1 files changed, 97 insertions, 0 deletions
diff --git a/nixos/modules/services/ttys/kmscon.nix b/nixos/modules/services/ttys/kmscon.nix
new file mode 100644
index 00000000000..4fe720bf044
--- /dev/null
+++ b/nixos/modules/services/ttys/kmscon.nix
@@ -0,0 +1,97 @@
+{ config, pkgs, lib, ... }:
+let
+  inherit (lib) mkOption types mkIf;
+
+  cfg = config.services.kmscon;
+
+  autologinArg = lib.optionalString (cfg.autologinUser != null) "-f ${cfg.autologinUser}";
+
+  configDir = pkgs.writeTextFile { name = "kmscon-config"; destination = "/kmscon.conf"; text = cfg.extraConfig; };
+in {
+  options = {
+    services.kmscon = {
+      enable = mkOption {
+        description = ''
+          Use kmscon as the virtual console instead of gettys.
+          kmscon is a kms/dri-based userspace virtual terminal implementation.
+          It supports a richer feature set than the standard linux console VT,
+          including full unicode support, and when the video card supports drm
+          should be much faster.
+        '';
+        type = types.bool;
+        default = false;
+      };
+
+      hwRender = mkOption {
+        description = "Whether to use 3D hardware acceleration to render the console.";
+        type = types.bool;
+        default = false;
+      };
+
+      extraConfig = mkOption {
+        description = "Extra contents of the kmscon.conf file.";
+        type = types.lines;
+        default = "";
+        example = "font-size=14";
+      };
+
+      extraOptions = mkOption {
+        description = "Extra flags to pass to kmscon.";
+        type = types.separatedString " ";
+        default = "";
+        example = "--term xterm-256color";
+      };
+
+      autologinUser = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Username of the account that will be automatically logged in at the console.
+          If unspecified, a login prompt is shown as usual.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # Largely copied from unit provided with kmscon source
+    systemd.units."kmsconvt@.service".text = ''
+      [Unit]
+      Description=KMS System Console on %I
+      Documentation=man:kmscon(1)
+      After=systemd-user-sessions.service
+      After=plymouth-quit-wait.service
+      After=systemd-logind.service
+      After=systemd-vconsole-setup.service
+      Requires=systemd-logind.service
+      Before=getty.target
+      Conflicts=getty@%i.service
+      OnFailure=getty@%i.service
+      IgnoreOnIsolate=yes
+      ConditionPathExists=/dev/tty0
+
+      [Service]
+      ExecStart=
+      ExecStart=${pkgs.kmscon}/bin/kmscon "--vt=%I" ${cfg.extraOptions} --seats=seat0 --no-switchvt --configdir ${configDir} --login -- ${pkgs.shadow}/bin/login -p ${autologinArg}
+      UtmpIdentifier=%I
+      TTYPath=/dev/%I
+      TTYReset=yes
+      TTYVHangup=yes
+      TTYVTDisallocate=yes
+
+      X-RestartIfChanged=false
+    '';
+
+    systemd.suppressedSystemUnits = [ "autovt@.service" ];
+    systemd.units."kmsconvt@.service".aliases = [ "autovt@.service" ];
+
+    systemd.services.systemd-vconsole-setup.enable = false;
+
+    services.kmscon.extraConfig = mkIf cfg.hwRender ''
+      drm
+      hwaccel
+    '';
+
+    hardware.opengl.enable = mkIf cfg.hwRender true;
+  };
+}