A Complete Guide On Understanding Embedded Testing



In the present world, almost all electrical devices use Integrated Circuits, where a lot of elements are fixed in a small board. These boards also contain the chips that control particular hardware or the whole devices. The chips and the circuit board work based on the software embedded in them.

Embedded software is the one that is programmed within devices like microchips, and have some specific hardware requirements.

On one hand, where application software can be easily installed on various computers, embedded software is coded for a particular device to provide specific functionality.

Embedded Testing is a very important stage in any software’s development life cycle to reduce bugs and to ensure the reliability of the software.

Testing is the process in which the software is made to execute in different situations and under different workloads and as a result, it generates some output.

At the same time, the Oracle produces the expected results for the instructions given. Then the expected and the achieved results are compared. The software passes the test if they are same and it fails if the two results are different.

what is embedded testing
Image Source: HCL Software Blog

Incorrect Way of Testing

1. Informal Testing: The way of testing in which people are just beating the software to see what happens, is not more than wastage of time if it requires a lot of efforts.

2. Without the Notion of Test Coverage: A test should ensure the developers that certain part of the software is working properly. It is inefficient to test software without deciding the areas of the software it’s going to test. 

3. No Pass/Fail criteria: There is no advantage of testing if there is no way to judge a test as pass/fail. There should be an expected result which should be compared with the generated result to get any value of the efforts invested.

Kinds of Testing

1. Unstructured Testing Approaches

This kind of testing embedded software is not recommended most of the time as it does not test the software in a detailed manner and as a result, a lot of bugs can be left undiscovered that can have a huge negative impact on it.

  • Smoke Testing

Smoke testing is a term generally used in the hardware world to test if it’s not catching fire or releasing smoke when the power is turned on.

Image Source: Testbytes

In embedded software testing it is just testing that the software embedded in the chip to see that it’s working at all or not. Of course, it is not an alternative to full software testing as it only informs that other testing should be done or not. 

As there is no need to waste time testing the software that cannot execute some simple instructions.

  • Exploratory Testing

In this embedded testing, the expert testers are exploring the software to find some bugs that can be easily encountered for fixing. This testing compares the achieved results with the expected results. But the productivity of this testing is dependent on the quality of the tester.

Unstructured Testing does not provide any clear idea about the test coverage and the number of requirements met by the software.

2. Methodical Testing Approaches

  • Black Box Testing

Black Box testing is that way of testing embedded software in which the tests are designed based on the functionality and the requirements that the software is build to provide and fulfil respectively.

The test design team has no idea about the code and hence it’s called BlackBox. 

  • White Box Testing

Embedded software testing through white box testing involves designing the tests to check that all the codes are working the way they are written to work. Here it is checked ‘whether the code is following the desired path or not?’.

Since the test design team has access to the source code, hence it is called white box testing.

Testing at Development Stages

There are various test that is done at different stages to check if the software is working going as intended.

Image Source: Testsigma

1. Unit Test: This type of testing is done frequently to check the accuracy of a small module of code.

2. Integration Test: It tests the compatibility of one module of code with the rest of the code. It requires the combination of Black Box and White Box testing.

3. Software Test: This test checks that ‘whether the software is meeting all the required specifications or not?’. It is a type of Black Box testing.

4. Acceptance Test: At this test, the testing is focused on the point of view of the customer. Here both hardware and software are tested to analyse the customer experience. 

It is completely a Black Box test but also involves some smoke and exploratory testing to quickly check ‘whether it seems to meet the expectations or nit?’.

Embedded Software Testing Tools

1. Tessy

Tessy is an embedded test automation framework that provides unit and integration testing tools for embedded software written in C / C++ and supports a wide range of microcontrollers and compiler environments.

Features

1. CTE – Classification Tree Editor transform the specifications into a set of test cases.

2. TOP/TRIM – Test Operator Platform creates test cases, run them and review the results.

3. ITE – Integrated Test Environment allows manage requirements and test cases in different documents and link them.

4. CCDL – Check Case Definition Language make it easy to specify the requirements of the test in a high-level language. It is an automated process hence reduces manpower.

Image Source: Sam Solutions

2. Klocwork

Klocwork test the security, quality, and reliability of software’s written in C, C++, C# and Java. It integrates the software automatically to prevent any vulnerability with every commit.

Features

1. Security Vulnerabilities detection due to SQL injection, Tainted data, Buffer overflow, vulnerable coding practices.

2. Tools are designed to function Continuous Integration and Continuous Delivery.

3. The portal dashboard displays the analysis data, trends, metrics and configuration for codebases across the organization.

4. Supports hundreds of compilers and cross-compilers make it easy to build integration.

5. Detailed information about the reason for any defect and code violation detected along with the remedial suggestions.

Embedded Testing allows developers to build quality software and ignore it of which can in major disasters, as in the case of software there is no fixed relationship between the size of the error and the impact it has on the system.