mount -o loop debian-10.0.0-amd64-netinst.iso /mnt/loop
mkdir debian-10.0.0-amd64-netinst
shopt -s dotglob; cp -rv /mnt/loop/* debian-10.0.0-amd64-netinst/
umount /mnt/loop
dd if=debian-10.0.0-amd64-netinst.iso of=isohdpfx.bin bs=1 count=432
cp debian-10.0.0-amd64-netinst/.disk/mkisofs .