Earlier this month, Linus Torvalds was reminded that Linux 3.8 will not run on i386 computers, such the one he used to create Linux back in 1991. "I'm not sentimental," Torvalds responded. "Good riddance."
In that same future-looking spirit, we anticipate the progression of embedded Linux in 2013, a year in which forecasters expect PCs will continue to shed market share to mobile devices. In 2013, the Linux-based Android should continue to dominate smartphones, while drawing closer to matching Apple's iPad on tablets. Meanwhile, three new mobile operating systems based on open source Linux are expected to launch on new smartphones.
In the wider world of embedded, from consumer electronics to retail, medical and industrial systems, Linux continues to gain market share over Windows Embedded and a range of real-time operating systems (RTOSes). Here we look at seven major embedded Linux stories we can expect to follow in 2013.
Linux Continues Advance on RTOSes
As devices are re-sculpted for wireless networking, IPv6 Internet access, and touchscreen interfaces, real-time operating systems continue to be replaced by more advanced embedded operating systems like Linux and Windows Embedded. According to 2012 surveys of embedded engineers from VDC Research and UBM Electronics, Linux is advancing at the faster rate, and it's bringing its younger cousin Android in tow. Over 20 percent of developers in VDC's survey are now working with Linux targets, or closer to 25 percent when Android is included. Some 35 percent of developers surveyed by UBM are working on Linux projects, or 48 percent including Android.
"We're seeing a lot of headway for Linux in just about all embedded categories, including automotive, home automation, retail, industrial, medical, and digital signage," says Jared Weiner, an analyst at VDC Research. "The exceptions are networking, where Linux was already strong, and in military applications."
In industrial and mil/aero applications, the continuing "hardening" of the Linux kernel with deterministic features, assisted by OSADL's PREEMPT RT patch, has improved the Linux argument vs. RTOS. Yet, Linux still has a long way to go as a "real-time" OS. It's till primarily used in those segments' less mission-critical applications, where its open nature, low cost, and multimedia, networking, and Internet capabilities are in increasing demand.
When you look at the topics being discussed at meetings like the Embedded Linux Conference (ELC) , there's still plenty of work being done on basics like file systems, debugging, audio, and booting. Much of the newer work focuses on power management, real-time Linux, and getting the most out of multicore processors.
Security will be a growing embedded concern in 2013, says VDC's Weiner. As device vendors add Internet access, a Catch-22 dilemma arises. Advanced OSes like Linux offer better web support, but are seen as being less secure than RTOSes. Fortunately for Linux, the perception of Windows security is even lower, says Weiner.
The Linux kernel continues to add security features, and commercial Linux vendors are adding more layers, but the challenge remains. One emerging solution is to use virtualization on hybrid devices to segregate critical RTOS functions from higher level Linux code, says Weiner.
Embedded Linux Opens Up
In 2012, several open source standardization projects have found surprising success in herding the heterogeneous Linux forces toward common goals. As we examined last week , commercial embedded Linux distributions like Wind River Linux and Mentor Embedded Linux are increasingly adopting the Linux Foundation's Yocto Project as a standard code base. Meanwhile, Linaro is standardizing ARM implementations from embedded Linux and Android devices all the way up to ARM mini-servers.
"Standard tools and processes such as those provided by the Yocto Project function similarly to the way having a common language helps diplomatic relations among people," says Jeffrey Osier-Mixon, Community Manager for the Yocto Project at Intel Corp. "They offer a common context and provide a stable answer to basic questions so developers can work on the harder ones."
In addition, open source hardware projects are creating new collaborative ecosystems for hobbyists, academics, students, and entrepreneurial startups. A number of Linux-driven open source board development projects  have copied BeagleBoard.org's formula for success, including PandaBoard.org and the Raspberry Pi Foundation. Meanwhile, the open source Android-based Ouya gaming console is due in March.
We're also seeing new open source Linux projects for more purpose-built hardware. These include robot projects like Qbo, open source cameras like Elphel, laser cutters like the Lasersaur, and tablets like Vivaldi, Trimble Yuma, and PengPod. Other open projects don't necessarily run embedded Linux -- or any OS at all -- but are closely aligned with the Linux development community. These include Arduino, as well as new small-scale replication projects like RepRap and MakerBot.
