Compile MicroPython code for Micro Bit locally on Ubuntu 22.04 with your own firmware

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Compile MicroPython code for Micro Bit locally on Ubuntu 22.04 with your own firmware by

Ciro Santilli 34 Updated 2024-11-19 Created 1970-01-01

TODO didn't manage from source Ubuntu 22.04, their setup bitrotted way too fast... it's shameful even. Until I gave up and went for the magic Docker of + github.com/bbcmicrobit/micropython, and it bloody worked:

git clone https://github.com/bbcmicrobit/micropython
cd micropython
git checkout 7fc33d13b31a915cbe90dc5d515c6337b5fa1660
docker pull ghcr.io/carlosperate/microbit-toolchain:latest
docker run -v $(pwd):/home --rm ghcr.io/carlosperate/microbit-toolchain:latest yt target bbc-microbit-classic-gcc-nosd@https://github.com/lancaster-university/yotta-target-bbc-microbit-classic-gcc-nosd
docker run -v $(pwd):/home --rm ghcr.io/carlosperate/microbit-toolchain:latest make all

# Build one.
tools/makecombinedhex.py build/firmware.hex examples/counter.py -o build/counter.hex
cp build/counter.hex "/media/$USER/MICROBIT/"

# Build all.
for f in examples/*; do b="$(basename "$f")"; echo $b; tools/makecombinedhex.py build/firmware.hex "$f" -o "build/${b%.py}.hex"; done

The pre-Docker attempts:

sudo add-apt-repository -y ppa:team-gcc-arm-embedded
sudo apt update
sudo apt install gcc-arm-embedded
sudo apt install cmake ninja-build srecord libssl-dev

# Rust required for some Yotta component, OMG.
sudo snap install rustup
rustup default 1.64.0

python3 -m pip install yotta

The line:

sudo add-apt-repository -y ppa:team-gcc-arm-embedded

warns:

E: The repository 'https://ppa.launchpadcontent.net/team-gcc-arm-embedded/ppa/ubuntu jammy Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

and then the update/sudo apt-get install gcc-arm-embedded fails, bibliography:

Attempting to install Yotta:

sudo -H pip3 install yotta

or:

python3 -m pip install --user yotta

was failing with:

Exception: Version mismatch: this is the 'cffi' package version 1.15.1, located in '/tmp/pip-build-env-dinhie_9/overlay/local/lib/python3.10/dist-packages/cffi/api.py'.  When we import the top-level '_cffi_backend' extension module, we get version 1.15.0, located in '/usr/lib/python3/dist-packages/_cffi_backend.cpython-310-x86_64-linux-gnu.so'.  The two versions should be equal; check your installation.

Running:

python3 -m pip install --user cffi==1.15.1

did not help. Bibliography:

From a clean virtualenv, it appears to move further, and then fails at:

Building wheel for cmsis-pack-manager (pyproject.toml) ... error
error: [Errno 2] No such file or directory: 'cargo'

So we install Rust and try again, OMG:

sudo snap install rustup
rustup default stable

which at the time of writing was rustc 1.64.0, and then OMG, it worked!! We have the yt command.

However, it is still broken, e.g.:

git clone https://github.com/lancaster-university/microbit-samples
cd microbit-samples
git checkout 285f9acfb54fce2381339164b6fe5c1a7ebd39d5
cp source/examples/invaders/* source
yt clean
yt build

blows up:

annot import name 'soft_unicode' from 'markupsafe'

bibliography:

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