Interesting: (https://dev.openwrt.org/ticket/6580)

"Would be nice. I have not seen any info if bcm4718 is supported by b43, and I don't know if the proprietary Broadcom driver works with newer 2.6 kernels. Currently the 2.6 builds available (dd-wrt, Tomato, stock) use kernel versions around 2.6.22-24 and the proprietary Broadcom driver. OpenWrt trunk currently uses 2.6.3x kernels."