->tm_mon = from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
+ tm->tm_year = from_bcd(s, s->cmos_data[RTC_YEAR]) + 100;
+}
+
+static void rtc_copy_date(RTCState *s)
+{
+ const struct tm *tm = &s->current_tm;
+
+ s->cmos_data[RTC_SECONDS] = to_bcd(s, tm->tm_sec);
+ s->cmos_data[RTC_MINUTES] = to_bcd(s, tm->tm_min);
+ if (s->cmos_data[RTC_REG_B] & 0x02) {
+ /* 24 hour format */
+ s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour);
+ } else {
+ /* 12 hour format */
+ s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour % 12);
+ if (tm->tm_hour >= 12)
+ s->cmos_data[RTC_HOURS] |= 0x80;
+ }
+ s->cmos_data[RTC_DAY_OF_WEEK] = to_bcd(s, tm->tm_wday);
+ s->cmos_data[RTC_DAY_OF_MONTH] = to_bcd(s, tm->tm_mday);
+ s->cmos_data[RTC_MONTH] = to_bcd(s, tm->tm_mon + 1);
+ s->cmos_data[RTC_YEAR] = to_bcd(s, tm->tm_year % 100);
+}
+
+/* month is between 0 and 11. */
+static int get_days_in_month(int month, int year)
+{
+ static const int days_tab[12] = {
+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+ };
+ int d;
+ if ((unsigned )month >= 12)
+ return 31;
+ d = days_tab[month];
+ if (month == 1) {
+ if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0))
+ d++;
+ }
+ return d;
+}
+
+/* update 'tm' to the next second */
+static void rtc_next_second(struct tm *tm)
+{
+ int days_in_month;
+
+ tm->tm_sec++;
+ if ((unsigned)tm->tm_sec >= 60) {
+ tm->tm_sec = 0;
+ tm->tm_min++;
+ if ((unsigned)tm->tm_min >= 60) {
+ tm->tm_min = 0;
+ tm->tm_hour++;
+ if ((unsigned)tm->tm_hour >= 24) {
+ tm->tm_hour = 0;
+ /* next day */
+ tm->tm_wday++;
+ if ((unsigned)tm->tm_wday >= 7)
+ tm->tm_wday = 0;
+ days_in_month = get_days_in_month(tm->tm_mon,
+ tm->tm_year + 1900);
+ tm->tm_mday++;
+ if (tm->tm_mday < 1) {
+ tm->tm_mday = 1;
+ } else if (tm->tm_mday > days_in_month) {
+ tm->tm_mday = 1;
+ tm->tm_mon++;
+ if (tm->tm_mon >= 12) {
+ tm->tm_mon = 0;
+ tm->tm_year++;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+static void rtc_update_second(void *opaque)
+{
+ RTCState *s = opaque;
+ int64_t delay;
+
+ /* if the oscillator is not in normal operation, we do not update */
+ if ((s->cmos_data[RTC_REG_A] & 0x70) != 0x20) {
+ s->next_second_time += ticks_per_sec;
+ qemu_mod_timer(s->second_timer, s->next_second_time);
+ } else {
+ rtc_next_second(&s->current_tm);
+
+ if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
+ /* update in progress bit */
+ s->cmos_data[RTC_REG_A] |= REG_A_UIP;
+ }
+ /* should be 244 us = 8 / 32768 seconds, but currently the
+ timers do not have the necessary resolution. */
+ delay = (ticks_per_sec * 1) / 100;
+ if (delay < 1)
+ delay = 1;
+ qemu_mod_timer(s->second_timer2,
+ s->next_second_time + delay);
+ }
+}
+
+static void rtc_update_second2(void *opaque)
+{
+ RTCState *s = opaque;
+
+ if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
+ rtc_copy_date(s);
+ }
+
+ /* check alarm */
+ if (s->cmos_data[RTC_REG_B] & REG_B_AIE) {
+ if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 ||
+ s->cmos_data[RTC_SECONDS_ALARM] == s->current_tm.tm_sec) &&
+ ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 ||
+ s->cmos_data[RTC_MINUTES_ALARM] == s->current_tm.tm_mon) &&
+ ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 ||
+ s->cmos_data[RTC_HOURS_ALARM] == s->current_tm.tm_hour)) {
+
+ s->cmos_data[RTC_REG_C] |= 0xa0;
+ pic_set_irq(s->irq, 1);
+ }
+ }
+
+ /* update ended interrupt */
+ if (s->cmos_data[RTC_REG_B] & REG_B_UIE) {
+ s->cmos_data[RTC_REG_C] |= 0x90;
