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RIOT Documentation

The Build System

RIOT uses GNU make as build system. The simplest way to compile and link an application with RIOT, is to set up a Makefile providing at least the following variables:

  • APPLICATION: should contain the (unique) name of your application
  • BOARD: specifies the platform the application should be built for by default
  • RIOTBASE: specifies the path to your copy of the RIOT repository (note, that you may want to use $(CURDIR) here, to give a relative path)

Additionally, it has to include the Makefile.include, located in RIOT’s root directory:

a minimal application Makefile
APPLICATION = mini-makefile
BOARD ?= native
RIOTBASE ?= $(CURDIR)/../RIOT


include $(RIOTBASE)/Makefile.include

You can use Make’s ?= operator in order to allow overwriting variables from the command line. For example, you can easily specify the target platform, using the sample Makefile, by invoking make like this:

Terminal window
make BOARD=iotlab-m3

Makefile targets

Section titled “Makefile targets”

Besides typical targets like clean, all, or doc, RIOT provides the special targets flash and term to invoke the configured flashing and terminal tools for the specified platform. These targets use the variable PORT for the serial communication to the device, which defaults to /dev/ttyACM0 and /dev/tty.usbmodem* on Linux and macOS, respectively. (source). Setting MOST_RECENT_PORT=1 enables a more sophisticated serial port selection algorithm, which selects the most recently connected serial port whose metadata matches the board’s known properties.

For the native port, PORT has a special meaning: it is used to identify the tap interface if the netdev_tap module is used. The target debug can be used to invoke a debugger on some platforms. For the native port additional targets such as all-valgrind and valgrind exist. Refer to cpu/native/README.md for additional information.

The make target help lists all available targets, of which the zsh completion script offers a short description.

Notable targets include info-* targets which provide further information about the build system. As such, info-modules list all (recursively) included modules in the build, and info-build shows more details about the build: among others, include paths, a list of included Makefiles, and the CFLAGS used for the build.

Build System Internals

Section titled “Build System Internals”

Basic

Section titled “Basic”

RIOT uses a recursive Makefile system. The starting point for these structure is typically the Makefile within the application’s Makefile. Among other variables it sets the path to the RIOT repository as RIOTBASE.

Makefiles

Section titled “Makefiles”

There is a number of special Makefiles in RIOT:

  • Makefile.include in RIOT module directories: appends target-specific information to variables like INCLUDES, setting the include paths, etc.
  • Makefile.include in RIOTBASE: Part of the internal build system architecture and should be included in an application’s Makefile as the last line.
  • Makefile.base: Meant for inclusion as the last line in a RIOT module’s Makefile.
  • Makefile.dep serves to define dependencies for RIOT modules.
  • makefiles/vars.inc.mk: All RIOT specific variables used in the Make build system are listed and briefly explained in Makefile.vars.

Unless specified otherwise, make will create an elf-file as well as an Intel hex file in the bin folder of your application directory.