The original "Wiring" board was based on an ATmega128; I think their libraries still support it.http://wiring.org.co/hardware/previous.html
See also http://avr-developers.com
I don't think there is any support in the Arduino core (ie pins_arduino.h) for m128, though some of the functions should work due to the general-ification that has been done in recent releases (checking for the existence of a UART1, instead of checking for a particular processor type that then implies the existence of UART1.)
pins_arduino.h is less about the pins on the chip, and more about the pins on the board you are using. To get a particular m128 board working, you'll have to write your own pins_arduino.h file, and to do that you'll have to figure out how it works. It's not too hard; it simply contains the definitions for a bunch of arrays that map from the "pin numbers" used in calls like digitalWrite() to the ports and bits that the processor actually needs to manipulate those pins...