+ pic_set_irq(s->irq, 1);
+ }
+
+ /* clear update in progress bit */
+ s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
+
+ s->next_second_time += ticks_per_sec;
+ qemu_mod_timer(s->second_timer, s->next_second_time);
+}
+
+static uint32_t cmos_ioport_read(void *opaque, uint32_t addr)
+{
+ RTCState *s = opaque;
+ int ret;
+ if ((addr & 1) == 0) {
+ return 0xff;
+ } else {
+ switch(s->cmos_index) {
+ case RTC_SECONDS:
+ case RTC_MINUTES:
+ case RTC_HOURS:
+ case RTC_DAY_OF_WEEK:
+ case RTC_DAY_OF_MONTH:
+ case RTC_MONTH:
+ case RTC_YEAR:
+ ret = s->cmos_data[s->cmos_index];
+ break;
+ case RTC_REG_A:
+ ret = s->cmos_data[s->cmos_index];
+ break;
+ case RTC_REG_C:
+ ret = s->cmos_data[s->cmos_index];
+ pic_set_irq(s->irq, 0);
+ s->cmos_data[RTC_REG_C] = 0x00;
+ break;
+ default:
+ ret = s->cmos_data[s->cmos_index];
+ break;
+ }
+#ifdef DEBUG_CMOS
+ printf("cmos: read index=0x%02x val=0x%02x\n",
+ s->cmos_index, ret);
+#endif
+ return ret;
+ }
+}
+
+void rtc_set_memory(RTCState *s, int addr, int val)
+{
+ if (addr >= 0 && addr <= 127)
+ s->cmos_data[addr] = val;
+}
+
+void rtc_set_date(RTCState *s, const struct tm *tm)
+{
+ s->current_tm = *tm;
+ rtc_copy_date(s);
+}
+
+static void rtc_save(QEMUFile *f, void *opaque)
+{
+ RTCState *s = opaque;
+
+ qemu_put_buffer(f, s->cmos_data, 128);
+ qemu_put_8s(f, &s->cmos_index);
+
+ qemu_put_be32s(f, &s->current_tm.tm_sec);
+ qemu_put_be32s(f, &s->current_tm.tm_min);
+ qemu_put_be32s(f, &s->current_tm.tm_hour);
+ qemu_put_be32s(f, &s->current_tm.tm_wday);
+ qemu_put_be32s(f, &s->current_tm.tm_mday);
+ qemu_put_be32s(f, &s->current_tm.tm_mon);
+ qemu_put_be32s(f, &s->current_tm.tm_year);
+
+ qemu_put_timer(f, s->periodic_timer);
+ qemu_put_be64s(f, &s->next_periodic_time);
+
+ qemu_put_be64s(f, &s->next_second_time);
+ qemu_put_timer(f, s->second_timer);
+ qemu_put_timer(f, s->second_timer2);
+}
+
+static int rtc_load(QEMUFile *f, void *opaque, int version_id)
+{
+ RTCState *s = opaque;
+
+ if (version_id != 1)
+ return -EINVAL;
+
+ qemu_get_buffer(f, s->cmos_data, 128);
+ qemu_get_8s(f, &s->cmos_index);
+
+ qemu_get_be32s(f, &s->current_tm.tm_sec);
+ qemu_get_be32s(f, &s->current_tm.tm_min);
+ qemu_get_be32s(f, &s->current_tm.tm_hour);
+ qemu_get_be32s(f, &s->current_tm.tm_wday);
+ qemu_get_be32s(f, &s->current_tm.tm_mday);
+ qemu_get_be32s(f, &s->current_tm.tm_mon);
+ qemu_get_be32s(f, &s->current_tm.tm_year);
+
+ qemu_get_timer(f, s->periodic_timer);
+ qemu_get_be64s(f, &s->next_periodic_time);
+
+ qemu_get_be64s(f, &s->next_second_time);
+ qemu_get_timer(f, s->second_timer);
+ qemu_get_timer(f, s->second_timer2);
+ return 0;
+}
+
+RTCState *rtc_init(int base, int irq)
+{
+ RTCState *s;
+
+ s = qemu_mallocz(sizeof(RTCState));
+ if (!s)
+ return NULL;
+
+ s->irq = irq;
+ s->cmos_data[RTC_REG_A] = 0x26;
+ s->cmos_data[RTC_REG_B] = 0x02;
+ s->cmos_data[RTC_REG_C] = 0x00;
+ s->cmos_data[RTC_REG_D] = 0x80;
+
+ s->periodic_timer = qemu_new_timer(vm_clock,
+ rtc_periodic_timer, s);
+ s->second_timer = qemu_new_timer(vm_clock,
+ rtc_update_second, s);
+ s->second_timer2 = qemu_new_timer(vm_clock,
+ rtc_update_second2, s);
+
+ s->next_second_time = qemu_get_clock(vm_clock) + (ticks_per_sec * 99) / 100;
+ qemu_mod_timer(s->second_timer2, s->next_second_time);
+
+ register_ioport_write(base, 2, 1, cmos_ioport_write, s);
+ register_ioport_read(base, 2, 1, cmos_ioport_read, s);
+
+ register_savevm("mc146818rtc", base, 1, rtc_save, rtc_load, s);
+ return s;
+}
+