Bonjour,

J'installé Ubuntu 20.10 en dual boot avec Windows. J'ai bien suivi les étapes puisque j'ai l'habitude de le faire mais à la fin de l'installation une erreur signifiant que le grub avait echoué pendant installation.
Après redémarrage j'ai ce message
Bios System BootOrder not found. Initializing defaults boot entry "Boot0008" with label "ubuntu" for file "\EFI\ubuntu\shimx64.efi"
ensuite ubuntu démarre mais sans afficher le menu me permattant de démarrer su windows.
J'ai tenté un boot repair, mais ca n'a pas fonctionné puisque j'ai le meme message au démarrage 
Le démarrage de l'ordinateur a été correctement réparé.

Un nouveau fichier (/var/log/boot-repair/20210117_173915/Boot-Info_20210117_1739.txt) va s'ouvrir dans votre visionneur de texte.


Si vous avez toujours des problèmes de démarrage, indiquez son contenu à :
boot.repair@gmail.com ou sur votre forum favori.

Vous pouvez maintenant redémarrer votre ordinateur.

N'oubliez pas de faire démarrer votre firmware UEFI sur l'entrée L'OS actuellement utilisé - Ubuntu 20.10 CurrentSession (fichier sda2/EFI/ubuntu/shimx64.efi) !
Si votre ordinateur redémarre directement dans Windows, essayez de changer l'ordre de démarrage dans votre firmware UEFI.

Si votre firmware UEFI ne permet pas de changer l'ordre de démarrage, changez l'entrée de démarrage par défaut de l'amorceur Windows.
Par exemple, vous pouvez démarrer Windows, puis saisir la commande suivante dans une invite de commande en mode administrateur :
bcdedit /set {bootmgr} path \EFI\ubuntu\
Voici mon boot info 
boot-repair-4ppa125                                              [20210117_1739]

============================= Boot Repair Summary ==============================



/usr/share/boot-sav/bs-cmd_terminal.sh: ligne 177: avertissement : substitution de commande: octet nul ignoré en entrée

Recommended repair: ____________________________________________________________

The default repair of the Boot-Repair utility will reinstall the grub-efi-amd64-signed of
sda8,
using the following options:        sda2/boot/efi,
Additional repair will be performed: unhide-bootmenu-10s win-legacy-basic-fix use-standard-efi-file


/boot/efi added in sda8/fstab
Quantity of real Windows: 1
Mount sda2 on /boot/efi

================= Reinstall the grub-efi-amd64-signed of sda8 ==================

grub-install --version
grub-install (GRUB) 2.04-1ubuntu35.1

efibootmgr -v from chroot before grub install
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000,0001,0002
Boot0000* Optical Disk Drive	BBS(CDROM,,0x0).......................................................................
Boot0001* Notebook Hard Drive	BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0003* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0004* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0005* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIubuntushimx64.efi)
Boot0006* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIubuntushimx64.efi)
Boot0007* Windows Boot Manager	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIMicrosoftBootbootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...M................
Boot0008* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIubuntushimx64.efi)

uname -r
5.8.0-38-generic

grub-install --efi-directory=/boot/efi --target=x86_64-efi --uefi-secure-boot
Installing for x86_64-efi platform.
Installation finished. No error reported.
df /dev/sda2
mv /boot/efi/EFI/Boot/bootx64.efi /boot/efi/EFI/Boot/bkpbootx64.efi
cp /boot/efi/EFI/ubuntu/shimx64.efi /boot/efi/EFI/Boot/bootx64.efi
cp /boot/efi/EFI/ubuntu/grubx64.efi /boot/efi/EFI/Boot/

grub-install --efi-directory=/boot/efi --target=x86_64-efi --uefi-secure-boot
Installing for x86_64-efi platform.
Installation finished. No error reported.

efibootmgr -v from chroot after grub install
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0005,0000,0001,0002
Boot0000* Optical Disk Drive	BBS(CDROM,,0x0).......................................................................
Boot0001* Notebook Hard Drive	BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0003* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0004* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0005* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIubuntushimx64.efi)
Boot0007* Windows Boot Manager	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(EFIMicrosoftBootbootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...M................

update-grub
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.8.0-38-generic
Found initrd image: /boot/initrd.img-5.8.0-38-generic
Found linux image: /boot/vmlinuz-5.8.0-25-generic
Found initrd image: /boot/initrd.img-5.8.0-25-generic
Found Windows Boot Manager on /dev/sda2@/EFI/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for UEFI Firmware Settings

Unhide GRUB boot menu in sda8/boot/grub/grub.cfg

Le démarrage de l'ordinateur a été correctement réparé.

