This crate provides an utility to flash ARM chips.
As of writing this, flashing works for the nRF51 using a DAPLink or an ST-Link only.
You can install this utility with
cargo install cargo-flash
You can use it like any cargo command would be used
cargo flash <args>
which will then build your binary and flash the contents onto the connected nRF51.
If you have a chip you want to flash, feel free to contribute to probe-rs.