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Last revision: 06-Jul-1994
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Included in this distribution of XNTP V3 is a configuration file suitable
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for use under Apple's A/UX Version 3.x.x There is also one for A/UX 2.0.1
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but it has not been fully tested. To make the executables follow the steps
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*** NOTE: You must have gcc installed to successfully compile the current
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distribution; the native cc supplied with A/UX will NOT correctly compile
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this source. See the FAQ in comp.unix.aux for places to obtain gcc from
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and how to install it.
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----------------------
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MAKING XNTPD FOR A/UX:
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----------------------
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First, you need to create the makefiles (after you've downloaded the
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After that, you should edit Config.local to make sure that BINDIR is
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correct for where you wish the programs to be "installed". The default
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(and what I use) is /usr/local/etc. Make sure that DEFS_LOCAL and
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CLOCKDEFS are commented out! Presently, only the LOCAL_CLOCK/REFCLOCK
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clock is used and supported.
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After this is done (you should be told that your system is A/UX 3), make
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'xntpd' (the options to 'gcc' are held in compilers/aux3.gcc):
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I do not normally use the `make install' option and so have not verified its
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compatibility with A/UX. Rather, I pull out each of the executables and
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place them in the locally appropriate locations.
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At this point you need to set things up so that 'xntpd' is started upon
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boot-up. You can do this in 1 of 2 ways: either add entries in /etc/inittab
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or, more ideally, create and use an /etc/rc.local file. Since rc.local is
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what I recommend, here's how you do it:
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By default, A/UX doesn't have rc.local, so you'll need to add the following to
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net6:2:wait:/etc/syslogd # set to "wait" to run a syslog daemon
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+ jmj0:2:wait:/etc/rc.local 1>/dev/syscon 2>&1 # Local stuff
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dbg2::wait:/etc/telinit v # turn off init's verbose mode
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Now, the look of a sample /etc/rc.local is as follows:
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# @(#)Copyright Apple Computer 1987 Version 1.17 of rc.sh on 91/11/08 15:56:21 (ATT 1.12)
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# Push line discipline/set the device so it will print
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echo "Entering rc.local..."
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/bin/echo " now setting the time..."
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/usr/local/etc/ntpdate -s -b <host.domain>
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# start up 'xntpd' if we want
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if [ -f /etc/ntp.conf ]
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/bin/echo " setting tick and tickadj..."
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/usr/local/etc/tickadj -t 16672 -a 54
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/bin/echo " starting xntpd..."
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/usr/local/etc/xntpd <&- > /dev/null 2>&1
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echo "Leaving rc.local..."
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There are a few things to notice about the above:
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o When run, 'ntpdate' forces your clock to the time returned by the
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host(s) specified by <host.domain> (you'll need to replace this
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be the IP address(es) of your timehosts. This is good since it gets
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things close to start off with. You can use more than one time
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o 'tickadj' is also called. This does two things: changes the
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default value of 'tick' (which the the amount of time, in ms, that
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is added to the clock every 1/60 seconds) and changes the value
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of 'tickadj' which the the amount that is added or subtracted
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from 'tickadj' when adjtime() is called.
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Now Mac clocks are pretty bad and tend to be slow. Sooo, instead of
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having A/UX add the default of 16666ms every 1/60th of a second, you
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may want it to add more (or less) so that it keeps better time. The
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above value works for me but your "best" value may be different and
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will likely require some fooling around to find the best value. As a
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general rule of thumb, if you see 'xntpd' make a lot of negative clock
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adjustments, then your clock is fast and you'll need to _decrease_
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the value of 'tick'. If your adjustments are positive, then you need
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to increase 'tick'. To make a guess on how fast/slow your clock is,
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use 'ntpdate' to sync your clock. Now watch 'xntpd' and see how it
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operates. If, for example, it resets your clock by 1 second every 30
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minutes, then your clock is (1/(30*60)) is about 0.056% off and you'll
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need to adjust 'tick' by 16666*0.00056 or about 9 (i.e. 'tick' should
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be ~16675 if slow or ~16657 if fast)
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A/UX's default value of 'tickadj' is 1666 which is too big for
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'xntpd'... so it also needs to be adjusted. I like using larger
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values then the recommended value of 9 for 'tickadj' (although not
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anything near as big as 1666) since this allows for quick slews
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when adjusting the clock. Even with semi-large values of 'tickadj'
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(~200), getting 5ms (1/200 s) accuracy is easy.
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Finally, before A/UX and 'xntpd' will work happily together, you need to
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patch the kernel. This is due to the fact that A/UX attempts to keep the
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UNIX-software clock and the Mac-hardware clock in sync. Neither the h/w or
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the s/w clock are too accurate. Also, 'xntpd' will be attempting to adjust
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the software clock as well, so having A/UX muck around with it is asking
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for headaches. What you therefore need to do is tell the kernel _not_ to
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sync the s/w clock with the h/w one. This is done using 'adb'. The
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following is a shell script that will do the patch for you:
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init_time_fix_timeout?4i
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init_time_fix_timeout?w 0x4e75
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init_time_fix_timeout?4i
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This must be done _every_ time you create a new kernel (via newconfig or
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newunix) or else 'xntpd' will go crazy.
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John Dundas was the original porter of 'xntpd' and a lot of the additions
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and A/UX-ports are from him. I got involved when I wanted to run 'xntpd'
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on jagubox. It was also around this time that the base-patchlevel of
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'xntpd' changed relatively (the so-called "jones" version). Since then,
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I've been maintaining 'xntpd' for A/UX for the xntp development team
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The original kernel patch (which patched 'time_fix_timeout') was from
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Richard Todd. I suggest patching 'init_time_fix_timeout' which prevents
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'time_fix_timeout' from even being called.
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o As configured (see machines/aux3), 'xntpd' will log messages via syslogd
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using the LOC_LOCAL1 facility. I would suggest the following in
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local1.notice /usr/adm/ntpd-syslog
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o As mentioned above, the clocks on A/UX and Macs are kinda bad. Not
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only that, but logging in and out of the MacOS mode as well as
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extensive floppy use causes A/UX to drop and lose clock interupts
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(these are sent every 1/60th of a second). So, if you do these
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activities a lot, you find out that you lose about 300ms of time
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(i.e., you become 300ms slow). 'xntpd' default way of handling this
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is to called 'settimeofday()' and step the clock to the correct
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time. I prefer having 'xntpd' slew the clock back into line by
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making gradual adjustments to the clock over a coupla minutes
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or so. It's for this reason that SLEWALWAYS is defined in
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include/ntp_machine.h for SYS_AUX3. It's also for this reason than
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I like larger values of 'tickadj'.
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Good luck! If you have problems under A/UX feel free to contact me (e-mail
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Jim Jagielski | "That is no ordinary rabbit... 'tis the
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jim@jagubox.gsfc.nasa.gov | most foul, cruel and bad-tempered
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NASA/GSFC, Code 734.4 | rodent you ever set eyes on"
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Greenbelt, MD 20771 | Tim the Enchanter
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