<channel>
<title>Petter Reinholdtsen - Entries from October 2013</title>
<description>Entries from October 2013</description>
- <link>http://people.skolelinux.org/pere/blog/</link>
+ <link>http://www.hungry.com/~pere/blog/</link>
+ <item>
+ <title>Teaching vmdebootstrap to create Raspberry Pi SD card images</title>
+ <link>http://www.hungry.com/~pere/blog/Teaching_vmdebootstrap_to_create_Raspberry_Pi_SD_card_images.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Teaching_vmdebootstrap_to_create_Raspberry_Pi_SD_card_images.html</guid>
+ <pubDate>Sun, 27 Oct 2013 17:00:00 +0100</pubDate>
+ <description><p>The
+<a href="http://packages.qa.debian.org/v/vmdebootstrap.html">vmdebootstrap</a>
+program is a a very nice system to create virtual machine images. It
+create a image file, add a partition table, mount it and run
+debootstrap in the mounted directory to create a Debian system on a
+stick. Yesterday, I decided to try to teach it how to make images for
+<a href="https://wiki.debian.org/RaspberryPi">Raspberry Pi</a>, as part
+of a plan to simplify the build system for
+<a href="https://wiki.debian.org/FreedomBox">the FreedomBox
+project</a>. The FreedomBox project already uses vmdebootstrap for
+the virtualbox images, but its current build system made multistrap
+based system for Dreamplug images, and it is lacking support for
+Raspberry Pi.</p>
+
+<p>Armed with the knowledge on how to build "foreign" (aka non-native
+architecture) chroots for Raspberry Pi, I dived into the vmdebootstrap
+code and adjusted it to be able to build armel images on my amd64
+Debian laptop. I ended up giving vmdebootstrap five new options,
+allowing me to replicate the image creation process I use to make
+<a href="https://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html">Debian
+Jessie based mesh node images for the Raspberry Pi</a>. First, the
+<tt>--foreign /path/to/binfm_handler</tt> option tell vmdebootstrap to
+call debootstrap with --foreign and to copy the handler into the
+generated chroot before running the second stage. This allow
+vmdebootstrap to create armel images on an amd64 host. Next I added
+two new options <tt>--bootsize size</tt> and <tt>--boottype
+fstype</tt> to teach it to create a separate /boot/ partition with the
+given file system type, allowing me to create an image with a vfat
+partition for the /boot/ stuff. I also added a <tt>--variant
+variant</tt> option to allow me to create smaller images without the
+Debian base system packages installed. Finally, I added an option
+<tt>--no-extlinux</tt> to tell vmdebootstrap to not install extlinux
+as a boot loader. It is not needed on the Raspberry Pi and probably
+most other non-x86 architectures. The changes were accepted by the
+upstream author of vmdebootstrap yesterday and today, and is now
+available from
+<a href="http://git.liw.fi/cgi-bin/cgit/cgit.cgi/vmdebootstrap/">the
+upstream project page</a>.</p>
+
+<p>To use it to build a Raspberry Pi image using Debian Jessie, first
+create a small script (the customize script) to add the non-free
+binary blob needed to boot the Raspberry Pi and the APT source
+list:</p>
+
+<p><pre>
+#!/bin/sh
+set -e # Exit on first error
+rootdir="$1"
+cd "$rootdir"
+cat &lt;&lt;EOF > etc/apt/sources.list
+deb http://http.debian.net/debian/ jessie main contrib non-free
+EOF
+# Install non-free binary blob needed to boot Raspberry Pi. This
+# install a kernel somewhere too.
