Booting Zephix from the GRUB 2 menu in a live USB stick.

Hello.

Has any one booted Zephix (Zephix-7R-x86_64.iso) from the GRUB 2 menu.

Here is what I have:
- A USB stick with two directories at the root: boot and ISO.
- ISO contains a few iso images for different distributions, among those is Zephix-7R-x86_64.iso.
- boot contains a grub sub-directory and a grub.cfg file.
- I am able to boot several linux distributions using this USB stick.
- I cannot at this point boot Zephix-7R-x86_64.iso. I assume it is because I do not use a proper menuentry in my grub.cfg file.

I hope someone can tell me what I need to modify.

Below are the few trials I have made, based on my knowledge of Grub 2 and some information I could find. But nothing really works.

menuentry "Boot Zephix 1" {
set root=(hd0,1)
set isofile='/ISO/Zephix-7R-x86_64.iso'
loopback loop $isofile
linux (loop)/Zephix/vmlinuz vga=769 prompt_ramdisk=0 rw printk.time=0 apparmor=0 quiet splash boot=zephix loglevel=0
initrd (loop)/Zephix/initrd
}

menuentry "Boot Zephix 2" {
set root=(hd0,1)
set isofile='/ISO/Zephix-7R-x86_64.iso'
loopback loop $isofile
linux (loop)/Zephix/vmlinuz gfxpayload=640x480x8,640x480 prompt_ramdisk=0 rw printk.time=0 apparmor=0 quiet splash boot=zephix loglevel=0
initrd (loop)/Zephix/initrd
}

menuentry "Boot Zephix 3" {
set root=(hd0,1)
set isofile='/ISO/Zephix-7R-x86_64.iso'
loopback loop $isofile
linux (loop)/Zephix/vmlinuz img_loop=$isofile gfxpayload=640x480x8,640x480 prompt_ramdisk=0 rw printk.time=0 apparmor=0 quiet splash boot=zephix loglevel=0
initrd (loop)/Zephix/initrd
}

menuentry "Boot Zephix 4" {
set root=(hd0,1)
set isofile='/ISO/Zephix-7R-x86_64.iso'
loopback loop $isofile
linux (loop)/Zephix/vmlinuz img_dev=/dev/sdb1 img_loop=$isofile gfxpayload=640x480x8,640x480 prompt_ramdisk=0 rw printk.time=0 apparmor=0 quiet splash boot=zephix loglevel=0
initrd (loop)/Zephix/initrd
}

menuentry "Boot Zephix 5" {
set root=(hd0,1)
set isofile='/ISO/Zephix-7R-x86_64.iso'
loopback loop $isofile
linux (loop)/Zephix/vmlinuz img_dev=/dev/disk/by-uuid/a32893ad-a0c1-463c-83c7-7f769cc3dcb7 img_loop=$isofile gfxpayload=640x480x8,640x480 prompt_ramdisk=0 rw printk.time=0 apparmor=0 quiet splash boot=zephix loglevel=0
initrd (loop)/Zephix/initrd
}

What would be a working menuentry ?