19 entries tagged with #Avionics
AdaCore has partnered closely with Lynx to deliver Ada language support alongside its LYNX MOSA.ic software framework that comprises a real-time operating system (LynxOS-178), Linux and hypervisor (LynxSecure) technology.
We are pleased to announce the publication of the initial draft of the Ferrocene Language Specification (FLS) - a qualification-oriented document that details the Rust language as it specifically relates to Ferrocene.
The GNAT light runtime library is a version of the runtime library targeted at embedded platforms and certification, which has been certified for use at the highest levels of criticality in several industrial domains. It contains around 180 units focused mostly on I/O, numerics, text manipulation, memory operations. We have used SPARK to prove the correctness of 40 of them: that the code is free of runtime errors, and that it satisfies its functional specifications.
For over 25 years, AdaCore has been committed to supporting the needs of safety- and mission-critical industries. This started with an emphasis on the Ada programming language and its toolchain, and over the years has been extended to many other technologies. AdaCore’s product offerings today include support for the Ada language and its formally verifiable SPARK subset, C and C++, and Simulink and Stateflow models. We have accomplished this while addressing the requirements of various safety standards such as DO-178B/C, EN 50128, ECSS-E-ST-40C / ECSS-Q-ST-80C, IEC 61508 and ISO 26262.
Through the HICLASS UK research group, AdaCore has been developing security-focused software development tools that are aligned with the objectives stated within the avionics security standards. In addition, they have been developing further guidelines that describe how vulnerability identification and security assurance activities can be described within a Plan for Security Aspects of Certification.
Part of AdaCore's ongoing efforts under the HICLASS project is to demonstrate how the SPARK technology can play an integral part in the security-hardening of existing software libraries written in other non-security-oriented programming languages such as C. This blog post presents the first white paper under this work-stream, “Security-Hardening Software Libraries with Ada and SPARK”.
The FACE™ approach is a government-industry initiative for reducing defense system life cycle costs through portable and reusable software components. It consists of a technical approach — a software standard based on well-defined common interfaces — and a business strategy for encouraging the development and deployment of FACE conformant products.
For nearly four decades the Ada language (in all versions of the standard) has been helping developers meet the most stringent reliability, safety and security requirements in the embedded market. As such, Ada has become an entrenched player in its historic A&D niche, where its technical advantages are recognized and well understood. Ada has also seen usage in other domains (such as medical and transportation) but its penetration has progressed at a somewhat slower pace. In these other markets Ada stands in particular contrast with the C language, which, although suffering from extremely well known and documented flaws, remains a strong and seldom questioned default choice. Or at least, when it’s not the choice, C is still the starting point (a gateway drug?) for alternatives such as C++ or Java, which in the end still lack the software engineering benefits that Ada embodies..
What's changed?In 2019 AdaCore created a UK business unit and embarked on a new and collaborative venture researching and developing advanced UK aerospace systems. This blog introduces the reader to ‘HICLASS’, describes our involvement and explains how participation in this project is aligned with AdaCore’s core values.
The promise behind the SPARK language is the ability to formally demonstrate properties in your code regardless of the input values that are supplied - as long as those values satisfy specified constraints. As such, this is quite different from static analysis tools such as our CodePeer or the typical offering available for e.g. the C language, which trade completeness for efficiency in the name of pragmatism. Indeed, the problem they’re trying to solve - finding bugs in existing applications - makes it impossible to be complete. Or, if completeness is achieved, then it is at the cost of massive amount of uncertainties (“false alarms”). SPARK takes a different approach. It requires the programmer to stay within the boundaries of a (relatively large) Ada language subset and to annotate the source code with additional information - at the benefit of being able to be complete (or sound) in the verification of certain properties, and without inundating the programmer with false alarms.
Following the current trend, the GNATcoverage project moves to GitHub! Our new address is: https://github.com/AdaCore/gnatcoverage
Last week, a few of us at AdaCore have attended a one-day workshop organized at Thales Research and Technologies, around the topic of "Verified, trustworthy code - formal verification of software". Attendees from many different branches of Thales (avionics, railway, security, networks) were given an overview of the state-of-practice in formal verification of software, focused on two technologies: the SPARK technology that we develop at AdaCore for programs in Ada, and the Frama-C technology developed at CEA research labs for programs in C. The most interesting part of the day was the feedback given by three operational teams who have experimented during a few months with either SPARK (two teams) or Frama-C (one team). The lessons learned by first-time adopters of such technologies are quite valuable.
AdaCore provides several tools with certification and qualification capabilities, for the rail and avionics industry. Quentin Ochem’s presentation on “Certification and Qualification” at the 2015 AdaCore Tech Days in Boston, Massachusetts provided more information about these two standards, namely DO-178C and EN:50128:2011.
We are pleased to announce our latest release of SPARK Pro! A product that has been jointly developed alongside our partner Altran and following the global AdaCore Tech Days, you can now see the SPARK 2014 talk, Formal Verification Made Easy by AdaCore’s Hristian Kirtchev, on YouTube.
Frederick Pothon of ACG Solutions has recently published a document entitled - Dissimilar tools: Use cases and impact on tool qualification level on the open-DO blog.
Object Oriented Programming is known for making it particularly difficult to analyze programs, because the subprograms called are not always known statically. The standard for civil avionics certification has recognized this specific problem, and defines a specific verification objective called Local Type Consistency that should be met with one of three strategies. SPARK allows using one of these strategies, by defining the behavior of an overridden subprogram using a special class-wide contract and checking that the behavior of the overriding subprogram is a suitable substitution, following the Liskov Substitution Principle.
Using SPARK or any other formal method in a certification requires that the applicant agrees with the certification authority on the verification objectives that this use of formal methods allows to reach, and how this is obtained and documented. In order to facilitate this process, the participants to the workshop on Theorem Proving in Certification have produced a draft set of guidelines, now publicly available.
The MISRA C subset of C defines around 150 rules that restrict C programs for critical software development. Of these, 27 rules are classified as undecidable, which means that few MISRA C checkers (if any) will help checking those hardest rules. Here is how SPARK 2014 can help checking similar rules in Ada programs.
After three years of hard work, we have reached last week the end of project Hi-Lite, whose goal was to simplify the use of formal methods. We're proud to publicize the results obtained, in particular the new version of SPARK and the associated tool GNATprove. Here's a summary of the wrap-up meeting.