我直接从 Windows 10 安装了 Linux Ubuntu 20.04。它重新启动了，我可以从 USB 闪存盘启动来执行安装。
正确安装所有东西后，我意识到，重新启动操作系统后，GRUB 没有显示出来，而是直接在 Ubuntu 上启动。我运行 grub-repair，下面显示了来自 sw 的截图。
从上图可以看出，我的操作系统似乎是以 UEFI 模式安装的。当我运行启动修复并重新启动时，同样的问题发生了。没有显示 Grub，它直接启动到 Ubuntu。
我意识到的一件事是，我的机器（一台全新的 PC）在启动时没有显示任何内容（我的 Windows OS/BIOS 上是否激活了快速启动？），而是直接在 Ubuntu 上启动。我尝试按 ESC、DELETE、F1、F2、F10、F11 和 F12 进入 BIOS。什么都没有。
/etc/default/grub以下是文件的内容
# 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
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
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"
以下是/boot/efi
以下是/boot/grub/grub.cfg
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#
### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
if [ "${initrdfail}" = 2 ]; then
set initrdfail=
elif [ "${initrdfail}" = 1 ]; then
set next_entry="${prev_entry}"
set prev_entry=
save_env prev_entry
if [ "${next_entry}" ]; then
set initrdfail=2
fi
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os 'osprober-efi-36CE-B279' {"
fi
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi
export menuentry_id_option
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi
function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}
function initrdfail {
if [ -n "${have_grubenv}" ]; then if [ -n "${partuuid}" ]; then
if [ -z "${initrdfail}" ]; then
set initrdfail=1
if [ -n "${boot_once}" ]; then
set prev_entry="${default}"
save_env prev_entry
fi
fi
save_env initrdfail
fi; fi
}
function recordfail {
set recordfail=1
if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
}
if [ x$feature_default_font_path = xy ] ; then
font=unicode
else
insmod part_msdos
insmod ext2
set root='hd1,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos5 --hint-efi=hd1,msdos5 --hint-baremetal=ahci1,msdos5 3d41e78e-87bd-4edf-801d-249386bf9857
else
search --no-floppy --fs-uuid --set=root 3d41e78e-87bd-4edf-801d-249386bf9857
fi
font="/usr/share/grub/unicode.pf2"
fi
if loadfont $font ; then
set gfxmode=640x480
load_video
insmod gfxterm
set locale_dir=$prefix/locale
set lang=en_US
insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
set timeout=10
else
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=hidden
set timeout=10
# Fallback hidden-timeout code in case the timeout_style feature is
# unavailable.
elif sleep --interruptible 10 ; then
set timeout=10
fi
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
set gfxpayload="${1}"
if [ "${1}" = "keep" ]; then
set vt_handoff=vt.handoff=7
else
set vt_handoff=
fi
}
if [ "${recordfail}" != 1 ]; then
if [ -e ${prefix}/gfxblacklist.txt ]; then
if hwmatch ${prefix}/gfxblacklist.txt 3; then
if [ ${match} = 0 ]; then
set linux_gfx_mode=keep
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=keep
fi
else
set linux_gfx_mode=text
fi
export linux_gfx_mode
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-3d41e78e-87bd-4edf-801d-249386bf9857' {
recordfail
load_video
gfxmode $linux_gfx_mode
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_msdos
insmod ext2
set root='hd1,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos5 --hint-efi=hd1,msdos5 --hint-baremetal=ahci1,msdos5 3d41e78e-87bd-4edf-801d-249386bf9857
else
search --no-floppy --fs-uuid --set=root 3d41e78e-87bd-4edf-801d-249386bf9857
fi
linux /boot/vmlinuz-5.4.0-42-generic root=UUID=3d41e78e-87bd-4edf-801d-249386bf9857 ro quiet splash $vt_handoff
initrd /boot/initrd.img-5.4.0-42-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-3d41e78e-87bd-4edf-801d-249386bf9857' {
menuentry 'Ubuntu, with Linux 5.4.0-42-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-42-generic-advanced-3d41e78e-87bd-4edf-801d-249386bf9857' {
recordfail
load_video
gfxmode $linux_gfx_mode
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_msdos
insmod ext2
set root='hd1,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos5 --hint-efi=hd1,msdos5 --hint-baremetal=ahci1,msdos5 3d41e78e-87bd-4edf-801d-249386bf9857
else
search --no-floppy --fs-uuid --set=root 3d41e78e-87bd-4edf-801d-249386bf9857
fi
echo 'Loading Linux 5.4.0-42-generic ...'
linux /boot/vmlinuz-5.4.0-42-generic root=UUID=3d41e78e-87bd-4edf-801d-249386bf9857 ro quiet splash $vt_handoff
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-5.4.0-42-generic
}
menuentry 'Ubuntu, with Linux 5.4.0-42-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-42-generic-recovery-3d41e78e-87bd-4edf-801d-249386bf9857' {
recordfail
load_video
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_msdos
insmod ext2
set root='hd1,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos5 --hint-efi=hd1,msdos5 --hint-baremetal=ahci1,msdos5 3d41e78e-87bd-4edf-801d-249386bf9857
else
search --no-floppy --fs-uuid --set=root 3d41e78e-87bd-4edf-801d-249386bf9857
fi
echo 'Loading Linux 5.4.0-42-generic ...'
linux /boot/vmlinuz-5.4.0-42-generic root=UUID=3d41e78e-87bd-4edf-801d-249386bf9857 ro recovery nomodeset
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-5.4.0-42-generic
}
}
### END /etc/grub.d/10_linux ###
### BEGIN /etc/grub.d/10_linux_zfs ###
### END /etc/grub.d/10_linux_zfs ###
### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os $menuentry_id_option 'osprober-efi-36CE-B279' {
insmod part_gpt
insmod fat
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root 36CE-B279
else
search --no-floppy --fs-uuid --set=root 36CE-B279
fi
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober ###
### BEGIN /etc/grub.d/30_uefi-firmware ###
menuentry 'UEFI Firmware Settings' $menuentry_id_option 'uefi-firmware' {
fwsetup
}
### END /etc/grub.d/30_uefi-firmware ###
### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###
### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
如何在启动时看到 GRUB？
答案1
我解决了错误，解决方案非常愚蠢和简单。
我的电脑很新。安装时，我没有意识到有一个塑料连接器覆盖我的一个视频卡插槽。我不知道我购买它的公司的人用一些塑料盖盖住了未使用的插槽。
实际情况是，每次启动时，PC 都会混淆正在使用哪个显卡所以它开始闪烁，试图读取所有连接的视频卡的信号。所以我看不到 Grub，也看不到显示器上的 BIOS 屏幕和主板上的其他启动步骤。我移除后，问题解决了。我可以看到 grub，也可以进入 BIOS。
也许它可以帮助其他尝试配置新 PCS 的人。非常感谢所有试图帮助我的人。