Upstreamed for the Linux 7.2 kernel was initial support for booting Linux on the Apple M3 SoC devices. But just the barebones suppport for booting with not yet any accelerated graphics or other typical function needed for daily use of M3 Apple devices on Linux, just booting to a console. Now this work is complemented by additional Device Tree patches for also booting M3 Pro / Max / Ultra devices on Linux.

Following that initial Apple M3 bring-up for Linux 7.2 and also some initial DT patches for the Apple M4 SoC on Linux, Device Tree patches are now out for review to boot Apple M3 Pro / M3 Max / M3 Ultra hardware with the mainline Linux kernel.

Asahi Linux contributor Janne Grunau explained with the patch series working on this M3 Pro/Max/Ultra bring-up:

"This series adds device trees for Apple silicon devices with M3 Pro, Max and Ultra SoCs. The M3 generation has fewer devices than their M1 and M2 predecessors. The only non-laptop device is the M3 Ultra Mac Studio. The Laptops are the known 14 and 16-inch Macbook Pros now with M3 Pro and M3 Max SoCs. The M3 Max variant with fewer CPU and GPU cores has additionally only a 384-bit wide memory bus instead of 512-bit of the full M3 Max. It has a separate identifier (T6034) and so there are six laptop device trees.

Another difference to M1 and M2 Pro/Max/Ultra is that the M3 Pro is distinct SoC design and not a smaller M3 Max. For this reason both M3 Max variants and the M3 Ultra will use "apple,t6030" as compatible prefix. In the M1 and M2 generations Pro, Max and Ultra SoCs shared "apple,t6000" / "apple,t6020" as common prefix. There is currently no known difference but M3 Pro and M3 Max are not as closely related as previously.

This series adds the same level of hardware as the base M3 (T8122) has in v7.2-rc1. This includes CPU cores, interrupt controller, power states, watchdog, serial, pin controller, i2c and the boot framebuffer. This is intended as base so that support for additional hardware can be added to all M3 based devices at the same time."

It's a start in the right direction for mainline Linux support for these Apple devices that launched back in November 2023. It will be longer before the Apple M3 class hardware is fully usable on Linux with GPU support and all other integrated device functionality in place, especially for the MacBook laptops.

Those interested can find the initial Device Tree work for the Apple M3 Pro/Max/Ultra on Linux via this patch series. If all goes well those initial DT patches could be mainlined as soon as the Linux v7.3 cycle.