Away Mission: A Vision for Embedded Linux

By Howard Dyckoff

Away Mission: A Vision for Embedded Linux

On the mark for its organization and on target for the current hot topics in the Embedded Linux Community, October's M-Vision was a gem in the small conference category. The "M" stands for MontaVista, a company committed to developing Linux kernels and tools for embedded and mobile devices. This conference, MontaVista Vision, was much more focused and satisfying than the competing mobile and embedded tracks at last August's LinuxWorld conference.

MVison in general

This was an excellent location for a small conference - the SF Palace Hotel entrance is just about 100-150 feet from the entrance to the regional 'subway' (BART). There are multiple bus and municipal rail lines that converge on the area, and it's only a 10-12 minute walk from the ferries.

The session presentations were not available on-line before the conference and there was at first a hint that they would not be posted later, a mistake cleared up by the first afternoon: most of these were on a 1GB USB drive (not included in the conference bag) that had to be requested in the afternoon in the registration area. There were 19 presentations on the USB stick and about 11 missing. The organizers said that all presentations would be posted, and most were indeed up after a week.
https://www.mvista.com/download/topic.php?t=18

Conference perk: a good roller bag with detachable, separate shoulder bag. The main bag was not padded for carrying laptops, however. Well, it would have been nice to be able to use it for every occasion. There were additional perks in the small expo area, but the best was the 2X binoculars at one of the MontaVista podiums.

Of the breakout sessions, only one room had enchained power cords -- this one had a session with hands-on exercises. My own 15-foot extension cord was invaluable in connecting to the few outlets in rooms I attended sessions in, allowing others to share the same power connection.

There was less competition for outlets as most participants took hand-written notes. This is largely due, I think, to MV's reliability in depositing slides and videos on-line after their events. There also were a few product managers and marketeers in the audience.

On the food front, there was a good full breakfast - it was eggs, potatoes, meats, fruit, cereals - and there was a decent box lunch with a bag of gourmet chips that could be carried away.

While there was soda and a tea/coffee service at the breaks, there were no snacks in the first afternoon. A small amount of breakfast pastry was available during the AM keynote break. Cookies and pretzels were put out for the afternoon break on the second day.

For the evening, there was a party with a SF theme and ethnic food stations. There also was an awesome dessert bar, and Nintendo Wii stations and computer arcade rides for fun. Considering that the regular conference cost was only $595.00 (USD) - $350 for customers - this was a very good value.

Besides good conference swag and edibles, there were a good set of keynotes and good mix of sessions on 5 separate tracks:

• Working with Open Source
• High Availability
• Bringing up HW
• Linux on Freescale
• Monte Vista How-to Sessions

M-Vision Keynotes

The MVison opening keynote was by Rusty Harris, CEO of MontaVista. Harris called for more support for open source and explicitly more contributions by members of the embedded community and more events like M-Vision. "It's tough to work together when we can't find each other," he told the attendees.

"The embedded Linux community is growing faster and is building more smart devices than ever, and it shows no signs of slowing," said Rusty Harris. "Generating this growth during today's economic uncertainty shows how strongly committed embedded engineers are to getting the most out of open source."

Harris said that the embedded community is driving Linux now that there is more uniformity and standardization. But he also spoke of a need to counteract the PC and Windows bias of developers and OEMs now that "Linux is the most viable model of open source on the planet!"

He said MV would work more closely with semiconductor companies and pledged MV resources to work with attendees to build a better embedded community.

The second keynote, "Linux for Internet Devices" was presented by Pete Kronowitt from Intel's Open Source Technology Center. He discussed the growth of Linux in mobile Internet devices (MIDs) and presented Intel's view, noting that the embedded market has grown rapidly since 2000.

"Now there are about about 1.4 billion of us attached to the Internet -- but there are another 4-5 billion who will soon be attached. They reside in underdeveloped countries. And affordability will be key to driving the next 2 billion users and probably the 2 billion users after that."

The number of people using mobile devices to get to the Internet is expected to triple from 2007 to 2012, and triple again in another 4-5 years. Kronowitt said the smart phone market is exploding and Linux is growing even faster: over 30% of units in 2012 will be Linux-based.

A Forrester survey in February of 2008 asked potential buyers of a mobile Internet device about the main deterring factor:

• 60% of respondents say phone screens are too small to use online
• 24% say laptops are too big and heavy to carry every where
• 38% say they would pay up to $20 a month for wireless broadband service

So this helps to define what Intel thinks of as the 3 pillars needed for a good mobile Internet experience:

• The right ultra mobile size and performance with long battery life
• Internet compatibility and SW consistency - with video especially
• Always-connected, high-speed wireless

He also gave a plug for Intel's Atom CPU, saying it was the "smallest piece of silicon we've launched to date with our most advanced (45nm) technology."

Intel launched Moblin.org last year with the goal of developing a lean FOSS SW stack to operate everywhere. It also has an application framework in development. The Moblin community is seeking to lower component count and costs with optimized memory footprints.

