My own configuration file for GRUB2 to boot various live distributions of Linux-based operating systems, along with some system tools. I tried to include a lot of sample configuration entries, even if I don't currently use them, so it may help others.

grub.cfg

# Config for GNU GRand Unified Bootloader (GRUB)
# /boot/grub/grub.cfg

# This grub.cfg file was created by Lance http://www.pendrivelinux.com
# Suggested Entries and the suggestor, if available, will also be noted.

# Sources:
#   http://www.pendrivelinux.com/boot-multiple-iso-from-usb-via-grub2-using-linux/#more-5352
#   https://gist.github.com/jamiekurtz/26c46b3e594f8cdd453a
#   https://gist.github.com/noisufnoc/e0053d738f5fbb679535
#   https://gist.github.com/samdoran/90056b8e4a2aedc6a3e8
#   https://gist.github.com/yeahunter/9eca12b3db064e5dc23b
#   https://gist.github.com/jeekl/5564476
#   https://wiki.archlinux.org/index.php/Multiboot_USB_drive
#   https://help.ubuntu.com/community/Grub2/ISOBoot/Examples

# Notes:
#  For variables, be sure to use double-quotes to have them actually resolve.
#  Need to re-declare variables inside sub-menus because they open a new "context"..... great..
#   Source: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1175127

# Timeout for menu
set timeout=10

# Default boot entry
set default=0

set isoPath="/ISOs"
set linuxPath="$isoPath/Linux"
set toolPath="$isoPath/Tools"
set memdiskPath="/boot/memdisk"

# Menu Colours
set menu_color_normal=white/black
set menu_color_highlight=white/cyan

submenu "Linux Distros" {

  set isoPath="/ISOs"
  set linuxPath="$isoPath/Linux"

  menuentry "kali-linux-1.1.0a-amd64" {
  	set isofile="$linuxPath/kali-linux-1.1.0a-amd64.iso"
  	loopback loop $isofile
  	linux (loop)/live/vmlinuz boot=live findiso=$isofile noconfig=sudo username=root hostname=kali
  	initrd (loop)/live/initrd.img
  }
  
  menuentry "Fedora-Live-Workstation-x86_64-21-5" {
  	set isofile="$linuxPath/Fedora-Live-Workstation-x86_64-21-5.iso"
  	loopback loop $isofile
  	linux (loop)/isolinux/vmlinuz0 root=live:CDLABEL=Fedora-Live-WS-x86_64-21-5 iso-scan/filename=$isofile rd.live.image
  	initrd (loop)/isolinux/initrd0.img
  }
  
  menuentry "Elementary OS" {
  	set isofile="$linuxPath/elementaryos-stable-amd64.20130810.iso"
  	loopback loop $isofile
  	linux	(loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile quiet splash --
  	initrd	(loop)/casper/initrd.lz
  }
  
  #menuentry "linuxmint-17.1-xfce-64bit" {
  #	set isofile="$linuxPath/linuxmint-17.1-xfce-64bit.iso"
  #	loopback loop $isofile
  #	linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile live-config quiet splash noeject noprompt
  #	initrd (loop)/casper/initrd.lz
  #}

  #menuentry "ubuntu-14.04.2-desktop-amd64" {
  #	set isofile="$linuxPath/ubuntu-14.04.2-desktop-amd64.iso"
  #	loopback loop $isofile
  #	linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=$isofile locale=en_US.UTF-8
  #	initrd (loop)/casper/initrd.lz
  #}
  
  #menuentry "Linux Mint ISO" {
  # set isofile="$linuxPath/linuxmint.iso"
  # loopback loop $isofile
  # linux (loop)/casper/vmlinuz file=/cdrom/preseed/mint.seed boot=casper initrd=/casper/initrd.lz iso-scan/filename=$isofile noeject noprompt splash --
  # initrd (loop)/casper/initrd.lz
  #}
  
  #menuentry "Tinycore ISO" {
  # set isofile="$linuxPath/tinycore.iso"
  # loopback loop $isofile
  # linux (loop)/boot/bzImage --
  # initrd (loop)/boot/tinycore.gz
  #}
  
