ls -l /boot/efi/EFI/Microsoft/Boot/*.efi
-rwxr-xr-x 1 root root 1527608 Sep 5 16:33 /boot/efi/EFI/Microsoft/Boot/bootmgfw.efi
-rwxr-xr-x 1 root root 1510712 Sep 5 16:33 /boot/efi/EFI/Microsoft/Boot/bootmgr.efi
-rwxr-xr-x 1 root root 1321800 Sep 5 16:33 /boot/efi/EFI/Microsoft/Boot/memtest.efi
I followed the instructions you gave to the point of moving and copying files. Here is what I have done:
I created a new folder /boot/efi/EFI/Boottrick
I moved /boot/efi/EFI/Microsoft/boot/bootmgfw.efi to /boot/efi/EFI/Boottrick bootmgfw.efi is now contained in that folder
I copied MokManager.efi grub.efi grub.cfg to /boot/efi/EFI/Microsoft/boot
I also copied grubx64.efi to /boot/efi/EFI/Microsoft/boot though you didn’t specify this.
I will need specific instructions to modify the grub boot menu.
When I rebooted the computer without the USB stick installed, I receive the following message:
Welcome to GRUB!
Entering rescue mode…
grub rescue>
Look inside the generated “grub.cfg”.
For me, that contains:
menuentry 'Windows Boot Manager (on /dev/sda1)' --class windows --class os $menu
entry_id_option 'osprober-efi-960A-3282' {
insmod part_gpt
insmod fat
set root='hd0,gpt1'
if x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-ef
i=hd0,gpt1 --hint-baremetal=ahci0,gpt1 960A-3282
else
search --no-floppy --fs-uuid --set=root 960A-3282
fi
chainloader /efi/Microsoft/Boot/bootmgfw.efi
}
The idea is to make a modified version of that, and put it at the end of “/etc/grub.d/40_custom” (so that it always shows up in the grub menu).
You can simplify that a bit, to maybe something like:
menuentry 'Alternative Windows Boot Manager (on /dev/sda1)' {
search --no-floppy --fs-uuid --set=root 960A-3282
chainloader /efi/Bootrick/bootmgfw.efi
}
Note that I have changed the path part to use “Bootrick” in place of “Microsoft/Boot”, based on what you posted. You should check that. And the “960A-3282” is going to be wrong. Replace that with the appropriate value for your system, which should already be in “/boot/grub2/grub.cfg”. Or you can find the appropriate value in “/etc/fstab” as the UUID for mounting “/boot/efi”.
I also changed the name in the “menuentry” line so that you can recognize it.
When I type set in at the grub rescue prompt, here is the result
cmdpath+(hd0,gpt1)/EFI/opensuse
prefix=(hd0,gpt6)/boot/grub2
root=hd0,gpt6
I’m not sure what you are asking there.
That string “960A-3282” that I showed is the UUID of the EFI partition. You need to instead use the UUID of your EFI partition. It will have a similar form – 8 hex digits with a hyphen in the middle, because that’s what the UUID of FAT file systems look like.
You can also get that UUID with the command “blkid” (at a root terminal prompt).
The computer will boot to the USB stick without hitting F12 now, and then I have to select boot from hard disk, and then the grub menu appears and I can boot opensuse.
If I leave the USB stick out of the computer, the computer boots to the grub rescue screen as I noted in my previous post.
when selecting Alternative Windows Boot Manager I receive the following notice:
error: file ‘/boot/efi/EFI/Boottrick/bootmgfw.efi’ not found
Press any key to continue…
I used the UUID of the EFI partition that I found in the grub.cfg file, not the one that you posted from your computer as the example.
I posted the grub rescue>set readout as a separate post, because I couldn’t go back to edit the previous post where I typed
When I rebooted the computer without the USB stick installed, I receive the following message:
Welcome to GRUB!
Entering rescue mode…
grub rescue>
In the meantime I had done some research on the google rescue commands, and typed in set. I supplied the information from the readout as an elaboration to my earlier post. But I couldn’t edit my previous post, because the time allowed for editing had expired. Sorry to have confused you.
I wonder where that message comes from?
Your “/etc/grub.d/40_custom” should not contain the string “/boot/efi”.
I removed the /boot/efi/ from the grub.cfg as you posted. What follows is the present state of booting:
If I remove the USB stick from the computer, I can’t boot anything. What presents is the Acer bootup screen with a superimposed
Welcome to GRUB!
Entering rescue mode…
grub rescue>
If I shut down the computer, reinsert the USB stick, then reboot the computer, I don’t have to select F12 as the computer boots to the USB stick menu. I then select “boot from hard drive,” and the computer next presents the grub menu. I have four selections presented on the menu, these are:
Opensuse 15.2
Opensuse 15.2 Additional options
Windows on HD0
Windows on HD1
I only have one hard drive in the computer, so I’m not sure why there are two HD options presented for windows boot. But I can boot windows from both selections on the Grub menu from my one installed harddrive. I can also boot 15.2 from the grub menu. But these are only possible if I have the USB stick installed on the computer. If I boot directly from the hard drive without the USB stick inserted, I can’t boot anything, as I have already stated, and I get the Grub rescue prompt.
It is counting the USB device as a hard drive. It is probably finding a copy of the Windows boot file “bootmgfw.efi” on both USB and hard drive.
My advice: just leave the USB plugged in and boot the way that works. Maybe prepare a spare USB as backup, just in case the first fails.