ConnectX-6 Dx Zephyr Ethernet Driver

ISO 26262 Compliance Toolkit

Achieving Zero MISRA C:2023 Violations

From Scan → to Certification

Parasoft C/C++test Amp AI Fixing PyQt6 Dashboard MC/DC Coverage ISO 26262

Swipe or use arrows to navigate →

The Three-Phase Workflow

🔍 PHASE 1: SCAN

Parasoft scans all source
against MISRA C:2023
Output: XML violation report

→

⚖️ PHASE 2: TRIAGE

Classify each violation:
Fix · Deviate · Suppress
Amp AI generates fixes

→

✅ PHASE 3: VERIFY

Re-scan confirms zero violations
Generate GCS + GRP docs
MC/DC coverage ≥ 80%

♻️ Iterate until: 0 Driver Violations + All Deviations Documented + Coverage Met

Phase 1 — Scanning

Step 1: Generate BDF

cpptesttrace west build \
  -b native_sim /path/to/driver \
  -- -DCONFIG_ETH_CX6_DX=y \
     -DUSE_CCACHE=0

Step 2: MISRA Scan

cpptestcli \
  -config "builtin://MISRA C 2023 \
    (MISRA C 2012)" \
  -bdf cx6_build.bdf \
  -resource cx6_driver \
  -compiler gcc_13-64

⚠️ Critical: ccache Interference

Zephyr's ccache.cmake wraps compiler calls, corrupting the BDF. Fix: always pass -DUSE_CCACHE=0.

BAD: ccache /usr/bin/gcc -DCONFIG... → "invalid option"

FIX: west build ... -- -DUSE_CCACHE=0

Source Classification

🟢 Driver

HIGH

Must reach zero violations

🟣 RTOS

LOW

Zephyr framework — not our scope

⚪ Build

Info

Excluded from metrics

Phase 2 — The Dashboard

10-tab PyQt6 application (5,591 lines) for complete MISRA compliance management:

📊

Overview

Violation trends

🔍

Violations

Filterable table

📋

Deviations

Formal permits

✅

Compliance

GCS / GRP docs

🚫

Suppressions

False positives

📝

Diff

Change tracking

🧪

Unit Tests

JUnit XML

📈

Coverage

LC/SC/DC/MC-DC

💻

Terminal

Amp AI prompts

⚙️

Settings

Tool config

Key Features

Stacked Bar Charts

■ Driver bright segments, ▤ RTOS dimmed with purple stripes. Delta indicators show scan-to-scan improvement.

Source-Aware Filtering

Filter by All, Driver, or RTOS. Subsystem dropdowns dynamically update (cx6_pcie, kernel, net/ip, etc.).

Fixing with Amp AI

🤖 How It Works

Research the MISRA rule via CandleKeep skill (looks up rule text in the standard)
Read the violating file and understand context
Apply a minimal fix following coding conventions
Verify the fix compiles with Zephyr build

✅ Required Patterns

/* goto-cleanup single return */
int32_t func(args) {
    int32_t ret = 0;
    if (error) {
        ret = -EINVAL;
        goto out;
    }
out:
    return ret;
}

❌ Prohibited

/* Multiple returns */
if (x) return -1;

/* Dynamic allocation */
buf = malloc(size);

/* Bare types */
int count;
unsigned len;

Example Prompt

Use candlekeep to research MISRA C:2023 Rule 10.3.
Fix violation in cx6_device.c line 148: "Value assigned to narrower essential type"
Constraints: goto-cleanup, fixed-width types, no malloc, verify with west build.

Formal Deviations

ISO 26262 allows deviations with documented safety rationale for unavoidable patterns.

7 Zephyr-Specific Categories

Code	Category	Used For
HWI	Hardware Interface	MMIO pointer-integer casts
ZAP	Zephyr API Pattern	CONTAINER_OF, K_WORK_INIT
PER	Performance	Data-path function-like macros
CEX	Compiler Extension	GCC __attribute__ (aligned, section)
ESM	Equiv. Safety Measure	Alternative safety mechanisms
DRV	Driver Architecture	Static single-device instance
DBG	Debug Only	LOG_* stdio-like formatting

Pre-Populated Deviations

Rule	Cat	Justification
11.4	HWI	MMIO register access requires pointer-integer casts
11.3	ZAP	Zephyr CONTAINER_OF() uses pointer-to-struct casts
20.7	ZAP	Zephyr macros don't parenthesise all parameters
Dir 4.9	PER	Data-path helpers use function-like macros
21.6	DBG	Zephyr LOG_* uses stdio internally

Phase 3 — Verification

📋 GCS

Guidelines Compliance Summary — per-rule status:

Compliant — no violations
Deviated — formal permit filed
N/A — rule doesn't apply

📑 GRP

Guidelines Re-categorization Plan — re-classify Advisory rules:

Promote to Required based on risk
Disapply with documented justification

Coverage Requirements (ISO 26262 Table 12)

ASIL	Method	Target
ASIL A	Statement Coverage	≥ 80%
ASIL B	Branch / Decision Coverage	≥ 80%
ASIL C	MC/DC	≥ 80%
ASIL D	MC/DC	≥ 80%

58 Unit Tests × 5 Modules

cx6_pcie · cx6_device · cx6_queue · cx6_interrupt · cx6_eth — with fake MMIO stubs for host testing and gcov / cpptestct coverage collection.

Path to Zero Violations

🔧

Fix

Code change resolves the violation

📋

Deviate

Formal permit with safety rationale

🚫

Suppress

False positive — tool limitation

Violation Burndown

110

Scan 1

Scan 2

Scan 3

Scan 4

Scan 5

Final ✅

🎯 Target: Zero Driver Violations

All flags documented · Coverage targets met · GCS/GRP generated

Setup & Quick Start

Prerequisites

Python 3.10+ with PyQt6
Parasoft C/C++test (Standard or Pro)
Zephyr SDK 0.16.8+ with west
GCC 13 for host testing
Driver project built at least once

Launch

pip install PyQt6

cd dashboard
python cx6_misra_dashboard.py

# First-time:
# Settings → Project Dir
# Settings → cpptestcli path
# Settings → ZEPHYR_BASE
# Overview → ▶ Run Scan

Project Structure

File	Purpose
`dashboard/cx6_misra_dashboard.py`	Main app — 5,591 lines, 10 tabs, dark theme
`dashboard/misra_rule_data.py`	MISRA rules, severities, fix strategies
`dashboard/app_logo.png`	ConnectX-6 Dx / NVIDIA logo
`misra_compliance/config/`	Settings + MISRA overlay Kconfig
`misra_compliance/deviations/`	Formal deviation database (JSON)
`misra_compliance/reports/`	Parasoft XML scan results (auto)
`misra_compliance/sessions/`	Session persistence (auto)

Summary

5,591

Lines of Dashboard Code

Dashboard Tabs

110

Violations Found (Scan 1)

Deviation Categories

Unit Tests

80%

MC/DC Coverage Target

Scan → Triage → Fix → Verify → Repeat

A complete, auditable workflow for achieving
Zero MISRA C:2023 Violations
on the ConnectX-6 Dx Zephyr Ethernet driver.

ISO 26262 Compliance Toolkit — March 2026
Designed for automotive safety engineers and ISO 26262 auditors.