Difference between revisions of "linux/kernel/user mode VM"

From Free Pascal wiki
(Typos, grammar, layout)
Line 6: Line 6:
 
=Installation=
 
=Installation=
 
First of all you need to install the package ''user-mode-linux''
 
First of all you need to install the package ''user-mode-linux''
<bash>apt-get install user-mode-linux</bash>
+
<syntaxhighlight lang="bash">apt-get install user-mode-linux</syntaxhighlight>
 
Then you need the package ''uml-utilities''
 
Then you need the package ''uml-utilities''
<bash>apt-get install uml-utilities</bash>
+
<syntaxhighlight lang="bash">apt-get install uml-utilities</syntaxhighlight>
  
 
=Configuration=
 
=Configuration=
 
==File System Image==
 
==File System Image==
 
The easiest way to do that is to download an already built image
 
The easiest way to do that is to download an already built image
<bash>wget ftp://ftp.freepascal.org/some path/umlrootfs.img.bz2</bash>
+
<syntaxhighlight lang="bash">wget ftp://ftp.freepascal.org/some path/umlrootfs.img.bz2</syntaxhighlight>
 
Then you need to decompress it
 
Then you need to decompress it
<bash>bunzip2 umlrootfs.img.bz2</bash>
+
<syntaxhighlight lang="bash">bunzip2 umlrootfs.img.bz2</syntaxhighlight>
 
Please note that this is really a minimal installation, including the fp-compiler and aptitude packages. The latter will allow you to install any package you want providing you set up your network correctly.
 
Please note that this is really a minimal installation, including the fp-compiler and aptitude packages. The latter will allow you to install any package you want providing you set up your network correctly.
  
Line 23: Line 23:
 
===Creating TAP interface===
 
===Creating TAP interface===
 
In order to setup networking you need to configure a tap interface:
 
In order to setup networking you need to configure a tap interface:
<bash>cat - > /etc/network/interfaces</bash>
+
<syntaxhighlight lang="bash">cat - > /etc/network/interfaces
 
  # /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
 
  # /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
 
  # In this configuration example we will setup two physical networking
 
  # In this configuration example we will setup two physical networking
Line 55: Line 55:
 
   uml_proxy_arp 192.168.3.2
 
   uml_proxy_arp 192.168.3.2
 
   uml_proxy_ether eth0
 
   uml_proxy_ether eth0
 +
</syntaxhighlight>
  
 
===Enabling IP forwarding===
 
===Enabling IP forwarding===
 
In addition to this networking configuration, you need to instruct your kernel to forward IP packets, so the VM can communicate with the rest of your network and the internet.
 
In addition to this networking configuration, you need to instruct your kernel to forward IP packets, so the VM can communicate with the rest of your network and the internet.
<bash>cat - > /etc/sysctl.conf</bash>
+
<syntaxhighlight lang="bash">cat - > /etc/sysctl.conf
 
  #
 
  #
 
  # /etc/sysctl.conf - Configuration file for setting system variables
 
  # /etc/sysctl.conf - Configuration file for setting system variables
Line 70: Line 71:
 
  # Uncomment the next line to enable packet forwarding for IPv4
 
  # Uncomment the next line to enable packet forwarding for IPv4
 
  net.ipv4.ip_forward=1
 
  net.ipv4.ip_forward=1
 +
</syntaxhighlight>
  
 
===Configuring UML switch===
 
===Configuring UML switch===
<bash>cat - > /etc/default/uml-utilities</bash>
+
<syntaxhighlight lang="bash">cat - > /etc/default/uml-utilities
 
   # Options to pass to uml_switch.
 
   # Options to pass to uml_switch.
 
   
 
   
Line 93: Line 95:
 
  # sources you may want to uncomment the following:
 
  # sources you may want to uncomment the following:
 
  #UML_SWITCH_CTL="/tmp/uml.ctl"
 
  #UML_SWITCH_CTL="/tmp/uml.ctl"
 +
</syntaxhighlight>
  
 
=Starting the UML VM=
 
=Starting the UML VM=
 
==Starting script==
 
==Starting script==
 
Starting UML VM requires too many arguments, but a small script can ease this task:
 
Starting UML VM requires too many arguments, but a small script can ease this task:
<bash>cat - > ${HOME}/bin/startUML.sh</bash>
+
<syntaxhighlight lang="bash">cat - > ${HOME}/bin/startUML.sh
 
