diff options
Diffstat (limited to 'payloads/libpayload/drivers/nvram.c')
| -rw-r--r-- | payloads/libpayload/drivers/nvram.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/payloads/libpayload/drivers/nvram.c b/payloads/libpayload/drivers/nvram.c index 9196d80b86..b28de92b78 100644 --- a/payloads/libpayload/drivers/nvram.c +++ b/payloads/libpayload/drivers/nvram.c @@ -93,3 +93,43 @@ void nvram_write(u8 val, u8 addr) outb(addr, rtc_port); outb(val, rtc_port + 1); } + +/** + * Return 1 if the NVRAM is currently updating and a 0 otherwise + * @return A 1 if the NVRAM is updating and 0 otherwise + */ + +int nvram_updating(void) +{ + return (nvram_read(NVRAM_RTC_FREQ_SELECT) & NVRAM_RTC_UIP) ? 1 : 0; +} + +/** + * Get the current time and date from the RTC + * + * @param time A pointer to a broken-down time structure + */ +void rtc_read_clock(struct tm *time) +{ + memset(time, 0, sizeof(*time)); + + while(nvram_updating()); + + time->tm_mon = bcd2dec(nvram_read(NVRAM_RTC_MONTH)) - 1; + time->tm_sec = bcd2dec(nvram_read(NVRAM_RTC_SECONDS)); + time->tm_min = bcd2dec(nvram_read(NVRAM_RTC_MINUTES)); + time->tm_mday = bcd2dec(nvram_read(NVRAM_RTC_DAY)); + time->tm_hour = bcd2dec(nvram_read(NVRAM_RTC_HOURS)); + + /* Instead of finding the century register, + we just make an assumption that if the year value is + less then 80, then it is 2000+ + */ + + time->tm_year = bcd2dec(nvram_read(NVRAM_RTC_YEAR)); + + if (time->tm_year < 80) + time->tm_year += 100; +} + + |