Re: [ntp:questions] NTP client with ability to write Windows NT system time to hardware clock?
Martin Burnicki wrote: Brolin, sorry for the late reply. I've been offline due to a really bad cold. I have kept deferring replying to your message, at least partly because of the nature of the medium. However, I am glad to report my hardware clock has been sufficiently accurate since I ran “ntpdate-debian” followed by “hwclock -w --utc” on Ubuntu probably at least 2 weeks ago. I know I should keep (better) records, but at least I am satisfied even without the ability to write the Windows NT system time to the hardware clock. After synchronising brolin-N900 with time.windows.com , brolin-V13 is 8 seconds behind brolin-N900 . I know this may be significant for certain applications, but it is good enough for me. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP client with ability to write Windows NT system time to hardware clock?
Steve Kostecke wrote: On 2011-02-01, Brolin Empeybro...@brolin.be wrote: After synchronising brolin-N900 with time.windows.com , brolin-V13 is 8 seconds behind brolin-N900 . I know this may be significant for certain applications, but it is good enough for me. FWIW ... NTP can typically keep your clock synced within +/- 0.01 sec across a WAN (e.g. The Internet) and better than +/- 0.005 sec across a LAN. Apparently you have not redd the previous messages in this thread. Synchronising brolin-V13’s Windows NT system clock with NTP is only useful until I shut down Windows NT because the synchronised system clock’s time is /not/ written to the hardware clock when RealTimeIsUniversal=1 . And your 8 second offset is well outside ntpd's 0.128 sec default step threshold. As I have already stated in a previous message in this thread, I am not using ntpd. I do not need ntpd: I need Microsoft to change Windows 7 so it can write the system time to the hardware clock during the shut down process when RealTimeIsUniversal=1 . Until that happens, I accept an 8 second offset as good enough. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP client with ability to write Windows NT system time to hardware clock?
Martin Burnicki wrote: Brolin, Brolin Empey wrote: I run Windows 7 Professional IA-32 with RealTimeIsUniversal=1 on brolin-V13, my Dell Vostro V13 laptop. This means brolin-V13?s hardware clock (RTC) runs in UTC, as it should, instead of the local time zone, as Microsoft still uses for the completely illogical default configuration. RealTimeIsUniversal=1 is /finally/ fixed and fully working beginning in Windows Vista SP2 + Windows 7, but there is still a problem: When RealTimeIsUniversal=0, which is also used when the RealTimeIsUniversal key does not exist, Windows 7 writes the Windows NT system time to the hardware clock during the shut down process. When RealTimeIsUniversal=1, though, the Windows NT system time is never written to the hardware clock. Hm, this sounds like a Windows bug ... No, it is by design. :( Consequently, I have to boot Ubuntu from a USB flash drive (brolin-V13 has no optical disc drive (ODD).), then use ntpdate-debian + hwclock to synchronise the Linux system clock with an NTP server on the Internet, then write the sufficiently-accurate-for-me Linux system time to the hardware clock so Windows 7 will set the Windows NT system clock from the accurate time in the hardware clock. After some time (at least 1 week, not sure.), though, my hardware clock is approximately 2 minutes behind the correct time from an NTP server, but Windows 7 never writes the Windows NT system time to the hardware clock when RealTimeIsUniversal=1, so I have to use my Ubuntu USB flash drive again. Do you need correct time for the on-board RTC for a special application? No, but I still want my clocks to have accurate time. As far as I know this is only used to initialize the Windows system time when Windows starts up, so your system time may be wrong until ntpd has a chance to correct it, i.e. it can reach an NTP server. I am using Microsoft’s w32time service, not ntpd. I have configured the w32time service to start automatically, but it does not seem to start automatically, so my system time is approximately 2 minutes behind until I run net start w32time w32tm /resync in an elevated (with administrative privileges) cmd.exe session. I know the proper solution is to get Microsoft to change Windows 7 so it can write the Windows NT system time to the hardware clock even when RealTimeIsUniversal=1, but that has not yet happened. I have at least asked a Microsoft employee about it, though, so they know users (well, at least 1 user. :)) want the feature. I can use w32time to force a synchronisation, but then I have to do that every time I boot Windows 7. brolin-V13 travels with me between home and work, so it is not always running. Maybe this causes the hardware clock to fall behind, but I do not think I can prevent having to shut down and boot brolin-V13 on a daily basis. Since I do not know if Microsoft will ever enable Windows 7 to write the Windows NT system time to the hardware clock when RealTimeIsUniversal=1, the next best solution is probably to write a hwclock.exe application for Windows NT, but I am hoping someone has already implemented this functionality in an application such as an NTP client. Googling ?hwclock.exe? returns lots of noise because some malware uses this file name, but I have not found any real hwclock.exe equivalent to hwclock used on Linux. During normal operation the ntpd service should not call the Windows SetSystemTime() API since doing so causes a time offset offset to be applied to the system time. As far as I know ntpd calls SetSystemTime() only when the Windows system time needs to be stepped anyway, or when the ntpd service shuts down. Calling SetSystemTime() should also set the HW clock. If this doesn't happen then the Windows bug mentioned above is probably inside that Windows API call. Again, I am using w32time, not ntpd. The behaviour you call a bug is by design. I looked up SetSystemTime on MSDN but could not find anything even suggesting SetSystemTime is supposed to update the hardware clock. I actually could not find any official documentation on how to set the hardware clock from a userspace application on Windows NT, but I have found how (see below). So, is there an NTP client or any other application for Windows NT which can write the Windows NT system time to the hardware clock so I do not have to write hwclock.exe for Windows NT? A proper solution would indeed be to write a program which just reads the current system time without changing it, and then writes the system time to the HW clock. However, this requires a devce driver to be able to write to the CMOS chip. I'm not sure whether there is a documented or undocumented software interface to the Windows kernel to call Windows' built-in driver. The HalSetRealTimeClock function in the Windows NT kernel’s HAL needs to be called but, AFAICT, even a device driver cannot call HalSetRealTimeClock. I actually downloaded and installed Microsoft’s Windows Driver
[ntp:questions] NTP client with ability to write Windows NT system time to hardware clock?
