So on arm64 this works by accident because the kernel loads the fw file: brcm/brcmfmac43455-sdio.raspberrypi,4-model-b.txt
[ 11.512059] brcmfmac: F1 signature read @0x18000000=0x15264345 [ 11.530710] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6 [ 11.540495] usbcore: registered new interface driver brcmfmac [ 11.781454] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6 [ 11.802739] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/6 wl0: Mar 23 2020 02:19:54 version 7.45.206 (r725000 CY) FWID 01-88ee44ea
But on armhf it tries to load a non-existing fw file: brcm/brcmfmac43455-sdio.raspberrypi,4-compute-module.txt
[ 11.212993] brcmfmac: F1 signature read @0x18000000=0x15264345 [ 11.255150] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6 [ 11.264126] usbcore: registered new interface driver brcmfmac [ 11.287281] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.raspberrypi,4-compute-module.txt failed with error -2 [ 11.301774] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.txt failed with error -2 [ 12.333944] brcmfmac: brcmf_sdio_htclk: HT Avail timeout (1000000): clkctl 0x50
So on arm64 this works by accident because the kernel loads the fw file: 455-sdio. raspberrypi, 4-model- b.txt
brcm/brcmfmac43
[ 11.512059] brcmfmac: F1 signature read @0x18000000= 0x15264345 alloc_request: using brcm/brcmfmac43 455-sdio for chip BCM4345/6 alloc_request: using brcm/brcmfmac43 455-sdio for chip BCM4345/6 preinit_ dcmds: Firmware: BCM4345/6 wl0: Mar 23 2020 02:19:54 version 7.45.206 (r725000 CY) FWID 01-88ee44ea
[ 11.530710] brcmfmac: brcmf_fw_
[ 11.540495] usbcore: registered new interface driver brcmfmac
[ 11.781454] brcmfmac: brcmf_fw_
[ 11.802739] brcmfmac: brcmf_c_
But on armhf it tries to load a non-existing fw file: 455-sdio. raspberrypi, 4-compute- module. txt
brcm/brcmfmac43
[ 11.212993] brcmfmac: F1 signature read @0x18000000= 0x15264345 alloc_request: using brcm/brcmfmac43 455-sdio for chip BCM4345/6 455-sdio. raspberrypi, 4-compute- module. txt failed with error -2 455-sdio. txt failed with error -2
[ 11.255150] brcmfmac: brcmf_fw_
[ 11.264126] usbcore: registered new interface driver brcmfmac
[ 11.287281] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43
[ 11.301774] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43
[ 12.333944] brcmfmac: brcmf_sdio_htclk: HT Avail timeout (1000000): clkctl 0x50