The Moblin Weblog

For the past decade, one of the leading commercial suppliers of embedded software development tools has been MontaVista. What’s new and noteworthy is that the Santa Clara, Calif., recently jumped onto the Moblin bandwagon. MontaVista is preparing a set of developer tools for Atom-based devices running Moblin. More details about them will come shortly.

“We are excited to be part of the Moblin community,” said MontaVista’s Jeorg Betholdt. “It offers compatibility with existing and future x86 development environments and tools allowing reuse of existing, mature development infrastructure. By delivering MontaVista’s embedded Linux commercialization based on Moblin, device manufacturers can bring commercial devices to market quickly and cost effectively.”

MontaVista also launched a community site, called Meld, for embedded Linux developers. The community, which is not specific to Moblin, has three goals:

* Connect: Leverage the experience of other embedded Linux developers.
* Share: Collaborate on information and ideas.
* Design: Develop products faster with information re-use.

“Linux is based on the idea of sharing knowledge, and there are strong underpinnings of this throughout the Linux community, yet there isn’t a place for embedded Linux developers to go to collaborate and experience that sense of community,” said Bertholdt. “Now, through Meld we want all embedded Linux device developers to come together to share their knowledge, collaborate with one another, and speed the design of innovative, commercial solutions running on embedded Linux. A strong community benefits all of its members and we believe this forum will allow Linux to grow and prosper in embedded devices.”

The company says that while it sponsors the Meld site, it’s is a non-commercial community open to any embedded Linux developer who wants to participate.

One of the least-well-publicized components of the Moblin2 alpha release is its inclusion of the Linux Connection Manager, also known as Connman. It’s a modular assembly that manages Internet connection using a very light-weight daemon. Everything is a plug-in, including Domain Name Service resolving (i.e., turning fully qualified URIs into IP addresses) and getting a network connection via DHCP.

According to the project’s description,

The project currently contains the following components:

* connman The core Connection Manager daemon (connmand) and plug-ins for Ethernet, WiFi, DHCP, and resolvconf.
* connman-gnome The GTK+-based user interfaces for an applet and a properties dialog.

Connection Manager uses modern infrastructure like D-Bus, HAL, and netlink to provide a native integration into the operating system. While HAL and netlink are used on the system level to communicate with networking devices, the whole separation between system daemon and user interface is done through D-Bus.

At the moment the following extra components or applications are required:

* wpa_supplicant (with D-Bus extensions) for WiFi access
* dhclient for the DHCP plug-in
* resolvconf for the domain name resolver plug-in
* libgdbus for D-Bus and GLib integration (provided by the project itself)

You can download a PDF overview of Connman here.

The Moblin 2 alpha hit last month, and developers have been diving deep. What’s astonishing is how fast the revamped operating system boots up. It’s  instantaneous. Well, it’s about 7-10 seconds on most devices, but it seems instantaneous.

How did the Moblin team pull it off? It was a lot of small things, they say, ranging from optimizing their compiling flag to spending a lot of time figuring out the order of loading and initializing modules.

Is there a secret? Is there a magic bullet that developers can use when trying to make their own distributions boot as fast? No, it’s more like a “magic shotgun” of lots of small things. Intel’s Auke Kok wrote on the Moblin Developer list,

We get this question a lot, and everyone who asks it wants an easy answer. But I can’t give you that.

And on top of that you will need to fix your own distribution - at least every component that is touched on startup. 5 + 20 equals 25, not 5.

Intel’s Austin Zhang added that using the fastinit script can help, but it’s only the start. He suggests, “You can use bootchart to measure and decide what’s the bottleneck in your whole booting process. This tool can show you the booting process picture which indicate the app launch order and how many app/service your booting process is depending on.”