Canonical announced it will port Ubuntu Desktop Linux to the ARMv7 architecture. Targeted at netbooks, the Ubuntu ARM distribution could set the stage for Intel to lose the “software advantage” that has enabled x86 to shrug off attacks from other architectures for the last 30 years.

Cellphone giant Nokia has long sponsored an unofficial project to port Ubuntu to ARM. Now, though, new ARM capabilities in the Linux kernel such as highmem support should make it possible to compile ALL of Ubuntu on ARM, including OpenOffice and Java. Especially now that both Canonical and ARM, Ltd. have gotten involved.

Compared to X86, ARM has always had a power advantage, especially in terms of the power used when idle. An ARM-based device such as Nokia's N810 Internet tablet can last several weeks in standby mode, with a cellphone-sized battery, while early devices based on Intel's most power-efficient Z5xx-series Atom processors are lasting typically less than six hours.

On the other hand, the “Intel Architecture” as Intel now styles x86 has a 30 year history of winning in the market thanks to the existence of so much x86 software. Software dominance enabled x86 to withstand many attacks from more elegant architectures through the years — DEC's Alpha, IBM/Apple/Motorola's PowerPC, Sun's SPARC, HP's PA-RISC, and so on.

Yet, with Ubuntu poised to bring practically the whole world of open source software to ARM, a tectonic shift away from x86 could well be underway.

Meanwhile, Intel's Atom chips are “first-generation” silicon and likely to improve up to 20 percent in subsequent iterations, if patterns typical of the chip market hold. And, Intel is not sitting quietly by. Instead, its own Moblin initiative aims to build even further on x86's software dominance by providing developers the tools they need to port and write software for LPIA (low-power Intel architecture) devices in the MID and netbook categories.

What's it all about?

Due to arrive in netbooks and energy-efficient “hybrid computers” in April, the ARMv7 port of Ubuntu will target system-on-chips (SoCs) based on ARM's Cortex-A processor cores. Presumably, the distro could also support SoCs built around cores created by ARMv7 architecture licensees. However, no such SoCs have been announced yet, to our knowledge. TI, which uses ARM's processors in its SoCs rather than licensing the ARMv7 architecture and creating its own, seems to have the only shipping ARMv7-based parts so far, with its Cortex-A8 based OMAP3 SoC family. Past ARM architecture licensees have included Intel, with its XScale implementation, and Freescale, with i.MX.

Canonical offered few details about the new ARM distribution except to say that its partnership with ARM would highlight and leverage the two companies's support for open source initiatives, including Linux kernel, Debian, GNOME, and Mozilla communities. ARM has actively supported ARM Linux development efforts on all of the above-mentioned projects for more than a year.

Last month, Rob Coombs, ARM's director of mobile solutions, was quoted in a ZDnet.co.uk story as saying that ARM's high-end Cortex-A family of processor cores would begin appearing soon in netbooks.

Canonical specifically mentioned SoCs based on ARM Cortex-A8 and the newer, multi-core Cortex-A9 as likely targets for the distro. The Cortex-A8, first announced in October 2005, can deliver 1,200 Dhrystone MIPS (millions of instructions per second), roughly the equivalent of a Pentium III processor, TI claims. Furthermore, the benchmark does not include the substantial processing power contributed by the DSP (digital signal processor) and IGP (integrated graphics processor) found in most OMAP3 chips.

ARM Cortex-A9 in MPCore configuration
(Click to enlarge)

Compared to earlier ARM processors, Cortex is more “superscalar,” meaning that more instruction can be dispatched on each clock cycle, provided the instructions are small enough (8- or 16-bit). Early Cortex parts include TI's OMAP3440, aimed at mobile phones, and the OMAP35xx, which is said to target “Internet appliances” and PMPs (portable media players). The top model in the latter family, the OMAP3530, is said to decode HD video at 30 frames per second, and also sports an OpenGL ES 2.0 graphics accelerator, TI says.

In 2007, ARM announced the multicore-enabled Cortex-A9, which, thanks to MPCore interconnect technology (above), is claimed to support SoCs with up to four A9 cores. Since the power used by a processor is the square of its clock frequency, two cores clocked at half the speed of one can in theory deliver the same processing power at a quarter the power (of course, the code has to be optimized for parallel execution, which certainly takes considerable “energy,” as it were). The Cortex-A9 will offer clock speeds over 1GHz, and provide “four to 16 times the performance” of ARM11 while still fitting within the same power envelope, says ARM.

