This is an update to the new Macbook post, in which I said I had to use Ndiswrapper to drive the BCM4331 wireless adapter. Now there is a native solution here. The steps are explained in detail. However I was not able to use patched compat-wireless-2011-08-27. In 2.6.39 (ck-patched) kernel, it refused to detect any wireless network; in 3.0 kernel, it simply wouldn't load. Modprobe complained about unknown symbols.

Today I tried an updated version of compat-wireless, which was labeled as 2011-09-27, and it worked in both kernels. Note that the patches mentioned in the link above are not needed anymore, and also that since kernel.org has been down forever, I downloaded the compat-wireless module from here. I made some PKGBUILDs for the firmware of BCM4331 and compat-wireless based on the PKGBUILD of compat-wireless-patched. Here they are~~

:::Bash
pkgname=b43-firmware
pkgver=5.100.138
pkgrel=1
pkgdesc='Firmware for BCM43xx wireless adapters'
url='http://wireless.kernel.org/'
arch=('x86_64')
license=('GPL')
depends=()
makedepends=("b43-fwcutter")
source=("http://www.lwfinger.com/b43-firmware/broadcom-wl-${pkgver}.tar.bz2")
sha1sums=('21691a8c99c66f58d18f863ee43593d1633b454c')

# install=install

build() {
  msg "Nothing to build..."
}

package() {
    mkdir -pv "${pkgdir}/lib/firmware"
    cd "${srcdir}"
    b43-fwcutter -w "${pkgdir}/lib/firmware" \
        broadcom-wl-5.100.138/linux/wl_apsta.o
}

Another one

:::Bash
pkgname=compat-wireless
pkgver=20110927
realver=2011-09-27
pkgrel=1
pkgdesc='Compat wireless driver, enabled for b43 support.'
url='http://wireless.kernel.org/'
arch=('x86_64')
license=('GPL')
depends=('linux'...