This is the verbatim copy of what I wrote as example code for an
article about time stamping. It's called "mini time protocol".  Some
of the code, in turn, comes from my previous experiments with White
Rabbit.

I'd better have the programs here as I use them often. As time permits
I'll add some more features and documentation in the ppsi manual.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This program monitors clock_monotonic and clock_realtime every 10ms
(or a different time lapse passed on the command line).

Whenever the difference between them is more than 0.5ms apart from the
previously-reported difference, it prints the current difference.  All
such differences are relative to the initial offset of the two clocks,
when the program started. The difference is prefixed with the current
date and time, to help logging.

This is something I already had in my toolbox, so I could see the leap
second that occurred on Jun 30th 2012.

Example:
   tornado.root# ./tools/chktime &
   [1] 23761
   ./tools/chktime: looping every 10 millisecs

   tornado.root# ./tools/jmptime .003
   Requesting time-jump: 0.003000 seconds

      13-02-11-12:22:44:       2997 us

   tornado.root# ./tools/jmptime .003
   Requesting time-jump: 0.003000 seconds

      13-02-11-12:22:52:       5994 us

   tornado.root# ./tools/jmptime -.006
   Requesting time-jump: -0.006000 seconds

      13-02-11-12:22:58:        -10 us
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Like adjtime (previous commit), this is used to adjust the local time,
but in this case the program performs a time jump (warp) using
settimeofday().
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This simple tool requests a time adjustment, specified in seconds
expressed as a floating point values ("0.001", "-.2", "-4" ...).

It can be used to force time differences between hosts while checking
how ppsi (or other time daemons) work.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This merges the work of Danilo Sabato, who made the ppsi daemon build
both on i386 and x86-64 in a lib-less fashion.  Such architectures
are meant to show ppsi running on bare metal, and are test benches
for any changes to the core, even for people who cannot build and run
on real bare-metal hosts.

According to configuration, pp_diag_verbosity can be "const" or not
(having it const saves a lot of space and we need it in our
white-rabbit core).

This avoids errors when building for all architectures, with or
without CONFIG_PPSI_RUNTIME_VERBOSITY.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

arch-bare-x86-64: bugfix for packet receive
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>