  #! /bin/sh
 
  #! /bin/sh
 
  UML_BIN=linux
 
  UML_BIN=linux
Line 108: Line 111:
 
  eth0=daemon,fe:fd:fe:ed:b0:0f,,${UML_SWITCH_SOCKET} \
 
  eth0=daemon,fe:fd:fe:ed:b0:0f,,${UML_SWITCH_SOCKET} \
 
  con0=xterm xterm=/usr/bin/xterm,-T,-e \
 
  con0=xterm xterm=/usr/bin/xterm,-T,-e \
 +
</syntaxhighlight>
  
 
+
[[Category:Linux]]
--[[User:Mazen|Mazen]] 23:52, 16 October 2007 (CEST)
 

Revision as of 09:25, 5 September 2013

Overview

This section is intended to help users interested in developing Linux kernel modules to setup an UML VM to debug it during development phase.

Please note that this page will focus in configuring a VM running on a Debian distribution based host.

Installation

First of all you need to install the package user-mode-linux

apt-get install user-mode-linux

Then you need the package uml-utilities

apt-get install uml-utilities

Configuration

File System Image

The easiest way to do that is to download an already built image

wget ftp://ftp.freepascal.org/some path/umlrootfs.img.bz2

Then you need to decompress it

bunzip2 umlrootfs.img.bz2

Please note that this is really a minimal installation, including the fp-compiler and aptitude packages. The latter will allow you to install any package you want providing you set up your network correctly.

The provided root file system image has networking configured already for the VM, so you need just to configure the host part as described in the next section.

Networking

Creating TAP interface

In order to setup networking you need to configure a tap interface:

cat - > /etc/network/interfaces
 # /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
 # In this configuration example we will setup two physical networking
 # cards eth0 and eth1. The first card, eth0, will be automatically
 # configured at host starting up, while the second one will be configured
 # on manual demand using "ifup eth1".
 # We will also configure a virtual networking card tap0 which will be
 # configured at system startup too.
 
 auto lo eth0 tap0
 
 # The loopback interface 
 iface lo inet loopback
 
 iface eth0 inet static
   address 192.168.1.2
   netmask 255.255.255.0
   network 192.168.1.0
   gateway 192.168.1.1
 
 iface eth1 inet static
   address 192.168.2.1
   netmask 255.255.255.0
   network 192.168.2.0
 
 iface tap0 inet static
   address 192.168.3.1
   netmask 255.255.255.0
   network 192.168.3.0
   tunctl_user uml-net
   uml_proxy_arp 192.168.3.2
   uml_proxy_ether eth0

Enabling IP forwarding

In addition to this networking configuration, you need to instruct your kernel to forward IP packets, so the VM can communicate with the rest of your network and the internet.

cat - > /etc/sysctl.conf
 #
 # /etc/sysctl.conf - Configuration file for setting system variables
 # See sysctl.conf (5) for information.
 #
 
 ##############################################################3
 # Functions previously found in netbase
 #
 
 # Uncomment the next line to enable packet forwarding for IPv4
 net.ipv4.ip_forward=1

Configuring UML switch

cat - > /etc/default/uml-utilities
  # Options to pass to uml_switch.
 
 # set to "false" if you want to prevent uml_switch from
 # starting with SysV scripts in /etc/init.d
 UML_SWITCH_START="true"
 
 # For preconfigured tap setup, see
 # /usr/share/doc/uml-utilities/examples/interfaces.example
 UML_SWITCH_OPTIONS="-tap tap0"
 
 # User as which to run uml_switch
 UML_SWITCH_USER="uml-net"
 
 # Socket file to use
 # Debian's default is:
 UML_SWITCH_CTL="/var/run/uml-utilities/uml_switch.ctl"
 #
 # if you instead use your rolled up kernel from upstream
 # sources you may want to uncomment the following:
 #UML_SWITCH_CTL="/tmp/uml.ctl"

Starting the UML VM

Starting script

Starting UML VM requires too many arguments, but a small script can ease this task:

cat - > ${HOME}/bin/startUML.sh
 #! /bin/sh
 UML_BIN=linux
 UML_ROOT_FS=${HOME}/umlrootfs.img
 UML_SWITCH_SOCKET=/var/run/uml-utilities/uml_switch.ctl
 exec ${UML_BIN} \
 	umid=uml1 \
 	mem=512M \
 	ubd0=${UML_ROOT_FS} \
 	eth0=daemon,fe:fd:fe:ed:b0:0f,,${UML_SWITCH_SOCKET} \
 	con0=xterm xterm=/usr/bin/xterm,-T,-e \