  #menuentry "ArchLinux x86_64" {
  #  set iso="/iso/archlinux-2014.06.01-dual.iso"
  #  loopback loop $iso
  #  linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=ARCH_201406 img_dev=/dev/disk/by-label/UNJEB img_loop=$iso earlymodules=loop
  #  initrd (loop)/arch/boot/x86_64/archiso.img
  #}
  #menuentry "ArchLinux 32 Bit" {
  #  set iso="/iso/archlinux-2014.06.01-dual.iso"
  #  loopback loop $iso
  #  linux (loop)/arch/boot/i686/vmlinuz archisolabel=ARCH_201406 img_dev=/dev/disk/by-label/UNJEB img_loop=$iso earlymodules=loop
  #  initrd (loop)/arch/boot/i686/archiso.img
  #}
  
  #menuentry "CentOS 6 x86_64 minimal" {
  #  set iso="/iso/CentOS-6.5-x86_64-minimal.iso"
  #  loopback loop $iso
  #  linux (loop)/isolinux/vmlinuz noeject inst.stage2=hd:LABEL=UNJEB:/$iso
  #  initrd (loop)/isolinux/initrd.img
  #}
  #menuentry "CentOS 6 x86_64 minimal with basic video driver" {
  #  set iso="/iso/CentOS-6.5-x86_64-minimal.iso"
  #  loopback loop $iso
  #  linux (loop)/isolinux/vmlinuz noeject inst.stage2=hd:LABEL=UNJEB:/$iso xdriver=vesa nomodset askmethod
  #  initrd (loop)/isolinux/initrd.img
  #}
  
  #menuentry "Xbuntu 14.04 Beta - 64bit" {
  #  set iso="/iso/xubuntu-14.04-beta1-desktop-amd64.iso"
  #  loopback loop $iso
  #  linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$iso noprompt noeject splash --
  #  initrd (loop)/casper/initrd.lz
  #}
  
  #menuentry "Boot Finnix 109 (64-bit)" {
  #  set iso="/iso/finnix-109.iso"
  #  loopback loop $iso
  #  linux (loop)/boot/x86/linux64 findiso=$iso vga=791 nomodeset quiet --
  #  initrd (loop)/boot/x86/initrd.xz
  #}
  #menuentry "Boot Finnix 109 (64-bit, text mode)" {
  #  set iso="/iso/finnix-109.iso"
  #  loopback loop $iso
  #  linux /boot/x86/linux64 findiso=$iso vga=normal nomodeset quiet --
  #  initrd /boot/x86/initrd.xz
  #}

  #menuentry "Boot Finnix 109 (32-bit)" {
  #  set iso="/iso/finnix-109.iso"
  #  loopback loop $iso
  #  linux /boot/x86/linux findiso=$iso vga=791 nomodeset quiet --
  #  initrd /boot/x86/initrd.xz
  #}
  #menuentry "Boot Finnix 109 (32-bit, text mode)" {
  #  set iso="/iso/finnix-109.iso"
  #  loopback loop $iso
  #  linux /boot/x86/linux findiso=${iso_path} vga=normal nomodeset quiet --
  #  initrd /boot/x86/initrd.xz
  #}
  
  #menuentry "TAILS - The Amnesic Incognito Live System" {
  #  set iso="/iso/tails-i386-0.17.2.iso"
  #  loopback loop $iso
  #  linux (loop)/live/vmlinuz boot=live config live-media=removable nopersistent noprompt quiet timezone=Europe/Stockholm block.events_dfl_poll_msecs=1000 splash nox11autologin module=Tails findiso=$iso quiet_
  #  initrd (loop)/live/initrd.img
  #}

  #menuentry "GRML - the sysadmins best friend" {
  #  set iso="/iso/grml64-full_2013.02.iso"
  #  loopback loop $iso
  #  set root=(loop)
  #  configfile /boot/grub/loopback.cfg
  #}

  #menuentry "Debian 7.0 Wheezy AMD64 Installer (netinst, firmware)" {
  #  set iso="/iso/debian-7.0.0-amd64-firmware-netinst.iso"
  #  loopback loop $iso
  #  linux (loop)/install.amd/vmlinuz
  #  initrd (loop)/install.amd/initrd.gz
  #}