Vous pouvez maintenant redémarrer votre ordinateur.

N'oubliez pas de faire démarrer votre firmware UEFI sur l'entrée L'OS actuellement utilisé - Ubuntu 20.10 CurrentSession (fichier sda2/EFI/ubuntu/shimx64.efi) !
Si votre ordinateur redémarre directement dans Windows, essayez de changer l'ordre de démarrage dans votre firmware UEFI.

Si votre firmware UEFI ne permet pas de changer l'ordre de démarrage, changez l'entrée de démarrage par défaut de l'amorceur Windows.
Par exemple, vous pouvez démarrer Windows, puis saisir la commande suivante dans une invite de commande en mode administrateur :
bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi

============================ Boot Info After Repair ============================

 => No boot loader is installed in the MBR of /dev/sda.

sda1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda2: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  Windows 8/2012: FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /efi/Boot/bkpbootx64.efi /efi/Boot/bootx64.efi 
                       /efi/Boot/fbx64.efi /efi/Boot/grubx64.efi 
                       /efi/Boot/mmx64.efi /efi/ubuntu/grubx64.efi 
                       /efi/ubuntu/mmx64.efi /efi/ubuntu/shimx64.efi 
                       /efi/ubuntu/grub.cfg /efi/HP/BiosUpdate/CryptRSA32.efi 
                       /efi/HP/BiosUpdate/CryptRSA.efi 
                       /efi/HP/BiosUpdate/HpBiosUpdate32.efi 
                       /efi/HP/BiosUpdate/HpBiosUpdate.efi 
                       /efi/Microsoft/Boot/bootmgfw.efi 
                       /efi/Microsoft/Boot/bootmgr.efi 
                       /efi/Microsoft/Boot/memtest.efi

sda3: __________________________________________________________________________

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

sda4: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  Windows 8 or 10
    Boot files:        /Windows/System32/winload.exe

sda5: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda6: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda7: __________________________________________________________________________

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

sda8: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  Ubuntu 20.10
    Boot files:        /boot/grub/grub.cfg /etc/fstab /etc/default/grub


================================ 2 OS detected =================================

OS#1:   L'OS actuellement utilisé - Ubuntu 20.10 CurrentSession on sda8
OS#2:   Windows 8 or 10 on sda4

============================ Architecture/Host Info ============================

CPU architecture: 64-bit
BOOT_IMAGE of the installed session in use:
/boot/vmlinuz-5.8.0-38-generic root=UUID=7eae5205-2b0d-4778-a812-0bb84390add2 ro quiet splash


===================================== UEFI =====================================

BIOS is EFI-compatible, and is setup in EFI-mode for this installed-session.
SecureBoot disabled.

efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000,0001,0002
Boot0000* Optical Disk Drive	BBS(CDROM,,0x0).......................................................................
Boot0001* Notebook Hard Drive	BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0003* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0004* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0005* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0006* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0007* Windows Boot Manager	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...M................
Boot0008* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)

78415fb8fb9b909f8029858113f1335f   sda2/Boot/bootx64.efi
2895d47544fd587b26c7e29be1295c27   sda2/Boot/fbx64.efi
dc3c47be2f78a78e5e57d097ae6c5c84   sda2/Boot/mmx64.efi
951288adcc81d2d86508f3f18d9753e0   sda2/ubuntu/grubx64.efi
dc3c47be2f78a78e5e57d097ae6c5c84   sda2/ubuntu/mmx64.efi
78415fb8fb9b909f8029858113f1335f   sda2/ubuntu/shimx64.efi
1b8c0684ede8539ccc205cf7a750eca3   sda2/HP/BiosUpdate/CryptRSA32.efi
6488d391f74263c9da3c3d47dffa6212   sda2/HP/BiosUpdate/CryptRSA.efi
28ccbac4a5471948714b53343c1a4db8   sda2/HP/BiosUpdate/HpBiosUpdate32.efi
668e03796f854694457d4960dac00b9d   sda2/HP/BiosUpdate/HpBiosUpdate.efi
4f0248591a11d5432380ba65f683879b   sda2/Microsoft/Boot/bootmgfw.efi
1feb5f9427494e6f598603caa3af7d99   sda2/Microsoft/Boot/bootmgr.efi


