Description: Add configure option to bypass boot menu if possible
 If other operating systems are installed, then automatically unhide the
 menu.  Otherwise, if GRUB_HIDDEN_TIMEOUT is 0, then use keystatus if
 available to check whether Shift is pressed.  If it is, show the menu,
 otherwise boot immediately.  If keystatus is not available, then fall back
 to a short delay interruptible with Escape.
 .
 This may or may not remain Ubuntu-specific, although it's not obviously
 wanted upstream.  It implements a requirement of
 https://wiki.ubuntu.com/DesktopExperienceTeam/KarmicBootExperienceDesignSpec#Bootloader.
 .
 If the previous boot failed (defined as failing to get to the end of one of
 the normal runlevels), then show the boot menu regardless.
Author: Colin Watson <cjwatson@ubuntu.com>
Author: Richard Laager <rlaager@wiktel.com>
Forwarded: no
Last-Update: 2013-11-13

Index: b/configure.ac
===================================================================
--- a/configure.ac
+++ b/configure.ac
@@ -1087,6 +1087,17 @@
 fi
 AC_SUBST([QUIET_BOOT])
 
+AC_ARG_ENABLE([quick-boot],
+              [AS_HELP_STRING([--enable-quick-boot],
+                              [bypass boot menu if possible (default=no)])],
+              [], [enable_quick_boot=no])
+if test x"$enable_quick_boot" = xyes ; then
+  QUICK_BOOT=1
+else
+  QUICK_BOOT=0
+fi
+AC_SUBST([QUICK_BOOT])
+
 LIBS=""
 
 AC_SUBST([FONT_SOURCE])
Index: b/docs/grub.texi
===================================================================
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -1289,6 +1289,15 @@
 Each module will be loaded as early as possible, at the start of
 @file{grub.cfg}.
 
+@item GRUB_RECORDFAIL_TIMEOUT
+If this option is set, it overrides the default recordfail setting. The
+default setting is -1, which causes GRUB to wait for user input. This option
+should be set on headless and appliance systems where access to a console is
+restricted or limited.
+
+This option is only effective when GRUB was configured with the
+@option{--enable-quick-boot} option.
+
 @end table
 
 For more detailed customisation of @command{grub-mkconfig}'s output, you may
Index: b/util/grub-mkconfig.in
===================================================================
--- a/util/grub-mkconfig.in
+++ b/util/grub-mkconfig.in
@@ -228,7 +228,8 @@
   GRUB_INIT_TUNE \
   GRUB_SAVEDEFAULT \
   GRUB_ENABLE_CRYPTODISK \
-  GRUB_BADRAM
+  GRUB_BADRAM \
+  GRUB_RECORDFAIL_TIMEOUT
 
 if test "x${grub_cfg}" != "x"; then
   rm -f "${grub_cfg}.new"
Index: b/util/grub.d/00_header.in
===================================================================
--- a/util/grub.d/00_header.in
+++ b/util/grub.d/00_header.in
@@ -23,6 +23,8 @@
 exec_prefix="@exec_prefix@"
 datarootdir="@datarootdir@"
 grub_lang=`echo $LANG | cut -d . -f 1`
+grubdir="`echo "/@bootdirname@/@grubdirname@" | sed 's,//*,/,g'`"
+quick_boot="@QUICK_BOOT@"
 
 export TEXTDOMAIN=@PACKAGE@
 export TEXTDOMAINDIR="@localedir@"
@@ -46,6 +48,7 @@
 
 cat << EOF
 if [ -s \$prefix/grubenv ]; then
+  set have_grubenv=true
   load_env
 fi
 EOF
@@ -86,7 +89,31 @@
     save_env saved_entry
   fi
 }
+EOF
+
+if [ "$quick_boot" = 1 ]; then
+    cat <<EOF
+function recordfail {
+  set recordfail=1
+EOF
+    FS="$(grub-probe --target=fs "${grubdir}")"
+    case "$FS" in
+      btrfs | cpiofs | newc | odc | romfs | squash4 | tarfs | zfs)
+	cat <<EOF
+  # GRUB lacks write support for $FS, so recordfail support is disabled.
+EOF
+	;;
+      *)
+	cat <<EOF
+  if [ -n "\${have_grubenv}" ]; then if [ -z "\${boot_once}" ]; then save_env recordfail; fi; fi
+EOF
+    esac
+    cat <<EOF
+}
+EOF
+fi
 
+cat <<EOF
 function load_video {
 EOF
 if [ -n "${GRUB_VIDEO_BACKEND}" ]; then
@@ -272,7 +299,15 @@
 
 make_timeout ()
 {
-    if [ "x${1}" != "x" ] ; then
+    if [ "$quick_boot" = 1 ] ; then
+	cat << EOF
+if [ "\${recordfail}" = 1 ]; then
+  set timeout=${GRUB_RECORDFAIL_TIMEOUT:--1}
+else
+  set timeout=${2}
+fi
+EOF
+    elif [ "x${1}" != "x" ] ; then
 	if [ "x${GRUB_HIDDEN_TIMEOUT_QUIET}" = "xtrue" ] ; then
 	    verbose=
 	else
Index: b/util/grub.d/10_linux.in
===================================================================
--- a/util/grub.d/10_linux.in
+++ b/util/grub.d/10_linux.in
@@ -21,6 +21,7 @@
 exec_prefix="@exec_prefix@"
 datarootdir="@datarootdir@"
 quiet_boot="@QUIET_BOOT@"
+quick_boot="@QUICK_BOOT@"
 
