Open Embedded Linux

[mdlbear]

... built successfully on my machine at work. Turned out that the problem was a set of (possibly buggy) cross-compilers hanging around in /usr/bin from an earlier experiment with the Debian cross-development tools.

So I am now a happy hacker again. OpenEmbedded is the basis for most of the free distributions for hand-held and portable systems, plus a number of others.

OE is what you might call a "top-down" build system -- you pick a target system and a set of packages to build, then say make and stand back. Many hours and 35GB later you have a root filesystem image and a big pile of .ipk files. Or more likely you have a broken build and a screen full of log messages that might or might not be helpful.

One of the common problems, as it turns out, is caused by the fact that OE has to download tarballs for all of the packages it builds, or else check them out of some version control system. If a config file specifies some bleeding-edge version that's only available from one or two of the places it knows about, and they're down or slow, you're hosed until one of them comes back up. Not quite the kind of thing you can leave and forget, at least not the first time you build it. After that, of course, everything you need is in the cache and everybody's happy.

Oh, and it's version-controlled using monotone, which makes a snail on Valium look speedy.

I've started writing up my little study of toolchains and build systems at work (in my typical ursine fashion, by populating /usr/local and its major subdirectories with HEADER.html files), and expect to be publishing it on the Web fairly soon.