openpower-pels/registry/README.md

# Platform Event Log Message Registry
On the BMC, PELs are created from the standard event logs provided by
phosphor-logging using a message registry that provides the PEL related fields.
The message registry is a JSON file.

## Contents
* [Component IDs](#component-ids)
* [Message Registry](#message-registry-fields)
* [Modifying and Testing](#modifying-and-testing)

## Component IDs
A component ID is a 2 byte value of the form 0xYY00 used in a PEL to:
1. Provide the upper byte (the YY from above) of an SRC reason code in `BD`
   SRCs.
2. Reside in the section header of the Private Header PEL section to specify
   the error log creator's component ID.
3. Reside in the section header of the User Header section to specify the error
   log committer's component ID.
4. Reside in the section header in the User Data section to specify which
   parser to call to parse that section.

Component IDs are specified in the message registry either as the upper byte of
the SRC reason code field for `BD` SRCs, or in the standalone `ComponentID`
field.

Component IDs will be unique on a per-repository basis for errors unique to
that repository.  When the same errors are created by multiple repositories,
those errors will all share the same component ID.  The master list of
component IDs is [here](O_component_ids.json).  That file can used by PEL
parsers to display a name for the component ID.  The 'O' in the name is the
creator ID value for BMC created PELs.

## Message Registry Fields
The message registry schema is [here](schema/schema.json), and the message
registry itself is [here](message_registry.json).  The schema will be validated
either during a bitbake build or during CI, or eventually possibly both.

In the message registry, there are fields for specifying:

### Name
This is the key into the message registry, and is the Message property
of the OpenBMC event log that the PEL is being created from.

```
"Name": "xyz.openbmc_project.Power.Fault"
```

### Subsystem
This field is part of the PEL User Header section, and is used to specify
the subsystem pertaining to the error.  It is an enumeration that maps to the
actual PEL value.  If the subsystem isn't known ahead of time, it can be passed
in at the time of PEL creation using the 'PEL\_SUBSYSTEM' AdditionalData field.
In this case, 'Subsystem' isn't required, though 'PossibleSubsystems' is.

```
"Subsystem": "power_supply"
```

### PossibleSubsystems
This field is used by scripts that build documentation from the message
registry to know which subsystems are possible for an error when it can't be
hardcoded using the 'Subsystem' field.  It is mutually exclusive with the
'Subsystem' field.

```
"PossibleSubsystems": ["memory", "processor"]
```

### Severity
This field is part of the PEL User Header section, and is used to specify
the PEL severity.  It is an optional field, if it isn't specified, then the
severity of the OpenBMC event log will be converted into a PEL severity value.

It can either be the plain severity value, or an array of severity values that
are based on system type, where an entry without a system type will match
anything unless another entry has a matching system type.

```
"Severity": "unrecoverable"
```

```
Severity":
[
    {
        "System": "system1",
        "SevValue": "recovered"
    },
    {
        "Severity": "unrecoverable"
    }
]
```
The above example shows that on system 'system1' the severity will be
recovered, and on every other system it will be unrecoverable.

### Mfg Severity
This is an optional field and is used to override the Severity field when a
specific manufacturing isolation mode is enabled.  It has the same format as
Severity.

```
"MfgSeverity": "unrecoverable"
```

### Event Scope
This field is part of the PEL User Header section, and is used to specify
the event scope, as defined by the PEL spec.  It is optional and defaults to
"entire platform".

```
"EventScope": "entire_platform"
```

### Event Type
This field is part of the PEL User Header section, and is used to specify
the event type, as defined by the PEL spec.  It is optional and defaults to
"not applicable" for non-informational logs, and "misc_information_only" for
informational ones.

```
"EventType": "na"
```

### Action Flags
This field is part of the PEL User Header section, and is used to specify the
PEL action flags, as defined by the PEL spec.  It is an array of enumerations.

The action flags can usually be deduced from other PEL fields, such as the
severity or if there are any callouts.  As such, this is an optional field and
if not supplied the code will fill them in based on those fields.