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

Disks info: ____________________________________________________________________

sda	: is-GPT,	no-BIOSboot,	has---ESP, 	not-usb,	not-mmc, has-os,	2048 sectors * 512 bytes

Partitions info (1/3): _________________________________________________________

sda8	: is-os,	64, apt-get,	signed grub-pc grub-efi ,	grub2,	grub-install,	grubenv-ok,	update-grub,	farbios
sda1	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	not-far
sda2	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	not-far
sda4	: is-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios
sda5	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios
sda6	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios

Partitions info (2/3): _________________________________________________________

sda8	: isnotESP,	fstab-has-goodEFI,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda1	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	recovery-or-hidden,	no-bmgr,	notwinboot
sda2	: is---ESP,	part-has-no-fstab,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda4	: isnotESP,	part-has-no-fstab,	no-nt,	haswinload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda5	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	recovery-or-hidden,	no-bmgr,	notwinboot
sda6	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot

Partitions info (3/3): _________________________________________________________

sda8	: not-sepboot,	with-boot,	fstab-without-boot,	not-sep-usr,	with--usr,	fstab-without-usr,	std-grub.d,	sda
sda1	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda2	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda4	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda5	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda6	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda

fdisk -l (filtered): ___________________________________________________________

Disk sda: 698.64 GiB, 750156374016 bytes, 1465149168 sectors
Disk identifier: C0887585-9B80-4F30-A8C9-E659B872E760
           Start        End   Sectors   Size Type
sda1        2048    1085439   1083392   529M Windows recovery environment
sda2     1085440    1290239    204800   100M EFI System
sda3     1290240    1323007     32768    16M Microsoft reserved
sda4     1323008  439849855 438526848 209.1G Microsoft basic data
sda5   439851008  441145343   1294336   632M Windows recovery environment
sda6   441145344 1321785343 880640000 419.9G Microsoft basic data
sda7  1321785344 1329784831   7999488   3.8G Linux swap
sda8  1329784832 1465147391 135362560  64.5G Linux filesystem

parted -lm (filtered): _________________________________________________________

sda:750GB:scsi:512:4096:gpt:ATA Hitachi HTS54107:;
1:1049kB:556MB:555MB:ntfs:Basic data partition:hidden, diag;
2:556MB:661MB:105MB:fat32:EFI system partition:boot, esp;
3:661MB:677MB:16.8MB::Microsoft reserved partition:msftres;
4:677MB:225GB:225GB:ntfs:Basic data partition:msftdata;
5:225GB:226GB:663MB:ntfs::hidden, diag;
6:226GB:677GB:451GB:ntfs:Basic data partition:msftdata;
7:677GB:681GB:4096MB:linux-swap(v1)::swap;
8:681GB:750GB:69.3GB:ext4::;

blkid (filtered): ______________________________________________________________

NAME   FSTYPE   UUID                                 PARTUUID                             LABEL        PARTLABEL
sda                                                                                                    
├─sda1 ntfs     1C54C8E054C8BDB0                     26d9a17a-c012-4e9f-86af-663efeb78c0f Récupération Basic data partition
├─sda2 vfat     26CC-BCC6                            bc9086f9-dd3a-4409-a221-109bb7d4c2c9              EFI system partition
├─sda3                                               9f64025a-f7ee-440c-a12c-9d4e19de0fa6              Microsoft reserved partition
├─sda4 ntfs     46DCD597DCD5821B                     384e2561-5959-4c8e-bb17-9fcd0155ae7f              Basic data partition
├─sda5 ntfs     D252CDFB52CDE3F7                     bc819c3f-320c-4356-a08e-850483ecf46b              
├─sda6 ntfs     823A914C3A913E5B                     0bf8ffd7-bd50-4d7d-8e2f-8742c6523cc5 DATA         Basic data partition
├─sda7 swap     1dd5dc6f-1558-4aa1-b5f5-f5b529c80d9e 87d3e57b-f2bf-479a-b008-84276454eba1              
└─sda8 ext4     7eae5205-2b0d-4778-a812-0bb84390add2 c26732fb-e98b-4f0c-8554-dc7c65aeaa71              

df (filtered): _________________________________________________________________

        Avail Use% Mounted on
sda1   516.7M   2% /mnt/boot-sav/sda1
sda4     144G  31% /mnt/boot-sav/sda4
sda5      86M  86% /mnt/boot-sav/sda5
sda6   419.8G   0% /mnt/boot-sav/sda6
sda8      53G  11% /

