Grub2 to boot iso

[Nirav Shah]

Hello

I am trying to boot iso on flashdrive using the loopback method

The iso is inside the boot/iso directory in the usb.
this how my menuentry looks likes

menuentry "myiso boot" {
loopback loop /boot/iso/myiso.iso
linux (loop)/isolinux/vmlinuz --
initrd (loop)/isolinux/initrd.img
}

but i get error saying You need to load the kernel first 

But using the same grub i can boot a ubuntu iso 

The iso i m trying to boot is a redhat with my software configured in it.