From a7a0d79ef3fd0bf86847612597f4b62ce6ec5a18 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Kr=C3=BCger?= <mkg20001@gmail.com>
Date: Sun, 5 Jul 2020 05:16:25 +0200
Subject: [PATCH] boot.loader.grub: add theme option

Co-authored-by: Eelco Dolstra <edolstra@gmail.com>

Co-authored-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
---
 .../modules/system/boot/loader/grub/grub.nix  | 16 +++++++++++-
 .../system/boot/loader/grub/install-grub.pl   | 25 +++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/system/boot/loader/grub/grub.nix b/nixos/modules/system/boot/loader/grub/grub.nix
index 49e73588ed6e..20e39628eabb 100644
--- a/nixos/modules/system/boot/loader/grub/grub.nix
+++ b/nixos/modules/system/boot/loader/grub/grub.nix
@@ -56,6 +56,7 @@ let
       bootloaderId = if args.efiBootloaderId == null then "NixOS${efiSysMountPoint'}" else args.efiBootloaderId;
       timeout = if config.boot.loader.timeout == null then -1 else config.boot.loader.timeout;
       users = if cfg.users == {} || cfg.version != 1 then cfg.users else throw "GRUB version 1 does not support user accounts.";
+      theme = f cfg.theme;
       inherit efiSysMountPoint;
       inherit (args) devices;
       inherit (efi) canTouchEfiVariables;
@@ -426,6 +427,19 @@ in
         '';
       };
 
+      theme = mkOption {
+        type = types.nullOr types.path;
+        example = literalExample "pkgs.nixos-grub2-theme";
+        default = null;
+        description = ''
+          Grub theme to be used.
+
+          <note><para>
+          This options has no effect for GRUB 1.
+          </para></note>
+        '';
+      };
+
       splashMode = mkOption {
         type = types.enum [ "normal" "stretch" ];
         default = "stretch";
@@ -697,7 +711,7 @@ in
         in pkgs.writeScript "install-grub.sh" (''
         #!${pkgs.runtimeShell}
         set -e
-        export PERL5LIB=${with pkgs.perlPackages; makePerlPath [ FileSlurp XMLLibXML XMLSAX XMLSAXBase ListCompare JSON ]}
+        export PERL5LIB=${with pkgs.perlPackages; makePerlPath [ FileSlurp FileCopyRecursive XMLLibXML XMLSAX XMLSAXBase ListCompare JSON ]}
         ${optionalString cfg.enableCryptodisk "export GRUB_ENABLE_CRYPTODISK=y"}
       '' + flip concatMapStrings cfg.mirroredBoots (args: ''
         ${pkgs.perl}/bin/perl ${install-grub-pl} ${grubConfig args} $@
diff --git a/nixos/modules/system/boot/loader/grub/install-grub.pl b/nixos/modules/system/boot/loader/grub/install-grub.pl
index 5d7f58e7c73e..59f5638044fe 100644
--- a/nixos/modules/system/boot/loader/grub/install-grub.pl
+++ b/nixos/modules/system/boot/loader/grub/install-grub.pl
@@ -6,9 +6,11 @@ use File::Basename;
 use File::Path;
 use File::stat;
 use File::Copy;
+use File::Copy::Recursive qw(rcopy pathrm);
 use File::Slurp;
 use File::Temp;
 use JSON;
+use File::Find;
 require List::Compare;
 use POSIX;
 use Cwd;
@@ -82,6 +84,7 @@ my $gfxpayloadBios = get("gfxpayloadBios");
 my $bootloaderId = get("bootloaderId");
 my $forceInstall = get("forceInstall");
 my $font = get("font");
+my $theme = get("theme");
 $ENV{'PATH'} = get("path");
 
 die "unsupported GRUB version\n" if $grubVersion != 1 && $grubVersion != 2;
@@ -370,6 +373,28 @@ else {
             fi
         ";
     }
+
+    rmtree("$bootPath/theme") or die "cannot clean up theme folder in $bootPath\n" if -e "$bootPath/theme";
+
+    if ($theme) {
+        # Copy theme
+        rcopy($theme, "$bootPath/theme") or die "cannot copy $theme to $bootPath\n";
+        $conf .= "
+            # Sets theme.
+            set theme=" . ($grubBoot->path eq "/" ? "" : $grubBoot->path) . "/theme/theme.txt
+            export theme
+            # Load theme fonts, if any
+         ";
+
+         find( { wanted => sub {
+             if ($_ =~ /\.pf2$/i) {
+                 $font = File::Spec->abs2rel($File::Find::name, $theme);
+                 $conf .= "
+                     loadfont " . ($grubBoot->path eq "/" ? "" : $grubBoot->path) . "/theme/$font
+                 ";
+             }
+         }, no_chdir => 1 }, $theme );
+     }
 }
 
 $conf .= "$extraConfig\n";