phosphor-time-manager is the time manager service that implements dbus
interface xyz/openbmc_project/Time/EpochTime.interface.yaml.
User can get or set the BMC's or HOST's time via this interface.
The service xyz.openbmc_project.Time.Manager provides two objects on dbus:
- /xyz/openbmc_project/time/bmc
- /xyz/openbmc_project/time/host
where each object implements interface xyz.openbmc_project.Time.EpochTime.
User can directly get or set the property Elasped of the objects to get or set
the time. For example on an authenticated session:
- To get BMC's time:
### With busctl on BMC busctl get-property xyz.openbmc_project.Time.Manager \ /xyz/openbmc_project/time/bmc xyz.openbmc_project.Time.EpochTime Elapsed ### With REST API on remote host curl -b cjar -k https://bmc-ip/xyz/openbmc_project/time/bmc - To set HOST's time:
### With busctl on BMC busctl set-property xyz.openbmc_project.Time.Manager \ /xyz/openbmc_project/time/host xyz.openbmc_project.Time.EpochTime \ Elapsed t <value-in-microseconds> ### With REST API on remote host curl -b cjar -k -H "Content-Type: application/json" -X PUT \ -d '{"data": 1487304700000000}' \ https://bmc-ip/xyz/openbmc_project/time/host/attr/Elapsed
Getting BMC or HOST time is always allowed, but setting the time may not be allowed depending on below two settings in settings manager.
- TimeSyncMethod
- NTP: Time is set via NTP server.
- MANUAL: Time is set manually.
- TimeOwner
- BMC: BMC owns the time and can set the time.
- HOST: Host owns the time and can set the time.
- SPLIT: BMC and Host owns separate time.
- BOTH: Both BMC and Host can set the time.
A summary of which cases the time can be set on BMC or HOST:
| Mode | Owner | Set BMC Time | Set Host Time |
|---|---|---|---|
| NTP | BMC | Fail to set | Not allowed |
| NTP | HOST | Not allowed | Not allowed |
| NTP | SPLIT | Fail to set | OK |
| NTP | BOTH | Fail to set | Not allowed |
| MANUAL | BMC | OK | Not allowed |
| MANUAL | HOST | Not allowed | OK |
| MANUAL | SPLIT | OK | OK |
| MANUAL | BOTH | OK | OK |
When host is on, the changes of the above time mode/owner are not applied but deferred. The changes of the mode/owner are saved to persistent storage.
When host is off, the saved mode/owner are read from persistent storage and are applied.
Note: user can set the time mode and owner in settings daemon at any time, but time manager applying them is governed by the above condition.