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Asahi

  • On Apple Silicon systems, external boot is not support on the native boot tooling (iBoot)
  • Therefore some tools are necessary to provide a PC-like boot environment

Installation

# main
curl -L https://alx.sh | sh

# dev branch
curl -L https://alx.sh/dev | sh

# Clean up garbage boot policies
curl -L https://alx.sh/cleanbp | sh

Partition configuration

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:             Apple_APFS_ISC Container disk1         524.3 MB   disk0s1
   2:                 Apple_APFS Container disk4         430.0 GB   disk0s2
   3:                 Apple_APFS Container disk2         2.5 GB     disk0s3
   4:                        EFI ESP                     524.3 MB   disk0s4
   5:           Linux Filesystem                         1.1 GB     disk0s5
   6:           Linux Filesystem                         60.3 GB    disk0s6
   7:        Apple_APFS_Recovery Container disk3         5.4 GB     disk0s7

/dev/disk2 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +2.5 GB     disk2
                                 Physical Store disk0s3
   1:                APFS Volume Fedora - Data           5.3 MB     disk2s1
   2:                APFS Volume Fedora                  1.1 MB     disk2s2
   3:                APFS Volume Preboot                 134.2 MB   disk2s3

m1n1

  • It's a bridge between Apple's boot firmware (iBoot) and the Linux world
  • m1n1 is installed as a faux macOS kernel into a stub macOS installation
  • The sub installation is by default created in a new APFS container, separate from your conventional macOS installs. It's also possible to move this volume into the container with your other macOS installs using the asr tool: https://www.reddit.com/r/AsahiLinux/comments/1fhe5dz/

  • This process is usually done by Finish Installation.app which is run in Recovery Mode (1TR) which is automatically run on the first recovery boot

  • m1n1 Stage 1

  • MacOS stub

  • m1n1 Stage 2

  • Provides a preboot environment
  • Loads to UEFI binary
  • Uses U-Boot by default

U-Boot

  • U-Boot is loaded by m1n1
  • It's used to set up a standard UEFI environment from which GRUB, systemd-boot, etc can be booted
  • It loads and executes a UEFI binary located at /EFI/BOOT/BOOTAA64.EFI at the EFI partition
  • Due to the limitations of the Apple boot picker (iBoot), there must be one EFI system partition per installed OS.
# boot from usb
env set boot_efi_bootmgr ; run bootcmd_usb0

# enter boot menu
bootmenu # select "usb 0" to boot from usb

Firmware

  • Non-free non-redistributable peripheral firmware files are required to use system hardware like Wi-Fi
  • The Asahi Linux installer grabs these from macOS and stores them on the EFI system partition when it is created
  • /mnt/boot/asahi/{all_firmware.tar.gz,kernelcache*}
  • Some distro installers load these drivers from the EFI partition so that all hardware is available during installation

NixOS

cp -r ./apple-silicon-support /etc/nixos/
chmod -R +w /etc/nixos/

and reference it in your configuration file

# /etc/nixos/configuration.nix
imports =
  [
    ./hardware-configuration.nix
    ./apple-silicon-support
  ];

Any changes to the Apple Silicon Support Module require a rebuild and reboot to take effect

You can also add the module as a channel. This way it will be upgraded in tandom with NixOS itself

# must run as sudo so that channel is defined as root user
sudo nix-channel --add https://github.com/tpwrules/nixos-apple-silicon/archive/main.tar.gz apple-silicon-support

# /etc/nixos/configuration.nix
imports =
  [
    ./hardware-configuration.nix
    <apple-silicon-support/apple-silicon-support>
  ];

sudo nix-channel --update
sudo nixos-rebuild switch
reboot