Add Dockerfile and build script for ESP32 firmware

firmware/esp32/Dockerfile

@@ -0,0 +1,37 @@
+FROM ubuntu:22.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    git \
+    wget \
+    flex \
+    bison \
+    gperf \
+    python3 \
+    python3-pip \
+    python3-venv \
+    cmake \
+    ninja-build \
+    ccache \
+    libffi-dev \
+    libssl-dev \
+    dfu-util \
+    libusb-1.0-0 \
+    && apt-get autoremove
+
+WORKDIR /usr/src/
+
+RUN mkdir -p ~/esp/firmware
+RUN git clone --recursive https://github.com/espressif/esp-idf.git ~/esp/esp-idf
+RUN cd ~/esp/esp-idf && ./install.sh esp32
+ENV IDF_PATH=~/esp/esp-idf
+RUN . $IDF_PATH/export.sh
+
+COPY . ~/esp/firmware/
+
+RUN cd ~/esp/firmware/
+RUN idf.py set-target esp32
+RUN idf.py menuconfig
+RUN idf.py build

firmware/esp32/build-esp32.sh

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+#!/usr/bin/env bash
+set -e
+
+IMAGE_NAME="esp32-builder"
+SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+DOCKERFILE="$SCRIPT_DIR/Dockerfile"
+BUILD_CTX="$SCRIPT_DIR"
+DEST_BIN="$SCRIPT_DIR/build/esp32.bin"
+
+docker build -t "$IMAGE_NAME" -f "$DOCKERFILE" "$BUILD_CTX"
+
+mkdir -p "$(dirname "$DEST_BIN")"
+
+docker run --rm "$IMAGE_NAME" \
+  cat /usr/src/build/esp32.bin > "$DEST_BIN"
+
+esptool.py --chip esp32c3 --port /dev/ttyUSB0 --baud 115200 write_flash 0x1000 firmware.bin \
+|| { echo "To find the correct port run: ls /dev/cu.*. Then modify build-esp32.sh"; exit 1; }