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Fix RTC clock reading in 24-hour mode

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This commit is contained in:
Josh Holtrop 2022-12-19 11:32:08 -05:00
parent 7c8744d1e0
commit a423cdf1b1
1 changed files with 18 additions and 12 deletions
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28
src/hulk/rtc.d
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@ -43,17 +43,19 @@ struct rtc
public static void initialize()
{
time t = read_rtc_time();
klog.writefln("System time is 20%02u-%02u-%02u %02u:%02u:%02u",
t.year, t.month, t.day, t.hour, t.minute, t.second);
/* Enable IRQ 8 to receive RTC interrupts. */
ubyte sr_b = read_register(REG_SR_B, true);
write_register(REG_SR_B, sr_b | SR_B_ENABLE_IRQ, true);
/* Record RTC mode flags from status register B. */
rtc_24hour_mode = (sr_b & SR_B_24HOUR) != 0u;
rtc_binary_mode = (sr_b & SR_B_BINARY) != 0u;
/* Read the current system time. */
time t = read_rtc_time();
klog.writefln("System time is 20%02u-%02u-%02u %02u:%02u:%02u",
t.year, t.month, t.day, t.hour, t.minute, t.second);
/* Send EOI to enable more RTC interrupts and re-enable NMIs. */
eoi();
}
@ -110,20 +112,24 @@ struct rtc
t.year = read_rtc_time_register(REG_RTC_YEAR);
t.month = read_rtc_time_register(REG_RTC_MONTH);
t.day = read_rtc_time_register(REG_RTC_DAY);
t.hour = read_register(REG_RTC_HOURS);
t.minute = read_rtc_time_register(REG_RTC_MINUTES);
t.second = read_rtc_time_register(REG_RTC_SECONDS);
if (!rtc_24hour_mode)
{
ubyte pm = (t.hour & 0x80u) >> 7u;
t.hour &= 0x7Fu;
/* Hour field is treated differently because it might have 'PM' flag
* in highest bit if we're in 24-hour mode. */
ubyte hour = read_register(REG_RTC_HOURS);
ubyte pm = hour >> 7u;
hour &= 0x7Fu;
if (!rtc_binary_mode)
{
t.hour = bcd_to_binary(t.hour);
/* Hour is in BCD format; convert to binary. */
hour = bcd_to_binary(hour);
}
if (!rtc_24hour_mode)
{
/* Hour is in 12-hour format; convert to 24-hour format. */
t.hour = cast(ubyte)((t.hour % 12u) + pm * 12u);
hour = cast(ubyte)((hour % 12u) + pm * 12u);
}
t.hour = hour;
return t;
}