add the oracle installer config

flake.nix

@@ -184,6 +184,10 @@
               config = ./machine/not522/installer;
               system = "riscv64-linux";
             };
+            oracle-installer = {
+              config = ./machine/oracle-installer;
+              system = "aarch64-linux";
+            };
             pc-installer = {
               config = ./machine/pc-installer;
               system = "x86_64-linux";

machine/oracle-installer/README.md

@@ -0,0 +1 @@
+Taken from https://github.com/cleverca22/nix-tests/tree/master/kexec, released under the apache 2.0 license

machine/oracle-installer/autoreboot.nix

@@ -0,0 +1,21 @@
+{ config, lib, ... }:
+
+{
+  options = {
+    kexec.autoReboot = lib.mkOption {
+      default = true;
+      description = "auto-reboot at the end of the hour";
+      type = lib.types.bool;
+    };
+  };
+  config = lib.mkIf config.kexec.autoReboot {
+    systemd.timers.autoreboot = {
+      partOf = [ "autoreboot.service" ];
+      wantedBy = [ "timers.target" ];
+      timerConfig.OnCalendar = "hourly";
+    };
+    systemd.services.autoreboot = {
+      script = "shutdown -r +5";
+    };
+  };
+}

machine/oracle-installer/configuration.nix

@@ -0,0 +1,32 @@
+# new cmd: nix-build '<nixpkgs/nixos>' -A config.system.build.kexec_tarball -I nixos-config=./configuration.nix -Q -j 4
+
+{
+  lib,
+  nixpkgs,
+  ...
+}:
+
+with lib;
+
+{
+  imports = [
+    "${nixpkgs}/nixos/modules/installer/netboot/netboot-minimal.nix"
+    ./autoreboot.nix
+    ./kexec.nix
+  ];
+
+  boot.supportedFilesystems = lib.mkForce [
+    "btrfs"
+    "vfat"
+  ];
+  boot.loader.grub.enable = false;
+  boot.kernelParams = [
+    "console=ttyS0,115200" # allows certain forms of remote access, if the hardware is setup right
+    "panic=30"
+    "boot.panic_on_fail" # reboot the machine upon fatal boot issues
+  ];
+  systemd.services.sshd.wantedBy = mkForce [ "multi-user.target" ];
+  networking.hostName = "kexec";
+  # example way to embed an ssh pubkey into the tar
+  # users.users.root.openssh.authorizedKeys.keys = [ "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC34wZQFEOGkA5b0Z6maE3aKy/ix1MiK1D0Qmg4E9skAA57yKtWYzjA23r5OCF4Nhlj1CuYd6P1sEI/fMnxf+KkqqgW3ZoZ0+pQu4Bd8Ymi3OkkQX9kiq2coD3AFI6JytC6uBi6FaZQT5fG59DbXhxO5YpZlym8ps1obyCBX0hyKntD18RgHNaNM+jkQOhQ5OoxKsBEobxQOEdjIowl2QeEHb99n45sFr53NFqk3UCz0Y7ZMf1hSFQPuuEC/wExzBBJ1Wl7E1LlNA4p9O3qJUSadGZS4e5nSLqMnbQWv2icQS/7J8IwY0M8r1MsL8mdnlXHUofPlG1r4mtovQ2myzOx clever@nixos" ];
+}

machine/oracle-installer/default.nix

@@ -0,0 +1,33 @@
+{
+  nixos-config,
+  pkgs,
+  lib,
+  ...
+}:
+{
+  imports = [
+    ./configuration.nix
+    "${nixos-config}/config"
+  ];
+
+  # Make it use predictable interface names starting with eth0
+  boot.kernelParams = [ "net.ifnames=0" ];
+
+  networking.useDHCP = true;
+  isInstaller = true;
+
+  environment.impermanence.enable = false;
+  boot.initrd.systemd.enable = lib.mkForce false;
+  home-manager.sharedModules = [ { home.persistence = lib.mkForce { }; } ];
+
+  environment.systemPackages = [
+    (pkgs.writeShellScriptBin "install-oracle-unattended" ''
+      set -eux
+      exec ${pkgs.disko}/bin/disko-install --flake "${nixos-config}#oracle" --disk main "${nixos-config.nixosConfigurations.thinkrac.config.disko.devices.disk.main.device}"
+    '')
+  ];
+
+  users.users.root.openssh.authorizedKeys.keys = [
+    "sk-ssh-ed25519@openssh.com AAAAGnNrLXNzaC1lZDI1NTE5QG9wZW5zc2guY29tAAAAIDXQlfvRUm/z6eP1EjsajIbMibkq9n+ymlbBi7NFiOuaAAAABHNzaDo= ssh:"
+  ];
+}

machine/oracle-installer/kexec.nix

@@ -0,0 +1,51 @@
+{ pkgs, config, ... }:
+
+{
+  system.build = rec {
+    image = pkgs.runCommand "image" { buildInputs = [ pkgs.nukeReferences ]; } ''
+      mkdir $out
+      cp ${config.system.build.kernel}/${config.system.boot.loader.kernelFile} $out/kernel
+      cp ${config.system.build.netbootRamdisk}/initrd $out/initrd
+      echo "init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}" > $out/cmdline
+      nuke-refs $out/kernel
+    '';
+    kexec_script = pkgs.writeTextFile {
+      executable = true;
+      name = "kexec-nixos";
+      text = ''
+        #!${pkgs.stdenv.shell}
+        export PATH=${pkgs.kexectools}/bin:${pkgs.cpio}/bin:$PATH
+        set -x
+        set -e
+        cd $(mktemp -d)
+        pwd
+        mkdir initrd
+        pushd initrd
+        if [ -e /ssh_pubkey ]; then
+          cat /ssh_pubkey >> authorized_keys
+        fi
+        find -type f | cpio -o -H newc | gzip -9 > ../extra.gz
+        popd
+        cat ${image}/initrd extra.gz > final.gz
+
+        kexec -l ${image}/kernel --initrd=final.gz --append="init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
+        sync
+        echo "executing kernel, filesystems will be improperly umounted"
+        kexec -e
+      '';
+    };
+  };
+  boot.initrd.postMountCommands = ''
+    mkdir -p /mnt-root/root/.ssh/
+    cp /authorized_keys /mnt-root/root/.ssh/
+  '';
+  system.build.kexec_tarball = pkgs.callPackage (pkgs.path + "/nixos/lib/make-system-tarball.nix") {
+    storeContents = [
+      {
+        object = config.system.build.kexec_script;
+        symlink = "/kexec_nixos";
+      }
+    ];
+    contents = [ ];
+  };
+}

machine/thinkrac/hardware.nix

@@ -47,7 +47,6 @@
     options usbcore autosuspend=2
     # Fan control for thinkpads
     options thinkpad_acpi fan_control=1
-    options zfs zfs_arc_max=4294967296
   '';
   boot.kernel.sysctl = {
     # Probably unnecessary