How-to boot Sidux from ISO file with grub2
There is no clear manual at sidux manuals. They only said, you should install their package named grub2-fll-iso or something like it. Sure, you can load and boot Sidux from iso file, in existing Linux installation, with grub2. I used Linux Mint 9.
Here is the part of my /boot/grub/grub.cfg
loopback loop (hd0,0)/sidux.iso
linux (loop)/boot/vmlinuz0.686 boot=fll fromiso=/sidux.iso
That's it. sidux.iso in located in my / directory, which is /dev/sda1