Wlan0 interface is not seen when running RPI4 minimal 20.12.1 image on RPI 3b+


I was able to boot the RPI4 minimal 20.12.1 image on a RPI 3b+, but it did not show the WIFI wlan0 interface. The RPI 3b+ has a Cypress CYW43455 and the dmesg log showed the correct driver module being loaded, as seen below.

Is there any workaround to make WIFI work on RPI 3b+ running the RPI4 minimal 20.12.1 image?


[ 8.984434] snd_bcm2835: module is from the staging directory, the quality is unknown, you have been warned.
[ 9.435786] brcmfmac: F1 signature read @0x18000000=0x15264345
[ 9.445288] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6

ls -la /sys/class/net/
total 0
drwxr-xr-x 2 root root 0 Dec 31 1969 .
drwxr-xr-x 59 root root 0 Dec 31 1969 …
lrwxrwxrwx 1 root root 0 Dec 20 19:51 eth0 → …/…/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.1/1-1.1.1/1-1.1.1:1.0/net/eth0
lrwxrwxrwx 1 root root 0 Dec 31 1969 lo → …/…/devices/virtual/net/lo

sudo lshw -short
H/W path Device Class Description

                      system         Raspberry Pi 3 Model B Plus Rev 1.3

/0 bus Motherboard
/0/0 processor cpu
/0/1 processor cpu
/0/2 processor cpu
/0/3 processor cpu
/0/4 memory 924MiB System memory
/1 usb1 bus DWC OTG Controller
/1/1 bus USB 2.0 Hub
/1/1/1 bus USB 2.0 Hub
/1/1/1/1 eth0 network Ethernet interface
/2 mmc0 bus MMC Host
/2/1 /dev/mmcblk0 disk 32GB EB1QT
/2/1/1 /dev/mmcblk0p1 volume 213MiB Windows FAT volume
/2/1/2 /dev/mmcblk0p2 volume 29GiB EXT4 volume
/3 mmc1 bus MMC Host
/3/0 generic SDIO Device
/3/0/1 mmc1:0001:1 generic 43430
/3/0/2 mmc1:0001:2 generic 43430
/3/0/3 mmc1:0001:3 communication 43430

sudo inxi -Fxxx
System: Host: rpi3b Kernel: 5.4.81-1-MANJARO-ARM aarch64 bits: 64 compiler: gcc v: 10.2.0 Console: tty 0
Distro: Manjaro ARM
Machine: Type: ARM Device System: Raspberry Pi 3 Model B Plus Rev 1.3 details: BCM2835 rev: a020d3 serial: 000000007008d2df
CPU: Info: Quad Core model: N/A variant: cortex-a53 bits: 64 type: MCP arch: ARMv8 rev: 4
features: Use -f option to see features bogomips: 0
Speed: 600 MHz min/max: 600/1400 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800
Graphics: Device-1: bcm2835-vc4 driver: vc4_drm v: N/A bus ID: N/A chip ID: brcm:soc
Device-2: bcm2835-hdmi driver: N/A bus ID: N/A chip ID: brcm:soc
Display: server: No display server data found. Headless machine? tty: 134x31
Message: Unable to show advanced data. Required tool glxinfo missing.
Audio: Device-1: bcm2835-audio driver: bcm2835_audio bus ID: N/A chip ID: brcm:bcm2835_audio
Device-2: bcm2835-hdmi driver: N/A bus ID: N/A chip ID: brcm:soc
Sound Server: ALSA v: k5.4.81-1-MANJARO-ARM
Network: Message: No ARM data found for this feature.
IF-ID-1: eth0 state: up speed: 1000 Mbps duplex: full mac: b8:27:eb:08:d2:df
Drives: Local Storage: total: 29.81 GiB used: 1.75 GiB (5.9%)
ID-1: /dev/mmcblk0 model: EB1QT size: 29.81 GiB serial: 0xf962676a scheme: MBR
Partition: ID-1: / size: 29.09 GiB used: 1.71 GiB (5.9%) fs: ext4 dev: /dev/mmcblk0p2
ID-2: /boot size: 213.4 MiB used: 44.5 MiB (20.8%) fs: vfat dev: /dev/mmcblk0p1
Swap: ID-1: swap-1 type: zram size: 1.35 GiB used: 768 KiB (0.1%) priority: 100 dev: /dev/zram0
Sensors: Missing: Required tool sensors not installed. Check --recommends
Info: Processes: 118 Uptime: 29m Memory: 988.1 MiB used: 240.5 MiB (24.3%) gpu: 64.0 MiB Init: systemd v: 247 Compilers:
gcc: N/A Packages: pacman: 191 Shell: Bash (sudo) v: 5.1.4 running in: tty 0 (SSH) inxi: 3.1.08

I plugged in my pb+ and also did not have wifi. Do this:

sudo rm /usr/lib/firmware/updates/brcm/brcmfmac43455-sdio.raspberrypi,3-model-b-plus.txt

The kill and reload the wifi module and see if you have wifi:

sudo modprobe -r brcmfmac
sudo modprobe brcmfmac

HI Darksky,

Your suggestion works perfectly. Thank you very much.

I went from Redhat to Ubuntu, and finally discovered Arch/Manjaro and fell in love with it ever since. Simply the very best Linux distribution and technical support.

Best regards.

1 Like

Thanks for reporting the issue. I pushed a new firmware package to correct this to the repo.