1 unstable release

0.0.3 Mar 12, 2019

#235 in #template



License License Crates


This is a (WIP!) Rust board support package for the open source Solo security key.

This key consists of:

  • an STM32L432KC microcontroller
  • either a USB-A or USB-C connector
  • a clicky dome button
  • 3 LEDs
  • an NCP114 voltage regulator
  • and various resistors, capacitors, and Zener diodes

One specialty is that it has a custom USB bootloader, allowing easy updates. To use it, FLASH ORIGIN in memory.x needs to be set to 0x800_5000 instead of the conventional 0x800_0000. Alternatively, the ST DFU bootloader can be used. Additionally, serial TX/RX and all SWD pins (SWDIO, SWCLK, SWO) are kind of broken out.


You need stable Rust 2018 edition, for details see the embedded book, in short:

curl https://sh.rustup.rs -sSf | sh
rustup target add thumbv7em-none-eabihf
cargo install cargo-binutils
rustup component add llvm-tools-preview

To build blinky, run make blinky. You end up with a blinky.hex file.

To flash it to your Solo Hacker:

  • insert Solo and boot to Solo bootloader by pressing the button for ~2 seconds (it starts to blink)
  • setup Solotool and make sure you can flash the original solo.hex
  • run tools/solotool.py /path/to/blinky.hex
  • watch the green LED blink 🎉


Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


~1.5M SLoC