#!/bin/bash -e IFILE=$1 OFILE=$2 dd if=/dev/zero bs=4M count=1 of=$OFILE 2>/dev/null dd if=$IFILE of=$OFILE conv=notrunc 2>/dev/null # 0xffff0000: fe 3f f0 ea b 0xffc00000 echo -n -e "\xfe\x3f\xf0\xea" | dd of=$OFILE bs=64K seek=63 conv=notrunc 2>/dev/null