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Aquarius_Girl avatar Ubuntu

How to add USB boot option to grub.cfg in Ubuntu 20.04?

in flag
Aquarius_Girl

I have confirmed that the USB has a proper bootable Ubuntu ISO on it with the file command.
USB is plugged in the laptop.
The grub menu does get shown on its own at the startup.

Problem is that there is no option to boot from USB.

Now I want to edit grub.cfg such that it contains USB boot options.
What do I do from here?

Also, /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="0"
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$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_gpt
insmod ext2
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
else
  search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
fi
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_IN
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=30
else
  if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=menu
    set timeout=5
  # Fallback normal timeout code in case the timeout_style feature is
  # unavailable.
  else
    set timeout=5
  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-e860e8f0-912f-4874-8f0f-97e343371f12' {
    recordfail
    load_video
    gfxmode $linux_gfx_mode
    insmod gzio
    if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
    insmod part_gpt
    insmod ext2
    set root='hd0,gpt2'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
    else
      search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
    fi
    linux   /boot/vmlinuz-5.13.0-27-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro  quiet splash $vt_handoff
    initrd  /boot/initrd.img-5.13.0-27-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-e860e8f0-912f-4874-8f0f-97e343371f12' {
    menuentry 'Ubuntu, with Linux 5.13.0-27-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.13.0-27-generic-advanced-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.13.0-27-generic ...'
        linux   /boot/vmlinuz-5.13.0-27-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.13.0-27-generic
    }
    menuentry 'Ubuntu, with Linux 5.13.0-27-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.13.0-27-generic-recovery-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.13.0-27-generic ...'
        linux   /boot/vmlinuz-5.13.0-27-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro recovery nomodeset dis_ucode_ldr 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.13.0-27-generic
    }
    menuentry 'Ubuntu, with Linux 5.11.0-37-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.11.0-37-generic-advanced-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.11.0-37-generic ...'
        linux   /boot/vmlinuz-5.11.0-37-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.11.0-37-generic
    }
    menuentry 'Ubuntu, with Linux 5.11.0-37-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.11.0-37-generic-recovery-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.11.0-37-generic ...'
        linux   /boot/vmlinuz-5.11.0-37-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro recovery nomodeset dis_ucode_ldr 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.11.0-37-generic
    }
    menuentry 'Ubuntu, with Linux 5.8.0-43-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-43-generic-advanced-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.8.0-43-generic ...'
        linux   /boot/vmlinuz-5.8.0-43-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.8.0-43-generic
    }
    menuentry 'Ubuntu, with Linux 5.8.0-43-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-43-generic-recovery-e860e8f0-912f-4874-8f0f-97e343371f12' {
        recordfail
        load_video
        insmod gzio
        if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
        insmod part_gpt
        insmod ext2
        set root='hd0,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  e860e8f0-912f-4874-8f0f-97e343371f12
        else
          search --no-floppy --fs-uuid --set=root e860e8f0-912f-4874-8f0f-97e343371f12
        fi
        echo    'Loading Linux 5.8.0-43-generic ...'
        linux   /boot/vmlinuz-5.8.0-43-generic root=UUID=e860e8f0-912f-4874-8f0f-97e343371f12 ro recovery nomodeset dis_ucode_ldr 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-5.8.0-43-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/20_memtest86+ ###
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
### 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 ###

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usb
kanehekili avatar
zw flag
kanehekili
Do **not ** use the Grub customizer to change anything - I might brick your bootloader... Check if GRUB_DISABLE_OS_PROBER=false in `etc/default/grub` is not commented out
0
Reply
oldfred avatar
cn flag
oldfred
Not sure if grub can boot installer correctly. You normally boot from UEFI/BIOS boot menu. Issues are most often incorrect flash drive either USB port, flash drive itself, download of ISO not verified or tool used to create bootable flash drive. Some systems also require UEFI setting to allow full USB support or allow USB boot, especially if UEFI Secure Boot is on. https://help.ubuntu.com/community/Installation/iso2usb
0
Reply
Aquarius_Girl avatar
in flag
Aquarius_Girl
@kanehekili well, that option `GRUB_DISABLE_OS_PROBER` isn't there at all.
0
Reply
abu-ahmed al-khatiri avatar
in flag
abu-ahmed al-khatiri
@Aquarius_Girl The grub.cfg file seems ok. what the iso and the flash tool are you using? . please provide us output of `cat /boot/grub/grubenv`.
2
Reply
Joepie Es avatar
eg flag
Joepie Es
Why don't you just boot directly from USB? I can change it in UEFI or press F11 on my HP ENVY laptop. Then you don't need to change anything. Isn't that much easier?
0
Reply
Aquarius_Girl avatar
in flag
Aquarius_Girl
@JoepieEs I want to directly boot from USB but don't know how to do it. Please write an answer.
0
Reply
Joepie Es avatar
eg flag
Joepie Es
Please specify your hardware. Motherboard make and model or laptop make and model. Then I will search for it.
0
Reply
Score:1
Jeff avatar Ubuntu
mx flag
Jeff

When you enter the black GRUB screen, press C or the escape key (ESC) to access command prompt, then enter the following commands (which should make it so that you can boot):

grub> root (hd0,0)   # first harddrive, first partition
grub> find /[tab]    # type the slash then press [tab], and it will try to list files on this partition
Error 17: Cannot mount selected partition   # Oops no file system here
grub> root (hd0,1)   # first harddrive, second partition
grub> find /[tab]
Possible files are: lost+found var etc media ...   # That was my hard drive with my linux install
grub> root (hd1,0)   # second hard drive usually is the USB drive if you have only one internal drive
grub> find /[tab]
Possible files are: ldlinux.sys mydoc myfile mystick syslinux.cfg  # Bingo, that's the USB stick

Now, boot the drive by entering the following commands:

chainloader +1
boot

For convenience, add these commands to your GRUB configuration (usually in /boot/grub/menu.lst):

# to boot from a USB device
title    Boot USB drive
root     (hd1,0)
chainloader +1
boot

Source: https://help.ubuntu.com/community/BootFromUSB#:~:text=The%20easiest%20way%20to%20boot,key%20to%20enter%20command%20mode.

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Score:0
Emoji avatar Ubuntu
ng flag
Emoji

In a nutshell: that's the BIOS's job, not GRUB's.

Usually, computers will have a method to go to the BIOS (or UEFI) setup page, for example, ThinkVantage on ThinkPads. On the BIOS setup page, there will be boot order change settings. Place USB HDD onto the top, then reboot the computer.

Use the answer above if there is no BIOS setup page (rare but not zero), or your computer cannot detect USB bootable disks. Never modify your GRUB config file to do so.

If you can provide the actual model of your computer, I can tell you the actual steps. Otherwise, you can also check the manuals about how to change the boot order.

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