I run Windows 7 Professional IA-32 with RealTimeIsUniversal=1 on brolin-V13, my Dell Vostro V13 laptop. This means brolin-V13’s hardware clock (RTC) runs in UTC, as it should, instead of the local time zone, as Microsoft still uses for the completely illogical default configuration. RealTimeIsUniversal=1 is /finally/ fixed and fully working beginning in Windows Vista SP2 + Windows 7, but there is still a problem: When RealTimeIsUniversal=0, which is also used when the RealTimeIsUniversal key does not exist, Windows 7 writes the Windows NT system time to the hardware clock during the shut down process. When RealTimeIsUniversal=1, though, the Windows NT system time is never written to the hardware clock. Consequently, I have to boot Ubuntu from a USB flash drive (brolin-V13 has no optical disc drive (ODD).), then use ntpdate-debian + hwclock to synchronise the Linux system clock with an NTP server on the Internet, then write the sufficiently-accurate-for-me Linux system time to the hardware clock so Windows 7 will set the Windows NT system clock from the accurate time in the hardware clock. After some time (at least 1 week, not sure.), though, my hardware clock is approximately 2 minutes behind the correct time from an NTP server, but Windows 7 never writes the Windows NT system time to the hardware clock when RealTimeIsUniversal=1, so I have to use my Ubuntu USB flash drive again. I know the proper solution is to get Microsoft to change Windows 7 so it can write the Windows NT system time to the hardware clock even when RealTimeIsUniversal=1, but that has not yet happened. I have at least asked a Microsoft employee about it, though, so they know users (well, at least 1 user. :)) want the feature. I can use w32time to force a synchronisation, but then I have to do that every time I boot Windows 7. brolin-V13 travels with me between home and work, so it is not always running. Maybe this causes the hardware clock to fall behind, but I do not think I can prevent having to shut down and boot brolin-V13 on a daily basis. Since I do not know if Microsoft will ever enable Windows 7 to write the Windows NT system time to the hardware clock when RealTimeIsUniversal=1, the next best solution is probably to write a hwclock.exe application for Windows NT, but I am hoping someone has already implemented this functionality in an application such as an NTP client. Googling “hwclock.exe” returns lots of noise because some malware uses this file name, but I have not found any real hwclock.exe equivalent to hwclock used on Linux. So, is there an NTP client or any other application for Windows NT which can write the Windows NT system time to the hardware clock so I do not have to write hwclock.exe for Windows NT? Thanks for reading, Brolin ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP client with ability to write Windows NT system time to hardware clock?
David Woolley wrote: unruh wrote: On 2010-12-11, Jan Ceuleers janspam.ceule...@skynet.be wrote: Piece of feedback below. There's no way I'm going to read all that. If you have a question for us, please can you put it a little more succinctly? Thanks. Actually, I /did/ write my question succinctly at the end of my post. To summarize as I understand it-- how do you keep the RTC synced to the true time under Windows? (System running ntp so assume that the system time is the true time). He wants the RTC to contain UTC, even though Windows isn't in the GMT timezone with DST disabled. Windows normally stores the system wall clock time. My RTC already runs in UTC, but my RTC is approximately 2 minutes behind because I have no way of writing the Windows NT system time to the hardware clock (RTC) after using an NTP client to synchronise the Windows NT system time. On Ubuntu, I use ntpdate-debian + hwclock, but I cannot find a real hwclock for Windows NT, only malware which uses the name hwclock.exe as a disguise. I need an hwclock.exe application for Windows NT so I can run “hwclock --utc --systohc” like on Ubuntu. I am asking in this group because I thought someone may know of an NTP client for Windows NT with this functionality, now that Microsoft has finally fully fixed support for RealTimeIsUniversal=1 beginning in Windows Vista SP2 + Windows 7. My original post (and this reply too) make perfect sense to me, but I suspect my readers did not have all of the required background knowledge. If you are not already familiar with Windows NT’s RealTimeIsUniversal registry key, please read http://www.cl.cam.ac.uk/~mgk25/mswish/ut-rtc.html. If you are not already familiar with the hwclock command from the util-linux(-ng) package, please read http://manpages.ubuntu.com/manpages/lucid/man8/hwclock.8.html. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
