RTC(3) RTC(3) NAME rtc - real-time clock and non-volatile memory SYNOPSIS bind -b '#r' /dev /dev/rtc /dev/rtcid /dev/nvram DESCRIPTION The rtc device provides access to the real-time clock and any associated non-volatile memory. Physical devices sup- ported include the Mostek MK48T12-15 Zeropower/Timekeeper, the Dallas Semiconductor DS1687 real-time clock, and the IBM PC real-time clock on various platforms. The rtc file when read returns the time as a decimal number, expressed as the number of seconds since the epoch, 1 Jan- uary 1970 00:00 GMT. The clock is set by writing the desired number of seconds since the epoch to the file. Set- ting the time in this device has no effect on system time returned by /dev/time (see cons(3)), which must be set sepa- rately if desired. For example, when rtc is available osinit (see init(8)) uses it to set /dev/time. The nvram file provides access to the non-volatile memory commonly implemented by these clock chips. There are no cross-platform standards for the range of addresses that can be safely used by Inferno, or for the content and format of the data. The rtcid file holds a decimal number giving the serial num- ber of the device, set during manufacturing. The file exists only if a particular device provides such a number. SOURCE /os/*/devrtc.c SEE ALSO cons(3) BUGS The rtc file returns seconds but /dev/time returns microsec- onds: it's history.