Re: [RFC PATCH 00/34] brcmfmac: Support Apple T2 and M1 platforms

From: Lukas Wunner
Date: Sun Dec 26 2021 - 14:18:01 EST


On Mon, Dec 27, 2021 at 12:35:50AM +0900, Hector Martin wrote:
> # On firmware
>
> As you might expect, the firmware for these machines is not available
> under a redistributable license; however, every owner of one of these
> machines *is* implicitly licensed to posess the firmware, and the OS
> packages containing it are available under well-known URLs on Apple's
> CDN with no authentication.

Apple's EFI firmware contains a full-fledged network stack for
downloading macOS images from osrecovery.apple.com. I suspect
that it also contains wifi firmware.

You may want to check if it's passed to the OS as an EFI property.
Using that would sidestep license issues. There's EDID data,
Thunderbolt DROM data and whatnot in those properties, so I
wouldn't be surprised if it contained wifi stuff as well.

Enable CONFIG_APPLE_PROPERTIES and pass "dump_apple_properties"
on the command line to see all EFI properties in dmesg.
Alternatively, check "ioreg -l" on macOS. Generally, what's
available in the I/O registry should also be available on Linux
either as an ACPI or EFI property.

Thanks,

Lukas