QEMU

From ArmadeusWiki
Revision as of 20:42, 8 November 2007 by JulienB (Talk | contribs) (Configuration)

Jump to: navigation, search

UNDER CONSTRUCTION

Construction.png

Well, you don't have enough money to buy an Armadeus board and just want to be part of the "Software" side of the project ? Then QEMU can be a good choice for you !!

Just be aware that currently Armadeus hardware is not emulated under QEMU, we are just using an other board hard and linux kernel to launch our Rootfs an test our software which is not custom hardware related (ie User interface, Network, etc...)

Installation

  • on Debian, *Ubuntu just do a:
[armadeus]$ sudo apt-get install qemu bridge-utils ?vde?

Configuration

QEMU has several ways of emulating the network:

  • user mode (by default): you can access Internet from your emulated target or an internal Samba/TFTP server but your are not directly accessible
  • bridge mode: you can communicate directly with the Host

As we want want to mimic the devt environment with a real target (that has its own IP adress and is eccesible from the host) we will use "bridged mode". This mode require some configuration on your Host:

  • Activate IPv4 forwarding, for example on Ubuntu, uncomment the following line in /etc/sysctl.conf:
$ sudo vim /etc/sysctl.conf

  # Uncomment the next line to enable packet forwarding for IPv4
  #net/ipv4/ip_forward=1
  • In /etc/network/interface comment the line refering to your current ethernet card and replace them with:
auto br0
iface br0 inet static
 address 192.168.1.2 ??
 network 192.168.1.0 ??
 netmask 255.255.255.0 
 broadcast 192.168.1.255 ??
 gateway 192.168.1.1 ??
 bridge_ports eth0
 bridge_fd 9
 bridge_hello 2
 bridge_maxage 12
 bridge_stp off 

#auto eth0
#iface eth0 inet dhcp

Get/generate simulation images

  • In our tests we used the QEMU Versatile PB emulated hardware. To get a compatible Linux kernel for this board then:
[armadeus]$ wget http://people.debian.org/~aurel32/arm-versatile/vmlinuz-2.6.18-5-versatile
  • Generate your Armadeus Rootfs as an EXT2 image, and zip it (we will use it as Ramdisk first):
[armadeus]$ gzip -9 buildroot/rootfs.arm_nofpu.ext2
  • Create a fake QEMU Hard disk image
[armadeus]$ qemu-img create -f qcow qemu.img 10M

Launch it

  • At first boot, you have to launch the system as a Ramdisk:
[armadeus]$ qemu-system-arm -m 32 -M versatilepb -kernel vmlinuz-2.6.18-5-versatile \
    -initrd rootfs.arm_nofpu.ext2.gz -append "root=/dev/ram" -hda ./rootfs.arm_nofpu2.img
  • When system has booted, we will create the "hard disk" image:
# mkdir /tmp/dev
# mknod /tmp/dev/sda b 8 0
# mknod /tmp/dev/sda b 8 1
# fdisk /tmp/dev/sda
  n p 1 <enter> <enter>
# mkfs.ext2 /tmp/dev/sda1

Links