my multiboot grub2 conf

grub.cfg

#set timeout="10"
#set default="0"

menuentry "FreeBSD 9.0 Release" {
 set isofile="/boot/iso/FreeBSD-9.0.iso"
 loopback loop $isofile
 kfreebsd (loop)/boot/kernel/kernel
 kfreebsd_module (loop)/boot/mfsroot.gz type=mfs_root
 set kFreeBSD.vfs.root.mountfrom=ufs:/dev/md0
}
menuentry "ArchLinux Azriel Remix i686" {
 set isofile="/boot/iso/archlinux-2012-07-13-core-i686.is"
 loopback loop $isofile
 linux (loop)/arch/boot/i686/vmlinuz img_loop=$isofile img_dev=/dev/disk/by-uuid/337A-A94A archisolabel=ARCH_201207 earlymodules=loop
 initrd (loop)/arch/boot/i686/archiso.img
}

menuentry "Memtest 86+" {
 linux16 /boot/iso/memtest86+-4.20.bin
}