apple/t2: init

Co-authored-by: networkException <git@nwex.de>

apple/t2/README.md

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+## NixOS on T2 Macs
+
+This is the `nixos-hardware` module of the [T2 Linux Project](https://t2linux.org).
+
+Overall, most features (WiFi, bluetooth, audio, touchbar, ...) of Macs are supported, [see this page](https://wiki.t2linux.org/state/) for a detailed list of things that work and things that don't/partially work.
+
+Following [this guide](https://wiki.t2linux.org/distributions/nixos/installation/) is the recommended way to install, as it incudes the extra things you have to do on a T2 Mac.
+
+You can consult the [wiki](https://wiki.t2linux.org/) for information specific to T2 Macs.

apple/t2/default.nix

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+{ pkgs, ... }:
+
+let
+  audioFiles = pkgs.fetchFromGitHub {
+    owner = "kekrby";
+    repo = "t2-better-audio";
+    rev = "e46839a28963e2f7d364020518b9dac98236bcae";
+    hash = "sha256-x7K0qa++P1e1vuCGxnsFxL1d9+nwMtZUJ6Kd9e27TFs=";
+  };
+
+  overrideAudioFiles = package: pluginsPath:
+    package.overrideAttrs (new: old: {
+      preConfigurePhases = old.preConfigurePhases or [ ] ++ [ "postPatchPhase" ];
+
+      postPatchPhase = ''
+        cp -r ${audioFiles}/files/{profile-sets,paths} ${pluginsPath}/alsa/mixer/
+      '';
+    });
+in
+{
+  # For keyboard and touchbar
+  boot.kernelPackages = with pkgs; recurseIntoAttrs (linuxPackagesFor (callPackage ./pkgs/linux-t2.nix { }));
+  boot.initrd.kernelModules = [ "apple-bce" ];
+
+  # For audio
+  boot.kernelParams = [ "pcie_ports=compat" "intel_iommu=on" "iommu=pt" ];
+  services.udev.extraRules = builtins.readFile (pkgs.substitute {
+    src = "${audioFiles}/files/91-audio-custom.rules";
+    replacements = [ "--replace" "/usr/bin/sed" "${pkgs.gnused}/bin/sed" ];
+  });
+
+  hardware.pulseaudio.package = overrideAudioFiles pkgs.pulseaudio "src/modules/";
+
+  services.pipewire = rec {
+    package = overrideAudioFiles pkgs.pipewire "spa/plugins/";
+
+    wireplumber.package = pkgs.wireplumber.override {
+      pipewire = package;
+    };
+  };
+
+  # Make sure post-resume.service exists
+  powerManagement.enable = true;
+
+  systemd.services.fix-keyboard-backlight-and-touchbar = {
+    path = [ pkgs.kmod ];
+    serviceConfig.ExecStart = ''${pkgs.systemd}/bin/systemd-inhibit --what=sleep --why="fixing keyboard backlight and touchbar must finish before sleep" --mode=delay ${./fix-keyboard-backlight-and-touchbar.sh}'';
+    serviceConfig.Type = "oneshot";
+    description = "reload touchbar driver and restart upower";
+    # must run at boot (and not too early), and after suspend
+    wantedBy = [ "display-manager.service" "post-resume.target" ];
+    # prevent running before suspend
+    after = [ "post-resume.target" ];
+  };
+}

apple/t2/fix-keyboard-backlight-and-touchbar.sh

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+#!/bin/sh
+
+set -eux
+
+unload () {
+  if modprobe -r "$1" 2>&1;
+  then echo ok
+  else echo fail
+  fi
+}
+
+wait_unload() {
+  while sleep 1; do
+    output="$(unload "$1")"
+    case "$output" in
+      *is\ in\ use*) :;;
+      *ok*) return 0;;
+      *) echo "modprobe said: $output"; echo giving up; return 1;
+    esac
+  done
+}
+
+wait_unload apple_touchbar
+modprobe apple_touchbar
+
+# After suspend, the inode for the backlight device has changed. This service
+# simply restarts upower to inform it of that change.
+systemctl restart upower.service

apple/t2/pkgs/linux-t2.nix

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+{ lib, buildLinux, fetchFromGitHub, fetchurl, ... } @ args:
+
+let
+  patchRepo = fetchFromGitHub {
+    owner = "t2linux";
+    repo = "linux-t2-patches";
+    rev = "c0db79a25bc37dbd0c27636914b3903016a2fc39";
+    hash = "sha256-VILJAK7F0E/8Z3sOzsUpS9dmtpull2XVXQkakZ0UTIA=";
+  };
+
+  version = "6.4";
+  majorVersion = with lib; (elemAt (take 1 (splitVersion version)) 0);
+in
+buildLinux (args // {
+  inherit version;
+
+  pname = "linux-t2";
+  # Snippet from nixpkgs
+  modDirVersion = with lib; "${concatStringsSep "." (take 3 (splitVersion "${version}.0"))}";
+
+  src = fetchurl {
+    url = "mirror://kernel/linux/kernel/v${majorVersion}.x/linux-${version}.tar.xz";
+    hash = "sha256-j6BYjwws7KRMrHeg45ukjJ8AprncaXYcAqXT76yNp/M=";
+  };
+
+  structuredExtraConfig = with lib.kernel; {
+    APPLE_BCE = module;
+    APPLE_GMUX = module;
+    BRCMFMAC = module;
+    BT_BCM = module;
+    BT_HCIBCM4377 = module;
+    BT_HCIUART_BCM = yes;
+    BT_HCIUART = module;
+    HID_APPLE_IBRIDGE = module;
+    HID_APPLE = module;
+    HID_APPLE_MAGIC_BACKLIGHT = module;
+    HID_APPLE_TOUCHBAR = module;
+    HID_SENSOR_ALS = module;
+    SND_PCM = module;
+    STAGING = yes;
+  };
+
+  kernelPatches = lib.attrsets.mapAttrsToList (file: type: { name = file; patch = "${patchRepo}/${file}"; })
+    (lib.attrsets.filterAttrs (file: type: type == "regular" && lib.strings.hasSuffix ".patch" file)
+      (builtins.readDir patchRepo));
+} // (args.argsOverride or {}))