3.3.1.1 Location and Naming Convention
The standard libraries, such as libc.a are found in
the avr/avr/lib directory. Emulation routines for operations not
natively supported in hardware are part of libgcc.a, found in
avr/lib/gcc/avr/. The libm.a math library is
also automatically linked in, as is libdevicename.a
(e.g.
libatxmega128b1.a) that contains device-specific routines for
working with watch dog timers, power management, eeprom access, etc., (see 8.1 Library Example Code for more
information).