BUILD.md

Building ArduPilot

Ardupilot is gradually moving from the make-based build system to Waf. The instructions below should be enough for you to build Ardupilot, but you can also read more about the build system in the Waf Book.

Waf should always be called from the ardupilot's root directory. Differently from the make-based build, with Waf there's a configure step to choose the board to be used (default is sitl).

Basic usage

There are several commands in the build system for advanced usages, but here we list some basic and more used commands as example.

• Build ArduCopter

  Here we use minlure as an example of Linux board. Other boards can be used and the next section shows how to get a list of available boards.

  ./waf configure --board minlure
  ./waf copter

  The first command should be called only once or when you want to change a configuration option. One configuration often used is the --board option to switch from one board to another one. For example we could switch to Pixhawk and build again:

  ./waf configure --board px4-v2
  ./waf copter

  If building for the bebop2 the binary must be built statically:

  ./waf configure --board bebop --static
  ./waf copter

  The "arducopter" and "arducopter-heli" binaries should appear in the build/<board-name>/bin directory.

• List available boards

  It's possible to get a list of supported boards on ArduPilot with the command below

  ./waf list_boards
  

• Clean the build

  Commands clean and distclean can be used to clean the objects produced by the build. The first keeps the configure information, cleaning only the objects for the current board. The second cleans everything for every board, including the saved configure information.

  Cleaning the build is very often not necessary and discouraged. We do incremental builds reducing the build time by orders of magnitude.

• Upload or install

  Build commands have a --upload option in order to upload the binary built to a connected board. This option is supported by Pixhawk. The command below uses the --targets option that is explained in the next item.

  ./waf --targets bin/arducopter --upload

  Currently Linux boards don't support the upload option, but there's an install command, which will install to a certain directory. This can be used by distributors to create .deb, .rpm or other package types:

  ./waf copter
  DESTDIR=/my/temporary/location ./waf install

• Use different targets

  The build commands in the items above use copter as argument. This builds all binaries that fall under the "copter" group. See the section Advanced usage below for more details regarding groups.

  This shows a list of all possible targets:

  ./waf list
  

  For example, to build only a single binary:

  # Quad frame of ArduCopter
  ./waf --targets bin/arducopter
  
  # unit test of our math functions
  ./waf --targets tests/test_math
  

• Other options

  It's possible to see all available commands and options:

  ./waf -h
  

  Also, take a look on the Advanced section below.

Advanced usage

This section contains some explanations on how the Waf build system works and how you can use more advanced features.

Waf build system is composed of commands. For example, the command below (configure) is for configuring the build with all the options used by this particular build.

# Configure the Linux board
./waf configure --board=linux

Consequently, in order to build, a "build" command is issued, thus waf build. That is the default command, so calling just waf is enough:

# Build programs from bin group
./waf

# Waf also accepts '-j' option to parallelize the build.
./waf -j8

By default waf tries to parallelize the build automatically to all processors so the -j option is usually not needed, unless you are using icecc (thus you want a bigger value) or you don't want to stress your machine with the build.

Program groups

Program groups are used to represent a class of programs. They can be used to build all programs of a certain class without having to specify each program. It's possible for two groups to overlap, except when both groups are main groups. In other words, a program can belong to more than one group, but only to one main group.

There's a special group, called "all", that comprises all programs.

Main groups

The main groups form a partition of all programs. Besides separating the programs logically, they also define where they are built.

The main groups are:

• bin: the main binaries, that is, ardupilot's main products - the vehicles and Antenna Tracker
• tools
• examples: programs that show how certain libraries are used or to simply test their operation
• benchmarks: requires --enable-benchmarks during configurarion
• tests: basically unit tests to ensure changes don't break the system's logic

All build files are placed under build/<board>/, where <board> represents the board/platform you selected during configuration. Each main program group has a folder with its name directly under build/<board>/. Thus, a program will be stored in build/<board>/<main_group>/, where <main_group> is the main group the program belongs to. For example, for a linux build, arduplane, which belongs to the main group "bin", will be located at build/linux/bin/arduplane.

Main product groups

Those are groups for ardupilot's main products. They contain programs for the product they represent. Currently only the "copter" group has more than one program - one for each frame type.

The main product groups are:

• antennatracker
• copter
• plane
• rover

Building a program group

Ardupilot adds to waf an option called --program-group, which receives as argument the group you want it to build. For a build command, if you don't pass any of --targets or --program-group, then the group "bin" is selected by default. The option --program-group can be passed multiple times.

Examples:

# Group bin is the default one
./waf

# Build all vehicles and Antenna Tracker
./waf --program-group bin

# Build all benchmarks and tests
./waf --program-group benchmarks --program-group tests

Shortcut for program groups

For less typing, you can use the group name as the command to waf. Examples:

# Build all vehicles and Antenna Tracker
./waf bin

# Build all examples
./waf examples

# Build arducopter binaries
./waf copter

Building a specific program

In order to build a specific program, you just need to pass its path relative to build/<board>/ to the option --targets. Example:

# Build arducopter for quad frame
./waf --targets bin/arducopter

# Build vectors unit test
./waf --targets tests/test_vectors

Checking

The command check builds all programs and then executes the relevant tests. In that context, a relevant test is a program from the group "tests" that makes one of the following statements true:

• it's the first time the test is built since the last cleanup or when the project was cloned.
• the program had to be rebuilt (due to modifications in the code or dependencies, for example)
• the test program failed in the previous check.

That is, the tests are run only if necessary. If you want waf to run all tests, then you can use either option --alltests or the shortcut command check-all.

Examples:

# Build everything and run relevant tests
./waf check

# Build everything and run all tests
./waf check --alltests

# Build everything and run all tests
./waf check-all

Debugging

It's possible to pass the option --debug to the configure command. That will set compiler flags to store debugging information in the binaries so that you can use them with gdb, for example. The build directory will be set to build/<board>-debug/. That option might come handy when using SITL.

Build-system wrappers

The waf binary on root tree is actually a wrapper to the real waf that's maintained in its own submodule. It's possible to call the latter directly via ./modules/waf/waf-light or to use an alias if you prefer typing waf over ./waf.

alias waf="<ardupilot-directory>/modules/waf/waf-light"

There's also a make wrapper called Makefile.waf. You can use make -f Makefile.waf help for instructions on how to use it.

Command line help

You can use waf --help to see information about commands and options built-in to waf as well as some quick help on those added by ardupilot.