  #menuentry "Debian 7.0 Wheezy AMD64 Live system (GNOME, firmware/non-free)" {
  #  set iso="/iso/debian-live-7.0.0-amd64-gnome-desktop+nonfree.iso"
  #  loopback loop $iso
  #  linux (loop)/live/vmlinuz boot=live
  #  initrd (loop)/live/initrd.img
  #}
  
  menuentry "Damn Small Linux" {
  # Maybe try this instead later: https://gist.github.com/oxplot/2041319
    linux16 /boot/bootdistro/damnsmall/isolinux/linux24 knoppix_dir=damnsmall ramdisk_size=100000 lang=en apm=power-off nomce noapic quiet BOOT_IMAGE=knoppix
    initrd16 /boot/bootdistro/damnsmall/isolinux/minirt24.gz
  }
}

#menuentry "win7" {
#	loopback loop "$isoPath/win7.iso"
#	chainloader (loop)
#}

submenu "Utils" {

  set isoPath="/ISOs"
  set toolPath="$isoPath/Tools"

  menuentry "Memtest 86+" {
    set isofile="$toolPath/memtest86+-5.01.iso"
    linux16 $isofile
  }
  
  menuentry "SpinRite" {
    set isofile="$toolPath/SpinRite.iso"
    set gfxpayload=text
    linux16 $memdiskPath raw
    initrd16 $isofile
  }
  menuentry "SpinRite 2" {
    set isofile="$toolPath/SpinRite.iso"
    loopback loop $isofile
    linux (loop)/vmlinuz boot=cd isofrom=$isofile xbmc=nvidia,nodiskmount,tempfs,setvolume loglevel=0 --
    initrd (loop)/initrd0.img
  }
  
  menuentry "gparted-live-0.22.0-2-i586" {
  	set isofile="$toolPath/gparted-live-0.22.0-2-i586.iso"
    # set gfxpayload=text
  	loopback loop $isofile
  	linux (loop)/live/vmlinuz boot=live username=user config components quiet noswap noeject findiso=$isofile toram=filesystem.squashfs nosplash   
  	initrd (loop)/live/initrd.img
  }
  
  #menuentry "Parted Magic" {
  #  set isofile="$isopath/pmagic.iso"
  #  loopback loop $isofile
  #  linux (loop)/pmagic/bzImage iso_filename=$isofile edd=off load_ramdisk=1 prompt_ramdisk=0 rw gfxpayload=800x600x16 loglevel=9 max_loop=256 vmalloc=384MiB keymap=dvorak
  #  initrd (loop)/pmagic/initrd.img
  #}
  
  menuentry "SystemRescueCd" {
    set isofile="$toolPath/systemrescuecd.iso"
    loopback loop $isofile
    linux (loop)/isolinux/rescuecd isoloop=$isofile setkmap=us docache dostartx
    # Or linux (loop)/isolinux/rescue32
    # Or linux (loop)/isolinux/rescue64
    initrd (loop)/isolinux/initram.igz
  }
  
  menuentry "CloneZilla" {
    set isofile="$toolPath/clonezilla-live-2.4.2-10-amd64.iso"
    loopback loop $isofile
    linux (loop)/live/vmlinuz boot=live live-config union=aufs nolocales noprompt gfxpayload=800x600x16 ip=frommedia findiso=$isofile
    initrd (loop)/live/initrd.img
  }
  
  #menuentry "Ophcrack No Tables" {
  #  set isofile="$isopath/ophcrack-notables.iso"
  #  set gfxpayload=text
  #  loopback loop $isofile
  #  linux (loop)/boot/bzImage root=/dev/null rw lang=en_US kmap=dvorak autologin iso-scan/filename=$isofile
  #  initrd (loop)/boot/rootfs.gz
  #}
  
  #menuentry "Ophcrack Vista/7 Tables" {
  #  set isofile="$isopath/ophcrack-vistatables.iso"
  #  set gfxpayload=text
  #  loopback loop $isofile
  #  linux (loop)/boot/bzImage root=/dev/null rw lang=en_US kmap=dvorak autologin iso-scan/filename=$isofile
  #  initrd (loop)/boot/rootfs.gz
  #}
  