+wget https://raw.github.com/Hexxeh/rpi-update/master/rpi-update \
+ -O $rootdir/usr/bin/rpi-update
+chmod a+x $rootdir/usr/bin/rpi-update
+mkdir -p $rootdir/lib/modules
+touch $rootdir/boot/start.elf
+chroot $rootdir rpi-update
+</pre></p>
+
+<p>Next, fetch the latest vmdebootstrap script and call it like this
+to build the image:</p>
+
+<pre>
+sudo ./vmdebootstrap \
+ --variant minbase \
+ --arch armel \
+ --distribution jessie \
+ --mirror http://http.debian.net/debian \
+ --image test.img \
+ --size 600M \
+ --bootsize 64M \
+ --boottype vfat \
+ --log-level debug \
+ --verbose \
+ --no-kernel \
+ --no-extlinux \
+ --root-password raspberry \
+ --hostname raspberrypi \
+ --foreign /usr/bin/qemu-arm-static \
+ --customize `pwd`/customize \
+ --package netbase \
+ --package git-core \
+ --package binutils \
+ --package ca-certificates \
+ --package wget \
+ --package kmod
+</pre></p>
+
+<p>The list of packages being installed are the ones needed by
+rpi-update to make the image bootable on the Raspberry Pi, with the
+exception of netbase, which is needed by debootstrap to find
+/etc/hosts with the minbase variant. I really wish there was a way to
+set up an Raspberry Pi using only packages in the Debian archive, but
+that is not possible as far as I know, because it boots from the GPU
+using a non-free binary blob.</p>
+
+<p>The build host need debootstrap, kpartx and qemu-user-static and
+probably a few others installed. I have not checked the complete
+build dependency list.</p>
+
+<p>The resulting image will not use the hardware floating point unit
+on the Raspberry PI, because the armel architecture in Debian is not
+optimized for that use. So the images created will be a bit slower
+than <a href="http://www.raspbian.org/">Raspbian</a> based images.</p>
+</description>
+ </item>
+
+ <item>
+ <title>Det er jo makta som er mest sårbar ved massiv overvåkning av Internett</title>
+ <link>http://www.hungry.com/~pere/blog/Det_er_jo_makta_som_er_mest_s_rbar_ved_massiv_overv_kning_av_Internett.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Det_er_jo_makta_som_er_mest_s_rbar_ved_massiv_overv_kning_av_Internett.html</guid>
+ <pubDate>Sat, 26 Oct 2013 20:30:00 +0200</pubDate>
+ <description><p>De siste måneders eksponering av
+<a href="http://www.aftenposten.no/nyheter/uriks/Her-er-Edvard-Snowdens-mest-omtalte-avsloringer-7351734.html">den
+totale overvåkningen som foregår i den vestlige verden dokumenterer
+hvor sårbare vi er</a>. Men det slår meg at de som er mest sårbare
+for dette, myndighetspersoner på alle nivåer, neppe har innsett at de
+selv er de mest interessante personene å lage profiler på, for å kunne
+påvirke dem.</p>
+
+<p>For å ta et lite eksempel: Stortingets nettsted,
+<a href="http://www.stortinget.no/">www.stortinget.no</a> (og
+forsåvidt også
+<a href="http://data.stortinget.no/">data.stortinget.no</a>),
+inneholder informasjon om det som foregår på Stortinget, og jeg antar
+de største brukerne av informasjonen der er representanter og
+rådgivere på Stortinget. Intet overraskende med det. Det som derimot
+er mer skjult er at Stortingets nettsted bruker
+<a href="http://en.wikipedia.org/wiki/Google_Analytics">Google
+Analytics</a>, hvilket gjør at enhver som besøker nettsidene der også
+rapporterer om besøket via Internett-linjer som passerer Sverige,
+England og videre til USA. Det betyr at informasjon om ethvert besøk