Android Goes Embedded
By unit and revenue measures based on smartphone and tablets alone, Android is the most dominant form of Linux in consumer electronics. In 2013, the Google-directed OS is expected to maintain or boost its smartphone share, and edge much closer to Apple on tablets.
Android 5.0 ("Key Lime Pie") will likely be unveiled at Google I/O on May 15, potentially bringing new video chat and multi-device integration features. More important for Android's continuing success is whether Google can boost security and help vendors speed updates.
Android is also beginning to extend  into the general embedded world. Initially, it's finding success in rugged handhelds, set-top media players , cameras, and IP phones. To a lesser degree, Android is appearing in robots, home automation devices, consumer appliances, medical devices, printers, and automotive infotainment devices, all areas in which embedded Linux is also on the move.
"We've been hearing about Android is spreading beyond smartphones and tablets for years, but now we're finally starting to see it happen," says VDC's Weiner.
In 2013, Android may also begin to show up in industrial HMI systems. It is not, however, likely to make much headway in the networking world where Linux dominates in devices ranging from network-attached storage (NAS) to 4G basestation equipment.
"The challenge with using Android for general embedded devices is that Android is designed for mobile devices," says Intel's Osier-Mixon. "There is always the risk that something developed today might not work for the next release of Android. Meanwhile, some of the main attractions of Android, such as gestural touch interfaces, are also becoming available via Linux platforms like Yocto Project."
As Android moves into embedded, it should benefit from greater alignment with the Linux kernel -- and vice versa. The schism between Google and the Linux community has lessened considerably in the last two years, as Google has taken a more active role in upstream contributions. The Linux 3.3 release in March was a milestone, for the first time enabling Android code to be compiled from the Linux kernel.
Linaro is playing an important role in this alignment, says Mark Orvek, Linaro Kernel Working Group Director. "Linaro works closely with the Android (AOSP) and Linux kernel communities to ensure key features and patches are included in the upstream source," says Orvek. "This enables Android to work more easily with the leading edge Linux kernel versions."
Linux Cleans Up its ARM Act
Linux/Android integration is also being advanced with improvements to the Linux kernel's ARM code. Embedded developers have struggled with the poorly maintained code in the Linux ARM subtree. Compared to x86, the ARM code has been challenged by ARM'S diversity of processors and lack of hardware discoverability. Whereas x86 is fairly monolithic, new ARM chips typically required the development of new kernels.
In recent years, the ARM community has taken up the challenge to clean up ARM Linux with renewed gusto. In 2010, ARM launched Linaro, whose charter was not only to provide standardized open source tools and middleware for Linux and Android applications running on ARM Cortex processors, but to help streamline ARM kernel code.
Linaro, together with the kernel community in general, has made considerable progress, according to Linaro CTO David Rusling. "Huge strides have been made in the Linux ARM code," he says.
Linux 3.7 added further enhancements to ARM Linux that should register in 2013, including ARM v8 64-bit support and ARM multi-platform support. The latter for the first time enables a single ARM kernel image to boot to multiple hardware platforms. (Here, the Linux community may be chastened to note that Microsoft beat Linux to the punch with Windows RT.)
While 64-bit ARM and multi-platform ARM support will be especially relevant to server applications, they will also play a role in embedded, says Rusling. "Linaro has been key in this process, promoting and supporting such technologies as device tree," says Rusling. Meanwhile, ongoing work with power management and Android support should more directly benefit embedded, he adds.
Both Rusling and VDC's Weiner predict that 2013 will be a breakout year for ARM Cortex-A15 processors. Rusling is particularly keen on the opportunities for the big.Little system-on-chip (SoC) design, which combines the speedy A15 with the Cortex-A7, the more energy-efficient heir to the Cortex-A8. In the embedded world, the combo SoC design should prove to be especially advantageous for automotive and networking applications, says Rusling.
"The way big.Little tasks and power are managed across multiple cores will be of major interest, especially in power efficiency," says Rusling. "big.Little is driving a lot of change into the Linux kernel that will benefit all multicore systems."
Meanwhile, the increasing use of ARM processors in off-the-shelf modules and boards is also helping ARM's cause. In particular, Kontron's new ULP-COM ARM module format should have a major impact in 2013.
Intel Aims for Android, 22nm Atoms, and M2M
Intel is still the world's leading semiconductor vendor, and has a huge presence in the embedded world with its Intel Core and Atom processors. Yet, it is increasingly challenged by ARM licensees like Samsung, Qualcomm, and Nvidia, which together dominate smartphones and tablets, as well as Texas Instruments (TI), which is now focusing exclusively on the embedded market.
