Considering building a custom embedded Linux distribution? Four great reasons to choose the Yocto Project.
By exercising the freedom to customize the Linux® operating system ‐ the ability to implement the ideal mix of features and capabilities for their product, while minimizing the OS’s memory footprint ‐ developers can bring to life embedded device ideas that would simply not be possible without the benefits of open source.
The developer has various options to choose from when considering which tool suite to use to build their custom Linux distro. Of these options, the most well-known is the Yocto Project, a suite of tools and processes which enable the developer to build, from the ground up, an embedded Linux distribution to run on their choice of hardware, from a broad set of system-on-chip (SoC) and microprocessor platforms.
What has made the Yocto Project so popular?
In fact, there are four special attributes of the Yocto Project which experienced Linux system developers value particularly highly.
1. Determinism: get exactly the OS you coded for
The first is a fundamental characteristic of the Yocto Project: that the source code determines the binary image produced by a build. So, every build based on a single version of source code can be guaranteed to produce exactly the same output ‐ it is deterministic. The output is not affected by previous builds or by the choice of libraries.
When using the Yocto Project, to get different features in the distro, the source code has to be different. This imposes a discipline on the development process that other, simpler tool suites do not require. The Yocto Project expects the developer to be rigorous in their selection of the distro's recipe, and in implementing features in source code before a build takes place.
The advantage of the Yocto Project's determinism is that the developer can rely absolutely on the consistency of the OS image from one build to another, provided it is based on the same source code.
2: Multi-layered and overridable: Portable software from one hardware platform to another
The output from the Yocto Project process looks superficially like a monolithic entity ‐ an OS and related applications running on the project’s chosen hardware target.
In fact, the Yocto Project output is structured as multiple independent layers of software organized in three blocks:
- Board support package (BSP)
- Distro layer
- Application layer
Because every layer is independent, the layers can be mixed-and-matched: for instance, the distro should not be tied to a specific BSP, so a distro originally developed for one SoC can be implemented instead on a different SoC without the need to change the distro's source code ‐ the developer only needs to change the BSP.
This gives the developer a great deal of control and flexibility to respond to changes in customer requirements, or to supply chain disruptions which might make the OEM’s preferred SoC hard to procure or too expensive.
3: Tailored images: greater freedom to customize
Users of other Linux build environments can be surprised when presented with the Yocto Project's requirement to build a tailored image when compiling a distro, rather than giving the developer a predefined image. In the Yocto Project, the developer defines how applications are built, and how the image is structured. For instance, the developer has the freedom to choose whether the image has one, two, three or more partitions, and which bootloader to use.
This process asks more of the developer than a predefined image does, but the developer benefits from more freedom to customize and shape the implementation of their distro in the final product.
4: The Yocto community: strong foundations for the future
The final unique attribute of the Yocto Project is not a software feature: it is the nature of the organization behind the Yocto Project. It is an open-source project which has the backing of many large companies as well as hundreds of individual developers. Some of the biggest contributors to the Yocto Project's code base include Wind River, Intel, Fujitsu, and Juniper Networks.
In addition, the project is managed under the umbrella of the Linux Foundation, with all the support and organizational infrastructure that this provides.
So, developers and OEMs who are considering which platform to use for building a custom Linux distro can be confident that the Yocto Project has a long-term future, and that the project will continue to enjoy contributions from companies and individuals which will keep it up to date with the latest developments in microprocessor, cybersecurity, connectivity and other technologies.
So, your destiny in your hands
In summary, the Yocto Project, which is supported by the FoundriesFactory™ Platform, is a proven and popular framework enabling developers to produce a custom Linux distro for embedded devices. In contrast to other simpler platforms, the Yocto Project imposes a certain level of discipline on the developer, requiring them to make design and configuration decisions rather than defaulting to pre-defined options.
This enables a high level of customization, and rewards the developer with the freedom to make exactly the Linux distro that they need for their application.