Booting floppy images without having a real floppy drive can be handy for example when updating the BIOS or maybe even installing operation systems.
|First get memdisk which is part of syslinux (also in the debian-package syslinux: dpkg -L syslinux||grep memdisk). memdisk is a small driver which emulates a disk in the RAM.|
Then configure GRUB to take memdisk as kernel and the floppy image as initrd. memdisk and the floppy images need to be accessed by grub, so put them in /boot.
A sample GRUB configuration is:
title Upgrade BIOS root (hd0,0) kernel /memdisk initrd /1KUJ09US.IMG