Enable QEMU network

bridge-utils

$sudo brctl addbr br0
$sudo ifconfig eth0 0.0.0.0 promisc up
$sudo brctl addif br0 eth0
$sudo dhclient br0
$sudo qemu-system-arm -M versatilepb -m 256M -kernel vmlinuz-926 -cpu arm926 -hda hasty.img -append "root=/dev/sda1" -net nic,vlan=0 -net tap,vlan=0,ifname=tap0,script=./qemu-ifup


qemu-ifup:

#!/bin/sh
ifconfig $1 0.0.0.0 promisc up
brctl addif br0 $1

[Note] Remember to chmod qemu-ifup to executable