1258945SrobertoHP e3000 MPE/iX NTP Hints - May 29, 2001 2258945Sroberto---------------------------------------- 3258945Sroberto 4258945SrobertoNTP was first ported to MPE several years ago, but those diffs were never 5258945Srobertosubmitted back to the official NTP distribution. For more information about 6258945Srobertothat deprecated port, please see http://www.bixby.org/mark/xntpix.html. 7258945Sroberto 8258945SrobertoNTP was re-ported to MPE in May 2001. What follows are hints learned from 9258945Srobertoworking with NTP 4.0.99k23. For additional information about NTP on MPE, 10258945Srobertoplease see http://jazz.external.hp.com/src/hp_freeware/ntp/. 11258945Sroberto 12258945SrobertoMPE lacks the clock-related APIs expected by NTP, so adjtime(), gettimeofday(), 13258945Srobertoand settimeofday() all had to be implemented from scratch by calling 14258945Srobertoprivileged, undocumented internal OS functions. 15258945Sroberto 16258945SrobertoUnfortunately the implementation of adjtime() has exposed a sub-second accuracy 17258945Srobertobug when slewing the system time. This bug is documented in SR 5003462838, and 18258945Srobertoexists on all current versions of MPE. It has not been fixed at the time of 19258945Srobertothis writing. The adjtime() code may possibly need to be altered if/when this 20258945Srobertobug is fixed. 21258945Sroberto 22258945SrobertoThis bug has a side-effect whereby the ntpd daemon will screw up the hardware 23258945SrobertoPDC clock time by many minutes if used for continuous clock adjustments or in 24258945Srobertothe one-time -q mode. But note that you can safely run ntpd in order to become 25258945Srobertoa time server if you include "disable ntp" in the ntp.conf configuration file. 26258945Sroberto 27258945SrobertoThe one-time clock adjustment functionality of ntpdate and ntp_timeset is not 28258945Srobertoaffected by this bug side-effect. You can safely use these commands to alter 29258945Srobertoyour system time with reasonable accuracy. 30258945Sroberto 31258945SrobertoThe only reference clock that has been tested on MPE is the local clock. So 32258945Srobertobuilding NTP with --disable-all-clocks --enable-LOCAL_CLOCK is strongly 33258945Srobertorecommended. 34258945Sroberto 35258945SrobertoNTP makes use of Privileged Mode (PM) capability in order to bind to the NTP 36258945Srobertonetwork port (123) and to access the low-level clock functions. 37258945Sroberto 38258945SrobertoNTP was ported using the gcc compiler. Attempting to use the HP C/iX compiler 39258945Srobertois not recommended and has not been tested. 40258945Sroberto 41258945SrobertoPlease note that NTP is not an HP product and is NOT supported by HP. The best 42258945Srobertoplace for asking MPE-specific questions about NTP is the HP3000-L mailing list 43258945Srobertoat http://raven.utc.edu/Archives/hp3000-l.html or the associated Usenet 44258945Srobertonewsgroup of comp.sys.hp.mpe. 45258945Sroberto 46258945SrobertoThe original author of this port is: 47258945Sroberto 48258945SrobertoMark Bixby 49258945SrobertoHP CSY MPE Internet & Interoperability Engineer 50258945Srobertomark_bixby@hp.com 51