/etc/default/grub 文件详解

加五角星标注为平常修改的选项
其他除特殊用途基本不需要修改

Notice： 修改完 /etc/default/grub ，需要执行 sudo update-grub 生成 /boot/grub/grub.cfg，重启后生效

**下面部分为文件内容，// 后面的为注释: **

# 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=0      
// ★ 默认启动项，按menuentry顺序，从0开始；若改为saved，则默认上次启动项      

#GRUB_HIDDEN_TIMEOUT=0      //隐藏菜单，grub2不再使

GRUB_HIDDEN_TIMEOUT_QUIET=true      
//true不显示倒计时，屏幕将会是空白的；false空白屏幕上有计时器

GRUB_TIMEOUT=3      
// ★ 设置进入默认启动项的等候时间，默认值10秒；若为-1则一直等待

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"     
// ★ 添加内核启动参数，这个为默认

GRUB_CMDLINE_LINUX="acpi_osi=Linux"     
// ★ 手动添加内核启动参数，比如 acpi=off noapic等可在这里添加



# 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      
//设置是否使用图形介面。去除前面#，仅使用控制台终端，不使用图形介面



# 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       
// ★ 设定图形介面分辨率，如不使用默认，把前面#去掉，分辨率按需修改



# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux

#GRUB_DISABLE_LINUX_UUID=true   
//设置grub命令是否使用UUID，去掉#，使用root=/dev/sdax而不用root=UUDI=xxx



# Uncomment to disable generation of recovery mode menu entries

#GRUB_DISABLE_RECOVERY="true"       
//设定是否创建修复模式菜单项



# Uncomment to get a beep at grub start

#GRUB_INIT_TUNE="480 440 1"

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Notice: Ubuntu 中 GRUB_TIMEOUT=xx 这一选项好像最低也得有一秒的显示时间