I recently got myself a shiny new toy, a 14" notebook, and installed
Gentoo (naturally). The biggest struggle was getting the Broadcom
BCM57780 ethernet chip recognized. For the benefit of anybody else who
runs into problems, here is the step-by-step solution...
Device Drivers --->[*] Network device support --->
-*- PHY Device support and infrastructure --->
<*> Drivers for Broadcom PHYs[*] Ethernet (1000 Mbit) --->
<*> Broadcom Tigon3 support
save .config, rebuild kernel, and reboot. Ethernet works fine.