HelenOS sources

ANAR_100TX_FD    1661 uspace/drv/nic/rtl8139/driver.c 		anar |= ANAR_100TX_FD;
ANAR_100TX_FD    1717 uspace/drv/nic/rtl8139/driver.c 	if (anar & ANAR_100TX_FD)
ANAR_100TX_FD     643 uspace/drv/nic/rtl8169/driver.c 		anar |= ANAR_100TX_FD;
HelenOS homepage, sources at GitHub