Build and Make Details

This is included for reference, and it’s not necessary to know all these details.

As described in Compiling, you use make at the root nuttx/ directory to build NuttX. This is also referenced as $(TOPDIR) in the Makefile.

Root Directory

The $(TOPDIR) directory holds:

The top level `Makefile <#topmakefile>`__ that controls the NuttX build.

That directory also holds:

The makefile fragment .config that describes the current configuration, and
The makefile fragment Make.defs that provides customized build targets.

Environment Variables

The specific environmental definitions are unique for each board but should include, as a minimum, updates to the PATH variable to include the full path to the architecture-specific toolchain identified in Make.defs.

First Time Make

Additional configuration actions will be taken the first time that system is built. These additional steps include:

Auto-generating the file include/nuttx/config.h using the $(TOPDIR)/.config file.
Auto-generating the file $(TOPDIR)/.version with version 0.0 if one does not exist.
Auto-generating the file include/nuttx/version.h using the $(TOPDIR)/.version file.
Creating a link to $(TOPDIR)/arch/<arch-name>/include at $(TOPDIR)/include/arch.
Creating a link to $(TOPDIR)/boards/<arch-name>/<chip-name>/<board-name>/include at $(TOPDIR)/include/arch/board.
Creating a link to $(TOPDIR)/boards/<arch-name>/<chip-name>/<board-name>/src at $(TOPDIR)/arch/<arch-name>/src/board
Creating a link to ${APPDIR}/include at $(TOPDIR)/include/apps
Creating make dependencies.