But something happened along the way: the netbook exploded on the scene! This has changed the game for device OEMs and consumers and expanded Moblin's base rapidly. Currently, Moblin is a Linux-based software platform for building applications that run on devices based on Intel Atom CPU.

Kronowitt said that Intel isn't doing any advertising for Moblin.org: "Code speaks louder than ads." He also hinted there would be new Moblin announcements in November.

Slides and video from this session are at www.mvista.com/download/author.php?a=66.

In another keynote, Deepak Saxena - a principal in the OLPC project - addressed "Linux Power Management Challenges for the OLPC and Beyond".

At first Saxena summarized vision and history of the XO and its current status. He noted it was built for both the tropics and deserts and also for rough handling. It needed a new model of networking for remote locations. The XO was also designed for collaboration up front. It also had a goal of 10-20 hours runtime -- doing something all the while.

Saxena pointed out that the key element in power control is that the graphics engine is not directly linked to the CPU, as in conventional notebooks - the frame buffer is driven from the display controller. The wireless chip also works even if the CPU is in sleep mode.

See the Saxena video at https://www.mvista.com/download/author.php?a=26.

State of the Linux Kernel

Jonathan Corbet, the editor at LWN.net, gave the second day keynote. Corbet reviewed the huge on-going effort that goes into a Linux release and ways to contribute. He put up a slide showing the wide diversity of of industry kernel contributors. Red Hat, IBM, Novell, and Intel are standouts.

Who contributes?

from 2.6.23 -> 2.6.27-rc5

(Non-affiliated)         19%
Red Hat                  12%
IBM                       7%
unknown                   6%
Novell                    6%
Intel                     5%
Parallels                 2%
Oracle                    2%
linutronix                2%
consultants               2%
Movial                    2%
SGI                       1%
academia                  1%
Analog Devices            1%
Renasas Tech              1%
Freescale                 1%
MontaVista                1%
Fujitsu                   1%
Google                    1%
Astaro                    1%

Corbet also spoke about new Linux file systems, specifically ext4 as a descendant of ext3. This adds journal checksums and also lifts size limits from files and filesystems. He also discussed btrfs, which has a faster fsck, full checksumming, subvolumes and snapshots.

Corbet said there was lots of on-going work in drivers and the kernel and also in userland space. He also asked why a project hasn't been started to port DTrace to Linux from Solaris.

The slide deck from his presentation and related videos are available here: https://www.mvista.com/download/author.php?a=8

Fast Boot Session

One session I'd recommend is "Fast boot: Tips & Techniques for Improving Linux Start-up Time" by Christopher Hallinan, who contributed to the u-boot boot loader.

A typical embedded system contains a bootloader and kernel, both of which are typically configured with many useful default features that may or may not be important for a given product requirement. This presentation shows how to significantly reduce boot time for embedded systems.

Hallinan saw Intel's 5-second boot demo at the recent IDF conference and wanted to see how far he could go on his own. He set this up as a personal project to see what was do-able in a short time. How short? How about 5-7 person-days over a month?

Hallinan said he thought that Intel spent over 40 man-weeks on its effort. And he got within 10% of Intel's 4.5-second boot. Not bad at all.

Hallinan based his efforts in part on suggestions from Tim Bird of the Linux CE forum, who had written a paper on reducing boot times (https://kernel.org/doc/ols/2004/ols2004v1-pages-79-88.pdf).

One key delay noted there is ide_init, which can take over 3 seconds at boot time, even in modern Linux kernels. Bird noted that "The call sequence underneath ide_init() shows that a large number of calls are made to the routine ide_delay_50ms()...." Many embedded devices use SSD storage so this can be stripped out of many embedded kernels.

Hallinan used a Freescale MPC8349 Emitx board and U-Boot loader. This setup had 256 MB of RAM and 16 MB of flash with a 533 MHz clock, plus serial and USB and net ports.

With a 2.6.25 kernel with typical configuration he had a boot time of 1:15 to cmd prompt, with ~5 seconds for U-Boot alone.

A full description of the tech sessions is here: https://www.mvista.com/vision/index.php?p=sessions#bordug

And all the presentations are here: https://www.mvista.com/download/topic.php?t=18

MontaVista also held a technical bootcamp on embedded Linux drivers the day before M-Vision, pricing it at only about $100 more for M-Vision conference attendees.

The tutorial instructor was Mike Anderson, chief scientist of the PTR Group, an experienced instructor on embedded development. Hands-on labs were included covering driver entry points, blocking I/O, moving between user and kernel space, driver debugging, and other topics.

Talkback: Discuss this article with The Answer Gang

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Howard Dyckoff is a long term IT professional with primary experience at Fortune 100 and 200 firms. Before his IT career, he worked for Aviation Week and Space Technology magazine and before that used to edit SkyCom, a newsletter for astronomers and rocketeers. He hails from the Republic of Brooklyn [and Polytechnic Institute] and now, after several trips to Himalayan mountain tops, resides in the SF Bay Area with a large book collection and several pet rocks.

Howard maintains the Technology-Events blog at blogspot.com from which he contributes the Events listing for Linux Gazette. Visit the blog to preview some of the next month's NewsBytes Events.