Ubuntu 22.04.4 LTS not dual booting (drops to busybox)

eigenhector · December 11, 2024, 5:38pm

I’m very new to Linux, so apologies in advance if my explanations are incomplete / confusing.

My current PC has an M.2 drive (Samsung 770 EVO 1TB), an SSD (Samsung 840 EVO 120GB), and an HDD (Western Digital WD10EZEX 1TB). I originally installed Windows 10 on the M.2 and Ubuntu 22.04 on the SSD, with the HDD used for backup. Everything worked fine until I “upgraded” to Windows 11 about a year ago. Whenever I try to boot Ubuntu from GRUB, I get dropped to a busybox prompt (see photo).

(photo replaced with text for good SEO and copy/pastability)

Gave up waiting for root file system device. Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
 - Missing modules (cat /proc/modules; 1s /dev)
ALERT! UUID=d9e66418-487c-4ae7-9e4a-a836fce38fb8 does not exist. Dropping to a shell!


BusyBox v1.30.1 (Ubuntu 1:1.30.1-7ubuntu3) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) -

Note that I’m unable to type anything into the prompt; I don’t know whether this is due to it not recognizing my keyboard or my PC being frozen.

Since this started happening I’ve been using Windows 11 without issue. However, I’d like to start using Ubuntu (or another distro) again with the ultimate goal of migrating off of Windows for good. I have all my important data backed up to the HDD, and a Windows system image on an external SSD, but before doing anything drastic I would like to get the current Ubuntu installation working again if possible, or otherwise, to reinstall it without compromising Windows.

I ran boot-repair from an Ubuntu live USB, which tried and failed to reinstall GRUB (a window popped up saying the installation was cancelled with no further explanation). Here is the diagnostic from boot-repair: Ubuntu Pastebin I’m not sure how to interpret this, so any suggestions would be appreciated.

I’ve read multiple solutions online for similar issues, but they all involve running some commands from the busybox prompt, which I’m unable to do. Now, I would be fine with wiping the SSD and installing Ubuntu again, but I’m concerned that this may somehow prevent me from booting Windows. Again, pardon my ignorance if that is not the case, but I want to be sure before proceeding.

Boot Priority                                            Switch all
Choose one and drag the items.

ubuntu (M.2_1: Samsung SSD 970 EVO 1TB) (1000.2GB)

Windows Boot Manager (M.2_1: Samsung SSD 970 EVO 1TB) (1000.2GB)

Boot Menu(F8)

(photo replaced with text for good SEO and copy/pastability)

Also attached is a photo of my BIOS interface showing the boot order. Note that it lists Ubuntu as booting from the M.2, although as far as I know it is only installed on the SSD. I’m not sure if that means that somehow Ubuntu and Windows were installed on the same partition, or if it is just indexed incorrectly.

popey · December 11, 2024, 6:10pm

This is likely just because that’s the disk containing the EFI partition. The small part of a disk that is accessible at boot time and contains the first part of the boot loader.

