What exactly does Linux kernel's `make defconfig` do?

Question

I can use the following command to create a Linux kernel .config file based on a specified architecture default for a custom ARM-based board:

AR         


        

Answer 1

It also generate include/generated/autoconf.h.

This header file is included by C source file. On the other hand, .config is for Makefile system.

Build system generate two files, and keep them consistent.