Загрузка ISO из виртуального раздела.

title LiveUSB Lubuntu
set ISO=/Lubuntu/casper-rw
ls %ISO% > nul  && partnew (hd0,3) 0x00 %ISO% > nul
map %ISO% (0xff)
map --hook
kernel /Lubuntu/vmlinuz iso-scan/filename=/Lubuntu/lubuntu-1010.iso boot=casper persistent locale=ru_RU splash
initrd /Lubuntu/initrd.lz

title Linux Mint
set iso=/path/to/linuxmint/image.iso
map %iso% (0xff)
map --hook
kernel (0xff)/casper/vmlinuz boot=casper iso-scan/filename=%iso% locale=ru_RU
initrd (0xff)/casper/initrd.lz

title linuxmint-19.2-mate-64bit from partition 0
map --unmap=0:0xff
map --unhook && map --rehook
cat --hex --locate=PoLPu@ (md)0x3D0+0x130 > nul && echo Cannot continue if PLoP is active, please start this entry without loading PLoP first && echo && pause Press any key to return to the main menu && configfile /menu.lst
set /a dev=*0x8280&0xff
root (%dev%,0)
set ISO=/ISO/linuxmint-19_2-mate-64bit.iso
ls %ISO% > nul || find --set-root --devices=hf /usbdrive.tag|| echo Error! Could not find usbdrive.tag && echo  && pause Press any key to return to the main menu && configfile /menu.lst
ls %ISO% > nul || find --set-root --devices=hf %ISO% || echo Error! Could not find %ISO% && echo  && pause Press any key to return to the main menu && configfile /menu.lst
map %ISO% (0xff) || map --heads=0 --sectors-per-track=0 %ISO% (0xff) || echo FATAL ERROR mapping %ISO%, please check if file is present and defragmented && pause Press any key to return to main menu && configfile /menu.lst
#http://reboot.pro/topic/9916-grub4dos-isohybrided/page-2#entry88531
#http://www.rmprepusb.com/tutorials/tails
set /a dev=*0x82a0&0xff
debug 1
parttype (%dev%,3) | set check=
debug off
set check=%check:~-5,4%
if "%check%"=="0x00" partnew (%dev%,3) 0 0 0 && partnew (%dev%,3) 0x00 %ISO%
if not "%check%"=="0x00" echo WARNING: PARTITION TABLE 4 IN BIOS DEVICE %dev% IS ALREADY IN USE! && echo  && echo To prevent possible data loss will not continue further && pause && configfile /menu.lst
map --rehook
root (0xff)
chainloader (0xff)