namespace apext::phm

The namespace apext::phm provides in the Platform Health Management module of the AUTOSAR Adaptive Platform (release R25-11) with WatchdogInterface a platform-specific extension for connecting physical hardware watchdogs. The interface serves for the cyclic transmission of trigger signals following successful internal system supervision. If the periodic signals fail to appear as a result of faults, this interpretationally leads to the triggering of the hardware watchdog and a controlled system reset. An essential constraint is the classification as PlatformExtension, whereby hardware-level details remain outside the standardized application core.

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Context

The namespace apext::phm provides platform-level extensions for the module Platform Health Management (phm) within the AUTOSAR Adaptive Platform in release R25-11. The central component of this namespace is class WatchdogInterface, which functions as an interface for physical hardware supervision (hardware watchdog). While standard interfaces of the platform primarily address the logical supervision of applications and processes, WatchdogInterface forms the link to the underlying hardware level. According to the specification notes, WatchdogInterface is syntactically and semantically identifiable in code as an interface, but is architecturally explicitly classified as PlatformExtension. Interpretation: This extension is likely intended to connect hardware-level watchdog drivers or board support packages to the standardized health management without burdening the vendor-independent interfaces of the core module with hardware-dependent details. Question Q-96fc2d8f01697e24 (open)

Lifecycle

The lifecycle of the components defined in namespace apext::phm is tightly coupled to the supervision phases of the platform. Interpretation: An instance of WatchdogInterface is typically expected to be created and initialized during the early startup phase of the Platform Health Management daemon. Question (open) During regular operation, the interface remains permanently active to forward cyclic trigger signals to the hardware watchdog. Destruction or release of the interface occurs only during a controlled shutdown of the platform or when deactivating the watchdog functionality. Because hardware-level watchdogs usually specify strict time windows for alive indications, interaction with WatchdogInterface is likely subject to deterministic execution and must withstand concurrent accesses from different supervision contexts.

Usage Path

The typical usage path of WatchdogInterface comprises the provisioning, configuration, and periodic servicing of the hardware watchdog interface by Platform Health Management:

• Initialization: The supervision system instantiates or binds the concrete implementation of WatchdogInterface, configuring time intervals and threshold values for physical supervision.
• Cyclic confirmation: After successful evaluation of internal logical supervision rules (such as alive, deadline, or logical supervision), the alive indication is dispatched to the hardware watchdog device via WatchdogInterface.
• Reaction control: If internal checks remain negative or the system reports critical error states, actuation of the hardware watchdog is deliberately omitted, or a deterministic error signal is transmitted.

Error Scenarios

Error scenarios around apext::phm primarily concern the loss of hardware connectivity or missing critical time bounds. If communication via WatchdogInterface with the hardware fails or the watchdog device stops responding, Platform Health Management can no longer guarantee physical protection of the platform. Interpretation: A failure of the cyclic trigger signal to the hardware watchdog is likely to lead deterministically to the expiration of the hardware timer and thus to a hardware reset or a safe system state of the ECU. Question Q-615f4c11f7da15fd (open) Preconditions for calls to WatchdogInterface include a successfully initialized hardware driver, whereas postconditions require confirmed signal delivery within the defined time tolerance window.