  #menuentry "DBAN ISO" {
  # set isofile="$toolPath/dban.iso"
  # loopback loop $isofile
  # linux (loop)/DBAN.BZI nuke="dwipe" iso-scan/filename=$isofile silent --
  #}
  
  
  #menuentry "Boot Hardware Detection Tool from iso using memdisk 4.05" {
  #  linux16 $memdiskPath iso
  #  initrd16 /customboot/hdt.iso
  #}
  #menuentry "Free Dos from iso using memdisk 4.05" {
  #  set isofile="/OS/fdbasecd.iso"
  #  linux16 $memdiskPath iso
  #  initrd16 (hd0,6)$isofile
  #}
  menuentry "Hiren's boot CD using memdisk 4.05" {
    set isofile="$toolPath/Hiren's.BootCD.15.2.iso"
    linux16 $memdiskPath iso
    initrd16 (hd0,6)$isofile
  }
  menuentry "Ultimate Boot CD iso using memdisk 4.05" {
    set isofile="$toolPath/UBCD4WinBuilder.iso"
    linux16 $memdiskPath iso
    initrd16 (hd0,6)$isofile
  }
  #menuentry "UBCD with MEMDISK" {
  #  linux16 /memdisk iso raw
  #  initrd /ubcd502.iso
  #}
  #menuentry "UBCD with grub4dos" {
  #  linux16 /grub.exe --config-file="map (rd) (hd32); map --hook; root (hd32); chainloader (hd32);"
  #  initrd /ubcd502.iso
  #}
}

menuentry "System shutdown" {
	echo "System shutting down..."
	halt
}

menuentry "System restart" {
	echo "System rebooting..."
	reboot
}

found that here with google

you could just loop all isos in that folder so you dont need to make an entry for each one

`function init_iso_loop {
iso_path="${1}"
export iso_path
search --set=root --file "$iso_path"
loopback loop "$iso_path"

}
submenu 'ISO boot' --class void --id 'iso-boot' {
submenu "iso prober" {

	#insmod all_video

	for iso_path in /iso/*.iso; do
		regexp --set=iso_name '^.+[\\\/](.*?$)' "$iso_path" 
		submenu "$iso_name" "$iso_path" {
			init_iso_loop "${2}"
			if [ -e (loop)/boot/grub/loopback.cfg ]; then
				menuentry "loopback" ${2} --id "iso-${2}-loopback" {
					init_iso_loop "${2}"
					configfile (loop)/boot/grub/loopback.cfg
					loopback --delete loop
				}
			fi				
			if [ -e (loop)/boot/grub/grub.cfg ]; then
				menuentry "grub" ${2} --id "iso-${2}-grub" {
					init_iso_loop "${2}"
					set prefix=(loop)'/boot/grub'
					configfile $prefix/grub.cfg
					loopback --delete loop
				}
			fi

			if [ -e (loop)/isolinux/isolinux.cfg ]; then
				menuentry "isolinux" ${2} --id "iso-${2}-isolinux" {
					init_iso_loop "${2}"
					set prefix=(loop)'/isolinux'
					configfile $prefix/isolinux.cfg
					loopback --delete loop
				}
			fi
			if [ -e (loop)/casper/vmlinuz ]; then
				menuentry "vmlinuz" ${2} --id "iso-${2}-vmlinuz" {
					set gfxpayload=keep
					loopback loop "${2}"
					linux	(loop)/casper/vmlinuz boot=casper iso-scan/filename=${2} quiet splash --- 
					initrd	(loop)/casper/initrd
					loopback --delete loop
				}
			fi
			if [ -e (loop)/casper_pop-os_22.04_amd64_nvidia_debug_497/vmlinuz ]; then
				menuentry "vmlinuz" ${2} --id "iso-${2}-vmlinuz" {
					set gfxpayload=keep
					loopback loop "${2}"
					linux	(loop)/casper_pop-os_22.04_amd64_nvidia_debug_497/vmlinuz boot=casper iso-scan/filename=${2} quiet splash --- 
					initrd	(loop)/casper_pop-os_22.04_amd64_nvidia_debug_497/initrd
					loopback --delete loop
				}
			fi
			loopback --delete loop
		}
	done
}

}
`

i've dont it like that