[SOLVED] Trying to get iso entry into Grub

[Snowhog]

I'm trying to get the Grub 40_custom file written correctly to I can boot a Gparted Live.iso. I'm putting in the code as per https://gparted.org/livehd.php (GParted Live on Hard Disk using GRUB)

This is what I've have in 40_custom:

exec tail -n +3 $0
# 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.
menuentry "Gparted live" {
 set isofile="/home/isos/gparted-live-1.3.1-1-amd64.iso"
 loopback loop $isofile
 linux (loop)/live/vmlinuz boot=live config union=overlay username=user components noswap noeject vga=788 ip= net.ifnames=0 toram=filesystem.squashfs findiso=$isofile
 initrd (loop)/live/initrd.img
}

Running sudo update-grub2 executes without errors.

Restarting, I'm presented with my Grub menu, and GParted live is the last item. I select it and get told that "/home/paul/Downloads/gparted-live-1.3.1-1-amd64.iso" doesn't exist and that the kernel has to be loaded first. I wait a few seconds and the Grub Menu is presented again.

What isn't Grub liking about the entry? I've made no typos, at least as compared to what the Gparted page says.

[verndog]

Maybe missing hd info as in

loopback loop (hd1,1)$isofile

, your hd would be different

[Snowhog]

Found the issue.

My laptop (where this is being done) is formatted btrfs, so I had to point the set isofile= entry to reflect that. So here is the 40_custom entry that works:

menuentry "Gparted live" {
set isofile="/@home/isos/gparted-live-0.28.1-1-i686.iso"
loopback loop $isofile
linux (loop)/live/vmlinuz boot=live config union=overlay username=user components noswap noeject vga=788 ip= net.ifnames=0 toram=filesystem.squashfs findiso=$isofile
initrd (loop)/live/initrd.img
}

My laptop is successfully booted into Gparted from the .iso. Sweet.

[GreyGeek]

Neat!
I suppose that one could run a distro from an ISO using that technique. And if one used a generic name in the grub menu and renamed new ISO's to that generic name they wouldn't have to touch the grub entry.

[jlittle]

BTW, using /boot/grub/custom.cfg can be easier than /etc/grub.d/40_custom, because there's no need to run update-grub, and it can be edited from a live USB or booted to any OS.

[GreyGeek]

BTW, using /boot/grub/custom.cfg can be easier than /etc/grub.d/40_custom, because there's no need to run update-grub, and it can be edited from a live USB or booted to any OS.

Don't have /boot/grub/custom.cfg on Neon, so I can't use that route. /boot/grub/grub.cfg contains

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

so editing that file is out as well. So that leaves just /etc/grub.d/40_custom as the file to modify.

[jlittle]

Don't have /boot/grub/custom.cfg on Neon...

You don't have /etc/grub.d/41_custom? Neon must have an old version of grub. But 41_custom is quite simple:

#!/bin/sh
cat <<EOF
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
EOF

If you are editing 40_custom, you could easily add a 41_custom as above.