Mount options: __________________________________________________________________

sda1   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda4   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda5   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda6   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda8   rw,relatime,errors=remount-ro

===================== sda2/efi/ubuntu/grub.cfg (filtered) ======================

search.fs_uuid 7eae5205-2b0d-4778-a812-0bb84390add2 root hd0,gpt8 
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg

====================== sda8/boot/grub/grub.cfg (filtered) ======================

Ubuntu   7eae5205-2b0d-4778-a812-0bb84390add2
Ubuntu, with Linux 5.8.0-38-generic   7eae5205-2b0d-4778-a812-0bb84390add2
Ubuntu, with Linux 5.8.0-25-generic   7eae5205-2b0d-4778-a812-0bb84390add2
Windows Boot Manager (on sda2)   osprober-efi-26CC-BCC6
### END /etc/grub.d/30_os-prober ###
UEFI Firmware Settings   uefi-firmware
### END /etc/grub.d/30_uefi-firmware ###

========================== sda8/etc/fstab (filtered) ===========================

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda8 during installation
UUID=7eae5205-2b0d-4778-a812-0bb84390add2 /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda2 during installation
# swap was on /dev/sda7 during installation
UUID=1dd5dc6f-1558-4aa1-b5f5-f5b529c80d9e none            swap    sw              0       0
UUID=26CC-BCC6  /boot/efi       vfat    defaults      0       1

======================= sda8/etc/default/grub (filtered) =======================

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=""

==================== sda8: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
 644,842098236 = 692,393930752  boot/grub/grub.cfg                             1
 689,197341919 = 740,020011008  boot/vmlinuz                                   1
 637,114253998 = 684,096221184  boot/vmlinuz-5.8.0-25-generic                  2
 689,197341919 = 740,020011008  boot/vmlinuz-5.8.0-38-generic                  1
 637,114253998 = 684,096221184  boot/vmlinuz.old                               2
 639,803394318 = 686,983663616  boot/initrd.img                                1
 639,698562622 = 686,871101440  boot/initrd.img-5.8.0-25-generic               2
 639,803394318 = 686,983663616  boot/initrd.img-5.8.0-38-generic               1
 639,698562622 = 686,871101440  boot/initrd.img.old                            2

===================== sda8: ls -l /etc/grub.d/ (filtered) ======================

-rwxr-xr-x 1 root root 17622 oct.   1 15:59 10_linux
-rwxr-xr-x 1 root root 42359 oct.   1 15:59 10_linux_zfs
-rwxr-xr-x 1 root root 12894 oct.   1 15:59 20_linux_xen
-rwxr-xr-x 1 root root 12059 oct.   1 15:59 30_os-prober
-rwxr-xr-x 1 root root  1424 oct.   1 15:59 30_uefi-firmware
-rwxr-xr-x 1 root root   214 oct.   1 15:59 40_custom
-rwxr-xr-x 1 root root   216 oct.   1 15:59 41_custom
si quelqu'un a une solution svp?
J'ai un HP Probook 450 G0
Depuis la 2004 le menu Grub reste caché meme en cas de dual-boot avec wi détecté ce qui est ton cas (il s'affiche par ailleurs en cas de mono-boot !)

Via F9 peux-tu lancer win et surtout ubuntu mais sans "insultes" ?
Sinon, vois en tapotant F9 au démarrage, si tu peux toujours démarrer via les entrées "Ubuntu" et "Windows boot manager". Car le résultat de efibootmgr est un peu étrange.
Je viens d'essayer, je peux booter sur Windows en tapant F9. Sinon par défaut il lance directement Ubuntu sans Grub.
C'est bizarre car j'ai un autre portable (elitebook 8460p) ; celui ci boot directement sur windows et pour aller sur ubuntu je tape sur F9. le dual Boot en UEFI avec les portables HP c'est vraiment compliqué.

