// FreeRTOS · ISO 14229 UDS

ISO 14229 UDS diagnostics
on FreeRTOS.

A complete, YAML-configured UDS stack that generates production C source for FreeRTOS. Same codegen engine as the Zephyr variant — switch platforms by changing one config flag. Covers all 17 UDS services, CAN ISO-TP and DoIP transports, and ASIL-B safety wrappers. GPL v2 runtime is free on GitHub.

View on GitHub → Get Developer license →

// FreeRTOS integration

One YAML, two RTOS targets.

EDS ships a clean platform abstraction layer. The same diagnostics_config.yaml generates a Zephyr build and a FreeRTOS build without modification. Switch targets by selecting the platform in codegen.

diagnostics_config.yaml (same for both RTOS targets)

ecu:
  name: Sensor_MCU
  platform: freertos        # or: zephyr
  addressing:
    can_id_request:  0x640
    can_id_response: 0x641

sessions:
  - default
  - extended

services:
  - id: 0x22   # ReadDataByIdentifier
  - id: 0x2E   # WriteDataByIdentifier
  - id: 0x27   # SecurityAccess
  - id: 0x19   # ReadDTCInformation
  - id: 0x14   # ClearDiagnosticInformation
  - id: 0x3E   # TesterPresent

dids:
  - id: 0xF190
    name: VIN
    length: 17
    read_sessions: [default, extended]
  - id: 0xD001
    name: Temperature_Raw
    length: 4
    read_sessions: [default, extended]

Generated FreeRTOS output

python3 tools/codegen.py \
  --config diagnostics_config.yaml \
  --platform freertos \
  --out build/ \
  --safety-wrappers \
  --asil-level B

build/
  uds_server.c/.h      # UDS dispatcher + FreeRTOS task
  uds_dids.c/.h        # DID handlers (no RTOS API)
  uds_dtcs.c/.h        # DTC storage (flash-backed)
  uds_sessions.c/.h    # session state machine
  uds_security.c/.h    # AES-128-CMAC SecurityAccess
  uds_safety.c/.h      # ASIL-B 5-step validation chain
  uds_platform_freertos.c  # FreeRTOS task + queue glue
  test_uds.py          # pytest suite

FreeRTOS task init

/* In your application startup */
#include "uds_server.h"

/* EDS creates its own task internally */
eds_init(&eds_config);

/* CAN receive hook — call from your ISR or CAN task */
void can_rx_callback(uint8_t *frame, size_t len) {
    eds_isotp_rx(frame, len);
}

FreeRTOS platform layer — what it does.

The FreeRTOS platform layer maps EDS threading primitives to FreeRTOS equivalents. No global state. No polling loop. A single UDS task owns the ISO-TP reassembly buffer and calls into the generated handlers.

UDS task — xTaskCreate with configurable stack size and priority
ISO-TP framing — xQueueReceive from CAN RX, internal reassembly FSM
Timing — P2 / P2* timers using xTimerCreate
NVM — pluggable flash backend for DTC persistence (SPI flash, internal flash)
SecurityAccess — AES-128-CMAC using mbedTLS or a bare-metal implementation
Tested on — STM32 (HAL + FreeRTOS), NXP LPC, ESP-IDF (FreeRTOS), bare-metal ARM Cortex-M

// example ECUs

FreeRTOS example ECUs included.

The Developer and Professional tiers include specialist examples. Three ship specifically for FreeRTOS targets.

basic_freertos — minimal FreeRTOS UDS ECU: session, TesterPresent, one DID. Starting point for new projects
sensor_freertos — sensor ECU with temperature/pressure DIDs, DTC storage on internal flash, FreeRTOS + CAN ISO-TP
safeboot_freertos — MCUboot + FreeRTOS UDS DFU: RequestDownload → TransferData → RequestTransferExit → ECUReset flow

sensor_freertos example layout

examples/sensor_freertos/
  diagnostics_config.yaml  # ECU description
  src/
    main.c                 # FreeRTOS init + eds_init()
    can_driver.c           # board-specific CAN RX/TX
    flash_backend.c        # NVM adapter for DTC storage
  build/
    uds_server.c/.h        # generated — do not edit
    uds_dids.c/.h
    uds_dtcs.c/.h
    uds_safety.c/.h
    uds_platform_freertos.c

// pricing

Three tiers. Annual license. Offline after activation.

Community

Free

GPL v2 · always free · GitHub

Full runtime source — core/, transport/, config/, platform/
CAN ISO-TP + DoIP transports
Zephyr + FreeRTOS platform layer
4 basic example ECUs (incl. basic_freertos)
Full CI test suite
Codegen templates
ARXML importer
AI assistant
Safety documentation

View on GitHub

Developer

€690/yr · per developer

Everything in Community, plus:

17 Jinja2 codegen templates — full generation engine
pytest + CAPL testgen
ARXML importer — AUTOSAR 4.x ECU Extract → YAML
AI config generation + NRC explain
MCP server — Claude, Cursor, Copilot integration
GUI dashboard + VS Code extension
FreeRTOS specialist examples: sensor_freertos, safeboot_freertos
OpenSOVD 1.0 CDA codegen
Email support · commercial license (1 seat)

Buy Developer →

Professional

€1,990/yr · per developer

Everything in Developer, plus:

68-test C integration harness (host GCC, no RTOS required)
ISO 26262 Safety Manual
HARA · Tool Qualification Argument
Requirements Traceability Matrix (30 ASIL-B requirements)
MISRA C:2012 deviation log
OEM key provisioning guide
Priority support (5 business days)
Commercial license (1 seat)

Buy Professional →

ISO 14229 UDS diagnosticson FreeRTOS.

One YAML, two RTOS targets.

FreeRTOS platform layer — what it does.

FreeRTOS example ECUs included.

Three tiers. Annual license. Offline after activation.

ISO 14229 UDS diagnostics
on FreeRTOS.