1. Get the "updated" el6 b43-firmware rpm from the Russian Fedora guys. (make sure it's the *el6* version)
wget "http://koji.russianfedora.ru/koji/buildinfo?buildID=1041"
2. Install it (current version depreciates the b43-openfwwf package nicely)
yum install b43-firmware-5.10.56.27.3-2.el6.noarch.rpm
3. Wait several seconds and the wifi light comes on and wifi works!
I originally tried with the documented b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" broadcom-wl-5.100.138/linux/wl_apsta.o but failed to extract the firmware needed.
I also looked into the kmod-compat-wireless but current information suggest, "RHEL6 packages are broken at present". Enjoy.
Here is all of the info from the BCM4312 card in question:
lspci | grep BCM
0c:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)
lspci -n | grep 14e4
0c:00.0 0280: 14e4:4315 (rev 01)
Original /var/log/messages indicated:
b43-phy0 ERROR: Firmware file "b43/ucode15.fw" not found
b43-phy0 ERROR: Firmware file "b43-open/ucode15.fw" not found
b43-phy0 ERROR: You must go to http://wireless.kernel.org/en/users/...devicefirmware and download the correct firmware for this driver version. Please carefully read all instructions on this website.
b43-phy0 ERROR: Firmware file "b43-open/ucode15.fw" not found
b43-phy0 ERROR: You must go to http://wireless.kernel.org/en/users/...devicefirmware and download the correct firmware for this driver version. Please carefully read all instructions on this website.