Linux Kernel Patches Posted For Review In Enabling Apple AirDrop Support

A set of Linux kernel patches have been posted for review with a hope of reaching the mainline kernel to provide Apple AirDrop support for Macs equipped with the T2 chip. Apple AirDrop allows wirelessly sharing of photos, documents, and other assets between nearby Apple devices. With the patches posted for the Linux kernel plus an associated user-space open-source software stack, Apple AirDrop can work to/from Linux as well when running on T2 Macs. Open-source developer Andre Eikmeyer posted the patches for the Broadcom brcmfmac driver for allowing AirDrop send and receive support using Apple Wireless Direct Link (AWDL). As for how this Apple AirDrop support works, Andre explained in the patch series cover letter: "This series adds AWDL support to brcmfmac, so Linux on the Apple T2 Macs can send and receive files over AirDrop with Macs, iPhones and iPads. AirDrop runs over Apple Wireless Direct Link (AWDL). On these Macs the Apple firmware runs AWDL itself. The host creates an AWDL interface and sets its parameters. From then on the firmware keeps the AWDL schedule, sends the AWDL frames it gets from the host and carries data frames to and from the peers. Election, peer discovery and AirDrop run in user space. The driver enables AWDL on any firmware that announces "awdl" in its capabilities and supports interface_create version 3. The linux-firmware image for the BCM4350 (7.35.180.133) on a pre-T2 MacBookPro14,1 announces "awdl" and answers interface_create with BCME_UNSUPPORTED, so it stays without the feature. Other Apple chips, such as the BCM4355, are untested." On the user-space side, there is t2-drop as a Rust-based program with NetworkManager integration for handling AirDrop. This is part of the kaiT2en project. This kernel code paired with the user-space t2-drop allows for Apple AirDrop to work in both directions on T2-equipped Macs. Those interested can find the kernel code out for review on the kernel mailing list.