Re: [Xenomai-help] CLOCK_REALTIME synchronized to NTP

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Jeff Weber wrote:
> On Wed, Mar 30, 2011 at 5:00 PM, Gilles Chanteperdrix <
> gilles.chanteperdrix@xenomai.org> wrote:
> 
>> Jeff Weber wrote:
>>> On Wed, Mar 23, 2011 at 2:37 AM, Gilles Chanteperdrix <
>>> gilles.chanteperdrix@xenomai.org> wrote:
>>>
>>>> Jeff Weber wrote:
>>>>> I need to timetag events from a realtime context with a
>> NPT-synchronized
>>>>> system clock.  This topic comes up periodically on the mailing list.
>>>>  Last I
>>>>> recall, there was talk of adding the capability via an alternate
>>>>> (non-CLOCK_REALTIME) clock_id. What is the status of this topic?
>>>> The CLOCK_HOST_REALTIME is available in the xenomai-head branch (to be
>>>> 2.6 branch, soon). It requires modifications of the I-pipe patch which
>>>> are available, at least, on x86, but are probably not really hard to
>>>> implement on other platforms.
>>>>
>>>  clock_gettime(CLOCK_HOST_REALTIME) fails when called from kernel, and
>> from
>>> clocktest.  Any ideas why?
>>> Does the CLOCK_HOST_REALTIME need to be initialized in some way?
>>> Test and config follow.

It definitely works here with clocktest. I get, for instance:

# clocktest -C 42 -D
hostrt data area is live
Sequence counter : 66552
wall_time_sec    : 1301523397
wall_time_nsec   : 660000002
wall_to_monotonic
          tv_sec : -1301523264
         tv_nsec : 785932050
cycle_last       : 465912010644
mask             : 0xffffffffffffffff
mult             : 1345300900
shift            : 31

== Tested clock: 42 (CLOCK_HOST_REALTIME)
CPU      ToD offset [us] ToD drift [us/s]      warps max delta [us]
--- -------------------- ---------------- ---------- --------------
  0                  1.2           -0.001          0            0.0
  1                  1.4            0.002          0            0.0
^C


-- 
                                                                Gilles.