This repository contains the software responsible for tracking and controlling the state of different objects within OpenBMC. This currently includes the BMC, Chassis, Host, and Hypervisor. The most critical feature of phosphor-state-manager (PSM) software is its support for requests to power on and off the system by the user.
This software also enforces any restore policy (i.e. auto power on system after a system power event or bmc reset) and ensures its states are updated correctly in situations where the BMC is rebooted and the chassis or host are in on/running states.
This repository also provides a command line tool, obmcutil, which provides basic command line support to query and control phosphor-state-manager applications running within an OpenBMC system. This tool itself runs within an OpenBMC system and utilizes D-Bus APIs. These D-Bus APIs are used for development and debug and are not intended for end users.
As with all OpenBMC applications, interfaces and properties within phosphor-state-manager are D-Bus interfaces. These interfaces are then used by external interface protocols, such as Redfish and IPMI, to report and control state to/by the end user.
phosphor-state-manager makes extensive use of systemd. There is a writeup here with an overview of systemd and its use by OpenBMC.
phosphor-state-manager monitors for systemd targets to complete as a trigger to updating the its corresponding D-Bus property. When using PSM, a user must ensure all generic services installed within the PSM targets complete successfully in order to have PSM properly report states.
phosphor-state-manager follows some basics design guidelines in its implementation and use of systemd:
phosphor-state-manager implements states and state requests as defined in phosphor-dbus-interfaces for each object it supports.
NotReady
when first started
and Ready
once all services within the default.target have executed. It is
Quiesced
when a critical service has entered the failed state. The only
state change request you can make of the BMC is for it to reboot itself.
On
, Off
, or in a fail state. A
BrownOut
state indicates there is not enough chassis power to fully power on
and UninterruptiblePowerSupply
indicates the chassis is running on a UPS.
Off
,
Running
, TransitioningToRunning
, TransitioningToOff
, Quiesced
(error
condition), or in DiagnosticMode
(collecting diagnostic data for a failure)
As noted above, PSM provides a command line tool, obmcutil, which takes a
state
parameter. This will use D-Bus commands to retrieve the above states and
present them to the user. It also provides other commands which will send the
appropriate D-Bus commands to the above properties to power on/off the chassis
and host (see obmcutil --help
within an OpenBMC system).
The above objects also implement other D-Bus objects like power on hours, boot progress, reboot attempts, and operating system status. These D-Bus objects are also defined out in the phosphor-dbus-interfaces repository.
The [RestorePolicy][6] defines the behavior the user wants when the BMC is
reset. If the chassis or host is on/running then this service will not run. If
they are off then the RestorePolicy
will be read and executed by PSM code.
The PowerRestoreDelay
property within the interface defines a maximum time the
service will wait for the BMC to enter the Ready
state before issuing the
power on request, this allows host to be powered on as early as the BMC is
ready.
There is an optional only-allow-boot-when-bmc-ready
feature which can be
enabled within PSM that will not allow chassis or host operations (other then
Off
requests) if the BMC is not in a Ready
state. Care should be taken to
ensure PowerRestoreDelay
is set to a suitable value to ensure the BMC reaches
Ready
before the power restore function requests the power on.
In situations where the BMC is reset and the chassis and host are on and running, its critical that the BMC software do two things:
Note that some of this logic is provided via service files in system-specific meta layers. That is because the logic to determine if the chassis is on or if the host is running can vary from system to system. The requirement to create the files defined below and ensure the common targets go active is a must for anyone wishing to enable this feature.
phosphor-state-manager discovers state vs. trying to cache and save states. This
ensure it's always getting the most accurate state information. It discovers the
chassis state by checking the pgood
value from the power application. If it
determines that power is on then it will do the following:
On
The chassis@0-on file is removed once the obmc-chassis-poweron\@0.target becomes active (i.e. all service have been successfully started which are wanted or required by this target).
The logic to check if the host is on sends a command to the host, and if a response is received then similar logic to chassis is done:
The host@0-on file is removed once the obmc-host-start\@0.target and obmc-host-startmin\@0.target become active (i.e. all service have been successfully started which are wanted or required by these targets).
To build this package, do the following steps:
meson setup build
ninja -C build
To clean the repository again run rm -rf build
.
[2]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/State/BMC.interface.yaml [3]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/State/Chassis.interface.yaml [4]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/State/Host.interface.yaml