initial commit

1 files changed, 64 insertions, 0 deletions

diff --git a/kexec.nix b/kexec.nix
new file mode 100644
index 0000000..0487197
--- /dev/null
+++ b/kexec.nix
@@ -0,0 +1,64 @@
+# Based on https://gist.github.com/misuzu/89fb064a2cc09c6a75dc9833bb3995bf
+{ config, lib, pkgs, ... }@attrs: {
+  imports = [
+    # this will work only under qemu, uncomment next line for full image
+    # <nixpkgs/nixos/modules/installer/netboot/netboot-minimal.nix>
+    <nixpkgs/nixos/modules/installer/netboot/netboot.nix>
+    <nixpkgs/nixos/modules/profiles/qemu-guest.nix>
+  ];
+
+  # stripped down version of https://github.com/cleverca22/nix-tests/tree/master/kexec
+  system.build = {
+    image = pkgs.runCommand "image" { buildInputs = [ pkgs.nukeReferences ]; } ''
+      mkdir $out
+      cp ${config.system.build.kernel}/bzImage $out/kernel
+      cp ${config.system.build.netbootRamdisk}/initrd $out/initrd
+      nuke-refs $out/kernel
+    '';
+    kexec_script = pkgs.writeTextFile {
+      executable = true;
+      name = "kexec-nixos";
+      text = ''
+        #!${pkgs.stdenv.shell}
+        set -efu
+        ${pkgs.kexectools}/bin/kexec -l ${config.system.build.image}/kernel --initrd=${config.system.build.image}/initrd --append="init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
+        sync
+        echo "executing kernel, filesystems will be improperly umounted" >&2
+        ${pkgs.kexectools}/bin/kexec -e
+      '';
+    };
+    kexec_tarball = pkgs.callPackage <nixpkgs/nixos/lib/make-system-tarball.nix> {
+      storeContents = [
+        {
+          object = config.system.build.kexec_script;
+          symlink = "/kexec_nixos";
+        }
+      ];
+      contents = [ ];
+    };
+  };
+
+  boot.initrd.availableKernelModules = [ "ata_piix" "uhci_hcd" ];
+  boot.kernelParams = [
+    "panic=30" "boot.panic_on_fail" # reboot the machine upon fatal boot issues
+    "console=ttyS0" # enable serial console
+    "console=tty1"
+  ];
+  boot.kernel.sysctl."vm.overcommit_memory" = "1";
+
+  environment.systemPackages = [ pkgs.cryptsetup ];
+  environment.variables.GC_INITIAL_HEAP_SIZE = "1M";
+
+  networking.hostName = "kexec";
+
+  services.getty.autologinUser = "root";
+
+  services.openssh.enable = true;
+  services.openssh.settings.KbdInteractiveAuthentication = false;
+  services.openssh.settings.PasswordAuthentication = false;
+
+  users.users.root.openssh.authorizedKeys.keys =
+    (import ./config.nix attrs).users.users.root.openssh.authorizedKeys.keys;
+
+  system.stateVersion = "23.05";
+}