HelenOS sources

ANAR_100TX_FD    1635 uspace/drv/nic/rtl8139/driver.c 		anar |= ANAR_100TX_FD;
ANAR_100TX_FD    1691 uspace/drv/nic/rtl8139/driver.c 	if (anar & ANAR_100TX_FD)
ANAR_100TX_FD     621 uspace/drv/nic/rtl8169/driver.c 		anar |= ANAR_100TX_FD;
HelenOS homepage, sources at GitHub