The Mbed team are pleased to announce the release of Mbed OS 6.5 today. The main content is the introduction of our new command line tooling, Mbed CLI 2, which will co-exist alongside the existing Mbed CLI tools for now, but which we plan to replace entirely in the future.

Back in August, my colleague Jaeden Amero introduced our plans for these tools in a blog As Jaeden explained then, because of the way the tools had evolved organically, the underlying architecture was such that developing new features was costly, difficult, and piled up technical debt.

When we decided to develop the new command line tooling we wanted to ensure that the underlying architecture was extensible, to make it easy to add new functionality, more maintainable and gave Mbed developers a better experience than the existing tools. We also wanted to base the tools on existing open source solutions, and, after an evaluation, settled on CMake as best meeting our needs. As an aside, whilst we were busy developing the new tools, the superb team at the USC Rocket Propulsion Lab announced their CMake based alternative to Mbed CLI. Thankfully, they were keen to assist us and we have been talking with them since and have incorporated many of their suggestions into our CMake based version. We’ve also learnt a valuable lesson, but more on that in the next week or so.

We know from the annual Mbed developer survey that build times continue to be an issue for our developer community, so a key requirement was that we’d be able to improve build times substantially, and the goal set was a 50% improvement. You may have noticed that we have made changes to the Mbed OS directory structure recently and this is part of the ongoing efforts to address Mbed build times. Whilst we are not quite where we want to be yet, we are working on it and plan to show further improvements soon.

The Mbed team are actively adding support for more targets, ensuring code examples are ported and adding support for pre and post build hooks. We would really appreciate feedback on what we have released today, to better understand concerns about usability, functionality and performance so please try out the new command line tools and let us know any feedback you have either through the Mbed forum or our GitHub repo.

Mbed OS 6.5 is available now using Mbed Studio and the Mbed Online Compiler, or directly on the Mbed GitHub repository.

• Mbed OS 6.5 documentation
• Mbed OS 6.5 source code on GitHub