1

I have an SSD and a HDD, on a UEFI Motherboard. I can switch OS by changing boot order in BIOS, but I would prefer it if Grub2 simply listed Windows7 as a boot option.

Solving should help anyone who has more than one drive on a UEFI motherboard. Have seen Booting multiple OSs from multiple disks with UEFI and rEFInd looks to be a good alternative; this question is about how to correctly configure Grub2 to see the bootloader for Windows7 (or any OS), if at all possible - without using Grub-legacy or another tool such as rEFInd.

I am using Ubuntu 12.10 with Grub2 is on the SSD, the primary boot device, and Windows7 is on the HDD, which it decided to split into three partitions as it installed.

Boot info script gives a lengthy breakdown:

                  Boot Info Script 0.61      [1 April 2012]


============================= Boot Info Summary: ===============================

 => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of 
    the same hard drive for core.img. core.img is at this location and looks 
    in partition 72 for .
 => No boot loader is installed in the MBR of /dev/sdb.

sda1: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  Ubuntu 12.10
    Boot files:        /boot/grub/grub.cfg /etc/fstab

sda2: __________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info: 

sdb1: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  Windows 7: FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /efi/Boot/bootx64.efi

sdb2: __________________________________________________________________________

    File system:       
    Boot sector type:  -
    Boot sector info: 
    Mounting failed:   mount: unknown filesystem type ''

sdb3: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows Vista/7: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  Windows 7
    Boot files:        /Windows/System32/winload.exe

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________

Disk /dev/sda: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sda1    *          2,048   218,439,679   218,437,632  83 Linux
/dev/sda2         218,439,680   234,440,703    16,001,024  82 Linux swap / Solaris


Drive: sdb _____________________________________________________________________

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
256 heads, 63 sectors/track, 121126 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sdb1                   1 4,294,967,295 4,294,967,295  ee GPT

/dev/sdb1 ends after the last sector of /dev/sdb

GUID Partition Table detected.

Partition    Start Sector    End Sector  # of Sectors System
/dev/sdb1           2,048       206,847       204,800 EFI System partition
/dev/sdb2         206,848       468,991       262,144 Microsoft Reserved Partition (Windows)
/dev/sdb3         468,992 1,953,523,711 1,953,054,720 Data partition (Windows/Linux)

"blkid" output: ________________________________________________________________

Device           UUID                                   TYPE       LABEL

/dev/sda1        e20b187a-c3b0-45e1-98df-c955b3cffdde   ext4       
/dev/sda2        7663b629-19c9-49fc-a744-2beb2dcdb317   swap       
/dev/sdb1        F428-FB77                              vfat       
/dev/sdb3        162C36632C363DD5                       ntfs       

================================ Mount points: =================================

Device           Mount_Point              Type       Options

/dev/sda1        /                        ext4       (rw,errors=remount-ro)


=========================== sda1/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
set default="0"

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 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
}

terminal_input console
terminal_output console
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=6
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
if background_color 44,0,30; then
  clear
fi
### 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 [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
recordfail
  gfxmode $linux_gfx_mode
  insmod gzio
  insmod part_msdos
  insmod ext2
  set root='hd0,msdos1'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
  else
    search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
  fi
  linux /boot/vmlinuz-3.5.0-27-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro   quiet splash $vt_handoff
  initrd  /boot/initrd.img-3.5.0-27-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  menuentry 'Ubuntu, with Linux 3.5.0-27-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-27-generic-advanced-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-27-generic ...'
    linux /boot/vmlinuz-3.5.0-27-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro   quiet splash $vt_handoff
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-27-generic
  }
  menuentry 'Ubuntu, with Linux 3.5.0-27-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-27-generic-recovery-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-27-generic ...'
    linux /boot/vmlinuz-3.5.0-27-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro recovery nomodeset 
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-27-generic
  }
  menuentry 'Ubuntu, with Linux 3.5.0-26-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-26-generic-advanced-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-26-generic ...'
    linux /boot/vmlinuz-3.5.0-26-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro   quiet splash $vt_handoff
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-26-generic
  }
  menuentry 'Ubuntu, with Linux 3.5.0-26-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-26-generic-recovery-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-26-generic ...'
    linux /boot/vmlinuz-3.5.0-26-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro recovery nomodeset 
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-26-generic
  }
  menuentry 'Ubuntu, with Linux 3.5.0-17-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-17-generic-advanced-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-17-generic ...'
    linux /boot/vmlinuz-3.5.0-17-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro   quiet splash $vt_handoff
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-17-generic
  }
  menuentry 'Ubuntu, with Linux 3.5.0-17-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.5.0-17-generic-recovery-e20b187a-c3b0-45e1-98df-c955b3cffdde' {
  recordfail
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  e20b187a-c3b0-45e1-98df-c955b3cffdde
    else
      search --no-floppy --fs-uuid --set=root e20b187a-c3b0-45e1-98df-c955b3cffdde
    fi
    echo  'Loading Linux 3.5.0-17-generic ...'
    linux /boot/vmlinuz-3.5.0-17-generic root=UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde ro recovery nomodeset 
    echo  'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.5.0-17-generic
  }
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

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

### BEGIN /etc/grub.d/30_uefi-firmware ###
### 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 ###
--------------------------------------------------------------------------------

