ARINC (Aeronautical Radio, Inc.) is a standardization organization that develops and publishes specifications for Avionics systems, particularly in the Aerospace and Defense industries. These specifications are widely used in embedded software for Aviation, ensuring interoperability, Safety, and reliability in aircraft systems.

There are various standards developed for a wide range of applications, such as:

• ARINC 429 (data bus for Avionics communication)
• ARINC 661 (cockpit display system interfaces)
• ARINC 818 (digital video interface for Avionics)

Therefore, ARINC 653 is the standard dedicated to partitioned real-time operating environments for Safety-critical Avionics applications. This standard is particularly relevant to Integrated Modular Avionics (IMA) architectures, allowing multiple avionics applications to run securely and deterministically on a shared computing platform.

Technical Background on ARINC 653

1. Definition and Purpose

ARINC 653 specifies an Application Executive (APEX) that provides partitioning mechanisms to support multiple avionics applications on the same hardware while ensuring strict spatial and temporal separation. It is essential for Safety-critical systems, as it ensures that faults in one partition do not affect others.

2. Key Features of ARINC 653

• Partitioning: Divides system resources (CPU time, memory) among applications, ensuring each partition operates independently
• Time and Space Isolation: Guarantees that each application receives dedicated execution time and memory space
• Health Monitoring: Detects failures in partitions and prevents cascading failures
• Inter-Partition Communication: Provides mechanisms for safe data exchange between partitions
• Deterministic Behavior: Ensures applications execute with known timing constraints

3. ARINC 653 Partitioning Mechanism

• Spatial Partitioning: Each partition has its own memory allocation, preventing one partition from corrupting another’s data
• Temporal Partitioning: Each partition is assigned a fixed execution window (time slice) within a repeating major frame schedule
• Scheduling: A pre-determined cyclic scheduling approach is followed, ensuring deterministic execution and preventing unbounded priority inversion

SYSGO's PikeOS RTOS & Hypervisor and ARINC 653

PikeOS is a real-time operating system (RTOS) and hypervisor that supports ARINC 653 and is designed for Safety-critical systems. It is widely used in Avionics, Automotive, Railway, and Industrial Automation applications where partitioning, Security, and real-time constraints are essential.

1. PikeOS as an ARINC 653 compliant RTOS

PikeOS is designed to meet the requirements of ARINC 653 by providing:

• Hard real-time performance with deterministic execution
• Safety and Security certification support (DO-178C for Avionics, IEC 61508 for Industrial systems, and ISO 26262 for Automotive applications)
• Virtualization capabilities, allowing legacy systems and new applications to co-exist

2. Integration of ARINC 653 with PikeOS

PikeOS implements ARINC 653 compliance through:

• Partitioned execution using the PikeOS microkernel, which enforces strict memory and CPU usage policies
• Health monitoring services for fault detection and handling
• Communication mechanisms such as ARINC 653 ports (sampling and queuing), allowing safe interaction between partitions
• Time and space partitioning to prevent interference between applications
• Support for mixed-criticality workloads, enabling safety-critical applications to run alongside less critical software

3. PikeOS as a Hypervisor for ARINC 653 Systems

PikeOS is not just an RTOS but also a hypervisor, meaning it can host multiple guest operating systems (e.g., ELinOS, Linux, Android, legacy RTOS, …) alongside ARINC 653 partitions. This capability is crucial for modern Avionics platforms, which often require a mix of real-time and general-purpose applications.

For example, a single PikeOS instance can run:

• ARINC 653 partitions for avionics control systems
• Linux-based partitions for user interface or maintenance applications
• Other RTOS partitions for specialized tasks, such as radar or flight control algorithms

4. Certification and Safety Aspects

PikeOS is designed to meet the highest safety standards required in avionics and aerospace, including:

• DO-178C DAL A Certification: Required for airborne software Safety
• Security Certification: Ensures system Cybersecurity and reliability
• Modular Certification Support: Allows system integrators to certify only the relevant parts of the system, reducing time and cost

Advantages of using ARINC 653 with PikeOS

1. Increased Safety and Security: Strong partitioning guarantees prevent software faults from propagating
2. High Performance with Low Latency: PikeOS is optimized for real-time execution, ensuring deterministic behavior
3. Flexibility and Reusability: Allows running different OSes in different partitions without affecting critical Avionics applications
4. Scalability: Supports multi-core architectures, enabling future-proof avionics systems
5. Reduced Certification Effort: Pre-certified components help streamline Safety approvals

Conclusion

ARINC 653 plays a crucial role in modern Avionics software, providing a robust framework for partitioned real-time execution. SYSGO's PikeOS enhances this standard with its microkernel-based architecture, hypervisor functionality, and certification-friendly design. The combination of ARINC 653 and PikeOS enables highly secure, reliable, and deterministic Avionics systems, making it an ideal choice for next-generation Aerospace applications.

By integrating ARINC 653 on PikeOS, Avionics manufacturers can achieve greater modularity, maintainability, and scalability, ensuring compliance with stringent industry standards while embracing modern software architectures.