AdaCore Blog

An Insight Into the AdaCore Ecosystem

by Thomas Quinot –

PolyORB now lives on Github

PolyORB, AdaCore's versatile distribution middleware, now lives on Github. Its new home is https://github.com/AdaCore/polyorbPolyORB is a development toolsuite and a library of runtime components that implements several distribution models, including CORBA and the Ada 95 Distributed Systems Annex. Originally developed as part of academic research at Telecom ParisTech, it became part of the GNAT Pro family in 2003.Since then, it has been used in a number of industrial applicationsin a wide variety of domains such as: * air traffic flow management * enterprise document management * scientific data processing in particle physics experimentsAdaCore has always been committed to involving the user community in the development of PolyORB. Over the past 15 years, many contributions from industrial as well as hobbyist users have been integrated, and community releases were previously made available in conjunction with GNAT GPL.Today we are pleased to further this community engagement and renew our commitment to an open development process by making the PolyORB repository (including full history) available on Github.  This will allow users of GNAT GPL to benefit from the latest developments and contribute fixes and improvements.We look forward to seeing your issues and pull requests on this repository!

by Rob Tice –

SPARKZumo Part 2: Integrating the Arduino Build Environment Into GPS

This is part #2 of the SPARKZumo series of blog posts. This post covers the build system that was used to build the SPARKZumo project and how to automate the process in GPS.

#GPS    #Python    #Libadalang    #Arduino    #CCG   

by Fabien Chouteau, Yannick Moy, Vasiliy Fofanov, Nicolas Setton –

A Modern Syntax for Ada

One of the most criticized aspect of the Ada language throughout the years has been its outdated syntax. Fortunately, AdaCore decided to tackle this issue by implementing a new, modern, syntax for Ada.

#Ada    #GPS    #Language   

by Fabien Chouteau –

Getting Rid of Rust with Ada

There are a lot of DIY CNC projects out there (router, laser, 3D printer, egg drawing, etc.), but I never saw a DIY CNC sandblaster. So I decided to make my own.

#STM32    #embedded    #ARM    #Makers   

by Rob Tice –

SPARKZumo Part 1: Ada and SPARK on Any Platform

So you want to use SPARK for your next microcontroller project? Great choice! All you need is an Ada 2012 ready compiler and the SPARK tools. But what happens when an Ada 2012 compiler isn’t available for your architecture?

#CCG    #SPARK    #Arduino    #RISC V    #embedded   

by Yannick Moy –

Two Days Dedicated to Sound Static Analysis for Security

​AdaCore has been working with CEA, Inria and NIST to organize a two-days event dedicated to sound static analysis techniques and tools, and how they are used to increase the security of software-based systems. The program gathers top-notch experts in the field, from industry, government agencies and research institutes, around the three themes of analysis of legacy code, use in new developments and accountable software quality. Here is why it is worth attending.

#SPARK    #Frama-C    #Security    #Formal Methods    #Static Analysis   

by Yannick Moy –

Secure Software Architectures Based on Genode + SPARK

​SPARK user Alexander Senier presented recently at BOB Konferenz​ in Germany their use of SPARK for building secure mobile architectures. What's nice is that they build on the guarantees that SPARK provides at software level to create a secure software architecture based on the Genode operating system framework​. They present 3 interesting architectural designs that make it possible to build a trustworthy system out of untrustworthy building blocks. Almost as exciting as Alchemy's goal of transforming lead into gold! Here is the video of that presentation.

#SPARK    #Mobile    #Security   

by Fabien Chouteau –

Ada on the micro:bit

The micro:bit is a very small ARM Cortex-M0 board designed by the BBC for computer education. It's fitted with a Nordic nRF51 Bluetooth enabled 32bit ARM microcontroller. At $15 it is one of the cheapest yet most fun piece of kit to start embedded programming.

#embedded    #Ada    #nRF51    #ARM   

by Yannick Moy –

Tokeneer Fully Verified with SPARK 2014

Tokeneer is a software for controlling physical access to a secure enclave by means of a fingerprint sensor. This software was created by Altran (Praxis at the time) in 2003 using the previous generation of SPARK language and tools, as part of a project commissioned by the NSA to investigate the rigorous development of critical software using formal methods. The project artefacts, including the source code, were released as open source in 2008. Tokeneer was widely recognized as a milestone in industrial formal verification. We recently transitioned this software to SPARK 2014, and it allowed us to go beyond what was possible with the previous SPARK technology. We have also shown how security vulnerabilities introduced in the code can be detected by formal verification.

