Fans of running Linux on Apple’s hardware are in for some bad news, with the Asahi Linux project warning that adding support for Apple’s latest M4 “is going to be rather painful.”

The Asahi Linux developers have been working over the last few years to reverse engineer drivers for Apple’s M-series chips, giving users a way to run Linux on some of the best hardware on the market. Unfortunately, in a post on Mastodon, Asahi developer Sven Peter says the M4 is proving to be more challenging.

Looks like M4 support for #asahilinux is going be rather painful. We’re still focusing on upstreaming M1/M2 support but other people have been trying to bring up m1n1 on M4 and it looks like a few things changed:

When configuring a macho boot object we now get dropped into an environment where Apple’s SPTM is running in GL2 and we are supposed to talk to it from EL2 with MMU already enabled to setup pagetables. This neither works for Linux nor for running XNU under our hypervisor to reverse engineer the new hardware.

When configuring a raw boot object we’re dropped into EL2 with GL2 and most (all?) Apple specific extensions disabled. This is totally fine for Linux but we can’t run XNU under our hypervisor that we use to reverse engineer the hardware in this state. This also seems to be broken for >=15.2 right now because it probably isn’t very well tested.

Linux has long supported the Mac platform, although primarily when Apple relied on Intel chips. Since the move to its M-series, running Linux on Macs has posed a greater challenge, primarily because Apple has not released open source drivers for its chipset, nor has it contributed to third-party development. As a result, the Asahi developers have had a difficult task reverse engineering and developing open source drivers.