Writing Device Drivers


This section uses the following terms:


A generic term used to describe fault manager modules that subscribe to fault.* or list.* events. Agents are used to retire faulty resources, communicate diagnosis results to Administrators, and bridge to higher-level management frameworks.

ASRU (Automated System Reconfiguration Unit)

The ASRU is a resource that can be disabled by software or hardware in order to isolate a problem in the system and suppress further error reports.

DE (Diagnosis Engine)

A fault management module whose purpose is to diagnose problems by subscribing to one or more classes of incoming error events and using these events to solve cases associated with each problem on the system.

ENA (Error Numeric Association)

An Error Numeric Association (ENA) is an encoded integer that uniquely identifies an error report within a given fault region and time period. The ENA also indicates the relationship of the error to previous errors as a secondary effect.


An unexpected condition, result, signal, or datum. An error is the symptom of a problem on the system. Each problem typically produces many different kinds of errors.

ereport (Error Report)

The data captured with a particular error. Error report formats are defined in advance by creating a class naming the error report and defining a schema using the Sun event registry.

ereport event (Error Event)

The data structure that represents an instance of an error report. Error events are represented as name-value pair lists.


Malfunctioning behavior of a hardware component.

Fault Boundary

Logical partition of hardware or software elements for which a specific set of faults can be enumerated.

Fault Event

An instance of a fault diagnosis encoded in the protocol.

Fault Manager

Software component responsible for fault diagnosis via one or more diagnosis engines and state management.

FMRI (Fault Managed Resource Identifier)

An FMRI is a URL-like identifier that acts as the canonical name for a particular resource in the fault management system. Each FMRI includes a scheme that identifies the type of resource, and one or more values that are specific to the scheme. An FMRI can be represented as URL-like string or as a name-value pair list data structure.

FRU (Field Replaceable Unit)

The FRU is a resource that can be replaced in the field by a customer or service provider. FRUs can be defined for hardware (for example system boards) or for software (for example software packages or patches).