I hope I didn't mess up the reply, I don't go on mailing lists often.
Does it make a difference if you install the bwfm-firmware package?
The one on http://firmware.openbsd.org/firmware/ right? I think I read somewhere it isn't for the Apple Silicon devices and that the Macs just use whatever is on the EFI partition. It doesn't seem to even have any files for the brcmfmac4378b1, which I think should be the correct model for the M1 Air's broadcom WiFi interface according to https://lore.kernel.org/all/20220104072658.69756-10-mar...@marcan.st/ which is linked to from https://asahilinux.org/docs
was the 7.6 problem
One of the (I think) OpenBSD devs on IRC said https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/004_aplsmc.patch.sig was the issue. So from what I understand you had OpenBSD already installed, upgraded to 7.7 and everything seems to be working fine with bwfm0 even after updating to MacOS 15.4? Could you maybe get a list of files and their hashes from /etc/firmware so I can compare if anything is different on my end?
