无法使用 Windows 10 和 Ubuntu 20.04 双启动-Ubuntu 启动时不显示 GRUB

Question

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？

Answer 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。