17 entries tagged with #Tasking
by Jon Andrew
CuBit: A General-Purpose Operating System in SPARK/AdaLast year, I started evaluating programming languages for a formally-verified operating system. I've been developing software for a while, but only recently began work in high integrity software development and formal methods. There are several operating system projects, like the SeL4 microkernel and the Muen separation kernel, that make use of formal verification. But I was interested in using a formally-verified language to write a general-purpose OS - an environment for abstracting the underlying hardware while acting as an arbiter for running the normal applications we're used to.
by Pat Rogers
Making an RC Car with Ada and SPARK
As a demonstration for the use of Ada and SPARK in very small embedded targets, I created a remote-controlled (RC) car using Lego NXT Mindstorms motors and sensors but without using the Lego computer or Lego software. I used an ARM Cortex System-on-Chip board for the computer, and all the code -- the control program, the device drivers, everything -- is written in Ada. Over time, I’ve upgraded some of the code to be in SPARK. This blog post describes the hardware, the software, the SPARK upgrades, and the repositories that are used and created for this purpose.
by Claire Dross
Using Pointers in SPARKIn this blog post, I will present one of the most interesting additions to the community 2019 version of SPARK: pointer support. One of the core assumption in SPARK has always been the absence of aliasing, so adding pointers without breaking this assumption was quite a challenge. I will explain how this was achieved using an ownership model for pointers (like is done in Rust) through small examples.
Winning DTU RoboCup with Ada and SPARKThe Danish Technical University has a yearly RoboCup where autonomous vehicles solve a number of challenges. We participated with RoadRunner, a 3D printed robot with wheel suspension, based on the BeagleBone Blue ARM-based board and the Pixy 1 camera with custom firmware enabling real-time line detection. Code is written in Ada and formally proved correct with SPARK at Silver level.
by Rob Tice
AdaFractal Part 2: Fixed Point and Floating Point Math Performance and Parallelization
In Part 1 of this blog post I discussed why I chose to implement this application using the Ada Web Server to serve the computed fractal to a web browser. In this part I will discuss a bit more about the backend of the application, the Ada part.
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.
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
Make with Ada 2017: Brushless DC Motor ControllerThis 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.
Ada on the first RISC-V microcontroller
Updated July 2018
New strings package in GNATCOLLThis post describes the new GNATCOLL.Strings package, and the various optimizations it performs to provide improved performance.
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.
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.
Verifying Tasking in Extended, Relaxed StyleTasking was one of the big features introduced in the previous release of SPARK 2014. However, GNATprove only supported tasking-related constructs allowed by the Ravenscar profile. Now it also supports the more relaxed GNAT Extended Ravenscar profile.
Make with Ada: ARM Cortex-M CNC controller
I started this project more than a year ago. It was supposed to be the first Make with Ada project but it became the most challenging from both, the hardware and software side.
SPARK 2014 Rationale: Variables That Are ConstantThe SPARK tools now support yet another feature that allows users to better specify the intended behavior of their programs. This new feature enables users to declare that specific variables can only be updated during the elaboration of their enclosing package. Read on if you want to know more...
Tetris in SPARK on ARM Cortex M4
Tetris is a well-known game from the 80's, which has been ported in many versions to all game platforms since then. There are even versions of Tetris written in Ada. But there was no version of Tetris written in SPARK, so we've repaired that injustice. Also, there was no version of Tetris for the Atmel SAM4S ARM processor, another injustice we've repaired.