Posted on

Welcome to the 5th issue of TMPDIR Weekly, a newsletter covering Embedded Linux, IoT systems, and technology in general. Please pass it on to anyone else you think might be interested and send any tips or feedback to our forum or

Subscribe Here

Embedded Linux

The 3.4 release of the Yocto Project will have a new overrides syntax. As an example, the following DISTRO_FEATURES_remove will be replaced with DISTRO_FEATURES:remove

Rust support has been added to OpenEmbeeded/Yocto Core layer. This support is migrating from meta-rust layer into core layer and will be helpful in getting ever increasing rust support in opensource components addressed at core level. There has been long standing issue with librsvg which required rust and is a core component for rendering SVG onto to cairo surface.

Glibc 2.34 has merged several libraries into this includes etc. much like what musl has done from its inception. While this change will help in long run, it has caused some unwanted issues in yocto project which uses its own tools like pseudo to emulate super user like conditions ( fakeroot ) and unique way of supporting modern toolchains on ancient distributions by using buildtools tarball which contains needed shims to run latest OE on such distributions. These tools work closely with system C library and provide a shim C library to overcome version differences, with structural changes in glibc packaging this needed extra work in these areas.

Yocto project provides specific tune files to oprimize builds for a given processor or architecture. This has been restructures to better organize these files by architectures. Some BSP layers have to change the machine configurations to use the files from new locations.

Yocto project has started making changes to support zstd compression as core element of the build infrastructure which means that now zstd and zstd tools is expected to be installed on build hosts. This will pave way for enabling compression in shared state eventually, speeding up shared state use in builds and reducing build time.


Focus this past week in Simple IoT has been on fixing performance issues. We recently deployed SIOT in a building automation project and the system was becoming unresponsive. Various metrics were added to instrument how long it took to process points and associated operations. Eventually I learned that a Windows machine used to host a InfluxDB instance (used as a historian) was set to sleep after 30m of inactivity. This caused InfluxDB calls in a NATS handler to block for long periods of time. Since NATS dispatches messages serially, everything got backed up bringing the system to a crawl. Along the way, I learned how the NATS and InfluxDB client libraries buffer and batch data -- pretty neat stuff. As a result, there are some good performance improvements that will be merged soon.


Quote for the week

The best way to complain is to make things -- James Murphy

Join our Discourse forum to discuss these or new topics. Listen to previous podcasts at

Thanks for reading! Khem and Cliff