#SPARK    #Formal Methods   

by Felix Krause –

The Road to a Thick OpenGL Binding for Ada: Part 2

This blog post is part two of a tutorial based on the OpenGLAda project and will cover implementation details such as a type system for interfacing with C, error handling, memory management, and loading functions.

#OpenGL    #Binding   

by Yannick Moy –

For All Properties, There Exists a Proof

With the recent addition of a Manual Proof capability in SPARK 18, it is worth looking at an example which cannot be proved by automatic provers, to see the options that are available for proving it with SPARK. We present three ways to complete a proof beyond what automatic provers can do: using an alternative automatic prover, proving interactively inside our GPS IDE, and using an alternative interactive prover.

#SPARK    #Formal Methods   

by Johannes Kanig –

Bitcoin blockchain in Ada: Lady Ada meets Satoshi Nakamoto

Bitcoin is getting a lot of press recently, but let's be honest, that's mostly because a single bitcoin worth 800 USD in January 2017 was worth almost 20,000 USD in December 2017. However, bitcoin and its underlying blockchain are beautiful technologies that are worth a closer look. Let’s take that look with our Ada hat on!

#Bitcoin    #Blockchain    #Ada   

by Felix Krause –

The Road to a Thick OpenGL Binding for Ada: Part 1

This blog post is part one of a tutorial based on the OpenGLAda project and will cover some the background of the OpenGL API and the basic steps involved in importing platform-dependent C functions.

#OpenGL    #Binding   

by Pierre-Marie de Rodat, Yannick Moy, Fabien Chouteau, Raphaël Amiard –

AdaCore at FOSDEM 2018

Every year, free and open source enthusiasts gather at Brussels (Belgium) for two days of FLOSS-related conferences. FOSDEM organizers setup several “developer rooms”, which are venues that host talks on specific topics. This year, the event will happen on the 3rd and 4th of February (Saturday and Sunday) and there is a room dedicated to the Ada programming language.

by Lionel Matias –

Leveraging Ada Run-Time Checks with Fuzz Testing in AFL

Fuzzing is a very popular bug finding method. The concept, very simple, is to continuously inject random (garbage) data as input of a software component, and wait for it to crash. If, like me, you find writing robustness test tedious and not very efficient in finding bugs, you might want to try fuzzing your Ada code. Here's a recipe to fuzz-test your Ada code, using American Fuzzy Lop and all the runtime checks your favorite Ada compiler can provide. Let's see (quickly) how AFL works, then jump right into fuzzing 3 open-source Ada libraries: ZipAda, AdaYaml, and GNATCOLL.JSON.

#Testing    #Ada    #VerificationTools   

by Pierre-Marie de Rodat, Raphaël Amiard –

Cross-referencing Ada with Libadalang

Libadalang has come a long way since the last time we blogged about it. In the past 6 months, we have been working tirelessly on name resolution, a pretty complicated topic in Ada, and it is finally ready enough that we feel ready to blog about it, and encourage people to try it out.

#Libadalang    #Ada   

by Manuel Iglesias Abbatermarco –

Make with Ada 2017- Ada Based IoT Framework

Summary The Ada IoT Stack consists of an lwIp (“lightweight IP”) stack implementation written in Ada, with an associated high-level protocol to support embedded device connectivity nodes for today’s IoT world. The project was developed for the Make With Ada 2017 competition based on existing libraries and ported to embedded STM32 devices.

#embedded    #Ada    #IoT   

by Jamie Ayre –

Welcoming New Members to the GNAT Pro Family

As we see the importance of software grow in applications, the quality of that software has become more and more important. Even outside the mission- and safety-critical arena customers are no longer accepting software failures (the famous blue screens of death, and there are many...). Ada has a very strong answer here and we are seeing more and more interest in using the language from a range of industries. It is for this reason that we have completed our product line by including an entry-level offer for C/C++ developers wanting to switch to Ada and reinforced our existing offer with GNAT Pro Assurance for programmers building the most robust software platforms with life cycles spanning decades.