Hier j'ai installé ubuntu , l'option installé Ubuntu a coté de Windows n'était pas proposé , et au démarrage le menu grub s'est bien affiché mais sans le Windows .

J'ai du refaire mon Windows et mettre à jour mon bios, cette fois ci lors de l'installation Windows était bien détecté et le grub ne s'affiche pas au démarrage. C'est compliqué tout ca.
m4 a écritJe viens d'essayer, je peux booter sur Windows en tapant F9. Sinon par défaut il lance directement Ubuntu sans Grub.
Et buntu via F9 ?
Essaie déjà cette piste : https://forum.ubuntu-fr.org/viewtopic.p … #p22397107
Ce lien m'a aidé j'ai résolu mon soucis en éditant 
gedit admin:///etc/default/grub
supprimant le # 
#GRUB_TERMINAL=console
GRUB_TERMINAL=console
j'ai enregistré le fichier puis 
sudo update-grub
Voilà mon Grub s'affiche au démarrage, je peux selectionné Windows ou Ubuntu, ouf.

Merci pour le lien
Bonjour,
Je souhaiterais vérifier le résultat final. Pour cela, je te prie de faire un Boot-info depuis une session de ton Ubuntu 20.10 et de donner l'URL de ce Boot-info dans ta réponse.
malbo a écritJe souhaiterais vérifier le résultat final. Pour cela, je te prie de faire un Boot-info depuis une session de ton Ubuntu 20.10 et de donner l'URL de ce Boot-info dans ta réponse.
voici le le lien du boot-info
Boot-info
Bonjour,
Je colle ci-dessous le contenu du Boot-info dont tu as donné le lien dans ton post #8 : 
boot-repair-4ppa125                                              [20210119_0957]

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

 => No boot loader is installed in the MBR of /dev/sda.

sda1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda2: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  Windows 8/2012: FAT32
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /efi/Boot/bootx64.efi /efi/Boot/fbx64.efi 
                       /efi/Boot/grubx64.efi /efi/Boot/mmx64.efi 
                       /efi/ubuntu/grubx64.efi /efi/ubuntu/mmx64.efi 
                       /efi/ubuntu/shimx64.efi /efi/ubuntu/grub.cfg 
                       /efi/HP/BiosUpdate/CryptRSA32.efi 
                       /efi/HP/BiosUpdate/CryptRSA.efi 
                       /efi/HP/BiosUpdate/HpBiosUpdate32.efi 
                       /efi/HP/BiosUpdate/HpBiosUpdate.efi 
                       /efi/Microsoft/Boot/bootmgfw.efi 
                       /efi/Microsoft/Boot/bootmgr.efi 
                       /efi/Microsoft/Boot/memtest.efi

sda3: __________________________________________________________________________

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

sda4: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  Windows 8 or 10
    Boot files:        /Windows/System32/winload.exe

sda5: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda6: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 8/2012: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        

sda7: __________________________________________________________________________

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

sda8: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  Ubuntu 20.10
    Boot files:        /boot/grub/grub.cfg /etc/fstab /etc/default/grub


================================ 2 OS detected =================================

OS#1:   L'OS actuellement utilisé - Ubuntu 20.10 CurrentSession on sda8
OS#2:   Windows 8 or 10 on sda4

============================ Architecture/Host Info ============================

CPU architecture: 64-bit
BOOT_IMAGE of the installed session in use:
/boot/vmlinuz-5.8.0-38-generic root=UUID=9a995f1e-eace-4bf5-a79c-f43006b83ca7 ro quiet splash vt.handoff=7


===================================== UEFI =====================================

BIOS is EFI-compatible, and is setup in EFI-mode for this installed-session.
SecureBoot disabled.

efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0012
Boot0000* Optical Disk Drive	BBS(CDROM,,0x0).......................................................................
Boot0001* Notebook Hard Drive	BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0003* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0004* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0005* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0006* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0007* Windows Boot Manager	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...M................
Boot0008* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0009* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000A* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000B* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000C* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000D* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000E* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000F* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0010* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0011* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0012* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)

