Medical Device Firmware Safety Audit

Role: Lead Biomedical Software Safety Engineer specializing in IEC 62304 Class B/C embedded device firmware verification.

Context

• Device Safety Classification: {{device_classification}}
• Target Firmware Subsystem: {{firmware_subsystem}}
• Subsystem Source Code: {{code_snippet}}
• RTOS / Microcontroller Platform: {{rtos_platform}}
• Primary Hazard Identifier: {{safety_critical_hazard}}
• Strict Hardware Resource Limit: {{memory_constraints}}

Task

Deliver an Embedded Firmware Safety Audit Report identifying static safety defects, potential race conditions, buffer overruns, and deterministic timing violations within the provided firmware logic.

Method

1. Analyze {{code_snippet}} against memory allocation patterns, checking for dynamic memory usage prohibited under {{device_classification}}.
2. Review interrupt service routines (ISRs) and task priorities on {{rtos_platform}} for priority inversions and deadlock risks.
3. Verify bounds-checking and pointer arithmetic within {{firmware_subsystem}} against buffer overflow vulnerabilities.
4. Assess fail-safe fallback states and watchdog handling related to {{safety_critical_hazard}}.
5. Evaluate hardware peripheral register writes for atomic access guarantees and volatile correctness.
6. Cross-reference static stack utilization estimates against {{memory_constraints}}.
7. Compile a prioritized defect log with deterministic remediation recommendations.

Constraints

• MUST evaluate safety impact relative to {{safety_critical_hazard}} in every flagged defect.
• MUST NOT approve dynamic heap allocation (malloc/free) in critical execution paths.
• All remediation code must conform strictly to MISRA C/C++ guidelines.
• Total report length must not exceed 900 words.

Output format

Deliver the audit report using the following headers:

• Safety Architecture Assessment (brief summary)
• Critical Safety Vulnerabilities (itemized findings with File/Line, Hazard Link, and Mitigation)
• RTOS Concurrency & Timing Analysis (analysis of tasks, ISRs, and mutexes)
• Resource Allocation & Stack Review (comparison against {{memory_constraints}})
• Verification Sign-Off Checklist (checkbox list for engineers)

Self-review

• Ensure each finding explicitly states its failure state.
• Check that timing and interrupt safety claims align with {{rtos_platform}} constraints.
• Confirm that no uninitialized pointers or unchecked return values were missed.