If we don't have writable grubenv and we're on EFI, always show the menu

If we don't have writable grubenv, recordfail doesn't work, which means our
quickboot behavior - with a timeout of 0 - leaves the user without a
reliable way to access the boot menu if they're on UEFI, because unlike
BIOS, UEFI does not support checking the state of modifier keys (i.e.
holding down shift at boot is not detectable).

Handle this corner case by always using a non-zero timeout on EFI when
save_env doesn't work.

Reuse GRUB_RECORDFAIL_TIMEOUT to avoid introducing another variable.

Signed-off-by: Steve Langasek <steve.langasek@canonical.com>
Bug-Ubuntu: https://bugs.launchpad.net/bugs/1800722
Last-Update: 2019-06-24

Patch-Name: quick-boot-lvm.patch

Gbp-Pq: Name quick-boot-lvm.patch

diff --git a/util/grub.d/00_header.in b/util/grub.d/00_header.in
index f3e04cca7d3e08cb8ade71659bc65729b5d6a976..b4112cdc36c430914dd522db84d6167ce60d5cfa 100644 (file)
--- a/util/grub.d/00_header.in
+++ b/util/grub.d/00_header.in
@@ -115,7 +115,7 @@ EOF
           cat <<EOF
   # GRUB lacks write support for $abstraction, so recordfail support is disabled.
 EOF
-          return
+          return 1
           ;;
       esac
     done
@@ -126,7 +126,7 @@ EOF
        cat <<EOF
   # GRUB lacks write support for $FS, so recordfail support is disabled.
 EOF
-       return
+       return 1
        ;;
     esac
 
@@ -135,7 +135,9 @@ EOF
 EOF
   }
 
-  check_writable
+  if ! check_writable; then
+    recordfail_broken=1
+  fi
 
   cat <<EOF
 }
@@ -379,6 +381,16 @@ EOF
   fi
 fi
 EOF
+if [ "$recordfail_broken" = 1 ]; then
+  cat << EOF
+if [ \$grub_platform = efi ]; then
+  set timeout=${GRUB_RECORDFAIL_TIMEOUT:-30}
+  if [ x\$feature_timeout_style = xy ] ; then
+    set timeout_style=menu
+  fi
+fi
+EOF
+fi
 }
 
 if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then