无论我在 /etc/default/grub 或 /boot/grub/menu.list 中更改什么，grub 总是隐藏菜单，显示 10 秒倒计时器，然后启动到默认值（Ubuntu 14.04）。
要访问 MacOs，我必须按 ESC。
我的 Macbook Pro 是（10,1；2013 年初）。
我的 menu.list 和 grub 如下所示：
# menu.lst - See: grub(8), info grub, update-grub(8)
# grub-install(8), grub-floppy(8),
# grub-md5-crypt, /usr/share/doc/grub
# and /usr/share/doc/grub-legacy-doc/.
## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not use 'savedefault' or your
# array will desync and will not let you boot your system.
default 2
## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 12
## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
# hiddenmenu
# Pretty colours
#color cyan/blue white/blue
## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line) and entries protected by the
# command 'lock'
# e.g. password topsecret
# password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret
#
# examples
#
# title Windows 95/98/NT/2000
# root (hd0,0)
# makeactive
# chainloader +1
#
# title Linux
# root (hd0,1)
# kernel /vmlinuz root=/dev/hda2 ro
#
#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST
### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below
## DO NOT UNCOMMENT THEM, Just edit them to your needs
## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
## kopt_2_6_8=root=/dev/hdc1 ro
## kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=7df00b2c-94f9-4010-a6ef-dd1c1e659369 ro
## default grub root device
## e.g. groot=(hd0,0)
# groot=7df00b2c-94f9-4010-a6ef-dd1c1e659369
## should update-grub create alternative automagic boot options
## e.g. alternative=true
## alternative=false
# alternative=true
## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
## lockalternative=false
# lockalternative=false
## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash
## should update-grub lock old automagic boot options
## e.g. lockold=false
## lockold=true
# lockold=false
## Xen hypervisor options to use with the default Xen boot option
# xenhopt=
## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0
## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
## altoptions=(recovery) single
# altoptions=(recovery mode) single
## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
## howmany=7
# howmany=all
## specify if running in Xen domU or have grub detect automatically
## update-grub will ignore non-xen kernels when running in domU and vice versa
## e.g. indomU=detect
## indomU=true
## indomU=false
# indomU=detect
## should update-grub create memtest86 boot option
## e.g. memtest86=true
## memtest86=false
# memtest86=true
## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false
## should update-grub add savedefault to the default options
## can be true or false
# savedefault=false
## ## End Default Options ##
title Ubuntu 14.04.3 LTS, kernel 3.19.0-25-generic.efi.signed
uuid 7df00b2c-94f9-4010-a6ef-dd1c1e659369
kernel /boot/vmlinuz-3.19.0-25-generic.efi.signed root=UUID=7df00b2c-94f9-4010-a6ef-dd1c1e659369 ro quiet splash
title Ubuntu 14.04.3 LTS, kernel 3.19.0-25-generic.efi.signed (recovery mode)
uuid 7df00b2c-94f9-4010-a6ef-dd1c1e659369
kernel /boot/vmlinuz-3.19.0-25-generic.efi.signed root=UUID=7df00b2c-94f9-4010-a6ef-dd1c1e659369 ro single
title Ubuntu 14.04.3 LTS, kernel 3.19.0-25-generic
uuid 7df00b2c-94f9-4010-a6ef-dd1c1e659369
kernel /boot/vmlinuz-3.19.0-25-generic root=UUID=7df00b2c-94f9-4010-a6ef-dd1c1e659369 ro quiet splash
initrd /boot/initrd.img-3.19.0-25-generic
title Ubuntu 14.04.3 LTS, kernel 3.19.0-25-generic (recovery mode)
uuid 7df00b2c-94f9-4010-a6ef-dd1c1e659369
kernel /boot/vmlinuz-3.19.0-25-generic root=UUID=7df00b2c-94f9-4010-a6ef-dd1c1e659369 ro single
initrd /boot/initrd.img-3.19.0-25-generic
title Ubuntu 14.04.3 LTS, memtest86+
uuid 7df00b2c-94f9-4010-a6ef-dd1c1e659369
kernel /boot/memtest86+.bin
### END DEBIAN AUTOMAGIC KERNELS LIST
我的 grub 文件如下所示：
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'
GRUB_DEFAULT=2 GRUB_HIDDEN_TIMEOUT=false GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=20 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
#GRUB_CMDLINE_LINUX=""
# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"
# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480
# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"
# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"