nixos: use new combined memtest86plus binary (#465509)

nixos/modules/installer/cd-dvd/iso-image.nix

@@ -1014,7 +1014,7 @@ in
       ]
       ++ lib.optionals (config.boot.loader.grub.memtest86.enable && config.isoImage.makeBiosBootable) [
         {
-          source = "${pkgs.memtest86plus}/memtest.bin";
+          source = pkgs.memtest86plus.efi;
           target = "/boot/memtest.bin";
         }
       ]

nixos/modules/system/boot/loader/grub/grub.nix

@@ -472,7 +472,7 @@ in
         type = types.attrsOf types.path;
         default = { };
         example = literalExpression ''
-          { "memtest.bin" = "''${pkgs.memtest86plus}/memtest.bin"; }
+          { "memtest.bin" = pkgs.memtest86plus.efi; }
         '';
         description = ''
           A set of files to be copied to {file}`/boot`.

nixos/modules/system/boot/loader/grub/memtest.nix

@@ -69,6 +69,6 @@ in
         linux @bootRoot@/memtest.bin ${toString cfg.params}
       }
     '';
-    boot.loader.grub.extraFiles."memtest.bin" = "${memtest86}/memtest.bin";
+    boot.loader.grub.extraFiles."memtest.bin" = memtest86.efi;
   };
 }

nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix

@@ -391,7 +391,7 @@ in
       type = types.attrsOf types.path;
       default = { };
       example = literalExpression ''
-        { "efi/memtest86/memtest.efi" = "''${pkgs.memtest86plus}/memtest.efi"; }
+        { "efi/memtest86/memtest.efi" = pkgs.memtest86plus.efi; }
       '';
       description = ''
         A set of files to be copied to {file}`$BOOT`.
@@ -578,7 +578,7 @@ in
 
     boot.loader.systemd-boot.extraFiles = mkMerge [
       (mkIf cfg.memtest86.enable {
-        "efi/memtest86/memtest.efi" = "${pkgs.memtest86plus.efi}";
+        "efi/memtest86/memtest.efi" = pkgs.memtest86plus.efi;
       })
       (mkIf cfg.netbootxyz.enable {
         "efi/netbootxyz/netboot.xyz.efi" = "${pkgs.netbootxyz-efi}";

pkgs/by-name/me/memtest86plus/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  nixosTests,
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -30,6 +31,8 @@ stdenv.mkDerivation (finalAttrs: {
     install -Dm0444 mt86plus $out/mt86plus.efi
   '';
 
+  passthru.tests.systemd-boot-memtest = nixosTests.systemd-boot.memtest86;
+
   meta = {
     homepage = "https://www.memtest.org/";
     description = "Tool to detect memory errors";