[Bug 2141060] [NEW] 25.10 doesn't support booting ubuntu isos

[Ed P]

Public bug reported:

UEFI system, 16GB RAM Windows 11 system  Acer Aspire 5 notebook

25.10 grub2 system supports booting many iso files on my system, but not
these:

menuentry " Ubuntu ISO 25.10"  --class ubuntu --class icon-ubuntu {

     set iso=/ISOs/ubuntu-25.10-desktop-amd64.iso
     set bootparms=`boot=casper iso-scan/filename=$root/$iso quiet splash `

#    To save changes add "persistance" to the boot parms and create a file 
#      named casper-rw with an ext3 file system. 
#      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

     search -f $iso --set=root  
     echo root=$root
     ls ($root)
     ls ($root)/ISOs/ubuntu*
     loopback loop $iso
     linux (loop)/casper/vmlinuz $bootparms
     initrd (loop)/casper/initrd 
     }

menuentry " Ubuntu ISO 21.04"  --class ubuntu --class icon-ubuntu {

     set iso=/ISOs/ubuntu-mate-21.04-desktop-amd64.iso
     set bootparms='boot=casper iso-scan/filename=$iso splash -- '

#    To save changes add "persistance" to the boot parms and create a file 
#      named casper-rw with an ext3 file system. 
#      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

     search -f $iso --set=root
     loopback loop $iso
     linux (loop)/casper/vmlinuz $bootparms
     initrd (loop)/casper/initrd
     }

menuentry " Ubuntu ISO 18.04"  --class ubuntu --class icon-ubuntu {

     set iso='/ISOs/ubuntu-18.04.1-desktop-amd64.iso'
     set bootparms='boot=casper iso-scan/filename='$iso' splash -- '

#    To save changes add "persistance" to the boot parms and create a file 
#      named casper-rw with an ext3 file system. 
#      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

     search -f $iso --set=root
     loopback loop $iso
     linux (loop)/casper/vmlinuz $bootparms
     initrd (loop)/casper/initrd.lz
     }


The boot window error is:

error: no such device: /ISOs/ubuntu.....

With Grub2Win I have booted the 2 lower menus in the past.

** Affects: grub2 (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/2141060

Title:
  25.10 doesn't support booting ubuntu isos

Status in grub2 package in Ubuntu:
  New

Bug description:
  UEFI system, 16GB RAM Windows 11 system  Acer Aspire 5 notebook

  25.10 grub2 system supports booting many iso files on my system, but
  not these:

  menuentry " Ubuntu ISO 25.10"  --class ubuntu --class icon-ubuntu {

       set iso=/ISOs/ubuntu-25.10-desktop-amd64.iso
       set bootparms=`boot=casper iso-scan/filename=$root/$iso quiet splash `

  #    To save changes add "persistance" to the boot parms and create a file 
  #      named casper-rw with an ext3 file system. 
  #      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

       search -f $iso --set=root  
       echo root=$root
       ls ($root)
       ls ($root)/ISOs/ubuntu*
       loopback loop $iso
       linux (loop)/casper/vmlinuz $bootparms
       initrd (loop)/casper/initrd 
       }

  menuentry " Ubuntu ISO 21.04"  --class ubuntu --class icon-ubuntu {

       set iso=/ISOs/ubuntu-mate-21.04-desktop-amd64.iso
       set bootparms='boot=casper iso-scan/filename=$iso splash -- '

  #    To save changes add "persistance" to the boot parms and create a file 
  #      named casper-rw with an ext3 file system. 
  #      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

       search -f $iso --set=root
       loopback loop $iso
       linux (loop)/casper/vmlinuz $bootparms
       initrd (loop)/casper/initrd
       }

  menuentry " Ubuntu ISO 18.04"  --class ubuntu --class icon-ubuntu {

       set iso='/ISOs/ubuntu-18.04.1-desktop-amd64.iso'
       set bootparms='boot=casper iso-scan/filename='$iso' splash -- '

  #    To save changes add "persistance" to the boot parms and create a file 
  #      named casper-rw with an ext3 file system. 
  #      https://www.pendrivelinux.com/how-to-create-a-larger-casper-rw-loop-file/ 

       search -f $iso --set=root
       loopback loop $iso
       linux (loop)/casper/vmlinuz $bootparms
       initrd (loop)/casper/initrd.lz
       }

  
  The boot window error is:

  error: no such device: /ISOs/ubuntu.....

  With Grub2Win I have booted the 2 lower menus in the past.

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