The aim of this article is to setup the use of a file system from qemu by NFS.

First step : configuration of the development PC station.

This phase consists to add and configure a "bridge".

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/usr/sbin/brctl addbr br0
/usr/sbin/brctl addif br0 eth0 
/sbin/dhclient br0
/sbin/iptables -F FORWARD

We also need to define a script which will be used during qemu boot, in order to configure the network for the virtual machine.

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touch qemu-ifup
chmod a+x qemu-ifup
vi qemu-ifup

Let's add the configuration in the script:

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

Second step : NFS server configuration

We are going to share the file system of the embedded ARM system, so it can be used during the system boot.

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vi /etc/exports

Let's add the folder:

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/opt/system-arm/root *(rw,no_subtree_check,no_root_squash)
 

Update of the configuration to take into account the add-on (in root):

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exportfs -a

Third step : qemu launch

Let say that the IP address of the development PC station is 192.168.1.3, and the virtual machine address is 192.168.1.10.

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qemu-system-arm --nographic -M pc -no-reboot \
-kernel /opt/system-arm/kernel/linuximage \
-append "root=/dev/nfs nfsroot=192.168.1.3:/opt/system-arm/root rw ip=192.168.1.10" \
-net nic,vlan=0 -net tap,vlan=0,ifname=tap0,script=./qemu-ifup 

© Copyright 2011, Oselis.