Ethan posts: > hwclock uses it to update the hardware clock, this > is done at shutdown to keep the clocks synchronized.
Agreed that 'hwclock' updates the hardware clock while shutting down the m/c. This does not have anything to do with the 'rtc' module and hwclock does in no way use it. The 'rtc' module gives you access to the real time clock (or hardware clock) built into your computer. Yup, it is a good thing to have rtc support if you do data sampling work or on an SMP machine. Otherwise it is not needed for a reasonably stable CMOS clock that you normally have on your uniprocessor m/b. It should not drift, that is you should have a stable clock tick. The hardware clock is synced with the system clock, when you go down with an init 0/6. I think that the system clock can adjust a drifting hardware clock. How was the system clock set ? It was set from the hardware clock when you booted up. See the script hwclock.sh in /etc/rcS.h. So, is 'rtc' really needed ? I would say no. Correct me if I am wrong, tnx anyway. -- ragOO, VU2RGU Keeping the Air-Waves FREE...........Amateur Radio Keeping your Software FREE.........the GNU Project Keeping the W W W FREE....Debian GNU/${kernel}