#GNAT Pro    #Ada   

by Fabien Chouteau –

There's a mini-RTOS in my language

The first thing that struck me when I started to learn about the Ada programing language was the tasking support. In Ada, creating tasks, synchronizing them, sharing access to resources, are part of the language

#Ada    #Ravenscar    #embedded    #STM32   

by J. German Rivera –

Make with Ada 2017- A "Swiss Army Knife" Watch

Summary  The Hexiwear is an IoT wearable development board that has two NXP Kinetis microcontrollers. One is a K64F (Cortex-M4 core) for running the main embedded application software. The other one is a KW40 (Cortex M0+ core) for running a wireless connectivity stack (e.g., Bluetooth BLE or Thread). The Hexiwear board also has a rich set of peripherals, including OLED display, accelerometer, magnetometer, gryroscope, pressure sensor, temperature sensor and heart-rate sensor. This blog article describes the development of a "Swiss Army Knife" watch on the Hexiwear platform. It is a bare-metal embedded application developed 100% in Ada 2012, from the lowest level device drivers all the way up to the application-specific code, for the Hexiwear's K64F microcontroller. I developed Ada drivers for Hexiwear-specific peripherals from scratch, as they were not supported by AdaCore's Ada drivers library. Also, since I wanted to use the GNAT GPL 2017 Ada compiler but the GNAT GPL distribution did not include a port of the Ada Runtime for the Hexiwear board, I also had to port the GNAT GPL 2017 Ada runtime to the Hexiwear. All this application-independent code can be leveraged by anyone interested in developing Ada applications for the Hexiwear wearable device.

by Yannick Moy, Martin Becker, Emanuel Regnath –

Physical Units Pass the Generic Test

The support for physical units in programming languages is a long-standing issue, which very few languages have even attempted to solve. This issue has been mostly solved for Ada in 2012 by our colleagues Ed Schonberg and Vincent Pucci who introduced special aspects for specifying physical dimensions on types. This dimension system did not attempt to deal with generics though. As was noted by others, handling generics in a dimensional analysis that is, like in GNAT, a compile-time analysis with no impact on the executable size or running time, is the source of the problem of dimension handling. Together with our partners from Technical Universitat München, we have finally solved this remaining difficulty.

#GNAT     #typing   

by Jonas Attertun –

Make with Ada 2017: Brushless DC Motor Controller

This project involves the design of a software platform that provides a good basis when developing motor controllers for brushless DC motors (BLDC/PMSM). It consist of a basic but clean and readable implementation of a sensored field oriented control algorithm. Included is a logging feature that will simplify development and allows users to visualize what is happening. The project shows that Ada successfully can be used for a bare-metal project that requires fast execution.

#Makers    #MakewithAda    #STM32    #embedded   

by Yannick Moy –

Prove in the Cloud

We have put together a byte (8 bits) of examples of SPARK code on a server in the cloud. The benefit with this webpage is that anyone can now experiment live with SPARK without installing first the toolset. Something particularly interesting for academics is that all the code for this widget is open source. So you can setup your own proof server for hands-on sessions, with your own exercises, in a matter of minutes.

#SPARK   

by Yannick Moy –

SPARK Tutorial at FDL Conference

Researcher Martin Becker is giving a SPARK tutorial next week at FDL conference. This post gives a link to his tutorial material (cookbook and slides) which I found extremely interesting.

#SPARK   

by Yannick Moy –

New SPARK Cheat Sheet

Our good friend Martin Becker has produced a new cheat sheet for SPARK, that you may find useful for a quick reminder on syntax that you have not used for some time.

#Formal Verification    #SPARK   

by Pierre-Marie de Rodat –

Highlighting Ada with Libadalang

While we are working very hard on semantic analysis in Libadalang, it is already possible to leverage its lexical and syntactic analyzers. A useful example for this is a syntax highlighter.

#Libadalang    #Ada   

by Pierre-Marie de Rodat –

Pretty-Printing Ada Containers with GDB Scripts

When things don’t work as expected, developers usually do one of two things: either add debug prints to their programs, or run their programs under a debugger. Today we’ll focus on the latter activity.

#gdb   

by Yannick Moy –

Proving Loops Without Loop Invariants

For all the power that comes with proof technology, one sometimes has to pay the price of writing a loop invariant. Along the years, we've strived to facilitate writing loop invariants by improving the documentation and the technology in different ways, but writing loops invariants remains difficult sometimes, in particular for beginners. To completely remove the need for loop invariants in simple cases, we have implemented loop unrolling in GNATprove. It turns out it is quite powerful when applicable.

#Formal Verification    #SPARK   

by Yannick Moy –

Research Corner - Focused Certification of SPARK in Coq

The SPARK toolset aims at giving guarantees to its users about the properties of the software analyzed, be it absence of runtime errors or more complex properties. But the SPARK toolset being itself a complex tool, it is not free of errors. To get confidence in its results, we have worked with academic partners to establish mathematical evidence of the correctness of a critical part of the SPARK toolset. The part on which we focused is the tagging of nodes requiring run-time checks by the frontend of the SPARK technology. This work has been accepted at SEFM 2017 conference.

