Hello
On RaspberryPi 4B wlan doesn't work out of the box with linux 5.10.16-3-ARCH.
$this->bbcode_second_pass_code('', ' # iw dev') or $this->bbcode_second_pass_code('', '# ip link') do not show any wlan device. wlan0 is not available.
Error in systemd log:
$this->bbcode_second_pass_code('', '# journalctl -b | grep bcrm
brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6')
It took me a while to solve the problem, for I am surely not the only one with this problem, here is a solution:
To solve the problem you have to download bcrmfmac-43456-sdio.bin, bcrmfmac-43456-sdio.clm_blob and bcrmfmac-43456-sdio.txt from https://github.com/RPi-Distro/firmware-nonfree/tree/master/brcm. Place the files in /lib/firmware/brcm.
$this->bbcode_second_pass_code('', '# cd /lib/firmware/bcrm
# wget https://github.com/RPi-Distro/firmware-nonfree/raw/master/brcm/brcmfmac43456-sdio.txt
# wget https://github.com/RPi-Distro/firmware-nonfree/raw/master/brcm/brcmfmac43456-sdio.clm_blob
# wget https://github.com/RPi-Distro/firmware-nonfree/raw/master/brcm/brcmfmac43456-sdio.bin')
Link or move the bcrmfmac-43456-sdio.txt file to '/lib/firmware/brcm/brcmfmac43455-sdio.Raspberry Pi Foundation-Raspberry Pi 4 Model B.txt' (the latter file already exists in the directory, backup it). This makes the system load the correct firmware.
$this->bbcode_second_pass_code('', '# cp '/lib/firmware/brcm/brcmfmac43455-sdio.Raspberry Pi Foundation-Raspberry Pi 4 Model B.txt' '/lib/firmware/brcm/brcmfmac43455-sdio.Raspberry Pi Foundation-Raspberry Pi 4 Model B.txt.backup'
# mv /lib/firmware/brcm/brcmfmac43456-sdio.txt '/lib/firmware/brcm/brcmfmac43455-sdio.Raspberry Pi Foundation-Raspberry Pi 4 Model B.txt'
')
Regenerate initramfs and reboot.
$this->bbcode_second_pass_code('', '# mkinitcpio -P
# reboot')
wlan0 should be available and working now.