Multiboot

Creare una partizione FAT32 (anche altri filesystem sono supportati) con label MULTIBOOT

Creare una cartella boot all'interno

grub-install --target=i386-pc --recheck --boot-directory=/media/scipio/MULTIBOOT/boot /dev/sdb

EFI

sudo grub-install --target x86_64-efi --efi-directory /media/scipio/MULTIBOOT/ --boot-directory=/media/scipio/MULTIBOOT/boot --removable

/media/scipio/MULTIBOOT/boot/grub/grub.cfg

set imgdevpath="/dev/disk/by-label/MULTIBOOT"
 
menuentry "SystemRescue CD" {
    set isofile="/boot/iso/systemrescuecd-x86-4.3.1.iso"
    loopback loop $isofile
    linux (loop)/isolinux/rescue64 setkmap=it isoloop=/boot/iso/systemrescuecd-x86-4.3.1.iso
    initrd (loop)/isolinux/initram.igz
} 
 
menuentry "Ubuntu 14.04.1 desktop amd64" {
    set isofile='/boot/iso/ubuntu-14.04.1-desktop-amd64.iso'
    loopback loop $isofile
    linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=$isofile locale=it_IT.UTF-8 console-setup/layoutcode=it
    initrd (loop)/casper/initrd.lz
}
 
 
menuentry "Livenet UNIVR" {
    set isofile='/boot/iso/univr/livenet.iso'
    loopback loop $isofile
 
    root=(loop)
    configfile /boot/grub/grub.cfg  
    loopback --delete loop
}

fonte

boot windows

insmod chain
ls
set root=(hd0,0)
chainloader +1
boot