TASK 03

Compile the software

Build the pinned Mini microSD image with the reader variant for your board.

You need

x86_64 Linux builder with Docker
Git, mise and uv
Internet for first-build downloads

You’ll have

A flashable .img, build.log and recorded reader configuration.

Compile on x86_64 Linux. The UR2 wrapper prepares the right reader setting; the historical benchmark proves the upstream baseline, not this new patched image.

Choose your target

This carrier uses Luckfox Pico Mini + microSD + SEC1210/PV-UR2.
Apple Silicon is rejected by the pinned upstream Docker runner. Use an x86_64 Linux machine/VM; clone the public repo there.
Mini NAND, Pro/Max and Pico Pi are different build/flash routes. Do not pick them by a similar filename.

Upstream Luckfox target matrix ↗Install Docker on Linux ↗Install mise ↗

Clone the project and prepare the reader

Run from the repo root on your builder. Preparation checks the OS commit and applies only the reviewed Luckfox UR2 reader setting.
The manifest records the exact reader file hash; unrelated source changes are rejected.

Prepare carrier sources

git clone https://github.com/lightningspore/shieldsigner-dev.git
cd shieldsigner-dev
mise install uv
mise run os:prepare

Inspect the recorded reader variant

cat dist/os/UR2/reader-config.json
cat tools/os/seedsigner-os/opt/luckfox/files/sec1210

Start the build

Six general jobs were used on our x86 builder. Rust/LLVM can dominate the first build; keep the named Docker caches.
The carrier wrapper now defaults to UR2. The previously benchmarked images were unchanged upstream URT builds.

Build the UR2 Mini SD image

SHIELDSIGNER_BUILD_JOBS=6 mise run os:build

Follow current work from another terminal

tail -f dist/os/UR2/build.log
docker stats

Collect and verify the output

Successful exit is necessary: a log file alone is not a finished image.
Locate the .img and sha256sums.txt under dist/os/UR2. Keep reader-config.json with them.
The new UR2 preparation was tested, but a complete UR2 image build and hardware boot have not been qualified here.

Locate images and calculate hashes

find dist/os/UR2 -type f \( -name '*.img' -o -name 'sha256sums.txt' \)
find dist/os/UR2 -type f -name '*.img' -exec sha256sum {} \;

Baseline build evidence and hashes ↗

Iterate without discarding caches

Run the same build again to reuse Docker/Rust/source caches. Our baseline rerun took 27m 5s instead of 2h 28m 26s.
Avoid the upstream clean task during ordinary iteration. Keep full rebuilds for toolchain/architecture changes.

Caching and targeted rebuild notes ↗

Continue the buildFlash & boot the software →

Sources & deeper reference

Checked 12 October 2026. Menu names can vary with firmware.

Detailed Buildroot notes ↗Edit this workflow on GitHub ↗