Other architectures are gradually fading. TI and Freescale are increasingly switching their PowerPC customers over to ARM. MIPS had a tough 2012, with licensees like Cavium increasingly moving to ARM, and MIPS Technologies is now on the verge of being acquired.
Intel still beats ARM on performance, but lags in power efficiency and price. Nevertheless, over the last year, its "Medfield" Atom chips have launched in over a half dozen Android phones, representing the first wave of Android/x86 products, They have shown surprisingly good battery life to go along with the expected strong performance benchmarks.
Intel's faster new "Clover Trail" Atoms have initially focused on Windows 8 tablets, but after some power management optimizations, will arrive for Android and Linux in 2013. By this time next year, we should see some more high-profile Atom-based Android phones and perhaps a few x86 Android tablets, and gain a better sense of whether Android-on-x86 is for real. Meanwhile, a quad-core, 22nm "Bay Trail" Atom design should arrive in 2014, boosting typical tablet battery life from 9 to 11 hours, relative to Clover Trail.
In September, Intel announced an Intelligent Systems Framework spec designed for M2M devices like network appliances, home automation devices, and security cameras. The spec defines an x86-based device that supports wireless technologies such as ZigBee, and incorporates middleware from its McAfee and Wind River subsidiaries. At the announcement, Intel claimed its embedded business has grown at a 20 percent per year compound rate to $2 billion a year.
Autos Don a Tux
Earlier this year, Linux made its first big splash in in-vehicle infotainment (IVI) with the Cadillac CUE computer found in the new Cadillac XTS. Many other emerging Linux-based platforms are aligned with the open source in-vehicle infotainment (IVI) spec maintained by the Genivi Alliance. Genivi's x86- and ARM-compatible spec appears to have growing support, according to VDC's Weiner. Already, Mentor Graphics, MontaVista, Wind River, Canonical (Ubuntu), and the Linux Foundation's Tizen platform have introduced Genivi-compliant IVI distributions, and several Genivi-based solutions are expected to reach market in 2013.
In addition, the Linux Foundation launched an “Automotive Grade” Linux workgroup focused initially on its Tizen platform. Supported by Toyota, as well as many of the same companies that have signed on to Genivi, the spec is intended as an automotive equivalent of the Linux Foundation's Carrier Grade Linux spec.
IVI device vendors are particularly interested in the Linux Foundation's Long Term Support Initiative (LTSI). The goal is to develop and maintain a kernel that will remain stable for two to three years, the duration of a typical consumer electronics product. The automotive industry, which is used to highly stable RTOS systems, is looking into the possibility of extending that to up to 10 years.
Linux Mobile Platforms Arise!
As Android enters the general embedded realm, several new Linux-based mobile OSes  are stepping out to compete in the smartphone market. In 2013, the Linux Foundation's Tizen, Mozilla's Firefox OS, and Jolla's Meego spinoff, Sailfish, all plan to ship on new phones. If that's not enough, an upcoming mobile version of Ubuntu is due in 2014, HP's Open WebOS may yet reawaken on new hardware, and even the GNOME Foundation is planning a mobile-ready, developer-focused GNOME OS.
Most of the mobile Linux contenders are initially targeting the high-growth market for low-cost phones in emerging nations . With a little help, they may also find a foothold in the developed world. If RIM's BlackBerry continues to slide and Windows Phone fails to gain traction, device vendors may start looking around for another OS to balance their dependence on Google.
All eyes are on Samsung to see if it moves significant resources toward Tizen, which it is already integrating with its own Bada OS. Meanwhile, Mozilla has added rising Chinese vendor ZTE to the Firefox OS cause. Tizen and Firefox OS, which both emphasize HTML5, could benefit if similarly web-focused platforms like Google's Chrome OS gain traction.
The new Linux OSes barely register on mobile forecasters projections, and it may well be that Android and Apple iOS will blot out any new platforms for years to come. However, when the time is ripe for a new platform to arise, the odds are good it will be open source Linux. To succeed without the advantages of open source -- especially low cost and the ability to quickly ramp up to speed by building on earlier platforms -- one would need to possess mobile technology that far outpaces the current leading edge. With any luck, that won't be an either/or situation.