peacememories / avr-device

Register access crate for AVR microcontrollers

avr-device

Auto-generated wrappers around registers for avr chips.

Usage

You need to have atdf2svd, svd2rust, form, rustfmt(for the nightly toolchain) and PyYAML installed:

rustup component add rustfmt
cargo install form
cargo install svd2rust
git clone https://github.com/Rahix/atdf2svd
cd atdf2svd
cargo install --path .
pip3 install --user pyyaml

Next, clone this repo and build the device definitions:

git clone https://github.com/Rahix/avr-device
cd avr-device
make
# You can build for just one specific chip using
# make atmega32u4
# I suggest building documentation as well
cargo +nightly doc --features <chip> --open

In your project add the following lines to Cargo.toml:

[dependencies.avr-device]
path = "path/to/avr-device/"
features = ["atmega32u4"]

Via the feature you can select which chip you want the register specifications for. The following list is what is currently supported:

• atmega1280
• atmega8
• atmega328p
• atmega32u4
• attiny85

Internals

avr-device is generated using atdf2svd and svd2rust. The vendor-provided atdf files can be found in vendor/. The intermediate svd files are patched by svdpatch.py (Adapted from svdpatch.py in stm32-rs) with device-dependent patches in patch/, mainly to improve undescriptive names and missing descriptions.

Adding a new Chip

To add a new chip, download the atdf from http://packs.download.atmel.com/ and place it in vendor/. Be sure to name it like the Rust module that should be generated. Next, you need to integrate it into the base crate and build system. Follow what was done in this commit. Please adhere to the alphabetical sorting that is present so far.

If patches need to be applied, create a <chipname>.yaml in patch/. The patching format is compatible to the YAML patching format of stm32, except that you do not need to provide the path to the svd file (_svd: ...) since it is generated in the build process. Additionally, the following patching was added:

PERIPHERIAL:
    REGISTER:
        _modify:
          FIELD:
            # If a field already contains a write-constraint, you can
            # change it using the _write_constraint modifier.  The
            # following values are allowed:

            # "enum": Only allow enumerated values (<useEnumeratedValues>)
            _write_constraint: "enum"

            # Remove any existing writeConstraint tag
            _write_constraint: "none"

            # Constrain to a range of values (<range>)
            _write_constraint: [min, max]
        FIELD:
            # Replaces the enumeratedValues definition for this field.
            # If it does not exist yet, it is created.
            _replace_enum:
                NAME: [VALUE, DESCRIPTION]

License

avr-device is licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

The vendored atdf files are licensed under the Apache License, Version 2.0 (LICENSE-VENDOR).