I`m having problem with memtest86+, I cant add option to grub.
root@zorinvm:~# aptitude install memtest86+
memtest86+ is already installed at the requested version (5.01-3.1ubuntu2.1)
memtest86+ is already installed at the requested version (5.01-3.1ubuntu2.1)
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.root@zorinvm:~# update-grub
Sourcing file/etc/default/grub' Sourcing file/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found theme: /usr/share/grub/themes/zorin/theme.txt
Found linux image: /boot/vmlinuz-5.13.0-35-generic
Found initrd image: /boot/initrd.img-5.13.0-35-generic
Found linux image: /boot/vmlinuz-5.13.0-30-generic
Found initrd image: /boot/initrd.img-5.13.0-30-generic
Adding boot menu entry for UEFI Firmware Settings
done
root@zorinvm:~# ls -l /boot/
total 225204
-rw-r--r-- 1 root root 257734 Feb 7 15:01 config-5.13.0-30-generic
-rw-r--r-- 1 root root 257734 Mar 7 08:40 config-5.13.0-35-generic
drwx------ 3 root root 4096 Jan 1 1970 efi
drwxr-xr-x 4 root root 4096 Mar 11 20:59 grub
lrwxrwxrwx 1 root root 28 Mar 10 20:34 initrd.img -> initrd.img-5.13.0-35-generic
-rw-r--r-- 1 root root 98622703 Mar 10 20:34 initrd.img-5.13.0-30-generic
-rw-r--r-- 1 root root 98623309 Mar 10 20:35 initrd.img-5.13.0-35-generic
lrwxrwxrwx 1 root root 28 Mar 10 20:34 initrd.img.old -> initrd.img-5.13.0-30-generic
-rw-r--r-- 1 root root 182704 Aug 18 2020 memtest86+.bin
-rw-r--r-- 1 root root 184380 Aug 18 2020 memtest86+.elf
-rw-r--r-- 1 root root 184884 Aug 18 2020 memtest86+_multiboot.bin
-rw------- 1 root root 5960334 Feb 7 15:01 System.map-5.13.0-30-generic
-rw------- 1 root root 5960381 Mar 7 08:40 System.map-5.13.0-35-generic
lrwxrwxrwx 1 root root 25 Mar 10 20:34 vmlinuz -> vmlinuz-5.13.0-35-generic
-rw------- 1 root root 10171040 Feb 7 15:03 vmlinuz-5.13.0-30-generic
-rw------- 1 root root 10171296 Mar 7 09:09 vmlinuz-5.13.0-35-generic
lrwxrwxrwx 1 root root 25 Mar 10 20:34 vmlinuz.old -> vmlinuz-5.13.0-30-generic
root@zorinvm:~#
This is fresh ZorinOS Core instalation inside vm (qemu)