=============================== sda1/etc/fstab: ================================

--------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda1 during installation
UUID=e20b187a-c3b0-45e1-98df-c955b3cffdde /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda2 during installation
UUID=7663b629-19c9-49fc-a744-2beb2dcdb317 none            swap    sw              0       0
--------------------------------------------------------------------------------

=================== sda1: Location of files loaded by Grub: ====================

           GiB - GB             File                                 Fragment(s)

               =                boot/grub/grub.cfg                             1
               =                boot/initrd.img-3.5.0-17-generic               1
               =                boot/initrd.img-3.5.0-26-generic               1
               =                boot/initrd.img-3.5.0-27-generic               1
               =                boot/vmlinuz-3.5.0-17-generic                  1
               =                boot/vmlinuz-3.5.0-26-generic                  1
               =                boot/vmlinuz-3.5.0-27-generic                  2
               =                initrd.img                                     1
               =                initrd.img.old                                 1
               =                vmlinuz                                        2
               =                vmlinuz.old                                    2

=============================== StdErr Messages: ===============================

awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in
awk: cmd. line:36: Math support is not compiled in

In summary, Ubuntu has a swap partition (sda2) in addition to its root partition (sda1) where it resides. Everything is fine there. Windows7 made 3 partitions, the first (sdb1) being for EFI, the second (sdb2) being reserved for windows which is not relevant, the third (sdb3) being the actual windows installation.

The file hierarchy of sdb1 is

> ls -aR
.:
.  ..  EFI

./EFI:
.  ..  Boot  Microsoft

./EFI/Boot:
.  ..  bootx64.efi

./EFI/Microsoft:
.  ..  Boot

./EFI/Microsoft/Boot:
.   BCD      BCD.LOG1  bootmgfw.efi  BOOTSTAT.DAT  da-DK  el-GR  es-ES  Fonts  hu-HU  ja-JP  memtest.efi  nl-NL  pt-BR  ru-RU  tr-TR  zh-HK
..  BCD.LOG  BCD.LOG2  bootmgr.efi   cs-CZ         de-DE  en-US  fi-FI  fr-FR  it-IT  ko-KR  nb-NO        pl-PL  pt-PT  sv-SE  zh-CN  zh-TW
etc

Through using

grub-mkdevicemap

The file "device.map" was generated in "/boot/grub" which identified that the SSD is (hd0) and the HDD is (hd1). hd0 is primary boot device, Grub2 lives here.

In grub-customizer I tried to create an entry which would direct grub2 to the Windows7 bootloader:

set root='(hd1,1)'
search-no-floppy-fs-uuid-set F428-FB77
drivemap -s (hd1) ${root}
chainloader +1

However selecting it from grub on restart gave this error:

error: no such device: F428-FB77.
error: invalid signature.

Press any key to continue..._

Am I close?

1 Answer 1

1

Your problem is that you've got a BIOS-mode installation of Linux and GRUB, whereas your Windows installation is in EFI mode. GRUB can't switch boot modes, so you can't do what you want to do with your current GRUB installation. You'll have to add an EFI-mode GRUB (or some other EFI-mode boot program, such as rEFInd) to do the job. Unfortunately, doing this from your working installation is tricky, since it requires using an EFI-mode program called efibootmgr, and that won't work in your current BIOS-mode Linux boot, thus creating a chicken-and-egg conundrum. You can do it from an emergency Ubuntu disc booted in EFI mode, but that complicates the GRUB setup process. See my Web page on the topic for information on EFI boot loaders and how to install them manually if you want to try this. It's possible that Ubuntu's Boot Repair tool, run from an EFI-mode emergency disc, will be able to install an EFI-mode GRUB relatively painlessly, but I'm not really sure of that. I'm also not a fan of Boot Repair, since it's rather ham-fisted with its changes.

Another option is to abandon GRUB in favor of rEFInd. If you boot Linux in BIOS mode, mount /dev/sdb1 (your ESP) at /boot/efi, and then install the Debian package version of rEFInd, it should set itself up to launch the next time you boot the computer in EFI mode (you might need to select the "Windows" option to get it to boot). This works by using a workaround that's also a bit on the ham-fisted side, but not quite as bad as what Boot Repair does, IMHO. It's also reversible once you boot Linux in EFI mode: Type sudo mount /dev/sdb1 /boot/efi to mount the ESP again (creating an /etc/fstab entry for this is a good idea, no matter what solution you choose) and then type sudo mvrefind.sh /boot/efi/EFI/Microsoft/Boot /boot/efi/EFI/refind.

A third option is to re-install Windows in BIOS mode. To do this, you'd need to wipe the partition table on /dev/sdb, converting it from GPT to MBR format, and then re-install Windows, ensuring that you do so in BIOS mode. This is the most inelegant solution, but if you're comfortable with Windows installation and have no data you need to preserve on /dev/sdb, it may be the most likely to succeed without causing complications.

4
  • another option is to install grub-efi to the efi partition of the second drive.
    – ravery
    Jun 16, 2017 at 21:28
  • @ravery, that's what Boot Repair does. Doing it manually is possible, but for most users, Boot Repair is much easier than doing it manually.
    – Rod Smith
    Jun 16, 2017 at 22:11
  • I have heard many say not to use boot repair on a uefi system.
    – ravery
    Jun 16, 2017 at 22:20
  • @ravery, I saw you make a similar claim in a comment on another question recently. Although Boot Repair is not perfect, credible advice to not use it on UEFI-based systems is old. If you must make such claims, please provide solid references.
    – Rod Smith
    Jun 16, 2017 at 22:38

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .