see: https://wiki.ubuntuusers.de/GRUB_2/Skripte/


# for a custom file in /etc/grub.d

**********
***     1

echo "Adding SystemRescue" >&2
cat << EOF

menuentry "SystemRescueCD 32bit" {

# on /dev/sdb7
#set root='hd1,gpt7'

# on /dev/sda7
set root='hd0,gpt7'

linux   /sysrcd/rescue32 subdir=sysrcd setkmap=de nonet docache
#linux   /sysrcd/rescue64 subdir=sysrcd setkmap=de nonet docache

initrd  /sysrcd/initram.igz
}
EOF


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***     2

#!/bin/sh

cat <<EOF
menuentry 'Linux Mint 17 Qiana (17) (auf /dev/sda9)' --class gnu-linux --class gnu --class os $menuentry_id_option 'ospr
    insmod part_gpt
    insmod ext2
    set root='hd0,gpt9'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt9 --hint-efi=hd0,gpt9 --hint-baremetal=ahci0,gpt9  cc12
    else
      search --no-floppy --fs-uuid --set=root cc123209-a422-4836-9239-d5307106be30
    fi
    linux /boot/vmlinuz-3.13.0-24-generic root=UUID=cc123209-a422-4836-9239-d5307106be30 ro quiet splash $vt_handoff nom
    initrd /boot/initrd.img-3.13.0-24-generic
}
EOF


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***     3