grub: Support 32bit EFI on 64bit x86 platforms

2 files changed, 29 insertions, 18 deletions

diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 9475da23b1ff..2d41370e8aec 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -165,6 +165,8 @@ let
     else
       "# No refind for ${targetArch}"
   ;
+  
+  grubPkgs = if config.boot.loader.grub.forcei686 then pkgs.pkgsi686Linux else pkgs; 
 
   grubMenuCfg = ''
     #
@@ -241,7 +243,7 @@ let
     # Modules that may or may not be available per-platform.
     echo "Adding additional modules:"
     for mod in efi_uga; do
-      if [ -f ${pkgs.grub2_efi}/lib/grub/${pkgs.grub2_efi.grubTarget}/$mod.mod ]; then
+      if [ -f ${grubPkgs.grub2_efi}/lib/grub/${grubPkgs.grub2_efi.grubTarget}/$mod.mod ]; then
         echo " - $mod"
         MODULES+=" $mod"
       fi
@@ -249,9 +251,9 @@ let
 
     # Make our own efi program, we can't rely on "grub-install" since it seems to
     # probe for devices, even with --skip-fs-probe.
-    ${pkgs.grub2_efi}/bin/grub-mkimage -o $out/EFI/boot/boot${targetArch}.efi -p /EFI/boot -O ${pkgs.grub2_efi.grubTarget} \
+    ${grubPkgs.grub2_efi}/bin/grub-mkimage -o $out/EFI/boot/boot${targetArch}.efi -p /EFI/boot -O ${grubPkgs.grub2_efi.grubTarget} \
       $MODULES
-    cp ${pkgs.grub2_efi}/share/grub/unicode.pf2 $out/EFI/boot/
+    cp ${grubPkgs.grub2_efi}/share/grub/unicode.pf2 $out/EFI/boot/
 
     cat <<EOF > $out/EFI/boot/grub.cfg
 
@@ -362,7 +364,7 @@ let
 
   # Name used by UEFI for architectures.
   targetArch =
-    if pkgs.stdenv.isi686 then
+    if pkgs.stdenv.isi686 || config.boot.loader.grub.forcei686 then
       "ia32"
     else if pkgs.stdenv.isx86_64 then
       "x64"
@@ -506,7 +508,7 @@ in
     # here and it causes a cyclic dependency.
     boot.loader.grub.enable = false;
 
-    environment.systemPackages = [ pkgs.grub2 pkgs.grub2_efi ]
+    environment.systemPackages =  [ grubPkgs.grub2 grubPkgs.grub2_efi ]
       ++ optional canx86BiosBoot pkgs.syslinux
     ;
 
diff --git a/nixos/modules/system/boot/loader/grub/grub.nix b/nixos/modules/system/boot/loader/grub/grub.nix
index a1537ad3cedc..d3cf8b29bb46 100644
--- a/nixos/modules/system/boot/loader/grub/grub.nix
+++ b/nixos/modules/system/boot/loader/grub/grub.nix
@@ -8,13 +8,17 @@ let
 
   efi = config.boot.loader.efi;
 
-  realGrub = if cfg.version == 1 then pkgs.grub
-    else if cfg.zfsSupport then pkgs.grub2.override { zfsSupport = true; }
+  grubPkgs = 
+    # Package set of targeted architecture
+    if cfg.forcei686 then pkgs.pkgsi686Linux else pkgs;
+
+  realGrub = if cfg.version == 1 then grubPkgs.grub
+    else if cfg.zfsSupport then grubPkgs.grub2.override { zfsSupport = true; }
     else if cfg.trustedBoot.enable
          then if cfg.trustedBoot.isHPLaptop
-              then pkgs.trustedGrub-for-HP
-              else pkgs.trustedGrub
-         else pkgs.grub2;
+              then grubPkgs.trustedGrub-for-HP
+              else grubPkgs.trustedGrub
+         else grubPkgs.grub2;
 
   grub =
     # Don't include GRUB if we're only generating a GRUB menu (e.g.,
@@ -58,14 +62,10 @@ let
         version extraConfig extraPerEntryConfig extraEntries forceInstall useOSProber
         extraEntriesBeforeNixOS extraPrepareConfig extraInitrd configurationLimit copyKernels
         default fsIdentifier efiSupport efiInstallAsRemovable gfxmodeEfi gfxmodeBios;
-      path = (makeBinPath ([
-        pkgs.coreutils pkgs.gnused pkgs.gnugrep pkgs.findutils pkgs.diffutils pkgs.btrfs-progs
-        pkgs.utillinux ]
-        ++ (optional (cfg.efiSupport && (cfg.version == 2)) pkgs.efibootmgr)
-        ++ (optionals cfg.useOSProber [pkgs.busybox pkgs.os-prober])
-      )) + ":" + (makeSearchPathOutput "bin" "sbin" [
-        pkgs.mdadm pkgs.utillinux
-      ]);
+      path = with pkgs; makeBinPath (
+        [ coreutils gnused gnugrep findutils diffutils btrfs-progs utillinux mdadm ]
+        ++ optional (cfg.efiSupport && (cfg.version == 2)) efibootmgr
+        ++ optionals cfg.useOSProber [ busybox os-prober ]);
       font = if cfg.font == null then ""
         else (if lib.last (lib.splitString "." cfg.font) == "pf2"
              then cfg.font
@@ -512,6 +512,15 @@ in
         '';
       };
 
+      forcei686 = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether to force the use of a ia32 boot loader on x64 systems. Required 
+          to install and run NixOS on 64bit x86 systems with 32bit (U)EFI.
+        '';
+      };
+
       trustedBoot = {
 
         enable = mkOption {