78415fb8fb9b909f8029858113f1335f   sda2/Boot/bootx64.efi
2895d47544fd587b26c7e29be1295c27   sda2/Boot/fbx64.efi
951288adcc81d2d86508f3f18d9753e0   sda2/Boot/grubx64.efi
dc3c47be2f78a78e5e57d097ae6c5c84   sda2/Boot/mmx64.efi
951288adcc81d2d86508f3f18d9753e0   sda2/ubuntu/grubx64.efi
dc3c47be2f78a78e5e57d097ae6c5c84   sda2/ubuntu/mmx64.efi
78415fb8fb9b909f8029858113f1335f   sda2/ubuntu/shimx64.efi
1b8c0684ede8539ccc205cf7a750eca3   sda2/HP/BiosUpdate/CryptRSA32.efi
6488d391f74263c9da3c3d47dffa6212   sda2/HP/BiosUpdate/CryptRSA.efi
28ccbac4a5471948714b53343c1a4db8   sda2/HP/BiosUpdate/HpBiosUpdate32.efi
668e03796f854694457d4960dac00b9d   sda2/HP/BiosUpdate/HpBiosUpdate.efi
4f0248591a11d5432380ba65f683879b   sda2/Microsoft/Boot/bootmgfw.efi
1feb5f9427494e6f598603caa3af7d99   sda2/Microsoft/Boot/bootmgr.efi


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

Disks info: ____________________________________________________________________

sda	: is-GPT,	no-BIOSboot,	has---ESP, 	not-usb,	not-mmc, has-os,	2048 sectors * 512 bytes

Partitions info (1/3): _________________________________________________________

sda8	: is-os,	64, apt-get,	signed grub-pc grub-efi ,	grub2,	grub-install,	grubenv-ok,	update-grub,	farbios
sda1	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	not-far
sda2	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	not-far
sda4	: is-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios
sda5	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios
sda6	: no-os,	32, nopakmgr,	no-docgrub,	nogrub,	nogrubinstall,	no-grubenv,	noupdategrub,	farbios

Partitions info (2/3): _________________________________________________________

sda8	: isnotESP,	fstab-has-goodEFI,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda1	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	recovery-or-hidden,	no-bmgr,	notwinboot
sda2	: is---ESP,	part-has-no-fstab,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda4	: isnotESP,	part-has-no-fstab,	no-nt,	haswinload,	no-recov-nor-hid,	no-bmgr,	notwinboot
sda5	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	recovery-or-hidden,	no-bmgr,	notwinboot
sda6	: isnotESP,	part-has-no-fstab,	no-nt,	no-winload,	no-recov-nor-hid,	no-bmgr,	notwinboot

Partitions info (3/3): _________________________________________________________

sda8	: not-sepboot,	with-boot,	fstab-without-boot,	not-sep-usr,	with--usr,	fstab-without-usr,	std-grub.d,	sda
sda1	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda2	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda4	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda5	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda
sda6	: not-sepboot,	no-boot,	part-has-no-fstab,	not-sep-usr,	no---usr,	part-has-no-fstab,	std-grub.d,	sda

fdisk -l (filtered): ___________________________________________________________

Disk sda: 698.64 GiB, 750156374016 bytes, 1465149168 sectors
Disk identifier: C0887585-9B80-4F30-A8C9-E659B872E760
           Start        End   Sectors   Size Type
sda1        2048    1085439   1083392   529M Windows recovery environment
sda2     1085440    1290239    204800   100M EFI System
sda3     1290240    1323007     32768    16M Microsoft reserved
sda4     1323008  439849855 438526848 209.1G Microsoft basic data
sda5   439851008  441145343   1294336   632M Windows recovery environment
sda6   441145344 1321785343 880640000 419.9G Microsoft basic data
sda7  1321785344 1329784831   7999488   3.8G Linux swap
sda8  1329784832 1465147391 135362560  64.5G Linux filesystem

