o Packages required
 - Previously, I use xorriso package. xorriso is no longer in the repositories. libisoburn is (was?) a package required for xorriso and others and is sufficient for this purpose. Also libisoburn was known by libisoburn-xxxx and I cannot remember this 'xxxx'
 - most of these packages are already default installed, not in net-install, so best check out first.
o To make a plain grub prompt (sufficient for all purposes)
grub-mkrescue -o anyname.iso
o To include a current working grub.cfg to isofile (such that it boots to grub menu, not prompt)
mkdir -p ~/burn/boot/grub sudo grub-mkconfig -o ~/burn/boot/grub/grub.cfg sudo grub-mkrescue -o anyname.iso burn
o Burn isofile anyname.iso to cd (less than 20 MB)
or dd to usb drive.
Some uses of grub rescue cd
o When system won't boot
o When dropped to grub rescue prompt
o When need to reinstall Windows
o When dropped to initramfs shell
o When installing another OS and it got clobbered (with your bootloader)
o When Windows only systems (no linux) won't boot