HelenOS sources

PHYAR_RW_SHIFT    279 uspace/drv/nic/rtl8169/defs.h 	PHYAR_RW_READ = (0 << PHYAR_RW_SHIFT),
PHYAR_RW_SHIFT    280 uspace/drv/nic/rtl8169/defs.h 	PHYAR_RW_WRITE = (1 << PHYAR_RW_SHIFT),
HelenOS homepage, sources at GitHub