#注释掉GRUB_HIDDEN_TIMEOUT=0
#GRUB_HIDDEN_TIMEOUT=0
#修改GRUB_TIMEOUT = 0 
GRUB_TIMEOUT = 0

### BEGIN /etc/grub.d/00_header ###
...
function recordfail {
 set recordfail=1
 # GRUB lacks write support for lvm, so recordfail support is disabled.
}
...
if [ "${recordfail}" = 1 ] ; then
 set timeout=30
...
if [ $grub_platform = efi ]; then
 set timeout=30
...
### END /etc/grub.d/00_header ###

...
  cat << EOF
if [ "\${recordfail}" = 1 ] ; then
 set timeout=${GRUB_RECORDFAIL_TIMEOUT:-30}
else
EOF
...
if [ "$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
...

GRUB_RECORDFAIL_TIMEOUT=0