+på stortingets nettsider kan snappes opp av svensk, britisk og USAs
+etterretningsvesen. De kan dermed holde et øye med hvilke
+Stortingssaker stortingsrepresentantene synes er interessante å sjekke
+ut, og hvilke sider rådgivere og andre på stortinget synes er
+interessant å besøke, når de gjør det og hvilke andre representanter
+som sjekker de samme sidene omtrent samtidig. Stortingets bruk av
+Google Analytics gjør det dermed enkelt for utenlands etteretning å
+spore representantenes aktivitet og interesse. Hvis noen av
+representantene bruker Google Mail eller noen andre tjenestene som
+krever innlogging, så vil det være enda enklere å finne ut nøyaktig
+hvilke personer som bruker hvilke nettlesere og dermed knytte
+informasjonen opp til enkeltpersoner på Stortinget.</p>
+
+<p>Og jo flere nettsteder som bruker Google Analytics, jo bedre
+oversikt over stortingsrepresentantenes lesevaner og interesse blir
+tilgjengelig for svensk, britisk og USAs etterretning. Hva de kan
+bruke den informasjonen til overlater jeg til leseren å undres
+over.</p>
+</description>
+ </item>
+
+ <item>
+ <title>A Raspberry Pi based batman-adv Mesh network node</title>
+ <link>http://www.hungry.com/~pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html</guid>
+ <pubDate>Mon, 21 Oct 2013 11:40:00 +0200</pubDate>
+ <description><p>The last few days I have been experimenting with
+<a href="http://www.open-mesh.org/projects/batman-adv/wiki">the
+batman-adv mesh technology</a>. I want to gain some experience to see
+if it will fit <a href="https://wiki.debian.org/FreedomBox">the
+Freedombox project</a>, and together with my neighbors try to build a
+mesh network around the park where I live. Batman-adv is a layer 2
+mesh system ("ethernet" in other words), where the mesh network appear
+as if all the mesh clients are connected to the same switch.</p>
+
+<p>My hardware of choice was the Linksys WRT54GL routers I had lying
+around, but I've been unable to get them working with batman-adv. So
+instead, I started playing with a
+<a href="http://www.raspberrypi.org/">Raspberry Pi</a>, and tried to
+get it working as a mesh node. My idea is to use it to create a mesh
+node which function as a switch port, where everything connected to
+the Raspberry Pi ethernet plug is connected (bridged) to the mesh
+network. This allow me to hook a wifi base station like the Linksys
+WRT54GL to the mesh by plugging it into a Raspberry Pi, and allow
+non-mesh clients to hook up to the mesh. This in turn is useful for
+Android phones using <a href="http://servalproject.org/">the Serval
+Project</a> voip client, allowing every one around the playground to
+phone and message each other for free. The reason is that Android
+phones do not see ad-hoc wifi networks (they are filtered away from
+the GUI view), and can not join the mesh without being rooted. But if
+they are connected using a normal wifi base station, they can talk to
+every client on the local network.</p>
+
+<p>To get this working, I've created a debian package
+<a href="https://github.com/petterreinholdtsen/meshfx-node">meshfx-node</a>
+and a script
+<a href="https://github.com/petterreinholdtsen/meshfx-node/blob/master/build-rpi-mesh-node">build-rpi-mesh-node</a>
+to create the Raspberry Pi boot image. I'm using Debian Jessie (and
+not Raspbian), to get more control over the packages available.
