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Annotation of embedaddon/ntp/html/hints/mpeix, revision 1.1.1.1

1.1       misho       1: HP e3000 MPE/iX NTP Hints - May 29, 2001
                      2: ----------------------------------------
                      3: 
                      4: NTP was first ported to MPE several years ago, but those diffs were never
                      5: submitted back to the official NTP distribution.  For more information about
                      6: that deprecated port, please see http://www.bixby.org/mark/xntpix.html.
                      7: 
                      8: NTP was re-ported to MPE in May 2001.  What follows are hints learned from
                      9: working with NTP 4.0.99k23.  For additional information about NTP on MPE,
                     10: please see http://jazz.external.hp.com/src/hp_freeware/ntp/.
                     11: 
                     12: MPE lacks the clock-related APIs expected by NTP, so adjtime(), gettimeofday(),
                     13: and settimeofday() all had to be implemented from scratch by calling
                     14: privileged, undocumented internal OS functions.
                     15: 
                     16: Unfortunately the implementation of adjtime() has exposed a sub-second accuracy
                     17: bug when slewing the system time.  This bug is documented in SR 5003462838, and
                     18: exists on all current versions of MPE.  It has not been fixed at the time of
                     19: this writing.  The adjtime() code may possibly need to be altered if/when this
                     20: bug is fixed.
                     21: 
                     22: This bug has a side-effect whereby the ntpd daemon will screw up the hardware
                     23: PDC clock time by many minutes if used for continuous clock adjustments or in
                     24: the one-time -q mode.  But note that you can safely run ntpd in order to become
                     25: a time server if you include "disable ntp" in the ntp.conf configuration file.
                     26: 
                     27: The one-time clock adjustment functionality of ntpdate and ntp_timeset is not
                     28: affected by this bug side-effect.  You can safely use these commands to alter
                     29: your system time with reasonable accuracy.
                     30: 
                     31: The only reference clock that has been tested on MPE is the local clock.  So
                     32: building NTP with --disable-all-clocks --enable-LOCAL_CLOCK is strongly
                     33: recommended.
                     34: 
                     35: NTP makes use of Privileged Mode (PM) capability in order to bind to the NTP
                     36: network port (123) and to access the low-level clock functions.
                     37: 
                     38: NTP was ported using the gcc compiler.  Attempting to use the HP C/iX compiler
                     39: is not recommended and has not been tested.
                     40: 
                     41: Please note that NTP is not an HP product and is NOT supported by HP.  The best
                     42: place for asking MPE-specific questions about NTP is the HP3000-L mailing list
                     43: at http://raven.utc.edu/Archives/hp3000-l.html or the associated Usenet
                     44: newsgroup of comp.sys.hp.mpe.
                     45: 
                     46: The original author of this port is:
                     47: 
                     48: Mark Bixby
                     49: HP CSY MPE Internet & Interoperability Engineer
                     50: mark_bixby@hp.com