The binary files of GRUB boot loader in this directory have been created by compiling GRUB for the 'i386-pc' target and then using the grub-mkrescue script to create the El Torito boot image. For licensing terms of GRUB boot loader see the file COPYING contained in this directory. Full version of GRUB, including its source code, can be downloaded from GRUB's project page: http://www.gnu.org/software/grub/