popey · December 11, 2024, 8:05pm

Well done on the comprehensive question - lots of detail there. But we need a bit more. Here’s a guide detailing that. Once you have this information, paste it in here between some backticks in a reply, which should make it easier to read, and search. This is preferable to a photo.

```
like this
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Ubuntu Live USB Diagnostic Guide

Initial Setup

Boot from your Ubuntu Live USB
Select “Try Ubuntu” when prompted
Once the desktop loads, open a terminal (Ctrl+Alt+T)

Basic Disk Information

Run these commands one at a time and save their output (you can copy/paste to a text file):

# Show basic disk and partition information
sudo lsblk -o NAME,SIZE,FSTYPE,LABEL,MOUNTPOINT

# Show detailed partition information
sudo fdisk -l

# Show all disk UUIDs
sudo blkid

# Show mounted filesystems
mount

# Show UEFI boot entries
sudo efibootmgr -v

Examining the EFI System Partition

# Create a temporary mount point
sudo mkdir /mnt/efi

# Mount the EFI partition (replace sdX1 with the actual EFI partition from lsblk)
sudo mount /dev/sdX1 /mnt/efi

# List EFI files
ls -R /mnt/efi

Checking GRUB Configuration

# Mount the Ubuntu root partition (replace sdXY with the actual partition)
sudo mkdir /mnt/ubuntu
sudo mount /dev/sdXY /mnt/ubuntu

# List GRUB configuration files
ls -l /mnt/ubuntu/boot/grub
cat /mnt/ubuntu/boot/grub/grub.cfg

# Check fstab entries
cat /mnt/ubuntu/etc/fstab

Important Notes:

Don’t run any commands that modify the system (like grub-install or update-grub) yet
Save all command outputs to a text file for analysis
Pay special attention to:
- The UUIDs of all partitions
- The location of the EFI System Partition
- Whether Windows and Ubuntu are using separate EFI partitions
- The presence and content of GRUB configuration files

Warning Signs to Look For:

Multiple EFI System Partitions
Missing or incorrect UUIDs in fstab
Mismatched partition types
Inconsistencies between UEFI boot entries and actual disk layout

Next Steps:

After gathering this information, we can:

Compare the UUID in the error message with actual partition UUIDs
Verify the boot partition configuration
Check if Windows 11 upgrade modified the EFI partition structure
Develop a safe plan to repair the boot configuration

eigenhector · December 12, 2024, 3:02am

Thanks; here are the terminal outputs. There seem to be two EFI partitions, sda1 and nvme0n1p1, so I listed the files in both.

ubuntu@ubuntu:~$ sudo lsblk -o NAME,SIZE,FSTYPE,LABEL,MOUNTPOINT
NAME      	SIZE FSTYPE   LABEL                	MOUNTPOINT
loop0     	1.6G squashfs                      	/rofs
loop1     	471M squashfs                     	 
loop2   	874.4M squashfs                     	 
loop3       	4K squashfs                      	/snap/bare/5
loop4    	74.3M squashfs                      	/snap/core22/1564
loop5   	505.1M squashfs                      	/snap/gnome-42-2204/176
loop6   	269.8M squashfs                      	/snap/firefox/4793
loop7    	10.7M squashfs                      	/snap/firmware-updater/127
loop8    	10.5M squashfs                      	/snap/snap-store/1173
loop9    	91.7M squashfs                      	/snap/gtk-common-themes/153
loop10   	38.8M squashfs                      	/snap/snapd/21759
loop11    	500K squashfs                      	/snap/snapd-desktop-integra
loop12  	149.6M squashfs                      	/snap/thunderbird/507
loop13  	116.8M squashfs                      	/snap/ubuntu-desktop-bootst
sda     	111.8G                              	 
├─sda1    	512M vfat                         	 
└─sda2  	111.3G ext4                         	 
sdb     	931.5G                              	 
└─sdb1  	931.5G ntfs 	WD-1TB              	 
sdc      	28.9G iso9660  Ubuntu 24.04.1 LTS amd64
├─sdc1    	5.8G iso9660  Ubuntu 24.04.1 LTS amd64 /cdrom
├─sdc2      	5M vfat 	ESP                 	 
├─sdc3    	300K                              	 
└─sdc4   	23.1G ext4 	writable             	/var/crash
nvme0n1 	931.5G                              	 
├─nvme0n1p1   100M vfat                         	 
├─nvme0n1p2	16M                              	 
└─nvme0n1p3 930.8G ntfs 	Samsung 970 EVO 1TB 	 

ubuntu@ubuntu:~$ sudo fdisk -l
