This is PUPA, the Preliminary Universal Programming Architecture for GRUB. PUPA is a research project for the next generation of GNU GRUB. The most important goal is to make GNU GRUB cleaner, safer, more robust, more powerful, and more portable. See the file NEWS for a description of recent changes to PUPA. See the file INSTALL for instructions on how to build and install the PUPA data and program files. Please visit the official web page of PUPA, for more information. The URL is . Because PUPA is still in developmental stage, PUPA is not for general use (yet). For now, you can install PUPA into a floppy by these instructions: $ configure && make $ ./pupa-mkimage -v -d . -o core.img _chain ext2 $ dd if=boot.img of=/dev/fd0 bs=512 count=1 $ dd if=core.img of=/dev/fd0 bs=512 seek=1 It would be easier to use Bochs than a real machine.