#SPARK   

by Yannick Moy –

Applied Formal Logic: Searching in Strings

A friend pointed me to recent posts by Tommy M. McGuire, in which he describes how Frama-C can be used to functionally prove a brute force version of string search, and to find a previously unknown bug in a faster version of string search called quick search. Frama-C and SPARK share similar history, techniques and goals. So it was tempting to redo the same proofs on equivalent code in SPARK, and completing them with a functional proof of the fixed version of quick search. This is what I'll present in this post.

#Dev Projects    #Formal Verification    #SPARK   

by Rob Tice –

The Adaroombot Project

The Adaroombot project consists of an iRobot CreateⓇ 2 and Ada running on a Raspberry Pi with a Linux OS. This is a great Intro-to-Ada project as it focuses on a control algorithm and a simple serial communications protocol. The iRobot CreateⓇ 2 platform was originally design for STEM education and has great documentation and support - making it very easy to create a control application using Ada. This blog looks at the creation of the project and some cool features of Ada that were learned along the way.

#Raspberry Pi    #ARM    #Linux    #Ada    #Roomba   

by Pierre-Marie de Rodat, Nicolas Setton –

GNAT GPL 2017 is out!

For those users of the GNAT GPL edition, we are pleased to announce the availability of the 2017 release of GNAT GPL and SPARK GPL.

#GNAT GPL   

by Fabien Chouteau –

Ada on the first RISC-V microcontroller

The RISC-V open instruction set is getting more and more news coverage these days. In particular since the release of the first RISC-V microcontroller from SiFive and the announcement of an Arduino board at the Maker Faire Bay Area 2017.

#Embedded Development    #Ada    #RISC-V   

by Yannick Moy –

Research Corner - FLOSS Glider Software in SPARK

Two years ago, we redeveloped the code of a small quadcopter called Crazyflie in SPARK, as a proof-of-concept to show it was possible to prove absence of run-time errors (no buffer overflows, not division by zero, etc.) on such code. The researchers Martin Becker and Emanuel Regnath have raised the bar by developing the code for the autopilot of a small glider in SPARK in three months only. Their paper and slides are available, and they have released their code as FLOSS for others to use/modify/enhance!

#Formal Verification    #Dev Projects    #SPARK   

by Yannick Moy –

Research Corner - Floating-Point Computations in SPARK

It is notoriously hard to prove properties of floating-point computations, including the simpler bounding properties that state safe bounds on the values taken by entities in the program. Thanks to the recent changes in SPARK 17, users can now benefit from much better provability for these programs, by combining the capabilities of different provers. For the harder cases, this requires using ghost code to state intermediate assertions proved by one of the provers, to be used by others. This work is described in an article which was accepted at VSTTE 2017 conference.

#Formal Verification    #SPARK   

by Yannick Moy –

Frama-C & SPARK Day Slides and Highlights

The Frama-C & SPARK Day this week was a very successful event gathering the people interested in formal program verification for C programs (with Frama-C) and for Ada programs (with SPARK). Here is a summary of what was interesting for SPARK users. We also point to the slides of the presentations.

#SPARK   

by Yannick Moy –

New Guidance for Adoption of SPARK

While SPARK has been used for years in companies like Altran UK, companies without the same know-how may find it intimidating to get started on formal program verification. To help with that process, AdaCore has collaborated with Thales throughout the year 2016 to produce a 70-pages detailed guidance document for the adoption of SPARK. These guidelines are based on five levels of assurance that can be achieved on software, in increasing order of costs and benefits: Stone level (valid SPARK), Bronze level (initialization and correct data flow), Silver level (absence of run-time errors), Gold level (proof of key properties) and Platinum level (full functional correctness). These levels, and their mapping to the Development Assurance Levels (DAL) and Safety Integrity Levels (SIL) used in certification standards, were presented at the recent High Confidence Software and Systems conference.

#Formal Verification    #SPARK   

by Fabien Chouteau –

DIY Coffee Alarm Clock

A few weeks ago one of my colleagues shared this kickstarter project : The Barisieur. It’s an alarm clock coffee maker, promising to wake you up with a freshly brewed cup of coffee every morning. I jokingly said “just give me an espresso machine and I can do the same”. Soon after, the coffee machine is in my office. Now it is time to deliver :)

#Embedded Development    #STM32    #Makers    #Ada    #ARM   

by Yannick Moy –

(Many) More Low Hanging Bugs

We reported in a previous post our initial experiments to create lightweight checkers for Ada source code, based on the new Libadalang technology. The two checkers we described discovered 12 issues in the codebase of the tools we develop at AdaCore. In this post, we are reporting on 6 more lightweight checkers, which have discovered 114 new issues in our codebase. This is definitely showing that these kind of checkers are worth integrating in static analysis tools, and we look forward to integrating these and more in our static analyzer CodePeer for Ada programs.

