4.14.1.1 Program Space Sections

The contents of common sections in program memory are described below.

.text
These sections contain all executable code that does not require a special link location.
.initn
These sections are used to define the runtime startup code, executed from the moment of reset right through to the invocation of main(). The code in these sections are executed in order from init0 to init9.
.finin
These sections are used to define the exit code, executed after main() terminates, either by returning or by calling to exit(). The code in the .finin sections are executed in descending order from .fini9 to .fini0.