Disk /dev/loop0: 1.63 GiB, 1752752128 bytes, 3423344 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop1: 471.01 MiB, 493887488 bytes, 964624 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop2: 874.37 MiB, 916840448 bytes, 1790704 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop3: 4 KiB, 4096 bytes, 8 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop4: 74.27 MiB, 77881344 bytes, 152112 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop5: 505.09 MiB, 529625088 bytes, 1034424 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop6: 269.77 MiB, 282873856 bytes, 552488 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop7: 10.72 MiB, 11239424 bytes, 21952 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/sda: 111.79 GiB, 120034123776 bytes, 234441648 sectors
Disk model: Samsung SSD 840
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A4D4AE17-7580-4F9C-9B6B-5AD58AEC26F7

Device   	Start   	End   Sectors   Size Type
/dev/sda1 	2048   1050623   1048576   512M EFI System
/dev/sda2  1050624 234440703 233390080 111.3G Linux filesystem


Disk /dev/sdb: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: WDC WD10EZEX-21M
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x8d5b3ead

Device 	Boot Start    	End	Sectors   Size Id Type
/dev/sdb1  * 	2048 1953521663 1953519616 931.5G  7 HPFS/NTFS/exFAT


Disk /dev/nvme0n1: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: Samsung SSD 970 EVO 1TB            	 
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: BFFE7CDA-4798-4158-8C10-2A75C8905F66

Device      	Start    	End	Sectors   Size Type
/dev/nvme0n1p1   2048 	206847 	204800   100M EFI System
/dev/nvme0n1p2 206848 	239615  	32768	16M Microsoft reserved
/dev/nvme0n1p3 239616 1952360564 1952120949 930.8G Microsoft basic data


Disk /dev/sdc: 28.91 GiB, 31042043904 bytes, 60628992 sectors
Disk model: USB DISK 2.0    
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: EED3DE8A-ACD3-4541-BA15-9014C007D874

Device    	Start  	End  Sectors  Size Type
/dev/sdc1    	64 12105119 12105056  5.8G Microsoft basic data
/dev/sdc2  12105120 12115263	10144	5M EFI System
/dev/sdc3  12115264 12115863  	600  300K Microsoft basic data
/dev/sdc4  12115968 60626943 48510976 23.1G Linux filesystem


Disk /dev/loop8: 10.54 MiB, 11051008 bytes, 21584 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop10: 38.83 MiB, 40714240 bytes, 79520 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop9: 91.69 MiB, 96141312 bytes, 187776 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop11: 500 KiB, 512000 bytes, 1000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop12: 149.63 MiB, 156901376 bytes, 306448 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop13: 116.78 MiB, 122449920 bytes, 239160 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

ubuntu@ubuntu:~$ sudo blkid
/dev/nvme0n1p1: UUID="E8A8-1513" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="41a4e6c5-8612-461d-bb8a-ed5f2414c081"
/dev/nvme0n1p3: LABEL="Samsung 970 EVO 1TB" BLOCK_SIZE="512" UUID="3A14A90F14A8CF67" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="2e50f0d7-fd4b-4278-a12d-5b400529b6b1"
/dev/sda1: UUID="BB4B-E2D2" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="879129a2-e363-4a98-9ed0-feec3873e311"
/dev/sda2: UUID="d9e66418-437c-4ae7-9e4a-a836fce38fb8" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="3007b008-eda9-4275-8af3-d47dc25e3a28"
/dev/sdb1: LABEL="WD-1TB" BLOCK_SIZE="512" UUID="F07C47D97C47996C" TYPE="ntfs" PARTUUID="8d5b3ead-01"
/dev/sdc1: BLOCK_SIZE="2048" UUID="2024-08-27-16-23-26-00" LABEL="Ubuntu 24.04.1 LTS amd64" TYPE="iso9660" PARTLABEL="ISO9660" PARTUUID="eed3de8a-acd3-4541-ba14-9014c007d874"
/dev/loop1: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop2: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop0: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/sdc2: SEC_TYPE="msdos" LABEL_FATBOOT="ESP" LABEL="ESP" UUID="3C53-CAEB" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="Appended2" PARTUUID="eed3de8a-acd3-4541-ba17-9014c007d874"
/dev/sdc4: LABEL="writable" UUID="79c66166-4de4-4b40-a77b-5596cc6f2497" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="aeea95b7-399a-4ac2-aca8-16fe0800e4dd"
/dev/nvme0n1p2: PARTLABEL="Microsoft reserved partition" PARTUUID="4badbde5-cfa6-4009-9188-44256ed82167"
/dev/loop8: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop6: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop13: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop4: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop11: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop9: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/sdc3: PARTLABEL="Gap1" PARTUUID="eed3de8a-acd3-4541-ba16-9014c007d874"
