I have done some further research on this issue and have determined that it is both an upstream and non-free issue, so it doesn’t belong here. For posterity, however, I have found that:
- The WiFi card _is_ the “ethernet” device seen in ‘ip address’. - The brcmfmac driver searches for the following missing files in the firmware directory: 1. brcmfmac43602-pcie.txt This file can be found in the attachments of this thread [1], where others encountering this issue made it via reverse-engineering. 2, brcmfmac43602-pcie.Apple Inc-<product name>.txt 3. brcmfmac43602-pcie.Apple Inc-<product name>.bin Where <product name> is in my case ‘MacBookPro-12,1’. These files are indicated to be searched for and missing by dmesg [2], but I have no idea where these would be found. I’d guess that some more “user-friendly” distros would ship them, so I’ll start the search with their install images. Again, if the .txt file’s licensing is OK, it should be in the libre kernel, I think? I’m going to try to write a package that includes these missing files. If anyone has any recommendations of relevant mailing lists or resources for this problem, I would be very appreciative. [1] https://bugzilla.kernel.org/show_bug.cgi?id=193121 [2] https://askubuntu.com/questions/1217400/how-can-i-solve-problems-\ from-dual-boot-on-macbookproubuntu-wifi