fbuild

fbuild

fbuild is a fast, multi-platform compiler, deployer, emulator runner, and serial monitor for embedded development. It reads the same platformio.ini files already used by PlatformIO sketches, but uses a Rust-native, data-driven build pipeline.

Check Ubuntu Check macOS Check Windows Formatting Documentation Build Native Binaries

Build Matrix

These board builds are part of the front door. They show the platform breadth that fbuild actively protects in CI.

AVR

Build Arduino Uno Build Leonardo Build ATmega8A Build ATtiny85 Build ATtiny88 Build ATtiny4313

MegaAVR

Build ATtiny1604 Build ATtiny1616 Build Nano Every

Renesas

Build UNO R4 WiFi

ESP8266

Build ESP8266

ESP32

Build ESP32 Dev Build ESP32-C2 Build ESP32-C3 Build ESP32-C5 Build ESP32-C6 Build ESP32-H2 Build ESP32-P4 Build ESP32-S2 Build ESP32-S3

CH32V (RISC-V)

Build CH32V003 Build CH32V103 Build CH32V203 Build CH32V208 Build CH32V303 Build CH32V307

CH32X (RISC-V, USB PD)

Build CH32X035

Teensy

Build Teensy 4.1 Build Teensy 4.0 Build Teensy 3.6 Build Teensy 3.5 Build Teensy 3.2 Build Teensy 3.1 Build Teensy 3.0 Build Teensy LC

STM32

Build STM32F103C8 Build STM32F103CB Build STM32F103TB Build STM32F411CE Build STM32H747XI Build Nucleo F429ZI Build Nucleo F439ZI Build Arduino Giga R1

SAM / SAMD

Build Arduino Due Build SAMD21 Build Arduino Zero Build SAMD51J Build SAMD51P

RP2040 / RP2350

Build RP2040 Build RP2350

Nordic NRF52

Build nRF52840 DK Build SuperMini nRF52840 Build nice!nano nRF52840 Build nRFMicro nRF52840 Build Adafruit Feather NRF52840 Sense

Apollo3

Build Apollo3 RedBoard Build Apollo3 expLoRaBLE

NXP LPC (Cortex-M0+)

Build LPC804 Build LPC845 Build LPC845-BRK Build LPCXpresso804 Build LPCXpresso845-MAX

Silicon Labs

Build MGM240 Build SparkFun Thing Plus Matter

Raspberry Pi Pico

Build Raspberry Pi Pico Build Raspberry Pi Pico 2

Board descriptions and family deep-dives live in docs/BOARD_STATUS.md.

Build performance

Arduino CLI vs PlatformIO vs fbuild Blink build benchmark

The chart is regenerated nightly from clean-output (cold) and immediate repeat (warm) Arduino Uno Blink builds. Raw measurements are discoverable through the benchmark manifest.

Installation

pip install fbuild

For source installs, platform notes, and first-run cache behavior, start with the getting started guide.

Command Quick Start

fbuild reads the same platformio.ini files as PlatformIO. Use these commands as direct replacements for the most common PlatformIO workflows:

fbuild PlatformIO equivalent Use it to
fbuild build pio run Compile the project.
fbuild build --clean pio run --target clean, then pio run Clean and compile the project.
fbuild deploy pio run --target upload Build and upload firmware.
fbuild deploy --clean Clean, then pio run --target upload Clean, build, and upload firmware.
fbuild monitor pio device monitor Monitor serial output without flashing.
fbuild ci pio ci Build one or more sketches for CI.

Pass --platformio to build, deploy, or monitor to delegate that workflow to the installed PlatformIO CLI. fbuild ci is a fbuild-native, PlatformIO-compatible CI command; detailed flags and nested commands are in the CLI reference.

fbuild-only commands

These commands extend beyond the PlatformIO workflow surface:

Command Purpose
fbuild symbols Report per-symbol firmware size and bloat details.
fbuild bloat Inspect symbol back-references and generate bloat graphs.
fbuild reset Reset a device without flashing it.
fbuild purge Purge downloaded packages or run cache garbage collection.
fbuild sync Resolve platformio.ini dependencies into a deterministic lock file.
fbuild daemon Manage the background build daemon, locks, and cache.
fbuild show Show daemon logs and other runtime information.
fbuild device List devices and manage device leases.
fbuild mcp Start the Model Context Protocol server for AI integrations.
fbuild clang-tidy Run clang-tidy static analysis on project sources.
fbuild iwyu Run include-what-you-use analysis on project sources.
fbuild clangd-config Generate clangd and VS Code configuration for the project.
fbuild test-emu Build and run firmware in an emulator for testing.
fbuild clang-query Run a clang-query matcher against project sources.
fbuild lnk Fetch, verify, and create .lnk resource pointers.
fbuild lib-select Diagnose the LDF-style library selection result.
fbuild compile-many Compile many sketches against one board in parallel stages.
fbuild serial Probe serial ports and read them with board-aware settings.
fbuild bringup Orchestrate build, flash, reset, monitor, and bring-up steps.
fbuild port Scan serial ports with vendor and product identification.
fbuild cache Save, restore, list, and verify portable cache archives.