parted -lm (filtered): _________________________________________________________

sda:750GB:scsi:512:4096:gpt:ATA Hitachi HTS54107:;
1:1049kB:556MB:555MB:ntfs:Basic data partition:hidden, diag;
2:556MB:661MB:105MB:fat32:EFI system partition:boot, esp;
3:661MB:677MB:16.8MB::Microsoft reserved partition:msftres;
4:677MB:225GB:225GB:ntfs:Basic data partition:msftdata;
5:225GB:226GB:663MB:ntfs::hidden, diag;
6:226GB:677GB:451GB:ntfs:Basic data partition:msftdata;
7:677GB:681GB:4096MB:linux-swap(v1)::swap;
8:681GB:750GB:69.3GB:ext4::;

blkid (filtered): ______________________________________________________________

NAME   FSTYPE   UUID                                 PARTUUID                             LABEL        PARTLABEL
sda                                                                                                    
├─sda1 ntfs     1C54C8E054C8BDB0                     26d9a17a-c012-4e9f-86af-663efeb78c0f Récupération Basic data partition
├─sda2 vfat     26CC-BCC6                            bc9086f9-dd3a-4409-a221-109bb7d4c2c9              EFI system partition
├─sda3                                               9f64025a-f7ee-440c-a12c-9d4e19de0fa6              Microsoft reserved partition
├─sda4 ntfs     46DCD597DCD5821B                     384e2561-5959-4c8e-bb17-9fcd0155ae7f              Basic data partition
├─sda5 ntfs     D252CDFB52CDE3F7                     bc819c3f-320c-4356-a08e-850483ecf46b              
├─sda6 ntfs     823A914C3A913E5B                     0bf8ffd7-bd50-4d7d-8e2f-8742c6523cc5 DATA         Basic data partition
├─sda7 swap     1dd5dc6f-1558-4aa1-b5f5-f5b529c80d9e 87d3e57b-f2bf-479a-b008-84276454eba1              
└─sda8 ext4     9a995f1e-eace-4bf5-a79c-f43006b83ca7 c26732fb-e98b-4f0c-8554-dc7c65aeaa71              

df (filtered): _________________________________________________________________

       Avail Use% Mounted on
sda1   516.7M   2% /mnt/boot-sav/sda1
sda4   144.5G  31% /media/mevan/46DCD597DCD5821B
sda5      86M  86% /mnt/boot-sav/sda5
sda6    62.7G  85% /media/mevan/DATA
sda8    47.6G  19% /

Mount options: __________________________________________________________________

sda1   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda4   rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096
sda5   rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096
sda6   rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096
sda8   rw,relatime,errors=remount-ro

===================== sda2/efi/ubuntu/grub.cfg (filtered) ======================

search.fs_uuid 9a995f1e-eace-4bf5-a79c-f43006b83ca7 root hd0,gpt8 
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg

====================== sda8/boot/grub/grub.cfg (filtered) ======================

Ubuntu   9a995f1e-eace-4bf5-a79c-f43006b83ca7
Ubuntu, with Linux 5.8.0-38-generic   9a995f1e-eace-4bf5-a79c-f43006b83ca7
Ubuntu, with Linux 5.8.0-25-generic   9a995f1e-eace-4bf5-a79c-f43006b83ca7
Windows Boot Manager (on sda2)   osprober-efi-26CC-BCC6
Windows Boot Manager (on sdb1)   osprober-efi-6019-C35B
Ubuntu 20.10 (20.10) (on sdb6)   13a807b2-e07a-4768-9ba8-359c82b9dda0
Ubuntu (on sdb6)   13a807b2-e07a-4768-9ba8-359c82b9dda0
Ubuntu, with Linux 5.8.0-25-generic (on sdb6)   13a807b2-e07a-4768-9ba8-359c82b9dda0
### END /etc/grub.d/30_os-prober ###
UEFI Firmware Settings   uefi-firmware
### END /etc/grub.d/30_uefi-firmware ###

========================== sda8/etc/fstab (filtered) ===========================

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda8 during installation
UUID=9a995f1e-eace-4bf5-a79c-f43006b83ca7 /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda2 during installation
UUID=26CC-BCC6  /boot/efi       vfat    umask=0077      0       1
# swap was on /dev/sda7 during installation
UUID=1dd5dc6f-1558-4aa1-b5f5-f5b529c80d9e none            swap    sw              0       0

