Tag Archives: quality

goto fail and embedded C Compilers

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.

I can’t imagine anyone reading this posting hasn’t already read about the Apple “goto fail” bug in SSL. My reaction was one of incredulity; I really couldn’t believe this code could have got into the wild on so many levels.

First we’ve got to consider the testing (or lack thereof) for this codebase. The side effect of the bug was that all SSL certificates passed, even malformed ones. This implies positive testing (i.e. we can demonstrate it works), but no negative testing […]

Posted in ARM, C/C++ Programming, Industry Analysis, Testing | Tagged , , , , , | 5 Comments

The hokey-cokey* of function calls

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

Functions are the lifeblood of a C program. The program flow is altered by passing parameters to functions, which are then manipulated. Conceptually function parameters are defined as being either:

Inputs (Read-only) – client-supplied objects manipulated within the function only
Outputs (Write-only) – objects generated by the function for use by the client.
Input-Outputs (Read-Write) – client objects that can be manipulated by the function.

Defining the use of a parameter gives vital information not only to the implementer, but (perhaps more importantly) to […]

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Effective Testing: The “Swiss Cheese” model

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

Why do we test?

Software development is a collaborative effort. You bring in input from customers, managers, developers, and QA and synthesize a result. You do this because mistakes in requirements or architecture are expensive, possibly leading to lost sales.

When we develop products we want them to be successful. We want our customers to buy, enjoy, and recommend our products or services. In other words, we want to build quality products. In this case, quality means four inter-related things:

Compliance quality– Can […]

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Fundamentals of Configuration Management

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

Configuration Management (CM) is a core process in any development activity. Software engineers realise this more than any other discipline, but for many software teams using Subversion as a source code repository is as far as they get. Configuration Management is a lot more than this.

These articles introduce the fundamental concepts of Configuration Management and what they mean to the development team. Revision control is the most well known and understood CM activity but few extend this to develop artefact […]

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Elizabethan guidance on Object-Oriented software design

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

So what did the Elizabethans know about software development?  Well, in truth, nothing whatsoever.  But what they had begun to do is codify and systematise the knowledge and experience of masters in manuals, treatises and books.  Some of the earliest documents of this form refer to the martial arts or, as it was known at the time the ‘Arts of Defence’

In martial arts one learns practical skills (in this case how to defend oneself against any enemy) through practice and […]

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