ArchLinux has an excellent Wiki that is easily applied to other Linux distros. Here is their discussion on using FreeDOS to flash a system BIOS and, interestingly, creating bootable DOS images that are bigger than standard floppy disk sizes. It offers step-by-step instructions on how to create a bootable CD using your FreeDOS image.
There's no need to repeat the wiki article here. I'll add more info if I develop more sources.
If you need an updated DOS memory extender, check this out.
DOSBox-X is a cross-platform DOS emulator based on the DOSBox project.
WARP v2.31 is a fast ANSI.SYS replacement if you need one.
FOSS DOS for 21st Century Hardware
ArchLinux and FreeDOS
DOS4GW.EXE Version 2.01a and Alternative DOS Extenders