Creating a bootable FreeDOS USB stick (thumb drive)
So I had to test some tiny detail of Intel VT-d variation and needed a normal PC. The only non-Apple hardware to spare in the office was some aging Sony Vaio VGN-SZ laptop which unfortunately comes with VT disabled in the BIOS. In the attempt to re-enable the VT support by some NVRAM poking I had the need to have some form of DOS for the BIOS utility and obviously I had none at hand.
So I grabbed the 1.0 release of FreeDOS and just used Qemu to install it onto a USB stick passed to the VM as hard disk:
qemu-system-x86_64 -hda /dev/sdb -cdrom fdbasecd.iso -boot d
After some minutes and a couple of Enters I had a bootable USB stick with FreeDOS for this arcane flashbacks of dancing with the high techology that is the PC BIOS.