I have had this problem in setting up my Broadcom BCM4401-B0 on the Dell XPS Laptop.
‘make install’ and then ./adddrv.sh runs fine on the bfe-2.3.0a driver, but when I run ‘devfsadm -i bfe’, I get
devfsadm:driver failed to attach: bfe
Further ‘ifconfig bfe0 plumb’ returns
bfe0: No such file or directory
I am running the i386 version, and make install only seems to be installing /kernel/drv/bfe. I have nothing like a /kernel/drv/i386 (in reference to /kernel/drv/amd64 as per this ML archive).