In fact, even if supplied here, the code may still modify them to ensure they
are correct.  The rules used for this are
[here](../README.md#action-flags-and-event-type-rules).

```
"ActionFlags": ["service_action", "report", "call_home"]
```

### Mfg Action Flags
This is an optional field and is used to override the Action Flags field when a
specific manufacturing isolation mode is enabled.

```
"MfgActionFlags": ["service_action", "report", "call_home"]
```

### Component ID
This is the component ID of the PEL creator, in the form 0xYY00.  For `BD`
SRCs, this is an optional field and if not present the value will be taken from
the upper byte of the reason code.  If present for `BD` SRCs, then this byte
must match the upper byte of the reason code.

```
"ComponentID": "0x5500"
```

### SRC Type
This specifies the type of SRC to create.  The type is the first 2 characters
of the 8 character ASCII string field of the PEL.  The allowed types are `BD`,
for the standard OpenBMC error, and `11`, for power related errors.  It is
optional and if not specified will default to `BD`.

Note: The ASCII string for BD SRCs looks like: `BDBBCCCC`, where:
* BD = SRC type
* BB = PEL subsystem as mentioned above
* CCCC SRC reason code

For `11` SRCs, it looks like: `1100RRRR`, where RRRR is the SRC reason code.

```
"Type": "11"
```

### SRC Reason Code
This is the 4 character value in the latter half of the SRC ASCII string.  It
is treated as a 2 byte hex value, such as 0x5678.  For `BD` SRCs, the first
byte is the same as the first byte of the component ID field in the Private
Header section that represents the creator's component ID.

```
"ReasonCode": "0x5544"
```

### SRC Symptom ID Fields
The symptom ID is in the Extended User Header section and is defined in the PEL
spec as the unique event signature string.  It always starts with the ASCII
string.  This field in the message registry allows one to choose which SRC words
to use in addition to the ASCII string field to form the symptom ID. All words
are separated by underscores.  If not specified, the code will choose a default
format, which may depend on the SRC type.

For example: ["SRCWord3", "SRCWord9"] would be:
`<ASCII_STRING>_<SRCWord3>_<SRCWord9>`, which could look like:
`B181320_00000050_49000000`.

```
"SymptomIDFields": ["SRCWord3", "SRCWord9"]
```

### SRC words 6 to 9
In a PEL, these SRC words are free format and can be filled in by the user as
desired.  On the BMC, the source of these words is the AdditionalData fields in
the event log.  The message registry provides a way for the log creator to
specify which AdditionalData property field to get the data from, and also to
define what the SRC word means for use by parsers.  If not specified, these SRC
words will be set to zero in the PEL.

```
"Words6to9":
{
    "6":
    {
        "description": "Failing unit number",
        "AdditionalDataPropSource": "PS_NUM"
    }
}
```

### Documentation Fields
The documentation fields are used by PEL parsers to display a human readable
description of a PEL.  They are also the source for the Redfish event log
messages.

#### Message
This field is used by the BMC's PEL parser as the description of the error log.
It will also be used in Redfish event logs.  It supports argument substitution
using the %1, %2, etc placeholders allowing any of the SRC user data words 6 -
9 to be displayed as part of the message.  If the placeholders are used, then
the `MessageArgSources` property must be present to say which SRC words to use
for each placeholder.

```
"Message": "Processor %1 had %2 errors"
```

#### MessageArgSources
This optional field is required when the Message field contains the %X
placeholder arguments. It is an array that says which SRC words to get the
placeholders from.  In the example below, SRC word 6 would be used for %1, and
SRC word 7 for %2.

```
"MessageArgSources":
[
    "SRCWord6", "SRCWord7"
]
```

#### Description
A short description of the error.  This is required by the Redfish schema to generate a Redfish message entry, but is not used in Redfish or PEL output.

```
"Description": "A power fault"
```

#### Notes
This is an optional free format text field for keeping any notes for the
registry entry, as comments are not allowed in JSON.  It is an array of strings
for easier readability of long fields.

```
"Notes": [
    "This entry is for every type of power fault.",
    "There is probably a hardware failure."
]
```

### Callout Fields
The callout fields allow one to specify the PEL callouts (either a hardware
FRU, a symbolic FRU, or a maintenance procedure) in the entry for a particular
error.  These callouts can vary based on system type, as well as a user
specified AdditionalData property field.   Callouts will be added to the PEL in
the order they are listed in the JSON.  If a callout is passed into the error,
say with CALLOUT_INVENTORY_PATH, then that callout will be added to the PEL
before the callouts in the registry.

