Introduction

phosphor-time-manager is the time manager service that implements D-Bus interface xyz/openbmc_project/Time/EpochTime.interface.yaml. The user can get or set the BMC's time via this interface.

Configuration

phosphor-time-manager is configured by setting -D flags that correspond to options in phosphor-time-manager/meson.options. The option names become C++ preprocessor symbols that control which code is compiled into the program.

• Compile phosphor-time-manager with default options:

     meson setup builddir
     ninja -C builddir

• Compile phosphor-time-manager with some configurable options:

     meson setup builddir -Dbuildtype=minsize  -Dtests=disabled
     ninja -C builddir

• Generate test coverage report:

     meson setup builddir -Db_coverage=true -Dtests=enabled
     ninja coverage -C builddir test

General usage

The service xyz.openbmc_project.Time.Manager provides an object on D-Bus:

• /xyz/openbmc_project/time/bmc

where each object implements interface xyz.openbmc_project.Time.EpochTime.

The user can directly get or set the property Elapsed 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 BMC's time:

  ### With busctl on BMC
  busctl set-property xyz.openbmc_project.Time.Manager \
      /xyz/openbmc_project/time/bmc 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/bmc/attr/Elapsed

Time settings

Getting BMC time is always allowed, but setting the time may not be allowed depending on the below two settings in the settings manager.

• TimeSyncMethod
  • NTP: The time is set via NTP server.
  • MANUAL: The time is set manually.

A summary of which cases the time can be set on BMC or HOST:

Mode	Set BMC Time
NTP	Fail to set
MANUAL	OK

• To set an NTP server:

  ### With busctl on BMC
  busctl set-property  xyz.openbmc_project.Network \
     /xyz/openbmc_project/network/eth0 \
     xyz.openbmc_project.Network.EthernetInterface NTPServers \
     as 1 "<ntp_server>"
  
  ### With REST API on remote host
  curl -c cjar -b cjar -k -H "Content-Type: application/json" -X  PUT  -d \
      '{"data": ["<ntp_server>"] }' \
      https://${BMC_IP}/xyz/openbmc_project/network/eth0/attr/NTPServers

• To go into NTP mode

  ### With busctl on BMC
  busctl set-property xyz.openbmc_project.Settings \
      /xyz/openbmc_project/time/sync_method xyz.openbmc_project.Time.Synchronization \
      TimeSyncMethod s "xyz.openbmc_project.Time.Synchronization.Method.NTP"
  
  ### With REST API on remote host
  curl -c cjar -b cjar -k -H "Content-Type: application/json" -X  PUT  -d \
      '{"data": "xyz.openbmc_project.Time.Synchronization.Method.NTP" }' \
      https://${BMC_IP}/xyz/openbmc_project/time/sync_method/attr/TimeSyncMethod

Special note on changing NTP setting

Starting from OpenBMC 2.6 (with systemd v239), systemd's timedated introduces a new beahvior that it checks the NTP services' status during setting time, instead of checking the NTP setting:

• When NTP server is set to disabled, and the NTP service is stopping but not stopped, setting time will get an error.

In OpenBMC 2.4 (with systemd v236), the above will always succeed.

This results in openbmc/openbmc#3459, and the related test cases are updated to cooperate with this behavior change.