 . "@datadir@/@PACKAGE@/grub-mkconfig_lib"
 
@@ -113,6 +114,9 @@
   else
       echo "menuentry '$(echo "$os" | grub_quote)' ${CLASS} \$menuentry_id_option 'gnulinux-simple-$boot_device_id' {" | sed "s/^/$submenu_indentation/"
   fi      
+  if [ "$quick_boot" = 1 ]; then
+      echo "recordfail" | sed "s/^/$submenu_indentation/"
+  fi
   if [ x$type != xrecovery ] ; then
       save_default_entry | sed -e "s/^/\t/"
   fi
Index: b/util/grub.d/30_os-prober.in
===================================================================
--- a/util/grub.d/30_os-prober.in
+++ b/util/grub.d/30_os-prober.in
@@ -20,18 +20,78 @@
 prefix="@prefix@"
 exec_prefix="@exec_prefix@"
 datarootdir="@datarootdir@"
+quick_boot="@QUICK_BOOT@"
 
 export TEXTDOMAIN=@PACKAGE@
 export TEXTDOMAINDIR="@localedir@"
 
 . "@datadir@/@PACKAGE@/grub-mkconfig_lib"
 
+found_other_os=
+
+make_timeout () {
+  if [ "x${found_other_os}" = "x" ] ; then
+    if [ "x${1}" != "x" ] ; then
+      if [ "x${GRUB_HIDDEN_TIMEOUT_QUIET}" = "xtrue" ] ; then
+	verbose=
+      else
+	verbose=" --verbose"
+      fi
+
+      if [ "x${1}" = "x0" ] ; then
+	cat <<EOF
+if [ "x\${timeout}" != "x-1" ]; then
+  if keystatus; then
+    if keystatus --shift; then
+      set timeout=-1
+    else
+      set timeout=0
+    fi
+  else
+    if sleep$verbose --interruptible 3 ; then
+      set timeout=0
+    fi
+  fi
+fi
+EOF
+      else
+	cat << EOF
+if [ "x\${timeout}" != "x-1" ]; then
+  if sleep$verbose --interruptible ${GRUB_HIDDEN_TIMEOUT} ; then
+    set timeout=0
+  fi
+fi
+EOF
+      fi
+    fi
+  fi
+}
+
+adjust_timeout () {
+  if [ "$quick_boot" = 0 ]; then
+    return
+  fi
+  if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then
+    cat <<EOF
+if cmostest $GRUB_BUTTON_CMOS_ADDRESS ; then
+EOF
+    make_timeout "${GRUB_HIDDEN_TIMEOUT_BUTTON}" "${GRUB_TIMEOUT_BUTTON}"
+    echo else
+    make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}"
+    echo fi
+  else
+    make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}"
+  fi
+}
+
 if [ "x${GRUB_DISABLE_OS_PROBER}" = "xtrue" ]; then
+  adjust_timeout
   exit 0
 fi
 
 if [ -z "`which os-prober 2> /dev/null`" -o -z "`which linux-boot-prober 2> /dev/null`" ] ; then
   # missing os-prober and/or linux-boot-prober
+  adjust_timeout
   exit 0
 fi
 
@@ -43,10 +103,12 @@
 OSPROBED="`os-prober | tr ' ' '^' | paste -s -d ' '`"
 if [ -z "${OSPROBED}" ] ; then
   # empty os-prober output, nothing doing
+  adjust_timeout
   exit 0
 fi
 
 osx_entry() {
+    found_other_os=1
     if [ x$2 = x32 ]; then
         # TRANSLATORS: it refers to kernel architecture (32-bit)
 	bitstr="$(gettext "(32-bit)")"
@@ -146,6 +208,7 @@
 	  ;;
       esac
 
+      found_other_os=1
 	  onstr="$(gettext_printf "(on %s)" "${DEVICE}")"
       cat << EOF
 menuentry '$(echo "${LONGNAME} $onstr" | grub_quote)' --class windows --class os \$menuentry_id_option 'osprober-chain-$(grub_get_device_id "${DEVICE}")' {
@@ -169,6 +232,7 @@
 EOF
     ;;
     efi)
+      found_other_os=1
       EFIPATH=${DEVICE#*@}
       DEVICE=${DEVICE%@*}
       cat << EOF
@@ -211,6 +275,7 @@
 	  [ "${prepare_boot_cache}" ] || continue
 	fi
 
+	found_other_os=1
 	onstr="$(gettext_printf "(on %s)" "${DEVICE}")"
 	recovery_params="$(echo "${LPARAMS}" | grep 'single\|recovery')" || true
 	counter=1
@@ -277,6 +342,7 @@
       osx_entry xnu_kernel64 64
     ;;
     hurd)
+      found_other_os=1
       onstr="$(gettext_printf "(on %s)" "${DEVICE}")"
       cat << EOF
 menuentry '$(echo "${LONGNAME} $onstr" | grub_quote)' --class hurd --class gnu --class os \$menuentry_id_option 'osprober-gnuhurd-/boot/gnumach.gz-false-$(grub_get_device_id "${DEVICE}")' {
@@ -309,3 +375,5 @@
     ;;
   esac
 done
+
+adjust_timeout