iso-image: Fix GRUB graphical menu on AArch64

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

@@ -162,12 +162,14 @@ let
   isolinuxCfg = concatStringsSep "\n"
     ([ baseIsolinuxCfg ] ++ optional config.boot.loader.grub.memtest86.enable isolinuxMemtest86Entry);
 
+  refindBinary = if targetArch == "x64" || targetArch == "aa64" then "refind_${targetArch}.efi" else null;
+
   # Setup instructions for rEFInd.
   refind =
-    if targetArch == "x64" then
+    if refindBinary != null then
       ''
       # Adds rEFInd to the ISO.
-      cp -v ${pkgs.refind}/share/refind/refind_x64.efi $out/EFI/boot/
+      cp -v ${pkgs.refind}/share/refind/${refindBinary} $out/EFI/boot/
       ''
     else
       "# No refind for ${targetArch}"
@@ -186,7 +188,10 @@ let
 
     # Fonts can be loaded?
     # (This font is assumed to always be provided as a fallback by NixOS)
-    if loadfont (hd0)/EFI/boot/unicode.pf2; then
+    if loadfont /EFI/boot/unicode.pf2; then
+      set with_fonts=true
+    fi
+    if [ "\$textmode" != "true" -a "\$with_fonts" == "true" ]; then
       # Use graphical term, it can be either with background image or a theme.
       # input is "console", while output is "gfxterm".
       # This enables "serial" input and output only when possible.
@@ -207,11 +212,11 @@ let
     ${ # When there is a theme configured, use it, otherwise use the background image.
     if config.isoImage.grubTheme != null then ''
       # Sets theme.
-      set theme=(hd0)/EFI/boot/grub-theme/theme.txt
+      set theme=/EFI/boot/grub-theme/theme.txt
       # Load theme fonts
-      $(find ${config.isoImage.grubTheme} -iname '*.pf2' -printf "loadfont (hd0)/EFI/boot/grub-theme/%P\n")
+      $(find ${config.isoImage.grubTheme} -iname '*.pf2' -printf "loadfont /EFI/boot/grub-theme/%P\n")
     '' else ''
-      if background_image (hd0)/EFI/boot/efi-background.png; then
+      if background_image /EFI/boot/efi-background.png; then
         # Black background means transparent background when there
         # is a background image set... This seems undocumented :(
         set color_normal=black/black
@@ -264,6 +269,8 @@ let
 
     cat <<EOF > $out/EFI/boot/grub.cfg
 
+    set with_fonts=false
+    set textmode=false
     # If you want to use serial for "terminal_*" commands, you need to set one up:
     #   Example manual configuration:
     #    → serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
@@ -273,8 +280,28 @@ let
     export with_serial
     clear
     set timeout=10
+
+    # This message will only be viewable when "gfxterm" is not used.
+    echo ""
+    echo "Loading graphical boot menu..."
+    echo ""
+    echo "Press 't' to use the text boot menu on this console..."
+    echo ""
+
     ${grubMenuCfg}
 
+    hiddenentry 'Text mode' --hotkey 't' {
+      loadfont /EFI/boot/unicode.pf2
+      set textmode=true
+      terminal_output gfxterm console
+    }
+    hiddenentry 'GUI mode' --hotkey 'g' {
+      $(find ${config.isoImage.grubTheme} -iname '*.pf2' -printf "loadfont /EFI/boot/grub-theme/%P\n")
+      set textmode=false
+      terminal_output gfxterm
+    }
+
+
     # If the parameter iso_path is set, append the findiso parameter to the kernel
     # line. We need this to allow the nixos iso to be booted from grub directly.
     if [ \''${iso_path} ] ; then
@@ -337,11 +364,15 @@ let
       }
     }
 
-    menuentry 'rEFInd' --class refind {
-      # UUID is hard-coded in the derivation.
-      search --set=root --no-floppy --fs-uuid 1234-5678
-      chainloader (\$root)/EFI/boot/refind_x64.efi
-    }
+    ${lib.optionalString (refindBinary != null) ''
+    # GRUB apparently cannot do "chainloader" operations on "CD".
+    if [ "\$root" != "cd0" ]; then
+      menuentry 'rEFInd' --class refind {
+        # \$root defaults to the drive the EFI is found on.
+        chainloader (\$root)/EFI/boot/${refindBinary}
+      }
+    fi
+    ''}
     menuentry 'Firmware Setup' --class settings {
       fwsetup
       clear

pkgs/tools/misc/grub/2.0x.nix

@@ -1,6 +1,8 @@
 { lib, stdenv, fetchgit, flex, bison, python3, autoconf, automake, gnulib, libtool
 , gettext, ncurses, libusb-compat-0_1, freetype, qemu, lvm2, unifont, pkg-config
 , buildPackages
+, fetchpatch
+, pkgsBuildBuild
 , nixosTests
 , fuse # only needed for grub-mount
 , runtimeShell
@@ -55,6 +57,12 @@ stdenv.mkDerivation rec {
 
   patches = [
     ./fix-bash-completion.patch
+    (fetchpatch {
+      name = "Add-hidden-menu-entries.patch";
+      # https://lists.gnu.org/archive/html/grub-devel/2016-04/msg00089.html
+      url = "https://marc.info/?l=grub-devel&m=146193404929072&q=mbox";
+      sha256 = "00wa1q5adiass6i0x7p98vynj9vsz1w0gn1g4dgz89v35mpyw2bi";
+    })
   ];
 
   postPatch = if kbdcompSupport then ''