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author | Paolo Bonzini <pbonzini@redhat.com> | 2012-10-01 14:22:08 +0200 |
---|---|---|
committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-10-05 08:02:30 -0500 |
commit | b8994faf2a8d6fc791669bb432bdb3a7a1711013 (patch) | |
tree | c1876480b0f09dd97806039e26451a151720c8d0 | |
parent | e67edb943f0c812530aaae2491da56f9542f928b (diff) | |
download | hqemu-b8994faf2a8d6fc791669bb432bdb3a7a1711013.zip hqemu-b8994faf2a8d6fc791669bb432bdb3a7a1711013.tar.gz |
rtc: implement century byte
Implement the century byte in the RTC emulation, and test that it works.
This leads to some annoying compatibility code because we need to treat
a value of 2000 for the base_year property as "use the century byte
properly" (which would be a value of 0).
The century byte will now be always-zero, rather than always-20,
for the MIPS Magnum machine whose base_year is 1980. Commit 42fc73a
(Support epoch of 1980 in RTC emulation for MIPS Magnum, 2009-01-24)
correctly said:
With an epoch of 1980 and a year of 2009, one could argue that [the
century byte] should hold either 0, 1, 19 or 20. NT 3.50 on MIPS
does not read the century byte.
so I picked the simplest and most sensible implementation which is to
return 0 for 1980-2079, 1 for 2080-2179 and so on.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r-- | hw/mc146818rtc.c | 27 | ||||
-rw-r--r-- | tests/rtc-test.c | 32 |
2 files changed, 48 insertions, 11 deletions
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c index a7d20d5..332a77d 100644 --- a/hw/mc146818rtc.c +++ b/hw/mc146818rtc.c @@ -519,7 +519,9 @@ static void rtc_get_time(RTCState *s, struct tm *tm) tm->tm_wday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]) - 1; tm->tm_mday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]); tm->tm_mon = rtc_from_bcd(s, s->cmos_data[RTC_MONTH]) - 1; - tm->tm_year = rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year - 1900; + tm->tm_year = + rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year + + rtc_from_bcd(s, s->cmos_data[RTC_CENTURY]) * 100 - 1900; } static void rtc_set_time(RTCState *s) @@ -552,10 +554,9 @@ static void rtc_set_cmos(RTCState *s, const struct tm *tm) s->cmos_data[RTC_DAY_OF_WEEK] = rtc_to_bcd(s, tm->tm_wday + 1); s->cmos_data[RTC_DAY_OF_MONTH] = rtc_to_bcd(s, tm->tm_mday); s->cmos_data[RTC_MONTH] = rtc_to_bcd(s, tm->tm_mon + 1); - year = (tm->tm_year - s->base_year) % 100; - if (year < 0) - year += 100; - s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year); + year = tm->tm_year + 1900 - s->base_year; + s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year % 100); + s->cmos_data[RTC_CENTURY] = rtc_to_bcd(s, year / 100); } static void rtc_update_time(RTCState *s) @@ -673,7 +674,6 @@ static void rtc_set_date_from_host(ISADevice *dev) { RTCState *s = DO_UPCAST(RTCState, dev, dev); struct tm tm; - int val; qemu_get_timedate(&tm, 0); @@ -683,9 +683,6 @@ static void rtc_set_date_from_host(ISADevice *dev) /* set the CMOS date */ rtc_set_cmos(s, &tm); - - val = rtc_to_bcd(s, (tm.tm_year / 100) + 19); - rtc_set_memory(dev, RTC_CENTURY, val); } static int rtc_post_load(void *opaque, int version_id) @@ -810,6 +807,18 @@ static int rtc_initfn(ISADevice *dev) s->cmos_data[RTC_REG_C] = 0x00; s->cmos_data[RTC_REG_D] = 0x80; + /* This is for historical reasons. The default base year qdev property + * was set to 2000 for most machine types before the century byte was + * implemented. + * + * This if statement means that the century byte will be always 0 + * (at least until 2079...) for base_year = 1980, but will be set + * correctly for base_year = 2000. + */ + if (s->base_year == 2000) { + s->base_year = 0; + } + rtc_set_date_from_host(dev); #ifdef TARGET_I386 diff --git a/tests/rtc-test.c b/tests/rtc-test.c index 2b9aa63..7fdc94a 100644 --- a/tests/rtc-test.c +++ b/tests/rtc-test.c @@ -179,12 +179,13 @@ static void check_time(int wiggle) static int wiggle = 2; -static void set_year(void) +static void set_year_20xx(void) { /* Set BCD mode */ cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) & ~REG_B_DM); cmos_write(RTC_REG_A, 0x76); cmos_write(RTC_YEAR, 0x11); + cmos_write(RTC_CENTURY, 0x20); cmos_write(RTC_MONTH, 0x02); cmos_write(RTC_DAY_OF_MONTH, 0x02); cmos_write(RTC_HOURS, 0x02); @@ -198,6 +199,7 @@ static void set_year(void) g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11); + g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20); /* Set a date in 2080 to ensure there is no year-2038 overflow. */ cmos_write(RTC_REG_A, 0x76); @@ -210,6 +212,7 @@ static void set_year(void) g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x80); + g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20); cmos_write(RTC_REG_A, 0x76); cmos_write(RTC_YEAR, 0x11); @@ -221,6 +224,30 @@ static void set_year(void) g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11); + g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20); +} + +static void set_year_1980(void) +{ + /* Set BCD mode */ + cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) & ~REG_B_DM); + cmos_write(RTC_REG_A, 0x76); + cmos_write(RTC_YEAR, 0x80); + cmos_write(RTC_CENTURY, 0x19); + cmos_write(RTC_MONTH, 0x02); + cmos_write(RTC_DAY_OF_MONTH, 0x02); + cmos_write(RTC_HOURS, 0x02); + cmos_write(RTC_MINUTES, 0x04); + cmos_write(RTC_SECONDS, 0x58); + cmos_write(RTC_REG_A, 0x26); + + g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04); + g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58); + g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x80); + g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x19); } static void bcd_check_time(void) @@ -313,7 +340,8 @@ int main(int argc, char **argv) qtest_add_func("/rtc/bcd/check-time", bcd_check_time); qtest_add_func("/rtc/dec/check-time", dec_check_time); qtest_add_func("/rtc/alarm-time", alarm_time); - qtest_add_func("/rtc/set-year", set_year); + qtest_add_func("/rtc/set-year/20xx", set_year_20xx); + qtest_add_func("/rtc/set-year/1980", set_year_1980); qtest_add_func("/rtc/fuzz-registers", fuzz_registers); ret = g_test_run(); |