/dev/loop7: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop5: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop12: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop3: BLOCK_SIZE="131072" TYPE="squashfs"
/dev/loop10: BLOCK_SIZE="131072" TYPE="squashfs"

ubuntu@ubuntu:~$ mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=16343416k,nr_inodes=4085854,mode=755,inode64)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=3276724k,mode=755,inode64)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
/dev/sdc1 on /cdrom type iso9660 (ro,noatime,nojoliet,check=s,map=n,blocksize=2048,iocharset=utf8)
/dev/loop0 on /rofs type squashfs (ro,noatime,errors=continue,threads=single)
/cow on / type overlay (rw,relatime,lowerdir=/minimal.standard.live.squashfs:/minimal.standard.squashfs:/minimal.squashfs,upperdir=/cow/upper,workdir=/cow/work,uuid=on,xino=off,nouserxattr)
/dev/sdc4 on /var/log type ext4 (rw,relatime)
/dev/sdc4 on /var/crash type ext4 (rw,relatime)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k,inode64)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=32,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=16089)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,nosuid,nodev,relatime,pagesize=2M)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,relatime,inode64)
/var/lib/snapd/snaps/bare_5.snap on /snap/bare/5 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/ubuntu-desktop-bootstrap_237.snap on /snap/ubuntu-desktop-bootstrap/237 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/thunderbird_507.snap on /snap/thunderbird/507 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/firmware-updater_127.snap on /snap/firmware-updater/127 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/snap-store_1173.snap on /snap/snap-store/1173 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/snapd-desktop-integration_178.snap on /snap/snapd-desktop-integration/178 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/firefox_4793.snap on /snap/firefox/4793 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/core22_1564.snap on /snap/core22/1564 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/gnome-42-2204_176.snap on /snap/gnome-42-2204/176 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/snapd_21759.snap on /snap/snapd/21759 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/gtk-common-themes_1535.snap on /snap/gtk-common-themes/1535 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /run/snapd/ns type tmpfs (rw,nosuid,nodev,noexec,relatime,size=3276724k,mode=755,inode64)
nsfs on /run/snapd/ns/firefox.mnt type nsfs (rw)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=3276720k,nr_inodes=819180,mode=700,uid=1000,gid=1000,inode64)
nsfs on /run/snapd/ns/firmware-updater.mnt type nsfs (rw)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
nsfs on /run/snapd/ns/snap-store.mnt type nsfs (rw)
portal on /run/user/1000/doc type fuse.portal (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
nsfs on /run/snapd/ns/snapd-desktop-integration.mnt type nsfs (rw)
nsfs on /run/snapd/ns/thunderbird.mnt type nsfs (rw)
ubuntu@ubuntu:~$ sudo efibootmgr -v
BootCurrent: 0003
Timeout: 1 seconds
BootOrder: 0002,0000,0003
Boot0000* Windows Boot Manager	HD(1,GPT,41a4e6c5-8612-461d-bb8a-ed5f2414c081,0x800,0x32000)/File(\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI)57494e444f5753000100000088000000780000004200430044004f0042004a004500430054003d007b00390064006500610038003600320063002d0035006300640064002d0034006500370030002d0061006300630031002d006600330032006200330034003400640034003700390035007d00000000000100000010000000040000007fff0400
  	dp: 04 01 2a 00 01 00 00 00 00 08 00 00 00 00 00 00 00 20 03 00 00 00 00 00 c5 e6 a4 41 12 86 1d 46 bb 8a ed 5f 24 14 c0 81 02 02 / 04 04 46 00 5c 00 45 00 46 00 49 00 5c 00 4d 00 49 00 43 00 52 00 4f 00 53 00 4f 00 46 00 54 00 5c 00 42 00 4f 00 4f 00 54 00 5c 00 42 00 4f 00 4f 00 54 00 4d 00 47 00 46 00 57 00 2e 00 45 00 46 00 49 00 00 00 / 7f ff 04 00
	data: 57 49 4e 44 4f 57 53 00 01 00 00 00 88 00 00 00 78 00 00 00 42 00 43 00 44 00 4f 00 42 00 4a 00 45 00 43 00 54 00 3d 00 7b 00 39 00 64 00 65 00 61 00 38 00 36 00 32 00 63 00 2d 00 35 00 63 00 64 00 64 00 2d 00 34 00 65 00 37 00 30 00 2d 00 61 00 63 00 63 00 31 00 2d 00 66 00 33 00 32 00 62 00 33 00 34 00 34 00 64 00 34 00 37 00 39 00 35 00 7d 00 00 00 00 00 01 00 00 00 10 00 00 00 04 00 00 00 7f ff 04 00
