Linux Boot /boot/iso/File.ISO by grub Custom.cfg

#!/bin/bash

# ~/bin/40_mk_custom_cfg, copy to /etc/grub.d/40_mk_custom_cfg for booting iso's

emit_ubuntu_iso_menuentry() {
cat << EOF | tr -d '\' 2>/dev/null
menuentry \'${1/.iso/} $2\'\{
 insmod part_msdos part_gpt fat iso9660 ext2 gzio lzopio loopback
 insmod search_fs_uuid search_fs_file search_label
 search -u $2 -s root
 set isofile=$1
 loopback loop \$\{isofile\}
 set root=loop
 linux /casper/vmlinuz.efi boot=casper iso-scan/filename=\$\{isofile\} initrd=/casper/initrd.lz
 initrd /casper/initrd.lz
\}
EOF
}

emit_kali_iso_menuentry() {
cat << EOF | tr -d '\' 2>/dev/null
menuentry \'${1/.iso/} $2\' \{
 insmod part_msdos part_gpt fat iso9660 ext2 gzio lzopio loopback
 insmod search_fs_uuid search_fs_file search_label
 search -u $2 -s root
 set isofile=$1
 loopback loop \$\{isofile\}
 set root=loop
 linux (loop)/live/vmlinuz boot=live findiso=\$\{isofile\} noconfig=sudo username=root hostname=kali
 initrd (loop)/live/initrd.img
\}
EOF
}

for d in `mount -t ext2,ext3,ext4 | cut -d' ' -f1,3 | tr ' ' '='`
 do b="${d/*=/}"
 b=${b}/boot
 b=${b//\/\///} ; d=${d/=*/}
 u=`lsblk -P -o UUID $d`
 u=${u/UUID=/}
 u=${u//\"/}
 if [ -d $b ]
  then sudo rm /tmp/stub 2>/dev/null
  for iso in $b/iso/*.iso
   do if [ -f $iso ]
    then #echo drive $d uuid $u bootdir $b iso $iso
    if [[ $iso =~ kali ]]
     then emit_kali_iso_menuentry $iso $u >> /tmp/stub
    elif [[ $iso =~ amd64 ]] || [[ $iso =~ rippa ]]
     then emit_ubuntu_iso_menuentry $iso $u >> /tmp/stub
    fi
   fi
  done
  if [ -s /tmp/stub ]
   then sudo mkdir -p $b/grub
   sudo mv /tmp/stub $b/grub/custom.cfg
   sudo rm /tmp/stub 2>/dev/null
  fi
 fi
done