+Unfortunately a huge binary blob need to be inserted into the boot
+image to get it booting, but I'll ignore that for now. Also, as
+Debian lack support for the CPU features available in the Raspberry
+Pi, the system do not use the hardware floating point unit. I hope
+the routing performance isn't affected by the lack of hardware FPU
+support.</p>
+
+<p>To create an image, run the following with a sudo enabled user
+after inserting the target SD card into the build machine:</p>
+
+<p><pre>
+% wget -O build-rpi-mesh-node \
+ https://raw.github.com/petterreinholdtsen/meshfx-node/master/build-rpi-mesh-node
+% sudo bash -x ./build-rpi-mesh-node > build.log 2>&1
+% dd if=/root/rpi/rpi_basic_jessie_$(date +%Y%m%d).img of=/dev/mmcblk0 bs=1M
+%
+</pre></p>
+
+<p>Booting with the resulting SD card on a Raspberry PI with a USB
+wifi card inserted should give you a mesh node. At least it does for
+me with a the wifi card I am using. The default mesh settings are the
+ones used by the Oslo mesh project at Hackeriet, as I mentioned in
+<a href="https://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html">an
+earlier blog post about this mesh testing</a>.</p>
+
+<p>The mesh node was not horribly expensive either. I bought
+everything over the counter in shops nearby. If I had ordered online
+from the lowest bidder, the price should be significantly lower:</p>
+
+<p><table>
+
+<tr><th>Supplier</th><th>Model</th><th>NOK</th></tr>
+<tr><td>Teknikkmagasinet</td><td>Raspberry Pi model B</td><td>349.90</td></tr>
+<tr><td>Teknikkmagasinet</td><td>Raspberry Pi type B case</td><td>99.90</td></tr>
+<tr><td>Lefdal</td><td>Jensen Air:Link 25150</td><td>295.-</td></tr>
+<tr><td>Clas Ohlson</td><td>Kingston 16 GB SD card</td><td>199.-</td></tr>
+<tr><td>Total cost</td><td></td><td>943.80</td></tr>
+
+</table></p>
+
+<p>Now my mesh network at home consist of one laptop in the basement
+connected to my production network, one Raspberry Pi node on the 1th
+floor that can be seen by my neighbor across the park, and one
+play-node I use to develop the image building script. And some times
+I hook up my work horse laptop to the mesh to test it. I look forward
+to figuring out what kind of latency the batman-adv setup will give,
+and how much packet loss we will experience around the park. :)</p>
+</description>
+ </item>
+
+ <item>
+ <title>Perl library to control the Spykee robot moved to github</title>
+ <link>http://www.hungry.com/~pere/blog/Perl_library_to_control_the_Spykee_robot_moved_to_github.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Perl_library_to_control_the_Spykee_robot_moved_to_github.html</guid>
+ <pubDate>Sat, 19 Oct 2013 10:20:00 +0200</pubDate>
+ <description><p>Back in 2010, I created a Perl library to talk to
+<a href="http://en.wikipedia.org/wiki/Spykee">the Spykee robot</a>
+(with two belts, wifi, USB and Linux) and made it available from my
+web page. Today I concluded that it should move to a site that is
+easier to use to cooperate with others, and moved it to github. If
+you got a Spykee robot, you might want to check out
+<a href="https://github.com/petterreinholdtsen/libspykee-perl">the
+libspykee-perl github repository</a>.</p>
+</description>
+ </item>
+
+ <item>
+ <title>Good causes: Debian Outreach Program for Women, EFF documenting the spying and Open access in Norway</title>
+ <link>http://www.hungry.com/~pere/blog/Good_causes__Debian_Outreach_Program_for_Women__EFF_documenting_the_spying_and_Open_access_in_Norway.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Good_causes__Debian_Outreach_Program_for_Women__EFF_documenting_the_spying_and_Open_access_in_Norway.html</guid>
+ <pubDate>Tue, 15 Oct 2013 21:30:00 +0200</pubDate>
+ <description><p>The last few days I came across a few good causes that should get
+wider attention. I recommend signing and donating to each one of
+these. :)</p>
+
+<p>Via <a href="http://www.debian.org/News/weekly/2013/18/">Debian
+Project News for 2013-10-14</a> I came across the Outreach Program for
+Women program which is a Google Summer of Code like initiative to get
+more women involved in free software. One debian sponsor has offered
+to match <a href="http://debian.ch/opw2013">any donation done to Debian
+earmarked</a> for this initiative. I donated a few minutes ago, and
+hope you will to. :)</p>
+
+<p>And the Electronic Frontier Foundation just announced plans to
+create <a href="https://supporters.eff.org/donate/nsa-videos">video
+documentaries about the excessive spying</a> on every Internet user that
