On Friday, 22 Feb, Donald R. Spoon wrote: > out. But WHY is it still trying to load something with modprobe? The > complaints happen right after the hwclock is accessed on boot-up, so I > suspect it is connected to whatever the hwclock script is doing. I have
Exactly; see below for explanations. > managed to dream up the following questions for the "gurus": > > 1. Are the "hardware clock" and the "real time clock" the same or are > they different devices in the BIOS? They are the same physical device. None of them is "in the BIOS," whatever this may mean. > 2. If they are the same, then does removing RTC support from the kernel > keep the system from accessing the hardware clock? Sometimes. There are two methods of accessing the hardware clock: via /dev/rtc and by directly messing with I/O ports. The first one is reliable, the second one is not: some Alpha systems exhibit incorrect behaviour when hardware is accessed directly from user mode code. This is why hwclock tries /dev/rtc first. > 3. If different, is RTC support needed in anyway to run the NTPDATE or > NTP programs? No. (I know this answer is redundant, because they are not different.) > 4. If the RTC is not needed and I have support turned off in the > kernel, can I just remove the /dev/rtc entry and make these complaints > go away without hurting anyting else on the system? There are more gentle ways of doing this: (a) there may be flags to hwclock that prevent it from trying /dev/rtc; or (b) you can add `alias char-major-10-135 off' to a file in /etc/modutils (say, /etc/modutils/aliases) and run update-modules. Removing /dev/rtc should also work (at least for a while). > that function. The "current" OS is Debian "Woody", and the kernel is > 2.2.20-generic + 256 Megs of RAM + Matrox Millenium Video card w/ 8 megs. 2.2.x kernels were known for doing silly things in their RTC driver; don't know if it still holds for the recent ones such as 2.2.20. For 2.2.x, a "light-weight" version of the driver exists as a patch. The light-weight driver only does what is needed for hwclock, disabling advanced functionality such as programmable interrupts for user programs. The RTC driver in 2.4.x is already light-weight. Nikita
