Enea has unveiled version 4.0 of its networking-oriented Enea Linux embedded distribution, introducing virtualization features and an updated Yocto Project 1.6 foundation. The Swedish telecom software vendor claims version 4.0 is “the most open commercial embedded distribution on the market.” We’ll await further evidence on that score, while also noting that all the major commercial embedded Linux platforms have become more open in recent years.

Embedded Linux vendors such as Enea, Wind River, MontaVista, and Mentor Graphics promote open source much more than they used to. Not so long ago, the chief pitches were for enterprise support, testing and validation services, and real-time “hardening” of the Linux kernel for deterministic, mission critical applications. These remain prime selling points, but the vendors are also starting to promote their new Yocto-based openness.

All these vendors primarily serve large, traditional networking and industrial firms. Like Wind River and Mentor Graphics, Enea is heavily invested in an older real-time operating system (RTOS). In the case of Enea, its OSE RTOS still dominates its business.

Yet Enea and others have also expanded into Linux to serve their customers’ need for more flexible and advanced applications with improved UIs and web connections. Improved real-time Linux support has also helped to lure RTOS customers, who have not always been comfortable using the same open code used by the great unwashed, especially considering the difficulty of tracking licensing compliance. Vendors, meanwhile, have wanted to differentiate their mostly proprietary value-added offerings from generic Linux code.

Trend toward open source

The trend toward openness was spurred on by the growing number of open source success stories both in server world and in the Android-based mobile consumer market. In the embedded world, meanwhile, customers are increasingly choosing open source, community-backed hardware.

Now open source is increasingly moving into high-end networking. Last week, for example, Facebook announced it was developing its own open source networking switch called Wedge based on an Intel microserver running a Linux-based FBOSS stack.

The major motivator, however, has been the increasing adoption of the Linux Foundation’s open source Yocto Project. We noted the Yocto trend among embedded Linux platforms back in 2012, and there’s been no turning back.

Yocto Project is now a requisite for most embedded customers, who don’t want to be trapped in proprietary walled gardens. Enea Linux, MontaVista Carrier Grade Edition, Mentor Embedded Linux, and Wind River Linux are all touted as being Yocto compliant. Smaller Timesys, which had backed away from Yocto, recently reaffirmed its Yocto support for its LinuxLink.

Yocto is based on an OpenEmbedded core, and comprises standardized templates, tools, and methods for embedded Linux. It also provides a large, collaborative community, and makes it much easier to track license compliance, a key concern for customers.

Linaro is also gaining traction; This ARM-directed nonprofit tools company consolidates and optimizes upstream Linux and Android code for ARM Cortex chips. Linaro has also established working groups that are helping to standardize vertical segments. These include the Linaro Networking Group (LNG), Security Working Group (SWG), and most recently the Digital Home Group. Enea promotes its role as an LNG kernel maintainer and contributor to the LNG’s OpenDataPlane (ODP) initiative for open networking interoperability.

Despite the Yocto and Linaro underpinnings, commercial distros still offer plenty of differentiation, based in part on each vendor’s customer base. Mentor Graphics, for example, merged MontaVista’s in-vehicle infotainment (IVI) stack with its own GENIVI-compliant stack and is pushing hard in the automotive segment. Enea is aligned with high-end networking, although registration with the Linux Foundation’s Carrier Grade Linux (CGL) 5.0 spec, enjoyed by MontaVista and Wind River, will await Enea Linux 5.0 later this year.

Commercial Linux platforms are also partially shaped by the need to integrate with sister RTOSes. Wind River customers, for example, can use a single vendor, and often single applications, to integrate both Linux and VxWorks deployments. Mentor Graphics offers some common tools that span both Mentor Embedded Linux and its Nucleus RTOS, while Enea is integrating its Linux platform with middleware that also runs on OSE.

All the vendors are processor agnostic, yet Intel’s Wind River tends to support new Intel chips earlier than others, and MontaVista recently came out with an SDK optimized for Cavium’s first ARMv8 SoC, ThunderX. Like Enea, Mentor Graphics is independent of a chipmaker, but it recently signed a deal to supply AMD with Mentor Embedded Linux SDKs.

Latest Commercial Embedded Distros

Here’s a quick look at the latest from the major commercial embedded Linux platforms, starting with Enea Linux. The names link to product pages:

Enea Linux — Enea has taken several stabs at the Linux market over the last decade, including an Enea Accelerator Platform middleware bundled with MontaVista or Wind River distros. In 2009, Enea launched an Eclipse-based Enea Linux Project Framework (ELPH), which it combined with Timesys’ LinuxLink to form the MIPS-focused Enea Linux PlatformBuilder. In 2012, Enea jettisoned LinuxLink and rebuilt ELPH on Yocto and a new real-time hardened runtime to form Enea Linux.

While Enea Linux 3.0 focused on real-time Linux support, version 4.0 is all about Network Function Virtualization (NFV), an increasing focus of all the vendors. Version 4.0 adds support for Intel’s DPDK (Data Plane Development Kit) for fast packet x86 processing, including its DPDK vSwitch and the underlying Open vSwitch. Version 4.0 also supports KVM virtualization on PowerPC and x86 targets. The Yocto 1.6 based platform adds support for Linux containers (LXC), among other features.

In February, Enea launched a free, community-backed Open Enea Linux, with Yocto and Linaro contributions. This lightweight version will target community-backed hacker boards.

Mentor Embedded Linux — The latest version of Mentor Graphics’ Linux distro ships with AMD’s latest for “Steppe Eagle” (G-Series) and “Bald Eagle” (R-Series) SoCs, along with Mentor’s Sourcery Codebench Lite toolchain. Much of Mentor’s Linux focus, however, has been on the related Mentor Embedded Automotive Technology Platform (ATP), which integrates MontaVista’s earlier IVI stack. In January, Mentor Embedded ATP added GENIVI 5.0 compliance.

MontaVista Carrier Grade Edition — Cavium’s software subsidiary is increasingly focused on its CGL 5.0 compliant MontaVista CGE 7. As noted, the platform has added support for Cavium’s ARMv8 ThunderX. In February, MontaVista announced a CGE variant called MontaVista MV Cloud which uses “standard IT API,” thereby supporting third-party software for NPV like DPDK, ODP, and open cloud platforms OpenStack and OpenDaylight.

Wind River Linux— Last October, the leading commercial distro reached version 6. Based on a Yocto kernel and toolchain, Wind River Linux 6 added support for ARMv8. The Intel subsidiary also announced a faster, Yocto-compatible version of its carrier-grade Wind River Open Virtualization.

In April, Wind River released a Yocto-based Security Profile for Wind River Linux aimed at Internet of Things. The EAL 4 compliant software adds a hardened Linux kernel, secure boot, and a security-focused user space.