Document on : Time Manager in OpenBMC --> Need your review.

Rick Altherr raltherr at
Tue Aug 23 09:44:05 AEST 2016

In the future, please just send the text inline instead of as an attachment.

I don't understand the setting hierarchy.  To me,
/org/openbmc/settings/Host/host0 implies I am modifying something related
to the host CPU, not the BMC.  TimeMode only applies to the BMC so having
it under host0 feels weird.

1. I like the clear separation of NTP vs manual.

2.1. "Both" seems like what we have today which doesn't really work at
all.  I suggest omitting it.  "Split" feels like it should work for all
cases.  If TimeMode is NTP, an offset is recorded.  If TimeMode is Manual,
the BMC time is set.

1. What time zone does SetTime assume?  If UTC, make sure to add tests for
a valid leap second and leap year.
2. I really dislike APIs that change behavior.  Provide separate GetBmcTime
and GetHostTime APIs if you must.
3. SetNTP is a very limiting name.  if this really changes TimeMode, call
it SetTimeMode.  That way we can support things like 1588, GPS, etc later.

Changes to NetworkManager:
- I don't see the point of UseNTP for SetDHCP.  Configuring an NTP address
is different from using NTP as a time source.  It's up to the DHCP server
to provide NTP options.  Whether the BMC uses them is controlled by
- Add a SetNtpServer API instead of adding to SetAddress4.  NTP is entirely
separate from IPv4 address configuration.

On Thu, Aug 18, 2016 at 4:08 AM, vishwa <vishwa at> wrote:

> Team,
> Please help look into this document that describes what I think the
> TimeManager on openBMC systems should look like.
> Please weigh in your thoughts.
> Thanks.
> Vishwanath.
> _______________________________________________
> openbmc mailing list
> openbmc at
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