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When Lives Depend on Safe and Secure Software

RTCA DO-178B / EUROCAE ED-12B is the Software Considerations in Airborne Systems and Equipment Certification safety standard.

Click here for a detailed overview of DO-178B »

GNAT Pro High-Integrity Edition for DO-178B is a complete development environment with full DO-178B Level A certification materials. It has passed formal certification as a part of multiple avionics flight critical systems. It is the ideal solution for any safety-critical development effort for avionics, high speed rail, nuclear shutdown, medical, and other industries where top levels of safety must be assured. It satisfies DO-178B and can support related standards including IEC 61508, RIA-23, and Def Stan 00-55/56.

GNAT Pro High-Integrity Edition for DO-178B is an enhanced version of GNAT Pro, designed for building safe and secure software. Its many features help to reduce the cost of developing and certifying systems that have to meet safety standards such as RTCA DO-178B / EUROCAE ED-12B and other high-integrity standards. Key to achieving this goal is the product’s fully configurable and customizable run-time library. You can select units in an a la carte fashion, thus limiting the run-time library to just those units that are required for the Ada features used in the application, and you can adapt their implementation if desired.

Configurable Run-Time Library

Using GNAT Pro High-Integrity Edition for DO-178B’s configurable run-time capability, you can specify any level of support for Ada’s dynamic features, from none at all to the full Ada 95 or Ada 2005 languages. The units included in the library may be either a subset of the standard units provided with GNAT Pro, or they may be specially tailored to the application. This capability is useful, for example, if one of the predefined profiles provides almost all the features needed to adapt an existing system to new safety-critical requirements, and where the costs of adaptation without the additional features are considered prohibitive.

GNATstack

The GNATstack static analysis tool is supplied with this edition. GNATstack statically calculates the maximum stack space required by each task in an application. The computed bounds can be used to ensure that sufficient space is reserved, thus guaranteeing safe, predictable execution with respect to stack usage. GNATstack uses conservative analysis to deal with complexities such as subprogram recursion, while avoiding unnecessarily pessimistic estimates. The tool’s output data can be used directly to satisfy DO-178B requirements (Table A-5, Objective 6, which relates to the Accuracy and consistency issues itemized in Section 6.3.4f) and the associated sections from DO-278 for native safety systems.

Certification

Full DO-178B Level A certification evidence is available for this package for the certified subset library supplied. This includes all life cycle artifacts required by DO-178B Level A, including all tests and object code testing results.

AdaCore has taken the additional quality step of using independent safety certification experts to produce the DO-178B certification materials. Safety-critical experts, Verocel have developed the certification package for the run-time library components accompanying the GNAT Pro High-Integrity Edition as well as many other avionic systems. Verocel specializes in the verification of safety-critical software at all levels of criticality and provides verification services and qualified tools to help satisfy the various regulatory objectives.

Traceability

Through a compiler switch you can generate a low-level version of the source program that reveals implementation decisions but stays basically machine independent. This helps support traceability requirements, and may be used as a reference point for verifying that the object code matches the source code. Another compiler switch produces details of data representation (sizes, record layout, etc.), which is also helpful in traceability.

Further AdaCore has partnerships with best in class source level test and coverage analysis providers. Source coverage capabilities can be obtained from:

• IPL – AdaTEST »
• Vector Software – VectorCAST/Ada »
• LDRA – LDRA tool suite® »

Simplification of Certification Effort

You can restrict language features that, although not requiring a run-time library, nevertheless could complicate the test coverage analysis part of the certification effort. For example, you can prohibit the use of constructs that would result in code with implicit loops and conditionals (such as a slice assignment).

Full Ada 2005 Implementation

In keeping with its status as the leading Ada technology, GNAT Pro is the first Ada environment to implement all of the major features included in Ada 2005, the latest revision of the Ada language. With Ada 2005, Ada continues to be on the cutting edge of programming language design. Some of the new features include:

• Mutually Dependent Package Specifications
• Aggregates for Limited Types
• More Contexts for Anonymous Access Types
• Java-like Interfaces
• Real-Time and High-Integrity Support
• New Pragmas
• Predefined Library extensions

Please visit the Ada 2005 page for more information.

Target Platforms

Wind River Platforms For Safety-Critical (PSC)

• Platform for Safety-Critical for DO-178B (VxWorks/Cert)
• Safety-Critical for ARINC-653 (VxWorks 653)

Bareboard Solutions

• PowerPC
• ERC32 / LEON