Multiboot USB drive - Grub2 configurations for direct ISO boot

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.

set timeout=10
set default=0
set pager=1


## Gentoo things
function load_video {
  insmod efi_gop
  insmod efi_uga
  insmod video_bochs
  insmod video_cirrus
  insmod all_video
}

if loadfont ($root)/boot/grub/fonts/unicode.pf2 ; then
   set gfxmode=1024x768
   load_video
   insmod gfxterm
   set locale_dir=$prefix/locale
   terminal_output gfxterm
   insmod gettext
fi

terminal_output gfxterm
insmod gfxmenu
loadfont ($root)/boot/grub/themes/GenGrub/Sans-10.pf2
loadfont ($root)/boot/grub/themes/GenGrub/Sans-12.pf2
loadfont ($root)/boot/grub/themes/GenGrub/Sans-14.pf2
insmod png
set theme=($root)/boot/grub/themes/GenGrub/theme.txt
export theme

if [ x = x$bootlang ]; then
  set bootlang=en_US
fi

if [ x = x$bootkeymap ]; then
   set bootkeymap=us
fi

if [ x = x$acpi_opt ]; then
   unset acpi_opt
fi

if [ x = x$modeset_opt ]; then
   unset modeset_opt
fi

if [ x = x$noefi_opt ]; then
   unset noefi_opt
fi

if [ x$feature_timeout_style = xy ] ; then
  set timeout_style=menu
  set timeout=5
  # Fallback normal timeout code in case the timeout_style feature is
  # unavailable.
else
  set timeout=5
fi
play 60 800 1
insmod part_gpt

menuentry 'Gentoo LiveDVD amd64 multilib ISO' --class gentoo {
  set gfxpayload=keep
  set isofile='/livedvd-amd64-multilib-20140826.iso'
  loopback loop $isofile
  echo "Language: $bootlang"
  echo "Keyboard: $bootkeymap"
  #echo 'Loading amd64-multilib 3.15.6 kernel'
  linux (loop)/isolinux/gentoo root=/dev/ram0 init=/linuxrc aufs looptype=squashfs loop=/image.squashfs cdroot isoboot=$isofile vga=791 splash=silent,theme:default vconsole.keymap=$bootkeymap locale=$bootlang $modeset_opt $nox $acpi_opt console=tty1 quiet --
  echo 'Loading initial ramdisk ...'
  initrd (loop)/isolinux/gentoo.igz
}


menuentry "Gentoo Install Minimal AMD64 multilib ISO" --class gentoo {
  set isofile='/install-amd64-minimal-20150319.iso'
  loopback loop $isofile
  linux (loop)/isolinux/gentoo root=/dev/ram0 init=/linuxrc looptype=squashfs loop=/image.squashfs cdroot isoboot=$isofile vga=791 splash=silent,theme:default console=tty1 quiet --
  echo 'Loading initial ramdisk ...'
  initrd (loop)/isolinux/gentoo.igz
}

## /Gentoo things

menuentry "Ubuntu Desktop ISO" --class ubuntu {
 loopback loop /ubuntu-14.04.1-desktop-amd64.iso
 linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=/ubuntu-14.04.1-desktop-amd64.iso noeject noprompt splash --
 initrd (loop)/casper/initrd.lz
}

#menuentry "Debian NetInstall ISO" --class debian {
# loopback loop /debian-testing-amd64-netinst.iso
# linux (loop)/install.amd/vmlinuz vga=normal --
# initrd (loop)/install.amd/initrd.gz
#}

#menuentry 'Debian NetInstall ISO' --class debian {
#	set isofile='/debian-testing-amd64-netinst.iso'
#	set initrdfile='/debian-loopback-initrd.gz'
#	loopback loop $isofile
#	linux (loop)/install.amd/vmlinuz vga=791 iso-scan/ask_second_pass=true iso-scan/filename=$isofile
#	# initrd $initrdfile
#	initrd (loop)/install.amd/initrd.gz
#}

menuentry "Linux Mint ISO" {
 loopback loop /linuxmint.iso
 linux (loop)/casper/vmlinuz file=/cdrom/preseed/mint.seed boot=casper initrd=/casper/initrd.lz iso-scan/filename=/linuxmint.iso noeject noprompt splash --
 initrd (loop)/casper/initrd.lz
}

#menuentry "DBAN ISO" {
# loopback loop /dban.iso
# linux (loop)/DBAN.BZI nuke="dwipe" iso-scan/filename=/dban.iso silent --
#} 

#menuentry "Tinycore ISO" {
# loopback loop /tinycore.iso
# linux (loop)/boot/bzImage --
# initrd (loop)/boot/tinycore.gz
#}

menuentry "SystemRescueCd" {
 loopback loop /systemrescuecd.iso
 linux (loop)/isolinux/rescuecd isoloop=/systemrescuecd.iso setkmap=us docache dostartx
 initrd (loop)/isolinux/initram.igz
}

#menuentry "FreeDOS 1.1" {
# #set root=(hd0,1)
# loopback loop /freedos/fd11src.iso
# linux16 (loop)/isolinux/memdisk 
# initrd16 (loop)/isolinux/fdboot.img
#}

menuentry "Samsung SSD 840 EVO performance restoration" {
 #set root=(hd0,1)
 loopback loop /Samsung_Performance_Restoration.iso
 linux16 (loop)/isolinux/memdisk
 initrd16 (loop)/isolinux/btdsk.img
}

menuentry "memtest86+ 4.20" --unrestricted {
        linux16 /memtest86plus/memtest
}

menuentry "memtest86+ 4.20 (netbsd)" --unrestricted {
        insmod bsd
        knetbsd /memtest86plus/memtest.netbsd
}