rectify-terminal-io.patch

diff --git a/util/grub.d/00_header.in b/util/grub.d/00_header.in
index b7135b655..5c6bc5213 100644
--- a/util/grub.d/00_header.in
+++ b/util/grub.d/00_header.in
@@ -252,27 +252,53 @@ fi
 EOF
 fi
 
-case x${GRUB_TERMINAL_INPUT} in
-  x)
-    # Just use the native terminal
-  ;;
-  x*)
-    cat << EOF
+#
+# If both 'serial' and 'gfxterm' are enabled, check if we can load
+# 'gfxterm' successfully. If gfxterm fails, terminal_output falls back
+# to 'console' by default which would cause double output in EFI boot
+# mode if serial is also enabled.
+#
+# 'gfxterm' would fail if there are no graphics option present on the
+# system and it outputs to graphics devices only. If we fail to load
+# 'gfxterm', reset terminal_input and temrinal_output to 'serial' only.
+#
+# If either serial or gfxterm is not enabled, follow the the default
+# path for routing terminal_input and terminal_output.
+#
+
+if [ "x$serial" = x1 ] && [ "x$gfxterm" = x1 ]; then
+  cat << EOF
+if terminal_output gfxterm; then
+  terminal_output --append serial
+  terminal_input ${GRUB_TERMINAL_INPUT}
+else
+  terminal_input serial
+  terminal_output serial
+fi
+EOF
+else
+  case x${GRUB_TERMINAL_INPUT} in
+    x)
+      # Just use the native terminal
+    ;;
+    x*)
+      cat << EOF
 terminal_input ${GRUB_TERMINAL_INPUT}
 EOF
-  ;;
-esac
+    ;;
+  esac
 
-case x${GRUB_TERMINAL_OUTPUT} in
-  x)
-    # Just use the native terminal
-  ;;
-  x*)
-    cat << EOF
+  case x${GRUB_TERMINAL_OUTPUT} in
+    x)
+      # Just use the native terminal
+    ;;
+    x*)
+      cat << EOF
 terminal_output ${GRUB_TERMINAL_OUTPUT}
 EOF
-  ;;
-esac
+    ;;
+  esac
+fi
 
 if [ "x$gfxterm" = x1 ]; then
     if [ "x$GRUB_THEME" != x ] && [ -f "$GRUB_THEME" ] \