Linaro seeks to simplify ARM Linux landscape

The ARM processor family is a complicated one, with many different variations, leading to large numbers of separate sub-architectures in the Linux kernel. A quick glance at the ARM directory in a recent kernel tree shows nearly 70 different sub-architectures, each corresponding to a different CPU or system-on-chip (SoC). That complexity has made it harder to develop new products for new or existing ARM devices. A new organization that was formed by six silicon vendors, Linaro, seeks to simplify that landscape, and allow easier—faster—development of ARM-Linux-based products.

Linaro was announced on June 3 as a non-profit company founded by ARM, Freescale, IBM, Samsung, ST-Ericsson, and Texas Instruments that intends to "provide a stable and optimized base for distributions and developers by creating new releases of optimized tools, kernel and middleware software validated for a wide range of SoCs, every six months." That six-month schedule aligns with Ubuntu's—the first release is due in November, one month after Ubuntu 10.10—and Canonical will be heavily involved in the effort. Linaro already has a project in Launchpad, Canonical's software collaboration platform, and it will seemingly take the place of Ubuntu-ARM.

The focus will be on the low-level plumbing for ARM-based systems: the kernel, development tools, boot loaders, and graphics. The Linaro FAQ and other pages on the web site make it clear that Linaro is not planning on creating a new distribution. It is, instead, pitching in on upstream projects to simplify and optimize for ARM systems. It is not a new distribution, but clearly the hope is that various distributions will adopt the Linaro contributions.

The company lists current mobile distributions as potential benefactors of its efforts. Android, MeeGo, LiMo, and Ubuntu are specifically mentioned as mobile ARM distributions that might benefit from the work Linaro is planning to do. Because the work will be done in conjunction with the upstream projects, any other existing or new distribution can also make use of the improvements.

In addition, Linaro touts its benefits to consumers. By reducing the complexity for device makers, it will be "enabling exciting innovative products to come to the market quicker". Focusing on power consumption will also result in devices that "have longer battery lives or slimmer cooler designs". Linaro clearly wants to maintain—increase—the level of ARM adoption in mobile devices.

Linaro will be well-funded, with a budget said to be tens of millions of dollars, much of which will pay for 80 employees. There are several levels of membership in Linaro, with two paying classes, Core and Club, which each provide money and engineers to the organization. For small organizations or individual contributors, there is the free Community Member class. There is a rather elaborate organizational structure that governs the company, as well as a management team in place. Based on all of that, it seems clear that Linaro wasn't just thrown together quickly, but has been in the works for some time.

There are already specific plans for what will be contained in the upcoming release. Canonical's Linaro release manager, Jamie Bennett, looks at the plan for Linaro 10.11 on his blog. There he also provides some more detail on the fragmentation in the Linux ARM world that led to the formation of Linaro:

That something is laid out in a detailed release document on the wiki. The tasks are broken up into four areas: Kernel, Graphics and User Experience, QA and Validation, and Infrastructure, with Linaro-specific as well as related Ubuntu tasks listed. Using device trees to describe different ARM hardware, which could reduce the complexity of configuring Linux for the platform, is high on the list. While some ARM hackers are not sold on device trees, a recent linux-kernel discussion about the proliferation of ARM configurations would indicate that Linus Torvalds, at least, is interested in seeing some kind of complexity reduction for that architecture. If Linaro can work with the upstream kernel developers to find a solution—device trees or something else—to that problem, it will have accomplished much.

There are other things on the agenda for the 10.11 release including standardizing and unifying the telephony stack for the platform, making Qt fully functional on ARM, optimizing web browsers for the architecture, and selecting the "best toolchain for ARM hardware". Overall, the list of planned achievements for the five months before the release is quite ambitious. Whether all that can be completed by a brand new organization—even with a great deal of Canonical know-how—remains to be seen. In the end, even completing a big chunk of it would be quite an accomplishment; presumably there will be 11.05 and further releases to fill in any gaps.

In many ways, Linaro is further proof that Linux is winning the battle for which OS will run on consumer electronics and other embedded devices. ARM chips are the dominant embedded Linux platform these days, but Intel has been targeting the low-power arena with its Atom processors. Linaro certainly looks like an effort to ensure that ARM-based devices maintain their lead in the embedded Linux world. It should be an interesting battle to watch.