use: /usr/share/nero/DosBootImage.ima (Caldera DR-DOS)

wget http://www.finnix.org/files/balder10.img -O /tmp/balder10.img

dd if=/dev/zero of=/tmp/disc.dd bs=1M count=16

qemu -boot a -fda /tmp/balder10.img -hda /tmp/disc.dd #-vnc :0
fdisk
reboot (press ALT + STRG + DEL)
format c: /S

# mount
#fdisk -ul disc.dd
mount /tmp/disc.dd /mnt/ -o loop,offset=32256

#apt-get install dosfstools

# PXE boot (/var/lib/tftpboot/pxelinux.cfg/bios.conf)
default linux
label linux
LINUX memdisk
INITRD bios.img
APPEND raw harddisk

Create FreeDOS boot ISO

get http://www.fdos.org/bootdisks/ISO/FDOEMCD.builder.zip
mkisofs \
    -boot-info-table \
    -boot-load-size 4 \
    -eltorito-boot isolinux/isolinux.bin \
    -eltorito-catalog boot.catalog \
    -hide boot.catalog \
    -hide-joliet boot.catalog \
    -joliet \
    -no-emul-boot \
    -omit-version-number \
    -output dos.iso \
    -rational-rock \
    CDROOT

Links
http://www.finnix.org/Balder
http://www.meta.net.nz/~daniel/blog/2009/06/10/creating-a-dos-usb-bootdisk-under-linux/
http://darkdust.net/writings/diskimagesminihowto