WiFi & Switch on ASUS RT-AC88U, OpenWRT 23.05.5

[floe]

Hi everyone, I recently installed OpenWRT 23.05.5 on my ASUS RT-AC88U and most things seems to be working. I did do a NVRAM reset before flashing the OpenWRT image.

There are two things I wasn't able to figure out, however:

• It seems I cannot activate the WiFi. Everything looks correct in the settings, but the indvidual SSID interfaces jump back to "disabled" within a few seconds of starting them. In the log, I can see
  Sun Dec 8 16:59:32 2024 daemon.notice netifd: radio1 (4087): command failed: I/O error (-5)
  and a bunch of related later errors, should I try resetting the NVRAM again? Would this be possible from within OpenWRT, or do I have to go through a full reset and re-flash again?

• I can't manage either of the two internal switches (neither the BCM53012 that's directly connected to the CPU, nor the RTL8365MB that's cascaded from port 5). The Network -> Switch tab in LuCI doesn't exist, and the overview page only shows the "extsw" interface for ports 5-8 on the Realtek switch, not their individual status.

Hope someone has a few suggestions for me to try, thanks for reading!

Best, Florian

[frollic]

Wifi is BCM, I doubt it'll ever work properly ...

[floe]

Hm, according to https://openwrt.org/unsupported/unsupported_features the BCM4366 should be supported for both 2.4 GHz and 5 GHz bands, and AFAICT it is working for other folks: Asus RT-AC88U only 1 device per radio can be enabled - #8 by jen1 (maybe not all features 100%, but at least the basics).

[floe]

OK, I've gotten the WiFi to (mostly) work by taking the following steps:

• Copy a firmware .bin file to /lib/firmware/brcm/brcmfmac4366c-pcie.asus,rt-ac88u.bin (note the manufacturer,model suffix). A list of potential firmware files is available at https://www.perfacilis.com/blog/systeembeheer/linux/install-asus-pce-ac88-on-linux.html - note that the preinstalled stock firmware file in brcmfmac4366c-pcie.bin does not seem to work.
• Dump the NVRAM contents into the firmware folder: nvram show > /lib/firmware/brcm/brcmfmac4366c-pcie.txt. (For reference, some background is described in https://elimo.io/2-4ghz-coexistence-reverse-engineering-broadcom-chips-to-enable-packet-traffic-arbitration/.)
• Disable channel autoselect when setting up the access points, ideally pick a non-DFS channel for 5 GHz.

At least the 2.4 GHz band works fine now, 5 GHz still seems glitchy, may have to try a few more different firmwares...