Boot0002* ubuntu	HD(1,GPT,41a4e6c5-8612-461d-bb8a-ed5f2414c081,0x800,0x32000)/File(\EFI\UBUNTU\SHIMX64.EFI)
  	dp: 04 01 2a 00 01 00 00 00 00 08 00 00 00 00 00 00 00 20 03 00 00 00 00 00 c5 e6 a4 41 12 86 1d 46 bb 8a ed 5f 24 14 c0 81 02 02 / 04 04 34 00 5c 00 45 00 46 00 49 00 5c 00 55 00 42 00 55 00 4e 00 54 00 55 00 5c 00 53 00 48 00 49 00 4d 00 58 00 36 00 34 00 2e 00 45 00 46 00 49 00 00 00 / 7f ff 04 00
Boot0003* UEFI:  USB DISK 2.0 PMAP, Partition 2	PciRoot(0x0)/Pci(0x8,0x1)/Pci(0x0,0x3)/USB(3,0)/HD(2,GPT,eed3de8a-acd3-4541-ba17-9014c007d874,0xb8b5a0,0x27a0)0000424f
  	dp: 02 01 0c 00 d0 41 03 0a 00 00 00 00 / 01 01 06 00 01 08 / 01 01 06 00 03 00 / 03 05 06 00 03 00 / 04 01 2a 00 02 00 00 00 a0 b5 b8 00 00 00 00 00 a0 27 00 00 00 00 00 00 8a de d3 ee d3 ac 41 45 ba 17 90 14 c0 07 d8 74 02 02 / 7f ff 04 00
	data: 00 00 42 4f

ubuntu@ubuntu:~$ sudo mkdir /mnt/efi
ubuntu@ubuntu:~$ sudo mount /dev/sda1 /mnt/efi
ubuntu@ubuntu:~$ ls -R /mnt/efi
/mnt/efi:
'System Volume Information'

'/mnt/efi/System Volume Information':

ubuntu@ubuntu:~$ sudo mount /dev/nvme0n1p1 /mnt/efi
ubuntu@ubuntu:~$ ls -R /mnt/efi
/mnt/efi:
 EFI  'System Volume Information'

/mnt/efi/EFI:
Boot  Microsoft  ubuntu

/mnt/efi/EFI/Boot:
bootx64.efi  fbx64.efi  mmx64.efi

/mnt/efi/EFI/Microsoft:
Boot  Recovery

/mnt/efi/EFI/Microsoft/Boot:
BCD                 	boot.stl     	es-ES  kd_02_10df.dll  kd_0C_8086.dll   	pt-BR   	uk-UA
BCD.LOG             	bootmgfw.efi 	es-MX  kd_02_10ec.dll  kdnet_uart16550.dll  pt-PT   	winsipolicy.p7b
BCD.LOG1            	bootmgr.efi  	et-EE  kd_02_1137.dll  kdstub.dll       	qps-ploc	zh-CN
BCD.LOG2            	cbmr_driver.efi  fi-FI  kd_02_14e4.dll  ko-KR            	ro-RO   	zh-TW
BOOTSTAT.DAT        	cs-CZ        	fr-CA  kd_02_15b3.dll  lt-LT            	ru-RU
CIPolicies          	da-DK        	fr-FR  kd_02_1969.dll  lv-LV            	sk-SK
Fonts               	de-DE        	hr-HR  kd_02_19a2.dll  memtest.efi      	sl-SI
Resources           	el-GR        	hu-HU  kd_02_1af4.dll  nb-NO            	sr-Latn-RS
SecureBootRecovery.efi  en-GB        	it-IT  kd_02_8086.dll  nl-NL            	sv-SE
bg-BG               	en-US        	ja-JP  kd_07_1415.dll  pl-PL            	tr-TR

/mnt/efi/EFI/Microsoft/Boot/CIPolicies:
Active

/mnt/efi/EFI/Microsoft/Boot/CIPolicies/Active:
{5DAC656C-21AD-4A02-AB49-649917162E70}.cip  {CDD5CB55-DB68-4D71-AA38-3DF2B6473A52}.cip
{82443e1e-8a39-4b4a-96a8-f40ddc00b9f3}.cip

/mnt/efi/EFI/Microsoft/Boot/Fonts:
chs_boot.ttf  kor_boot.ttf  	meiryo_boot.ttf   msjhn_boot.ttf  segmono_boot.ttf   wgl4_boot.ttf
cht_boot.ttf  malgun_boot.ttf   meiryon_boot.ttf  msyh_boot.ttf   segoe_slboot.ttf
jpn_boot.ttf  malgunn_boot.ttf  msjh_boot.ttf 	msyhn_boot.ttf  segoen_slboot.ttf

/mnt/efi/EFI/Microsoft/Boot/Resources:
bootres.dll  en-US

/mnt/efi/EFI/Microsoft/Boot/Resources/en-US:
bootres.dll.mui

/mnt/efi/EFI/Microsoft/Boot/bg-BG:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/cs-CZ:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/da-DK:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/de-DE:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/el-GR:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/en-GB:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/en-US:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/es-ES:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/es-MX:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/et-EE:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/fi-FI:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/fr-CA:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/fr-FR:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/hr-HR:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/hu-HU:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/it-IT:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/ja-JP:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/ko-KR:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/lt-LT:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/lv-LV:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/nb-NO:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/nl-NL:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/pl-PL:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/pt-BR:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/pt-PT:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/qps-ploc:
memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/ro-RO:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/ru-RU:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/sk-SK:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/sl-SI:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/sr-Latn-RS:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/sv-SE:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/tr-TR:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/uk-UA:
bootmgfw.efi.mui  bootmgr.efi.mui

/mnt/efi/EFI/Microsoft/Boot/zh-CN:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Boot/zh-TW:
bootmgfw.efi.mui  bootmgr.efi.mui  memtest.efi.mui

/mnt/efi/EFI/Microsoft/Recovery:
BCD  BCD.LOG  BCD.LOG1  BCD.LOG2

/mnt/efi/EFI/ubuntu:
BOOTX64.CSV  grub.cfg  grubx64.efi  mmx64.efi  shimx64.efi

'/mnt/efi/System Volume Information':
ubuntu@ubuntu:~$ sudo mkdir /mnt/ubuntu
ubuntu@ubuntu:~$ sudo mount /dev/sda2 /mnt/ubuntu
ubuntu@ubuntu:~$ ls -l /mnt/ubuntu/boot/grub
total 2388
drwxr-xr-x 2 root root	4096 May  4  2022 fonts
-rw-r--r-- 1 root root 	712 Apr 19  2022 gfxblacklist.txt
-rw-r--r-- 1 root root   11405 Jul  1 15:41 grub.cfg
-rw-r--r-- 1 root root	1024 Jul  1 16:28 grubenv
drwxr-xr-x 2 root root	4096 Jul  1 15:40 locale
-rw-r--r-- 1 root root 2392289 Jul  1 15:40 unicode.pf2
drwxr-xr-x 2 root root   20480 Jul  1 15:40 x86_64-efi

ubuntu@ubuntu:~$ cat /mnt/ubuntu/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$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_gpt
insmod ext2
set root='hd1,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
else
  search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
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_US
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=30
else
  if [ x$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=0
  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 [ ${grub_platform} != pc ]; then
  	set linux_gfx_mode=keep
	elif 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-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
	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='hd1,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
  	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
	else
  	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
	fi
	linux	/boot/vmlinuz-6.5.0-41-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro  quiet splash $vt_handoff
	initrd	/boot/initrd.img-6.5.0-41-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
	menuentry 'Ubuntu, with Linux 6.5.0-41-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.0-41-generic-advanced-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	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='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 6.5.0-41-generic ...'
    	linux	/boot/vmlinuz-6.5.0-41-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro  quiet splash $vt_handoff
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-6.5.0-41-generic
	}
	menuentry 'Ubuntu, with Linux 6.5.0-41-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.5.0-41-generic-recovery-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	recordfail
    	load_video
    	insmod gzio
    	if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
    	insmod part_gpt
    	insmod ext2
    	set root='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 6.5.0-41-generic ...'
    	linux	/boot/vmlinuz-6.5.0-41-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro recovery nomodeset dis_ucode_ldr
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-6.5.0-41-generic
	}
	menuentry 'Ubuntu, with Linux 5.15.0-33-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-33-generic-advanced-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	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='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 5.15.0-33-generic ...'
    	linux	/boot/vmlinuz-5.15.0-33-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro  quiet splash $vt_handoff
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-5.15.0-33-generic
	}
	menuentry 'Ubuntu, with Linux 5.15.0-33-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-33-generic-recovery-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	recordfail
    	load_video
    	insmod gzio
    	if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
    	insmod part_gpt
    	insmod ext2
    	set root='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 5.15.0-33-generic ...'
