xref: /freebsd/contrib/ntp/util/README (revision 3078531de10dcae44b253a35125c949ff4235284)
1README file for directory ./util of the NTP Version 4 distribution
2
3This directory contains the sources for the various utility programs.
4See the README and RELNOTES files in the parent directory for directions
5on how to make and install these programs.
6
7The ntptime.c program checks the kernel configuration for the NTP user
8interface syscalls ntp_gettime() and ntp_adjtime().  If present, the
9current timekeeping data are displayed.  If not, a dissapointment is
10displayed.  See the kernel page file in the HTML documentation in
11distribution for further details. ntptime will be built be if configure
12believes your system can use it.
13
14The jitter.c program can be used to determine the timing jitter due to
15the operating system in a gettimeofday() call.  For most systems the
16dominant contribution to the jitter budget is the period of the hardware
17interrupt, usually in the range 10 us-1 ms.  For those systems with
18microsecond counters, such as recent Sun and certain HP and DEC systems,
19the jitter is dominated only by the operating system.
20
21The timetrim.c program can be used with SGI machines to implement a
22scheme to discipline the hardware clock frequency.  See the source code
23for further information.
24
25The byteorder.c and longsize.c programs are used during the configuration
26process to determine the byte order (little or big endian) and longword
27size (32 or 64 bits).  See the configure scripts for further details.
28
29The testrs6000.c program is used for testing purposes with the IBM
30RS/6000 AIX machines. Bill Jones <jones@chpc.utexas.edu> reports:
31"I could not get a tickadj of less than 40 us to work on a RS6000.
32If you set it less than 40 us do so at your own risk!"
33
34The tickadj.c program can be used to read and set various kernel
35parameters affecting NTP operations. See the tickadj page in the HTML
36documentation for further details.  tickadj will be built if configure
37believes your system can use it.
38
39tg.c and tg2.c are tone generators.  They make audio signals
40that emulate WWV or IRIG (-B and -E).  tg runs on Solaris.
41tg2 is a clone that runs on Linux, FreeBSD, and NetBSD.
42Read the source for the fine print.  tg2 has a help option
43available via -h.
44
45