# Building EdgeTX

This guide covers how to build EdgeTX firmware, the SDL simulator, and the
Companion application from source using CMake Presets. For platform-specific
environment setup (installing toolchains, Qt, etc.), see the platform guides
in this section.

!!! note
    The instructions here are meant to help you develop or test changes to
    EdgeTX on your PC, not to build flight/radio-safe versions of binaries.

## Prerequisites

| Component | Required for | Notes |
|-----------|-------------|-------|
| **CMake >= 3.21** | Everything | |
| **arm-none-eabi-gcc** | Firmware | 14.2.rel1 recommended |
| **Python >= 3.10** | Firmware, Companion | Code generation at build time |
| **Qt 6** | Companion | 6.9+ recommended |
| **SDL2** | Simulator | |
| **Ninja** (optional) | Everything | Faster than Make |

### Python dependencies

The build invokes Python scripts for code generation (YAML parsers, hardware
definitions, bitmap encoding, etc.). Install the required packages with
[uv](https://docs.astral.sh/uv/):

```bash
uv sync
source .venv/bin/activate   # CMake needs the venv activated to find Python
```

The virtual environment must stay activated when running CMake, so that the
build can find the installed packages. On Windows, use `.venv\Scripts\activate`
instead.

## Quick start with CMake Presets

The repository ships CMake presets for all supported radios and build types.
These work in VSCode (CMake Tools), CLion, and the command line.

### Firmware

```bash
# Configure for a specific radio
cmake --preset tx16s

# Build
cmake --build build/tx16s --target firmware
```

Replace `tx16s` with any supported radio preset. Run `cmake --list-presets` to
see all available presets. A few examples:

| Preset | Radio |
|--------|-------|
| `tx16s` | RadioMaster TX16S |
| `tx16smk3` | RadioMaster TX16S MK3 |
| `boxer` | RadioMaster Boxer |
| `pocket` | RadioMaster Pocket |
| `zorro` | RadioMaster Zorro |
| `t20` | Jumper T20 |
| `t14` | Jumper T14 |
| `tpro` | Jumper T-Pro |
| `x9dp2019` | FrSky X9D+ 2019 |
| `x10` | FrSky X10 |
| `nv14` | FlySky NV14 |
| `pl18` | FlySky PL18 |

### Simulator

```bash
cmake --preset simu -DPCB=X10 -DPCBREV=TX16S
cmake --build build/simu --target simu
```

### Companion

Companion embeds a radio simulator that uses WASM plugins — one per radio
target. With presets, this requires two build directories: one for the WASM
plugins and one for Companion itself.

Build the WASM plugins for all radios:

```bash
tools/build-wasm-modules.sh

# or limit to specific radios
FLAVOR="tx16s;boxer" tools/build-wasm-modules.sh
```

Then build Companion:

```bash
cmake --preset companion
cmake --build build/companion --target companion --parallel
```

When developing for a specific radio, you can build just that one WASM plugin
using the superbuild instead (see [Manual CMake](#manual-cmake-without-presets)
below):

```bash
cmake -S . -B build-tx16s -DPCB=X10 -DPCBREV=TX16S
cmake --build build-tx16s --target wasi-module --parallel
cmake --build build-tx16s --target companion --parallel
```

### Tests

```bash
cmake --preset simu -DPCB=X10 -DPCBREV=TX16S
cmake --build build/simu --target tests-radio
```

## Manual CMake (without presets)

If you prefer to invoke CMake directly, the superbuild takes care of toolchain
selection and sub-build configuration automatically:

```bash
# configure
cmake -S . -B build-tx16s -DPCB=X10 -DPCBREV=TX16S

# build firmware
cmake --build build-tx16s --target firmware --parallel

# build simulator (same build directory)
cmake --build build-tx16s --target simu --parallel

# run tests
cmake --build build-tx16s --target tests-radio --parallel
```

## Key CMake variables

| Variable | Default | Description |
|----------|---------|-------------|
| `PCB` | (required) | Target radio family (X7, X10, PL18, ...) |
| `PCBREV` | (varies) | Radio variant within a PCB family (TX16S, BOXER, ...) |
| `CMAKE_BUILD_TYPE` | | `Release` or `Debug` (native builds only; firmware ELF always includes debug symbols, stripped for .bin/.uf2) |
| `TRANSLATIONS` | EN | Firmware language (EN, FR, DE, ES, ...) |
| `DEFAULT_MODE` | | Stick mode 1-4 |
| `LUA` | ON | Lua scripting support |

For the full list, see [Compilation Options](compilation-options.md). For
radio-specific build flags (`PCB`, `PCBREV`) not covered above, refer to the
build scripts at
[https://github.com/EdgeTX/edgetx/tree/main/tools](https://github.com/EdgeTX/edgetx/tree/main/tools).

## FetchContent dependency cache

Downloaded third-party dependencies (googletest, yaml-cpp, imgui, etc.) are
cached in `.cache/fetchcontent/` at the repository root. This cache is shared
across all build directories so that switching targets or doing clean rebuilds
does not re-download dependencies.

To override the cache location, set the `FETCHCONTENT_BASE_DIR` environment
variable or pass it as a CMake variable:

```bash
export FETCHCONTENT_BASE_DIR=~/edgetx-deps
cmake --preset tx16s
```

## CI builds

CI uses the scripts in `tools/`:

| Script | Purpose |
|--------|---------|
| `build-gh.sh` | Firmware release builds (all targets) |
| `commit-tests.sh` | Debug builds with warnings-as-errors |
| `build-companion.sh` | Companion app (Linux, macOS, Windows) |
| `build-wasm-modules.sh` | WebAssembly simulator modules |
| `build-common.sh` | Shared helpers and target definitions |

These scripts use `FLAVOR` environment variables and are tailored for GitHub
Actions. For local development, prefer the CMake presets above.