AdaCore Blog

An Insight Into the AdaCore Ecosystem

by Julia Teissl

Train control using Ada on a Raspberry Pi

I was looking for a topic for my master thesis in embedded systems engineering when one of my advisor proposed the idea of programming a control system for autonomous trains in Ada. Since I am fascinated by the idea of autonomous vehicles I agreed immediately without knowing Ada. 

by Fabien Chouteau

Ada on FPGAs with PicoRV32

When I bought the TinyFPGA-BX board, I thought it would be an opportunity to play a little bit with FPGA, learn some Verilog or VHDL. But when I discovered that it was possible to have a RISC-V CPU on it, I knew I had to run Ada code on it.

#embedded    #RISC-V    #Ada   

by Yannick Moy

How Ada and SPARK Can Increase the Security of Your Software

There is a long-standing debate about which phase in the Software Development Life Cycle causes the most bugs: is it the specification phase or the coding phase? A recent study by NIST shows that, in the software industry at large, coding bugs are causing the majority of security issues. Choosing a safer language like Ada or SPARK is a critical component for reducing these vulnerabilities that result from simple mistakes. In a new freely available booklet, we explain how these languages and the associated toolsets can be used to increase the security of software.

#Ada    #SPARK    #Security   

by Johannes Kanig

Taking on a Challenge in SPARK

Last week, the programmer Hillel posted a challenge (the link points to a partial postmortem of the provided solutions) on Twitter for someone to prove a correct implementation of three small programming problems: Leftpad, Unique, and Fulcrum.

#Formal Verification    #Formal Methods    #SPARK   

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

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 Fabien Chouteau

Ada on the micro:bit

Updated July 2018

#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 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

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

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 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

Updated July 2018

#Embedded Development    #Ada    #RISC-V   

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, 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 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 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 Claire Dross

Research Corner - Auto-active Verification in SPARK

GNATprove performs auto-active verification, that is, verification is done automatically, but usually requires annotations by the user to succeed. In SPARK, annotations are most often given in the form of contracts (pre and postconditions). But some language features, in particular ghost code, allow proof guidance to be much more involved. In a paper we are presenting at NASA Formal Methods symposium 2017, we describe how an imperative red black tree implementation in SPARK was verified using intensive auto-active verification.

#Formal Verification    #SPARK   

by Pat Rogers

Getting started with the Ada Drivers Library device drivers

The Ada Drivers Library (ADL) is a collection of Ada device drivers and examples for ARM-based embedded targets. The library is maintained by AdaCore, with development originally (and predominantly) by AdaCore personnel but also by the Ada community at large.  It is available on GitHub and is licensed for both proprietary and non-proprietary use.

#Ada    #Devices    #drivers    #STM32    #embedded   

by Raphaël Amiard, Yannick Moy, Pierre-Marie de Rodat

Going After the Low Hanging Bug

At AdaCore, we have a strong expertise in deep static analysis tools (CodePeer and SPARK), and we have been relying on the compiler GNAT and our coding standard checker GNATcheck to deal with more syntactic or weakly-semantic checks. The recent Libadalang technology, developed at AdaCore, provided us with an ideal basis to develop specialized light-weight static analyzers. As an experiment, we implemented two simple checkers using the Python binding of Libadalang. The results on our own codebase were eye-opening: we found a dozen bugs in the codebases of the tools we develop at AdaCore (including the compiler and static analyzers).

#Static Analysis   

by Raphaël Amiard, Pierre-Marie de Rodat

Introducing Libadalang

AdaCore is working on a host of tools that works on Ada code. The compiler, GNAT, is the most famous and prominent one, but it is far from being the only one. At AdaCore, we already have several other tools to process Ada code: the ASIS library, GNAT2XML, the GPS IDE. A realization of the past years, however, has been that we were lacking a unified solution to process code that is potentially evolving, potentially incorrect Ada code. Hence Libadalang.

#Ada    #tooling   

by Johannes Kanig

SPARK and CodePeer, a Good Match!

It turns out that the CodePeer engine can be used as a powerful prover for SPARK programs. This feature will be available in the next version of SPARK Pro, make sure you try it out!

#Formal Verification    #SPARK   

by Fabien Chouteau

Make with Ada: DIY instant camera

There are moments in life where you find yourself with an AdaFruit thermal printer in one hand, and an OpenMV camera in the other.

#Makers    #Ada    #STM32    #ARM    #Embedded Development   

by Emmanuel Briot

Integrate new tools in GPS (2)

Customizing build target switches In the first post in this series (Integrate new tools in GPS) we saw how to create new build targets in GPS to spawn external tools via a menu or toolbar button, and then display the output of that tool in its own console, as well as show error messages in the Locations view.

#GPS   

by Yannick Moy

GNATprove Tips and Tricks: What’s Provable for Real Now?

One year ago, we presented on this blog what was provable about fixed-point and floating-point computations (the two forms of real types in SPARK). Since then, we have integrated static analysis in SPARK, and modified completely the way floating-point numbers are seen by SMT provers. Both of these features lead to dramatic changes in provability for code doing fixed-point and floating-point computations.

#Formal Verification    #SPARK   

by Emmanuel Briot

Integrate new tools in GPS

This blog, the first in a series, explains the basic mechanisms that GPS (the GNAT Programming Studio) provides to integrate external tools. A small plugin might make your daily workflow more convenient by providing toolbar buttons and menus to spawn your tool and parse its output.

#GPS   

by Pat Rogers

Driving a 3D Lunar Lander Model with ARM and Ada

One of the interesting aspects of developing software for a bare-board target is that displaying complex application-created information typically requires more than the target board can handle. Although some boards do have amazing graphics capabilities, in some cases you need to have the application on the target interact with applications on the host. This can be due to the existence of special applications that run only (or already) on the host, in particular.

#Bareboard    #Embedded Development    #STM32    #Ada   

by Emmanuel Briot

GNAT On macOS Sierra

GNAT and all the tools work great on the newly released macOS Sierra, but gdb needs some tweaking of the system.

#osx    #gdb   

by Emmanuel Briot

Debugger improvements in GPS 17

The GNAT Programming Studio support for the debugger has been enhanced. This post describes the various changes you can expect in this year's new release of GPS.

#GPS   

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