20 Yocto Interview Questions and Answers

Yocto is a Linux distribution for embedded systems. It is popular for its small footprint and ease of use. When applying for a position that involves Yocto, it is important to be prepared to answer questions about your experience and knowledge. In this article, we discuss some of the most common Yocto questions and how you should answer them.

Yocto Interview Questions and Answers

Here are 20 commonly asked Yocto interview questions and answers to prepare you for your interview:

1. What is Yocto?

Yocto is a Linux Foundation project that provides templates, tools and methods to help create custom embedded Linux distributions for embedded and IoT devices.

2. Why do you think it’s important to use an open source embedded Linux distribution like Yocto?

I think it’s important to use an open source embedded Linux distribution like Yocto because it allows you to have complete control over your embedded Linux system. With Yocto, you can customize your system to include only the features and components that you need, which makes it very efficient. Yocto is also constantly being updated and improved by the community, so you can always be sure that you’re using the latest and greatest software.

3. Can you explain what a BSP layer is in the context of Yocto?

A BSP layer is a Board Support Package layer. This type of layer provides support for a specific hardware board. It typically contains device drivers, board-specific configuration files, and other low-level code.

4. How many types of layers are there in Yocto?

There are five types of layers in Yocto:

1. Metadata Layers
2. Software Layers
3. Configuration Layers
4. Application Layers
5. BSP Layers

5. How does Yocto help with cross-compiling?

Yocto is a build system that is designed to help with cross-compiling. It can be used to generate images for different target devices, and it can also be used to compile software for those devices. Yocto can help to make sure that the software you are compiling will run on the target device, and it can also help to automate the process of cross-compiling.

6. What are the main components of a Yocto recipe?

The main components of a Yocto recipe are the recipe file itself, which contains metadata about the recipe, the source files, which are the actual files needed to build the recipe, and the patches, which are any changes that have been made to the source files.

7. In which directory do custom recipes for your project go in Yocto?

The custom recipes for your project go in the “recipes” directory.

8. Is it possible to create custom images using Yocto? If yes, then how?

Yes, it is possible to create custom images using Yocto. To do this, you will need to create a new recipe that inherits from the core image recipe. From there, you can add in any customizations that you need.

9. What are the different flavors of Bitbake available?

The three main flavors of Bitbake available are Standard, Core, and Advantages. Standard is the most widely used and recommended for most projects. Core is a smaller, more lightweight version that is suitable for embedded projects. Advantages is the most feature-rich version and is recommended for larger projects.

10. What does the bitbake command do?

The bitbake command is used to compile software for the Yocto Project. It is typically used to compile Linux kernel images, bootloaders, and user-space applications.

11. What is Poky?

Poky is a build system used to construct complete Linux distributions from source code. It is used by the Yocto Project to create a reference distribution, as well as by many commercial embedded Linux vendors and device makers.

12. What is Toaster?

Toaster is a web interface for the Yocto build system. It provides a way to manage and monitor Yocto builds, and can be used to create custom images.

13. How can you access Toaster from your browser?

Toaster is a web interface for the Yocto build system. To access it, you need to go to the Toaster URL, which is typically http://localhost:8000.

14. What are some common problems faced while building and running Yocto projects on Windows?

Some common problems that can be faced when building and running Yocto projects on Windows include:

– Lack of support for certain features in the Windows operating system
– Difficulty in setting up the development environment
– Incompatibility between different versions of Yocto
– Lack of documentation on how to use Yocto on Windows

15. Is it possible to build multiple packages at once using Yocto?

Yes, it is possible to build multiple packages at once using Yocto. This is accomplished by using the bitbake -b command followed by the names of the recipes that you wish to build. For example, to build the foo and bar recipes at the same time, you would use the following command:

bitbake -b foo bar

16. What is the best way to extend an existing meta layer in Yocto?

One way to extend an existing meta layer in Yocto is to create a new layer that inherits from the layer you want to extend. You can then add or modify recipes and configuration files as needed in your new layer.

17. What are some features that make Yocto popular with developers?

Yocto is popular with developers because it is a very powerful and flexible build system. Yocto can be used to create custom Linux distributions for a variety of embedded devices. Yocto is also easy to use and has a large number of available recipes, which makes it possible to create a wide variety of custom Linux distributions.

18. What is the significance of LICENSE_FLAGS_WHITELIST in Yocto? When should it be used?

LICENSE_FLAGS_WHITELIST is a variable in Yocto that is used to control which licenses are accepted when building images. If you are building an image that will be distributed, then you will want to use this variable to ensure that only licenses that are acceptable for distribution are included.

19. What are the different ways a package can be added to a target image in Yocto?

There are a few different ways that a package can be added to a target image in Yocto. One way is to simply add the package to the IMAGE_INSTALL variable in the image recipe. Another way is to create a separate packagegroup recipe and add that to the image recipe. Finally, the package can also be added to the EXTRA_IMAGE_FEATURES variable.

20. What is meant by “recipe” when working with the Yocto framework?

A recipe is a set of instructions for the Yocto build system to follow in order to generate a particular software package. A recipe will specify the source code to use, the dependencies that are needed, and how to configure and build the software.