POP_OS是一个非常好的Linux系统，它基于Ubuntu，但是有一个经过精心调教的GNOME桌面，窗口排布（Tile Windows）非常有新意，总体而言美轮美奂！系统对中文支持非常好，安装时若直接选“中文”，则一切和中文输入法有关的东西都自然搞定。唯一的不足是：它并不会默认安装GRUB，所以对多系统启动不太友好。

POP_OS默认是使用systemd-boot作为硬盘头部的启动程序的，这使得安装后，每次开机都只能直接进入POP_OS，没得选，原来的其他OS（我这个硬盘里，原来有个Win10，还有个Linux Mint）就都找不到了，抓狂！为了开机时能多系统启动，需要进入POP_OS后，手动安装GRUB，覆盖掉原来默认的systemd-boot启动程序。

apt install os-prober

grub-install /dev/sda 这是安装GRUB到第一块硬盘MBR头部的操作，非常重要！以此覆盖掉系统默认的 systemd-boot 启动程序
os-prober
update-grub

如果进一步想把启动选择界面调得好看点，可以参考如下 /etc/default/grub 文件，别忘了最后运行一次 update-grub

/etc/default/grub

# 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=saved # 重要！
GRUB_SAVEDEFAULT=true # 重要！
GRUB_DISABLE_OS_PROBER=false
GRUB_TIMEOUT=15
 
GRUB_TIMEOUT_STYLE=hidden
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"