Masatoshi Nishiguchi

Posted on Jan 15

Where Nerves-related Mix tasks are defined?

#elixir #nerves #raspberrypi #iot

Nerves comes with a number of powerful and convenient Mix tasks.

Since I have not used many of those Mix tasks, first I want to learn what Mix tasks are available for my Nerves projects.

The Nerves project is made up of separate per-scope sub-projects. So Mix tasks are maintained in different repositories. It is great for maintainability, but finding source code can be a bit hard without prior knowledge. For that reason, it is nice to familiarize ourselves with Nerves sub-projects by casually visiting them.

Mix

In case, somebody is new to Mix, here is some info.

Mix is a build tool that provides tasks such as creating, compiling, testing, and managing dependencies for Elixir projects.

https://hexdocs.pm/mix/Mix.html

https://elixirschool.com/en/lessons/basics/mix

Enumerating Mix tasks in Elixir project

First of let's try and enumerate Mix tasks available for your Nerves project. We can achieve that just by running mix help.

As an example, let's try it under the nerves_livebook project.

cd path/to/nerves_livebook

mix help

At this point, the results include non-Nerves Mix tasks. As I counted the number of lines, it was a total of 65. It might vary depending on projects.

mix help | wc -l

Filtering down to only Nerves-related Mix tasks

I simply ran grep and was able to narrow it down to only Nerves related Mix tasks!

mix help | grep 'mix' | grep -iE 'nerves|firmware'

The results are as follows.

mix burn                    # Write a firmware image to an SDCard
mix compile.nerves_package  # Nerves Package Compiler
mix firmware                # Build a firmware bundle
mix firmware.burn           # Build a firmware bundle and write it to an SDCard
mix firmware.gen.gdb        # Generates a helper shell script for using gdb to analyze core dumps
mix firmware.gen.script     # Generates a shell script for pushing firmware updates
mix firmware.image          # Create a firmware image file
mix firmware.metadata       # Print out metadata for the current firmware
mix firmware.patch          # Build a firmware patch
mix firmware.unpack         # Unpack a firmware bundle for inspection
mix local.nerves            # Checks for updates to nerves_bootstrap
mix nerves.artifact         # Creates system and toolchain artifacts for Nerves
mix nerves.artifact.details # Prints Nerves artifact details
mix nerves.clean            # Cleans dependencies and build artifacts
mix nerves.info             # Prints Nerves information
mix nerves.new              # Creates a new Nerves application
mix nerves.system.shell     # Enter a shell to configure a custom system
mix nerves_key.device       # Simulate NervesKey device key creation
mix nerves_key.signer       # Manages NervesKey signing keys
mix upload                  # Uploads firmware to a Nerves device over SSH

In case we want to learn the innerworkings of the commands later, it is nice to know where their souce code is located.