See fbuild help <command> or the full CLI reference for options and nested subcommands.

Quick Start

Create a minimal Arduino project:

mkdir my-project
cd my-project
mkdir src

Add platformio.ini:

[env:uno]
platform = atmelavr
board = uno
framework = arduino

Add src/main.ino:

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);
  delay(1000);
  digitalWrite(LED_BUILTIN, LOW);
  delay(1000);
}

Build it:

fbuild build

On the first build, fbuild downloads the toolchain and framework packages it needs, then caches them for later builds. A successful Uno build writes .fbuild/build/uno/firmware.hex.

Examples

Common workflows:

fbuild build
fbuild deploy --clean
fbuild deploy --monitor
fbuild test-emu . -e uno
fbuild monitor --timeout 60 --halt-on-success "TEST PASSED"

Detailed build, deploy, monitor, and emulator examples live in the CLI reference and emulator testing guide.

Docs Index

The full FAQ-style map is docs/INDEX.md. Common entry points:

Goal Start here
Install fbuild and run the first build docs/getting-started/
Use build, deploy, monitor, or test-emu docs/reference/cli.md
Configure platformio.ini docs/reference/platformio-ini.md
Check board and platform support docs/platforms/
Understand the project rationale docs/WHY.md
Work on fbuild itself docs/development/
Read architecture internals docs/architecture/overview.md

Key Features

  • platformio.ini compatibility for existing Arduino and ESP32 sketches
  • Fast incremental builds with cached toolchains, frameworks, and libraries
  • URL-based package and library management, including GitHub lib_deps
  • Build, deploy, serial monitor, and emulator test workflows from one CLI
  • Cross-platform support on Windows, macOS, and Linux
  • Transparent architecture with Rust workspace internals documented under docs/architecture/

See docs/WHY.md for the full rationale, benefits, and performance notes.

CLI Usage

The user-facing command reference is docs/reference/cli.md. It covers core workflows (build, deploy, monitor, test-emu) and diagnostics such as symbols, bloat, lib-select, compile-many, and ci.

Configuration

fbuild reads platformio.ini project files. The configuration reference, including default_envs, build_flags, lib_deps, upload and monitor settings, and compatibility notes, lives in docs/reference/platformio-ini.md.

Emulator Testing

fbuild can build firmware and run it without hardware via fbuild test-emu or fbuild deploy --to emu. Emulator backends, auto-detection rules, QEMU notes, and known limitations live in docs/guides/emulator-testing.md.

PlatformIO Compatibility: .eh_frame Strip

On supported release builds, fbuild may strip unused GCC .eh_frame unwind metadata to reduce firmware size. The policy, opt-out controls, and rationale are documented in docs/reference/platformio-compatibility.md.

Supported Platforms

fbuild supports AVR, MegaAVR, Renesas RA, ESP8266, ESP32 variants, CH32 RISC-V, Teensy, STM32, SAM/SAMD, RP2040/RP2350, Nordic NRF52, Apollo3, Silicon Labs EFR32, NXP LPC, and WASM via Emscripten.

For the canonical per-board CI badge matrix, support table, and board-family notes, see docs/BOARD_STATUS.md or the platforms docs.

Project Structure

The repository is a Rust workspace with a Python package boundary. The human development guide is docs/development/, and the crate dependency map is crates/CLAUDE.md.

Architecture

Architecture docs are decentralized under docs/architecture/. Start with docs/architecture/overview.md, then follow the subsystem-specific docs.

Development

Testing, troubleshooting, linting, release, and local setup instructions live in docs/development/. Project-wide rules for contributors and LLM agents are in CLAUDE.md.

License

In the spirit of Dan Garcia's permissively licensed software, fbuild is presented as free software.

BSD 3-Clause License

Key dates

PyPI data
Data sourced directly from PyPI's database.
  • Released:
Newer release available (2.5.17)

1 maintainer

PyPI data
Data sourced directly from PyPI's database.
Avatar for niteris from gravatar.com niteris

Requires

Python >=3.10

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