QEMU

apt-get install ssh qemu vde nfs-kernel-server debootstrap uml-utilities bridge-utils dnsmasq

• In the file /etc/sysctl uncomment the following line to allow IP forwarding:

net.ipv4.conf.default.forwarding=1

• In the file /etc/modules, add a new line with "tun", to make that module load on boot.

• Configure DNSmasq. Edit the file /etc/dnsmasq.conf and change the following options:

user=nobody
domain=qemu.lan
interface=qtap0
dhcp-range=10.1.1.1,10.1.1.253,255.255.255.0,10.1.1.255,8h

• To avoid the need for root privileges add the group "vde2-net" to all users that will use VDE (log-out and log-in for this to take effect)

sudo usermod -aG vde2-net $USER

• Add the new network interface. Edit the file /etc/network/interfaces and paste this:

auto qtap0
iface qtap0 inet static
      	address 10.1.1.1
      	netmask 255.255.255.0
      	pre-up /sbin/modprobe ipt_MASQUERADE
      	pre-up /usr/bin/vde_switch --tap qtap0 --sock /var/run/vde.ctl  \
                                 	--daemon --group vde2-net --mod 775  \
                                 	--mgmt /var/run/vde.mgmt --mgmtmode 770  \
                                 	--pidfile /var/run/vde_switch.pid
      	pre-up /etc/init.d/dnsmasq restart
      	up iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
      	down iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
      	post-down kill -s HUP `cat /var/run/vde_switch.pid`

• Either restart the PC or simply do:

sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
sudo modprobe tun
sudo ifup qtap0

• Share the new directory out via NFS, by adding the following entry to /etc/exports:

/nfs/share/arm 127.0.0.0/24(rw,no_root_squash,sync)

It may also be necessary to share with 10.1.1.0/24(rw,no_root_squash,sync); however in my experience the NFS request came to the server from 127.0.0.1.

• Then export the filesystem:

/etc/init.d/nfs-kernel-server restart

or

exportfs -a

• Download a kernel for arm-linux;

http://fabrice.bellard.free.fr/qemu/arm-test-0.2.tar.gz

• Place the arm-linux zimage in /usr/local/etc/images/zImage.arm, and then create the following script as /usr/local/bin/start-qemu-arm:

#!/bin/sh
	
#console="ttyAMA0"		# serial console
nfsserver="10.1.1.1"		# address of NFS server
nfsdir="/nfs/share/arm"		# exported share where debian/arm is installed
address="10.1.1.100"		# address for guest server
gateway="10.1.1.1"		# default gateway
netmask="255.255.255.0"		# subnet mask
hostname="arm.home"		# hostname for guest server
device="eth0"			# interface that guest server will use
mem=256				# memory for guest server in Mb
#tap="/var/run/vde/tap0.ctl"	# vde tap socket

kernel="/usr/local/etc/images/zImage.arm"	# arm kernel
nfsopts="rsize=8192,wsize=8192,hard,intr,tcp,nolock"	# nfs options

#consoleopt="console=$console"
nfsrootopt="nfsroot=$nfsserver:$nfsdir,$nfsopts"
ipopt="ip=$address::$gateway:$netmask:$hostname:$device"
	
init=""
	
if [ "x$1" = "xsingle" ]
then
	init="init=/bin/bash"
fi

vdeq qemu-system-arm -net vde,vlan=0 -net nic,vlan=0 -m $mem \
       -kernel $kernel -append "root=/dev/nfs $nfsrootopt $ipopt $init"

Then from the command prompt run:

sudo /usr/local/bin/start-qemu-arm single

Now you should get a window with the famous penguin and a login prompt.

The rest of this HOWTO is unverified.

The emulated guest server should start up and boot into a bash prompt. The filesystem will be mounted read-only, and it will be necessary to remount it read-write before any further work can be done on it:

guest# mount -n -o remount,rw / guest# mount /proc

Now run the second stage of debootstrap, within the guest system, to finalise the installation:

guest# cd / guest# ./debootstrap/debootstrap --second-stage

This will probably take a while to run; the emulator isn't particularly fast. When it's finished, adjust a few remaining files, such as /etc/hostname and /etc/resolv.conf; also install ssh:

guest# apt-get install ssh

Once this is done, you can shut the server down. It's safe to just kill the qemu process from the host machine - since its filesystem is mounted from an NFS server, there's no need to shut it down cleanly.

Now you can start it up completely:

host$ /usr/local/bin/start-qemu-arm

When it finishes booting, you should be able to ssh into it on 10.1.6.50, and you'll have a working Debian installation running on an emulated ARM processor.