Trezor Core

Trezor Core is the second-gen firmware running on Trezor devices. It currently runs on Trezor T and Trezor Safe 3, but it might be used on Trezor One in the future as well (see issue #24).

Trezor Core is part of the trezor-firmware monorepo to be found on GitHub, in the core subdirectory.

Trezor Core uses MicroPython, it is a Python implementation for embedded systems, which allows us to have an application layer in Python, which makes the code significantly more readable and sustainable. This is what you find in the src folder.

Not everything is in Python though, we need to use C occasionally, usually for performance reasons. That is what embed/upymod is for. It extends MicroPython's modules with a number of our owns and serves as a bridge between C and Python codebase. Related to that, mocks contain Python mocks of those functions to improve readability and IDE functioning.

Where appropriate, we also use Rust. For example, all UI components and animations are implemented in embed/rust. Similarly to C bindings, you can find Python mocks for the Rust functions in mocks directory. Developing new features in Rust is preferred in the future.

Boot

Module src/main.py is the first one to be invoked in MicroPython. It starts the USB, initializes the wire codec and boots applications (see Apps).