Paul LaCrosse

Clément, this p.r. simply has changes from running the default rustfmt, as well as implementing the changes required for all clippy lints/warnings to pass. Your test suite appears to pass....

I found that the px4 (original instructions) only work if they had been used at some point in the past prior to "some change" being made. While setting up a...

I agree with @utzig . There is an official repo now. Let's use it and avoid a source of inconsistency and issues. https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads

The `brew cask install gcc-arm-embedded` doc change I suggested is just an alternate installation method for Mac. Either way (brew or tar-ball), using the current official toolchain from developer.arm.com is...

@bors