boot-progress: tracking the boot of a system
Users of OpenBMC systems have a desire to know the overall state when
booting. Some of OpenBMC's bigger systems can take multiple minutes to
boot.
This document summarizes what is in place, what is coming, and how it
all will fit together.
Change-Id: I25dfe25d87d07e4fe49ee2383e441f8a4ea906e9
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
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+# System Boot Progress on OpenBMC
+
+Author: Andrew Geissler (geissonator)
+
+Primary assignee: Andrew Geissler (geissonator)
+
+Other contributors: None
+
+Created: May 27, 2020
+
+## Problem Description
+The boot progress of an OpenBMC managed system is complex. There are a mix
+of phosphor D-Bus properties, IPMI sensors, PLDM sensors, and Redfish
+properties to represent it. The goal of this design document is to highlight
+these different entities and provide a base for system implementors on what
+to implement.
+
+## Background and References
+[phosphor-state-manager][1] implements D-Bus properties which track the state
+of the BMC, Chassis, and Host. This design is primarily focused on the status
+of the Host since it is the most complex. Specifically the goal is to provide
+detailed information on what the host is doing during a boot.
+
+[HostState][2] provides basic `Off`/`Running` type information along
+with an error state (`Quiesced`) and debug state (`DiagnosticMode`). The focus
+of this document is the `Running` state. This simply indicates whether something
+is running on the host processors.
+
+phosphor-state-manager implements some other D-Bus properties that represent
+the host boot progress:
+
+- [xyz.openbmc_project.State.Boot.Progress][3]
+- [xyz.openbmc_project.State.OperatingSystem.Status][4]
+
+These two D-Bus properties are very IPMI-centric. They were defined based on
+two IPMI sensors which are set by the host firmware as it boots the system.
+
+PLDM also has a boot progress sensor. Search for "Boot Progress" in this
+[doc][5]. A subset of this maps fairly well to the IPMI sensors above. This
+PLDM sensor is not implemented yet in OpenBMC code.
+
+Redfish represents system state in a variety of ways. The BMC, Chassis,
+and System all implement a [Status][6] object. This provides a list of generic
+`State` options which are applicable to Redfish objects. OpenBMC has the
+following mapping for phosphor-state-manager to the Redfish System
+[Status][State]:
+- `xyz.openbmc_project.State.Host.HostState.Running` : `Enabled`
+- `xyz.openbmc_project.State.Host.HostState.Quiesced` : `Quiesced`
+- `xyz.openbmc_project.State.Host.HostState.DiagnosticMode` : `InTest`
+
+As of [ComputerSystem.v1_13_0][7], the `BootProgress` object is officially in
+the Redfish ComputerSystem schema.
+
+To summarize, the `LastState` property under this new `BootProgress` object
+tracks the following boot states of the system:
+
+- None
+- PrimaryProcessorInitializationStarted
+- BusInitializationStarted
+- MemoryInitializationStarted
+- SecondaryProcessorInitializationStarted
+- PCIResourceConfigStarted
+- SystemHardwareInitializationComplete
+- OSBootStarted
+- OSRunning
+- OEM
+
+There is also a `LastStateTime` associated with this new BootProgress object
+which should be updated with the date and time the `LastState` was last
+updated.
+
+In the end, the goal is to be able to map either the IPMI or PLDM boot sensors
+into all or some of the values in this new Redfish property.
+
+Note that this design does not include multi-host computer system concepts but
+it also does not preclude them. The `BootProgress` D-Bus property is associated
+with a `/xyz/openbmc_project/state/host<X>` instance where <X> is the host
+instance. Similarly, the Redfish system object is also an instance based
+object.
+
+## Requirements
+- Enhance the existing [BootProgress][3] D-Bus property to cover all supported
+ PLDM boot progress codes
+- Create a new `BootProgressLastUpdate` D-Bus property that will hold the
+ date and time of the last update to `BootProgress`
+- Ensure the `BootProgress` and `BootProgressLastUpdate` properties are updated
+ appropriately in both IPMI and PLDM based stacks
+ - It is the responsibility of the IPMI or PLDM implementation to update
+ the `BootProgress` property on D-Bus
+ - It is the responsiblity the phosphor-state-manager to update the
+ `BootProgressLastUpdate` property on D-Bus when it sees `BootProgress`
+ updated
+- Ensure the new Redfish `LastState` and `LastStateTime` properties
+ have the appropriate mappings to the `BootProgress` and
+ `BootProgressLastUpdate D-Bus properties
+
+Different OpenBMC systems could support different boot progress codes, and
+support them in different orders. This document does not try to set any
+requirements on this other than that they must all be defined within
+the `BootProgress` D-Bus property and the ones which have a mapping
+to the Redfish BootProgress object will be shown via the Redfish interface.
+
+## Proposed Design
+[BootProgress][3] will be enhanced to support a superset of what is provided
+by IPMI and PLDM.
+
+IPMI code already sets the `BootProgress` D-Bus property based on a config
+file. Look for `fw_boot_sensor` in this [file][8] for an example of how a
+particular IPMI sensor is mapped to this D-Bus property.
+
+PLDM software will do something similar.
+
+bmcweb will then use this `BootProgress` D-Bus interface to respond
+appropriately to Redfish requests.
+
+## Alternatives Considered
+A lot of system BIOS's provided some form of a detailed boot progress codes.
+UEFI has POST codes, POWER has istep progress codes. If more fine grained
+details were needed, we could look into using these. Currently though the
+need is just high level boot progress. Note that these POST/istep codes
+could be mapped to the appropriate BootProgress value if desired (or for
+cases where the host does not support an IPMI or PLDM stack that has
+BootProgress in it).
+
+## Impacts
+Each system will need to document which `BootProgress` codes they support
+and the expected order of them when a system is booting.
+
+## Testing
+Ensure an IPMI and PLDM based system boot and update the `BootProgress` D-Bus
+property as expected.
+
+
+[1]: https://github.com/openbmc/phosphor-state-manager#state-tracking-and-control
+[2]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/State/Host.interface.yaml
+[3]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/State/Boot/Progress.interface.yaml
+[4]: https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/xyz/openbmc_project/State/OperatingSystem/Status.interface.yaml
+[5]: https://www.dmtf.org/sites/default/files/standards/documents/DSP0249_1.0.0.pdf
+[6]: http://redfish.dmtf.org/schemas/v1/Resource.json#/definitions/Status
+[7]: https://redfish.dmtf.org/schemas/v1/ComputerSystem.v1_13_0.json
+[8]: https://github.com/openbmc/meta-ibm/blob/master/recipes-phosphor/configuration/acx22-yaml-config/acx22-ipmi-sensors-mrw.yaml