+take place these days, and their need to fund the work. I've already
+donated. Are you next?</p>
+
+<p>For my Norwegian audience, the organisation Studentenes og
+Akademikernes Internasjonale Hjelpefond is collecting signatures for a
+statement under the heading
+<a href="http://saih.no/Bloggers_United/">Bloggers United for Open
+Access</a> for those of us asking for more focus on open access in the
+Norwegian government. So far 499 signatures. I hope you will sign it
+too.</p>
+</description>
+ </item>
+
<item>
<title>Oslo community mesh network - with NUUG and Hackeriet at Hausmania</title>
- <link>http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</guid>
+ <link>http://www.hungry.com/~pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</guid>
<pubDate>Fri, 11 Oct 2013 14:10:00 +0200</pubDate>
<description><p>Wireless mesh networks are self organising and self healing
networks that can be used to connect computers across small and large
from the Freifunk community to Oslo to talk about mesh networks. I
came across this video where Hans Jørgen Lysglimt interview the
speakers about this talk (from
-<a href="https://www.youtube.com/watch?v=N2Kd7CLkhSY">youtube</a>:</p>
-
+<a href="https://www.youtube.com/watch?v=N2Kd7CLkhSY">youtube</a>):</p>
<p><iframe width="420" height="315" src="https://www.youtube.com/embed/N2Kd7CLkhSY" frameborder="0" allowfullscreen></iframe></p>
figure out which one would be "best" for some definitions of best, but
given that the community mesh group in Oslo is so small, I believe it
is best to hook up with the existing one instead of trying to create a
-completely different setup, and thus this have decided to focus on
+completely different setup, and thus I have decided to focus on
batman-adv for now. It sure help me to know that the very cool
<a href="http://www.servalproject.org/">Serval project in Australia</a>
is using batman-adv as their meshing technology when it create a self
organizing and self healing telephony system for disaster areas and
less industrialized communities. Check out this cool video presenting
that project (from
-<a href="https://www.youtube.com/watch?v=30qNfzJCQOA">youtube</a>:</p>
+<a href="https://www.youtube.com/watch?v=30qNfzJCQOA">youtube</a>):</p>
<p><iframe width="560" height="315" src="https://www.youtube.com/embed/30qNfzJCQOA" frameborder="0" allowfullscreen></iframe></p>
B.A.T.M.A.N. advanced are protocols used by several free software
based community mesh networks.</p>
-</p>The batman-adv protocol is a bit special, as it provide layer 2
+<p>The batman-adv protocol is a bit special, as it provide layer 2
(as in ethernet ) routing, allowing ipv4 and ipv6 to work on the same
network. One way to think about it is that it provide a mesh based
vlan you can bridge to or handle like any other vlan connected to your
introduction</a> is available from the Open Mesh project. These are
the key settings needed to join the Oslo meshfx network:</p>
-<table>
+<p><table>
<tr><th>Setting</th><th>Value</th></tr>
<tr><td>Protocol / kernel module</td><td>batman-adv</td></tr>
<tr><td>ESSID</td><td>meshfx@hackeriet</td></tr>
<td>Channel / Frequency</td><td>11 / 2462</td></tr>
<td>Cell ID</td><td>02:BA:00:00:00:01</td>
-</table>
+</table></p>
<p>The reason for setting ad-hoc wifi Cell ID is to work around bugs
in firmware used in wifi card and wifi drivers. (See a nice post from
to figure out a good business plan for mesh networking and as far as I
know have closed down the experiment. Perhaps Telenor or others would
be interested in a cooperation?</p>
+
+<p><strong>Update 2013-10-12</strong>: I was just
+<a href="http://lists.alioth.debian.org/pipermail/freedombox-discuss/2013-October/005900.html">told
+by the Serval project developers</a> that they no longer use
+batman-adv (but are compatible with it), but their own crypto based
+mesh system.</p>
</description>
</item>
<item>
<title>Skolelinux / Debian Edu 7.1 install and overview video from Marcelo Salvador</title>
- <link>http://people.skolelinux.org/pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html</guid>
+ <link>http://www.hungry.com/~pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html</link>
+ <guid isPermaLink="true">http://www.hungry.com/~pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html</guid>
<pubDate>Tue, 8 Oct 2013 17:10:00 +0200</pubDate>
<description><p>The other day I was pleased and surprised to discover that Marcelo
Salvador had published a
projects / homepage.git / blobdiff