Chipmakers licensed to produce Cortex-A9 CPUs include NEC, Nvidia, STmicroelectronics, Texas Instruments, and Toshiba, ARM says. Meanwhile, those licensed to produce Cortex-A8 products are Broadcom, Freescale, Matsushita, Samsung, STMicroelectronics, TI, and PMC-Sierra, adds ARM.

ARM's chief rival, Intel, coined the netbook moniker as defining low-cost sub-notebooks that use low-powered x86 processors such as the A110 (“McCaslin”) or the Intel Atom. The latter has appeared in the vast majority of netbooks to date. Intel also defined the smaller MIDs (mobile Internet device) category as being linked to its Atom, but according to a June report on the MID market from Forward Concepts, MIDs will be dominated by ARM.

Intel and ARM aren't alone in the booming netbook processor market. Via has promoted its C7-M ULV processor in mini-laptops, and has developed two reference platforms, the 2007 NanoBook and this year's OpenBook, but the C7 has only appeared in a few netbooks, such as the Eltrinix MobilePC. Via may well have more success with its new Nano processor, which uses Via's 64-bit Isiah architecture. The Nano has been reported to benchmark favorably in comparison with the Intel Atom in terms of performance and power.

Meanwhile, at least one dark horse in the netbook processor race may emerge. For example, several netbooks, including Emtec Gdium, use the MIPS64-based Loongson 2 (formerly “Godson-2”) processor, which is manufactured by ST, and originally developed by China's Institute of Computing Technology (ICT).

Will Windows be left out?

Future “netbooks” based on ARM cores would run on Linux, Windows Mobile, or Windows CE, but not Windows XP or Vista, unless Microsoft chose to port to the architecture. Given Windows 7's focus on netbook support, a port to ARM of that OS certainly seems likely, if ARM starts to win a significant portion of the netbook market. Meanwhile, Quarta Mobile has announced a version of Windows CE 6.0 tailored for netbooks and MIDs (mobile internet devices).

So far, the only ARM-based netbooks we know about run Windows CE. U.K. retailer Robert Dyas announced a mini-laptop based on Windows CE 5.0 called the Cuol Book that sells for about $300. Hong Kong-based Join Tech announced an ARM- and CE-based device that it claims to be the first sub-$100 mini-laptop, called the J-Pro JL7100.

Ubuntu's road toward embedded

While several desktop Linux distributions have spun off netbook versions over the the last year, Canonical has been especially rigorous in expanding Ubuntu into netbooks and other mobile devices. In early 2007, Canonical launched the Ubuntu Mobile and Embedded (UME) project, and in June of this year, Canonical launched a UME-based release of of Ubuntu 8.04 called Ubuntu MID Edition, in cooperation with the Intel sponsored Moblin project. The initial developer release is available for both the Intel Atom and Intel's A100/110 platform, targeting the Samsung Q1U ultra-mobile PC.

Mark Shuttleworth

Earlier this year Canonical and Ubuntu Founder Mark Shuttleworth (pictured) predicted Linux dominance in devices. The very next month, Ampro began distributing a Ubuntu Linux derivative with its x86-compatible single-board computers (SBCs) called “Ampro Embedded Linux” (AEL).

Canonical has also launched an Ubuntu Netbook remix version of its distribution. In September, the Foresight group adopted Ubuntu Netbook remix for a new version of its Foresight Linux desktop distribution called Foresight Mobile Edition 1.0.

Desktop Linux distributions have long been popular as a starting point for device development, because they provide better-tested software than raw upstream source code. Ubuntu is probably the world's most popular desktop Linux distribution, which also makes it perhaps the best-tested. Another advantage is the familiarity provided by using the same distribution on both development host and target systems. Ubuntu's popularity among device developers has soared in the last two years, according to LinuxDevices.com's 2008 Reader Survey.

Stated Ian Drew, ARM VP of Marketing, “The release of a full Ubuntu desktop distribution supporting latest ARM technology will enable rapid growth, with internet everywhere, connected ultra portable devices.”

Stated Jane Silber, COO of Canonical, “Joining the considerable community of free software developers working on the ARM platform ensures that a fully-functional, optimized Ubuntu distribution is available to the ARM ecosystem.”

Availability

Ubuntu for ARM is expected to arrive in products in April, 2009, says ARM.

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This article was originally published on LinuxDevices.com and has been donated to the open source community by QuinStreet Inc. Please visit LinuxToday.com for up-to-date news and articles about Linux and open source.