diff options
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/mc146818rtc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c index ec7c4ecdb6..a1b0e31ee5 100644 --- a/hw/mc146818rtc.c +++ b/hw/mc146818rtc.c @@ -247,7 +247,15 @@ static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) rtc_set_time(s); } } - s->cmos_data[RTC_REG_B] = data; + if (((s->cmos_data[RTC_REG_B] ^ data) & (REG_B_DM | REG_B_24H)) && + !(data & REG_B_SET)) { + /* If the time format has changed and not in set mode, + update the registers immediately. */ + s->cmos_data[RTC_REG_B] = data; + rtc_copy_date(s); + } else { + s->cmos_data[RTC_REG_B] = data; + } rtc_timer_update(s, qemu_get_clock(rtc_clock)); break; case RTC_REG_C: |