How do I install the Build Sitl skill?

Run npx skillmds@latest add sensei-hacker/build-sitl in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Build Sitl skill do?

Build INAV SITL (Software In The Loop) firmware for testing without hardware It is listed under Coding & Dev Tools on SkillMD.

Is Build Sitl safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Build Sitl?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Build Sitl free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Build Sitl?

sensei-hacker (@sensei-hacker) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Build Sitl by sensei-hacker — Agent Skill

Name: Build Sitl
Author: sensei-hacker

File contents

Building INAV SITL

SITL (Software In The Loop) allows testing the full firmware on your host system without hardware.

Quick Build (Recommended)

Use the build script which handles cmake configuration and toolchain compatibility:

claude/developer/scripts/build/build_sitl.sh

To clean and rebuild:

claude/developer/scripts/build/build_sitl.sh clean

The binary will be at: inav/build_sitl/bin/SITL.elf

Manual Build (Alternative)

Use a separate build directory to avoid conflicts with hardware target builds:

cd inav
mkdir -p build_sitl
cd build_sitl
cmake -DSITL=ON ..
make SITL.elf -j4

Rebuild After Code Changes

cd inav/build_sitl
make SITL.elf -j4

No need to run cmake again unless CMakeLists.txt files changed.

Alternative - Shared Build Directory

If you must use the shared build/ directory:

cd inav/build
rm -f CMakeCache.txt  # If switching from hardware build
cmake -DSITL=ON ..
make SITL.elf -j4     # MUST specify target!

WARNING: Running make without SITL.elf target will attempt to build all 281 hardware targets.

You already have permission

You have permission to build. Do not ask the user for permission each time

Running SITL

Quick Start (Recommended)

Use the start script which handles killing existing instances and waiting for ready:

claude/developer/scripts/testing/start_sitl.sh

This will:

Kill any existing SITL process
Start SITL in background
Wait for it to be ready (port listening)
Report connection info

Manual Start

cd inav/build_sitl
./bin/SITL.elf

SITL will:

Bind TCP to ports 5760-5767 (UART1-8)
Bind WebSocket to ports 5770-5777 (UART1-8) [if WebSocket support compiled in]
Listen on all interfaces [::]
Load/save eeprom.bin in current directory

Connect Configurator

Once SITL is running, connect via: tcp://127.0.0.1:5760

Or select "SITL" from the port dropdown in INAV Configurator.

Common Issues

Problem	Solution
Build tries to compile all 281 targets	Use separate `build_sitl/` dir OR specify `make SITL.elf`
CMake path errors	`rm CMakeCache.txt && cmake -DSITL=ON ..`
Wrong toolchain (ARM instead of host)	Ensure `-DSITL=ON` in cmake command
Hardware builds disappeared	Use separate `build_sitl/` directory
Linker error: `unrecognized option '--no-warn-rwx-segments'`	Older ld versions (< 2.39) don't support this flag. Use `build_sitl.sh` which handles this automatically

Full Documentation

cat claude/test_tools/inav/BUILDING_SITL.md

Related Skills

sitl-arm - Arming SITL via MSP for automated testing
test-crsf-sitl - Complete CRSF telemetry testing workflow with SITL
run-configurator - Using INAV Configurator with SITL
msp-protocol - MSP protocol reference for SITL testing
pr-review - Build SITL to test firmware PRs

---name: build-sitldescription: Build INAV SITL (Software In The Loop) firmware for testing without hardware---# Building INAV SITLSITL (Software In The Loop) allows testing the full firmware on your host system without hardware.## Quick Build (Recommended)Use the build script which handles cmake configuration and toolchain compatibility:```bashclaude/developer/scripts/build/build_sitl.sh```To clean and rebuild:```bashclaude/developer/scripts/build/build_sitl.sh clean```The binary will be at: `inav/build_sitl/bin/SITL.elf`## Manual Build (Alternative)Use a separate build directory to avoid conflicts with hardware target builds:```bashcd inavmkdir -p build_sitlcd build_sitlcmake -DSITL=ON ..make SITL.elf -j4```## Rebuild After Code Changes```bashcd inav/build_sitlmake SITL.elf -j4```No need to run cmake again unless CMakeLists.txt files changed.## Alternative - Shared Build DirectoryIf you must use the shared `build/` directory:```bashcd inav/buildrm -f CMakeCache.txt # If switching from hardware buildcmake -DSITL=ON ..make SITL.elf -j4 # MUST specify target!```**WARNING:** Running `make` without `SITL.elf` target will attempt to build all 281 hardware targets.## You already have permissionYou have permission to build. Do not ask the user for permission each time## Running SITL### Quick Start (Recommended)Use the start script which handles killing existing instances and waiting for ready:```bashclaude/developer/scripts/testing/start_sitl.sh```This will:1. Kill any existing SITL process2. Start SITL in background3. Wait for it to be ready (port listening)4. Report connection info### Manual Start```bashcd inav/build_sitl./bin/SITL.elf```SITL will:- Bind TCP to ports 5760-5767 (UART1-8)- Bind WebSocket to ports 5770-5777 (UART1-8) [if WebSocket support compiled in]- Listen on all interfaces [::]- Load/save eeprom.bin in current directory### Connect ConfiguratorOnce SITL is running, connect via: `tcp://127.0.0.1:5760`Or select "SITL" from the port dropdown in INAV Configurator.## Common Issues| Problem | Solution ||---------|----------|| Build tries to compile all 281 targets | Use separate `build_sitl/` dir OR specify `make SITL.elf` || CMake path errors | `rm CMakeCache.txt && cmake -DSITL=ON ..` || Wrong toolchain (ARM instead of host) | Ensure `-DSITL=ON` in cmake command || Hardware builds disappeared | Use separate `build_sitl/` directory || Linker error: `unrecognized option '--no-warn-rwx-segments'` | Older ld versions (< 2.39) don't support this flag. Use `build_sitl.sh` which handles this automatically |## Full Documentation```bashcat claude/test_tools/inav/BUILDING_SITL.md```## Related Skills- **sitl-arm** - Arming SITL via MSP for automated testing- **test-crsf-sitl** - Complete CRSF telemetry testing workflow with SITL- **run-configurator** - Using INAV Configurator with SITL- **msp-protocol** - MSP protocol reference for SITL testing- **pr-review** - Build SITL to test firmware PRs

Frequently asked questions

Build Sitl