#Static Analysis    #Libadalang   

by Yannick Moy, Emmanuel Briot, Nicolas Roche –

A Usable Copy-Paste Detector in A Few Lines of Python

After we created lightweight checkers based on the recent Libadalang technology developed at AdaCore, a colleague gave us the challenge of creating a copy-paste detector based on Libadalang. It turned out to be both easier than anticipated, and much more efficient and effective than we could have hoped for. In the end, we hope to use this new detector to refactor the codebase of some of our tools, and we expect to integrate it in our IDEs.

#Libadalang    #Static Analysis    #refactoring   

by Yannick Moy –

VerifyThis Challenge in SPARK

This year again, the VerifyThis competition took place as part of ETAPS conferences. This is the occasion for builders and users of formal program verification platforms to use their favorite tools on common challenges. The first challenge this year was a good fit for SPARK, as it revolves around proving properties of an imperative sorting procedure. In this post, I am using this challenge to show how one can reach different levels of software assurance with SPARK.

#Formal Verification    #SPARK   

by Anthony Leonardo Gracio –

GPS for bare-metal developers

In my previous blog article, I exposed some techniques that helped me rewrite the Crazyflie’s firmware from C into Ada and SPARK 2014, in order to improve its safety.

#GPS    #Embedded Development    #Makers   

by Emmanuel Briot –

User-friendly strings API

User friendly strings API In a previous post, we described the design of a new strings package, with improved performance compared to the standard Ada unbounded strings implementation. That post focused on various programming techniques used to make that package as fast as possible.

#Ada    #gnatcoll   

by Yannick Moy –

GNATprove Tips and Tricks: Proving the Ghost Common Divisor (GCD)

Euclid's algorithm for computing the greatest common divisor of two numbers is one of the first ones we learn in school, and also one of the first algorithms that humans devised. So it's quite appealing to try to prove it with an automatic proving toolset like SPARK. It turns out that proving it automatically is not so easy, just like understanding why it works is not so easy. In this post, I am using ghost code to prove correct implementations of the GCD, starting from a naive linear search algorithm and ending with Euclid's algorithm.

#Formal Verification    #SPARK   

by Emmanuel Briot –

New strings package in GNATCOLL

This post describes the new GNATCOLL.Strings package, and the various optimizations it performs to provide improved performance.

#gnatcoll    #strings    #Ada   

by Jerome Guitton, Jérôme Lambourg, Joel Brobecker –

Simics helps run 60 000 GNAT Pro tests in 24 hours

This post has been updated in March 2017 and was originally posted in March 2016.

#Simics    #WindRiver    #GNAT Pro   

by Yannick Moy –

Two Projects to Compute Stats on Analysis Results

Two projects by Daniel King and Martin Becker facilitate the analysis of GNATprove results by exporting the results (either from the log or from the generated JSON files) to either Excel or JSON/text.

#Dev Projects    #Open Source    #SPARK   

by Pierre-Marie de Rodat –

GNATcoverage moves to GitHub

Following the current trend, the GNATcoverage project moves to GitHub! Our new address is: https://github.com/AdaCore/gnatcoverage

#GitHub    #GNATcoverage   

by Jorge Real –

Writing on Air

While searching for motivating projects for students of the Real-Time Systems course here at Universitat Politècnica de València, we found a curious device that produces a fascinating effect. It holds a 12 cm bar from its bottom and makes it swing, like an upside-down pendulum, at a frequency of nearly 9 Hz. The free end of the bar holds a row of eight LEDs. With careful and timely switching of those LEDs, and due to visual persistence, it creates the illusion of text... floating in the air!

#STM32    #Ravenscar    #Ada    #Makers    #Embedded Development   

by Fabien Chouteau, Arnaud Charlet, Yannick Moy –

SPARK Tetris on the Arduboy

One of us got hooked on the promise of a credit-card-size programmable pocket game under the name of Arduboy and participated in its kickstarter in 2015. The kickstarter was successful (but late) and delivered  the expected working board in mid 2016. Of course, the idea from the start was to program it in Ada , but this is an 8-bits AVR microcontroller (the ATmega32u4 by Atmel) not supported anymore by GNAT Pro. One solution would have been to rebuild our own GNAT compiler for 8-bit AVR from the GNAT FSF repository and use the AVR-Ada project. Another solution, which we explore in this blog post, is to use the SPARK-to-C compiler that we developed at AdaCore to turn our Ada code into C and then use the Arduino toolchain to compile for the Arduboy board.

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