Currently, external parties will not be able to build Bitkey firmware, because we use a 3rd party fingerprint sensor that comes with a proprietary matching algorithm and we are contractually obligated not to publicly release the library that implements this functionality.
You can build the tests and fuzzers - as well as the firmware, if you implement stubs for the missing 3rd party library functionality.
Toolchain management is done with Hermit. To get started, run:
# ensure you have submodules
$ git submodule update --init --recursive
# bootstrap a new environment with pyenv
$ ./bootstrap.sh
# activate Hermit
$ source activate
# install JLinkGDBServer, only needed to flash and debug
$ inv install.jlink
# install SVD file (only if debugging with vscode)
$ inv install.svdcd firmware
. ./activate
code ../wallet.code-workspaceThe build system is Meson, with an invoke wrapper for convenience.
Read more about invoking tasks here.
# View all available commands
$ inv --list
# Get help for a specific command
$ inv --help build
# Chain multiple commands
$ inv clean build flashW1 supports two application layer NFC interfaces:
- NDEF
- WCA (Wallet Custom APDUs)
NDEF is a standard protocol to interact with all NFC tags. NDEF is basically a simple API that lets you select, read, and write “NDEF files” (arbitrary data blocks) on a tag. We intend to use NDEF only for firmware update.
WCA is protobufs-over-APDUs, and will be used for all other app to firmware comms.
The WCA command set is fully documented in Github. Refer there for the most up-to-date information. Since protos can be bigger than APDUs, WCA allows splitting up protos while sending or receiving.