mkconfig.c, cfgdefine.c, cfgdefine.h

These are C files that are used to build mkconfig program. The mkconfig program is used during the initial NuttX build.

When you configure NuttX, you will copy a configuration file called .config in the top level NuttX directory (See Boards Support or Documentation/NuttXPortingGuide.html). The first time you make NuttX, the top-level makefile will build the mkconfig executable from mkconfig.c (using Makefile.host). The top-level Makefile will then execute the mkconfig program to convert the .config file in the top level directory into include/nuttx/config.h. config.h is a another version of the NuttX configuration that can be included by C files.