    	linux	/boot/vmlinuz-5.15.0-33-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro recovery nomodeset dis_ucode_ldr
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-5.15.0-33-generic
	}
	menuentry 'Ubuntu, with Linux 5.15.0-27-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-27-generic-advanced-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	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='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 5.15.0-27-generic ...'
    	linux	/boot/vmlinuz-5.15.0-27-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro  quiet splash $vt_handoff
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-5.15.0-27-generic
	}
	menuentry 'Ubuntu, with Linux 5.15.0-27-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.15.0-27-generic-recovery-d9e66418-437c-4ae7-9e4a-a836fce38fb8' {
    	recordfail
    	load_video
    	insmod gzio
    	if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
    	insmod part_gpt
    	insmod ext2
    	set root='hd1,gpt2'
    	if [ x$feature_platform_search_hint = xy ]; then
      	search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	else
      	search --no-floppy --fs-uuid --set=root d9e66418-437c-4ae7-9e4a-a836fce38fb8
    	fi
    	echo	'Loading Linux 5.15.0-27-generic ...'
    	linux	/boot/vmlinuz-5.15.0-27-generic root=UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 ro recovery nomodeset dis_ucode_ldr
    	echo	'Loading initial ramdisk ...'
    	initrd	/boot/initrd.img-5.15.0-27-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 ###
menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os $menuentry_id_option 'osprober-efi-E8A8-1513' {
	insmod part_gpt
	insmod fat
	search --no-floppy --fs-uuid --set=root E8A8-1513
	chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
set timeout_style=menu
if [ "${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/35_fwupd ###
### END /etc/grub.d/35_fwupd ###

### 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 $prefix/custom.cfg
fi
### END /etc/grub.d/41_custom ###
ubuntu@ubuntu:~$ cat /mnt/ubuntu/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/sdb2 during installation
UUID=d9e66418-437c-4ae7-9e4a-a836fce38fb8 /           	ext4	errors=remount-ro 0   	1
# /boot/efi was on /dev/nvme0n1p1 during installation
#UUID=E8A8-1513  /boot/efi   	vfat	umask=0077  	0   	1
/swapfile                             	none        	swap	sw          	0   	0
UUID=BB4B-E2D2  /boot/efi   	vfat	defaults  	0   	1

tea-for-one · December 12, 2024, 10:22am

Windows on one disk and Ubuntu on a separate disk is ideal.
However, it would be better if each OS had the boot files in the respective Efi System Partitions (ESP).

Each OS would then be able to boot independently of the other via the PC boot menu.
Subsequently, Grub can be edited to boot Windows if required

From your boot-repair report, you have all the boot files in the Windows ESP (nvme0n1p1)
See Lines 9 to 22 in the boot-repair report

The Ubuntu ESP is empty (sda1)
See Lines 38 to 44

Three solutions possible:-

Repair using boot-repair - fairly easy
Repair by copying the Ubuntu boot files from nvme0n1p1 to sda1 - more complicated
Reinstall without causing Windows boot problems - best solution

My advice would be to re-install because:-

You are a new user
It would help you become familiar with the installer and build confidence in using Ubuntu
It’s a perfect test for restoring your backups

Before you re-install:-

De-activate, isolate or physically remove your Windows disk (nvme0n1). Only have the target disk available
Boot the installer in UEFI mode
Double check by opening a terminal and entering
[ -d /sys/firmware/efi ] && echo "UEFI" || echo "Legacy"
Also check via gparted that your disk is GPT

If you would rather try boot-repair again, as above, ensure the Windows disk is inaccessible so that the repair targets the Ubuntu disk (sda). It should work because an ESP exists (sda1)

Lastly, if you look at line 5 of the boot-repair report

Windows is installed in the MBR of /dev/nvme0n1.

This is unusual because Windows 11 boots in UEFI mode.
Just making an observation in case something untoward transpires in the future.

tea-for-one · December 12, 2024, 11:03am

Another observation
You can avoid the inclusion of loop mounts with a terminal command similar to:-

lsblk -e 7 -o NAME,SIZE,FSTYPE,LABEL,MOUNTPOINT

The output is slightly easier to read