======================= sda8/etc/default/grub (filtered) =======================

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=""
GRUB_TERMINAL=console

==================== sda8: Location of files loaded by Grub ====================

           GiB - GB             File                                 Fragment(s)
 682,698226929 = 733,041639424  boot/grub/grub.cfg                             3
 639,291091919 = 686,433583104  boot/vmlinuz                                   1
 636,259838104 = 683,178799104  boot/vmlinuz-5.8.0-25-generic                  1
 639,291091919 = 686,433583104  boot/vmlinuz-5.8.0-38-generic                  1
 636,259838104 = 683,178799104  boot/vmlinuz.old                               1
 641,958003998 = 689,297158144  boot/initrd.img                                7
 645,506603241 = 693,107437568  boot/initrd.img-5.8.0-25-generic               2
 641,958003998 = 689,297158144  boot/initrd.img-5.8.0-38-generic               7
 645,506603241 = 693,107437568  boot/initrd.img.old                            2

===================== sda8: ls -l /etc/grub.d/ (filtered) ======================

-rwxr-xr-x 1 root root 17622 oct.   1 15:59 10_linux
-rwxr-xr-x 1 root root 42359 oct.   1 15:59 10_linux_zfs
-rwxr-xr-x 1 root root 12894 oct.   1 15:59 20_linux_xen
-rwxr-xr-x 1 root root 12059 oct.   1 15:59 30_os-prober
-rwxr-xr-x 1 root root  1424 oct.   1 15:59 30_uefi-firmware
-rwxr-xr-x 1 root root   214 oct.   1 15:59 40_custom
-rwxr-xr-x 1 root root   216 oct.   1 15:59 41_custom


Suggested repair: ______________________________________________________________

The default repair of the Boot-Repair utility would reinstall the grub-efi-amd64-signed of
sda8,
using the following options:        sda2/boot/efi,
Additional repair would be performed: unhide-bootmenu-10s win-legacy-basic-fix use-standard-efi-file    

Final advice in case of suggested repair: ______________________________________


Please do not forget to make your UEFI firmware boot on the L'OS actuellement utilisé - Ubuntu 20.10 CurrentSession entry (sda2/efi/****/shim****.efi (**** will be updated in the final message) file) !
If your computer reboots directly into Windows, try to change the boot order in your UEFI firmware.

If your UEFI firmware does not allow to change the boot order, change the default boot entry of the Windows bootloader.
For example you can boot into Windows, then type the following command in an admin command prompt:
bcdedit /set {bootmgr} path \EFI\****\shim****.efi (**** will be updated in the final message)
Dans cet extrait, on peut voir que tu as bien effectué la modif que tu as décrites dans le post #6 : 
======================= sda8/etc/default/grub (filtered) =======================

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=""
GRUB_TERMINAL=console
C'est à dire que tu as bien enlevé le # qui se trouvait devant "GRUB_TERMINAL=console"
D'autre part, on peut voir qu'à chaque démarrage, il y a une entrée "ubuntu" qui s'ajoute dans le menu UEFI : 
===================================== UEFI =====================================

BIOS is EFI-compatible, and is setup in EFI-mode for this installed-session.
SecureBoot disabled.

efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0012
Boot0000* Optical Disk Drive	BBS(CDROM,,0x0).......................................................................
Boot0001* Notebook Hard Drive	BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0003* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0004* Notebook Ethernet	BBS(128,,0x0).......................................................................
Boot0005* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0006* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0007* Windows Boot Manager	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...M................
Boot0008* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0009* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000A* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000B* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000C* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000D* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000E* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot000F* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0010* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0011* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)
Boot0012* ubuntu	HD(2,GPT,bc9086f9-dd3a-4409-a221-109bb7d4c2c9,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)

Ce phénomène est causé par le verrouilage du démarrage, une spécialité bien pourrie du fabricant HP. On a pu voir récemment le même problème (création d'une entrée ubuntu à chaque démarage) avec l'ordi HP EliteBook Folio 9480m de Mario2020C (voir ce fil)
Salut,

La nouvelle stratégie d'ajout d'entrée "Ubuntu" en Nvram au démarrage du PC appliquée dans la 20-10 et confirmée dans la 21-04 va rendre cette situation très fréquente. Ça promet.

Pour moi, c'est moins HP qu'Ubuntu qu'il faut incriminer. Que fait GRUB au démarrage ? J''avoue encore ne pas trop savoir exactement ce qu'il en est.