Category Archives: Cortex

An Introduction to Docker for Embedded Developers – Part 4 Reducing Docker Image Size

Niall Cooling

Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.

In Part 3  we managed to build a Docker image containing the tools required to compile and link C/C++ code destined for our embedded Arm target system. However, we’ve paid little attention to the size of the image. Doing a quick Docker image listing we can see its grown to a whopping 2.14GB:

$ docker image ls
REPOSITORY TAG IMAGE ID […]

Posted in Agile, ARM, C/C++ Programming, Cortex, Testing | Tagged , , , | 3 Comments

An Introduction to Docker for Embedded Developers – Part 3 Cross-Compiling for Cortex-M

Niall Cooling

Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.

In the previous posting we looked at defining a custom Dockerfile where we can add specific tools (and their dependencies). From that we created a Docker image and this allowed us to build C/C++ code in a Docker container, ensuring a consistent build environment.

So far we have to build all our code using the native GCC toolchain which is part of the base Docker image (gcc:7.2). However, I want to be able to build an image I can download and run […]

Posted in Agile, ARM, C/C++ Programming, Cortex, Testing | Tagged , , | Leave a comment

Making things do stuff – Part 4

Glennan Carnie

Glennan Carnie

Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.

He specialises in C++, UML, software modelling, Systems Engineering and process development.
Glennan Carnie

In the last article we explored the design of a class to encapsulate a physical hardware device.  In that article I deliberately ignored how the class would actually interact with the hardware.

In this article we explore the options available to us for accessing hardware and the consequences of those

Posted in ARM, C/C++ Programming, Cortex, General | Tagged , , , , , , | Leave a comment

Making things do stuff – Part 3

Glennan Carnie

Glennan Carnie

Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.

He specialises in C++, UML, software modelling, Systems Engineering and process development.
Glennan Carnie

Previously, we’ve looked at the basics of hardware manipulation in C++ and applied that to a simple GPIO implementation.

In this article we’re going to have a look at encapsulating our code in a class and look at some of the design choices we have to make.

If you’re not familiar with hardware manipulation in C++ I’d highly recommend reading the previous articles in this series before continuing.

Even if you’re familiar with the concepts of hardware manipulation, if you haven’t read the […]

Posted in C/C++ Programming, Cortex, Design Issues | Tagged , , , , , , , , | 1 Comment

Making things do stuff – Part 2

Glennan Carnie

Glennan Carnie

Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.

He specialises in C++, UML, software modelling, Systems Engineering and process development.
Glennan Carnie

Last time we looked at the basics of hardware manipulation in C++.   This time we’ll apply this to some real hardware and have a look at the code

Posted in C/C++ Programming, Cortex, General | Tagged , , , , , , , | 4 Comments

Making things do stuff – Part 1

Glennan Carnie

Glennan Carnie

Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.

He specialises in C++, UML, software modelling, Systems Engineering and process development.
Glennan Carnie

C has long been the language of choice for smaller, microcontroller-based embedded systems; particularly for close-to-the-metal hardware manipulation.

C++ was originally conceived with a bias towards systems programming; performance and efficiency being key design highlights.  Traditionally, many of the advancements in compiler technology, optimisation, etc., had centred around generating code for PC-like platforms (Linux, Windows, etc).  In the last few years C++ compiler support for microcontroller targets has advanced dramatically, to the point where Modern C++ is a increasingly attractive language […]

Posted in C/C++ Programming, Cortex | Tagged , , , | 13 Comments

The three ‘No’s of sequential consistency

Glennan Carnie

Glennan Carnie

Technical Consultant at Feabhas Ltd
Glennan is an embedded systems and software engineer with over 20 years experience, mostly in high-integrity systems for the defence and aerospace industry.

He specialises in C++, UML, software modelling, Systems Engineering and process development.
Glennan Carnie

In the previous article we looked at the memory consistency problem that occurs when writing multi-threaded code for modern multi-processor systems.

In this article is we’ll have a look at how we can solve the sequential consistency problem and restore some sanity to our programming

Posted in ARM, C/C++ Programming, Cortex | Tagged , , , , , , | Leave a comment

Function Parameters and Arguments on 32-bit ARM

Niall Cooling

Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.

Function call basics

When teaching classes about embedded C  or embedded C++ programming, one of the topics we always address is “Where does the memory come from for function arguments?“

Take the following simple C function:

void test_function(int a, int b, int c, int d);

when we invoke the function, where are the function arguments stored?

int main(void)
{
  //…
  test_function(1,2,3,4);
  //…
}

Unsurprisingly, the most common answer after “I don’t know” is “the stack“; and of course if you were compiling for x86 this would […]

Posted in ARM, C/C++ Programming, Cortex | Tagged , , | 5 Comments

ARM TechCon 2013

Niall Cooling

Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.

ARM’s Technical Conference called TechCon™ is running between October 29th and 31st at the Santa Clara Convention Center in California.

This year I shall be making the trip over to present three classes:

Can Existing Embedded Applications Benefit from Multicore Technology?
Virtual Functions in C++ on the ARM Architecture
Developing a Generic Hard-Fault Handler for ARM Cortex-M3/Cortex-M4

For those of you who are regular readers of this blog you’ll recognise the Generic Hard-Fault Handler from a previous post.

The class “Can Existing Embedded Applications Benefit from […]

Posted in ARM, C/C++ Programming, Cortex | Tagged | 3 Comments

Test Driven Development (TDD) with the mbed

Niall Cooling

Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.

One of the most useful fallout’s from the acceptance of Agile techniques is the use of Test-Driven-Development (TDD) and the growth of associated test frameworks, such as GoogleTest and CppUTest, etc.

I won’t get into the details of TDD here as they are well covered elsewhere (I recommend James Grenning’s book “Test Driven Development for Embedded C” for a good coverage of the subject area), but the principle is

Write a test
Develop enough code to compile and build (but will fail the test)
Write the application code […]

Posted in ARM, C/C++ Programming, CMSIS, Cortex, Testing | 4 Comments