There is room for up to 10 callouts in a PEL.

#### Callouts example based on the system type

```
"Callouts":
[
    {
        "System": "system1",
        "CalloutList":
        [
            {
                "Priority": "high",
                "LocCode": "P1-C1"
            },
            {
                "Priority": "low",
                "LocCode": "P1"
            }
        ]
    },
    {
        "CalloutList":
        [
            {
                "Priority": "high",
                "Procedure": "SVCDOCS"
            }
        ]

    }
]

```

The above example shows that on system 'system1', the FRU at location P1-C1
will be called out with a priority of high, and the FRU at P1 with a priority
of low.  On every other system, the maintenance procedure SVCDOCS is called
out.

#### Callouts example based on an AdditionalData field

```
"CalloutsUsingAD":
{
    "ADName": "PROC_NUM",
    "CalloutsWithTheirADValues":
    [
        {
            "ADValue": "0",
            "Callouts":
            [
                {
                    "CalloutList":
                    [
                        {
                            "Priority": "high",
                            "LocCode": "P1-C5"
                        }
                    ]
                }
            ]
        },
        {
            "ADValue": "1",
            "Callouts":
            [
                {
                    "CalloutList":
                    [
                        {
                            "Priority": "high",
                            "LocCode": "P1-C6"
                        }
                    ]
                }
            ]
        }
    ]
}

```

This example shows that the callouts were selected based on the 'PROC_NUM'
AdditionalData field.  When PROC_NUM was 0, the FRU at P1-C5 was called out.
When it was 1, P1-C6 was called out.  Note that the same 'Callouts' array is
used as in the previous example, so these callouts can also depend on the
system type.

#### CalloutType
This field can be used to modify the failing component type field in the
callout when the default doesn\'t fit:

```
{

    "Priority": "high",
    "Procedure": "FIXIT22"
    "CalloutType": "config_procedure"
}
```

The defaults are:
- Normal hardware FRU: hardware_fru
- Symbolic FRU: symbolic_fru
- Procedure: maint_procedure

#### Symbolic FRU callouts with dynamic trusted location codes

A special case is when one wants to use a symbolic FRU callout with a trusted
location code, but the location code to use isn\'t known until runtime. This
means it can\'t be specified using the 'LocCode' key in the registry.

In this case, one should use the 'SymbolicFRUTrusted' key along with the
'UseInventoryLocCode' key, and then pass in the inventory item that has the
desired location code using the 'CALLOUT_INVENTORY_PATH' entry inside of the
AdditionalData property.  The code will then look up the location code for that
passed in inventory FRU and place it in the symbolic FRU callout.  The normal
FRU callout with that inventory item will not be created.  The symbolic FRU
must be the first callout in the registry for this to work.

```
{

    "Priority": "high",
    "SymbolicFRUTrusted": "AIR_MOVR",
    "UseInventoryLocCode": true
}
```

## Modifying and Testing

The general process for adding new entries to the message registry is:

1. Update message_registry.json to add the new errors.
2. If a new component ID is used (usually the first byte of the SRC reason
   code), document it in O_component_ids.json.
3. Validate the file. It must be valid JSON and obey the schema.  The
   `process_registry.py` script in `extensions/openpower-pels/registry/tools`
   will validate both, though it requires the python-jsonschema package to do
   the schema validation.  This script is also run to validate the message
   registry as part of CI testing.

```
 ./tools/process_registry.py -v -s schema/schema.json -r message_registry.json
```

4. One can test what PELs are generated from these new entries without writing
   any code to create the corresponding event logs:
    1. Copy the modified message_registry.json into `/etc/phosphor-logging/` on
       the BMC. That directory may need to be created.
    2. Use busctl to call the Create method to create an event log
       corresponding to the message registry entry under test.

```
busctl call xyz.openbmc_project.Logging /xyz/openbmc_project/logging \
xyz.openbmc_project.Logging.Create Create ssa{ss} \
xyz.openbmc_project.Common.Error.Timeout \
xyz.openbmc_project.Logging.Entry.Level.Error 1 "TIMEOUT_IN_MSEC" "5"
```

    3. Check the PEL that was created using peltool.
    4. When finished, delete the file from `/etc/phosphor-logging/`.