- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Debian_Edu_interview__Giorgio_Pioda.html">Debian Edu interview: Giorgio Pioda</a></div>
- <div class="date">17th September 2012</div>
- <div class="body"><p>After a long break in my row of interviews with people in the
-<a href="http://www.skolelinux.org/">Debian Edu and Skolelinux</a>
-community, I finally found time to wrap up another. This time it is
-Giorgio Pioda, which showed up on the mailing list at the start of
-this year, asking questions and inspiring us to improve the first time
-administrators experience with Skolelinux. :) The interview was
-conduced in May, but I only found time to publish it now.</p>
-
-<p><strong>Who are you, and how do you spend your days?</strong></p>
-
-<p>I have a PhD in chemistry but since several years I work as teacher
-in secondary (15-18 year old students) and tertiary (a kind of "light"
-university) schools. Five years ago I started to manage a Learning
-Management Service server and slowly I got more and more involved with
-IT. 3 years ago the graduating schools moved completely to Linux and I
-got the head of the IT for this. The experience collected in chemistry
-labs computers (for example NMR analysis of protein folding) and in
-the IT-courses during university where sufficient to start. Self
-training is anyway very important</p>
-
-<p>I live in the Italian speaking part of Switzerland, and the
-<a href="http://www.spse.ch/">SPSE school</a> (secondary) is a very
-special sport school for young people who try to became sport pro (for
-all sports, we have dozens of disciplines represented) and we are
-recognised by the Olympic Swiss Organisation.
-
-<p><strong>How did you get in contact with the Skolelinux/Debian Edu
-project?</strong></p>
-
-<p>Looking for Linux / Primary Domain Controller (PDC) I found it
-already several years ago. But since the system was still not
-Kerberized and since our schools relies strongly on laptops I didn't
-use it. I plan to introduce it in the next future, probably for the
-next school year, since the squeeze release solved this security
-hole.</p>
-
-<p><strong>What do you see as the advantages of Skolelinux/Debian
-Edu?</strong></p>
-
-<p>Many. First of all there is a strong and living community that is
-very generous for help and hints. Chat help is crucial, together with
-the mailing list. Second. With Skolelinux you get an already well
-engineered platform and you don't have to start to build up your PDC
-and your clients from GNU/scratch; I've already done this once and I
-can tell it, it is hard. Third, since Skolelinux is a standard
-platform, it is way easier to educate other IT people and even if the
-head IT is sick another one could pick up the task without too much
-hassle.</p>
-
-<p><strong>What do you see as the disadvantages of Skolelinux/Debian
-Edu?</strong></p>
-
-<p>The only real problem I see is that it is a little too less
-flexible at client level. Debian stable is rocky and desirable, but
-there are many reasons that force for another choice. For example the
-need of new drivers for new PC, or the need for a specific OS for some
-devices that have specific software packages for another specific
-distribution (I have such a case for whiteboards that have only
-Ubuntu packages). Thus, I prepared compatibility packages educlient
-and eduroaming, hoping not to use them ;-)</p>
-
-<p><strong>Which free software do you use daily?</strong></p>
-
-<p>I have a Debian Stable PDC at school (Kerberos, NIS, NFS) with
-mixed Debian and Ubuntu clients. If you think that this triad
-combination is exotic... well I discovered right yesterday that
-<a href="http://moo.nac.uci.edu/~hjm/Perceus-Report.html">Perceus</a>
-has the same...</p>
-
-<p>For myself I run Debian wheezy/sid, but this combination is good
-only I you have enough competence to fix stuff for yourself, if
-something breaks. Daily I use texmacs, gnumeric, a little bit of R
-statistics, kmplot, and less frequently OpenOffice.org.</p>
-
-<p><strong>Which strategy do you believe is the right one to use to
-get schools to use free software?</strong></p>
-
-<P>I think that the only real argument that school managers "hear" is
-cost reduction. They don't give too much weight on quality, stability,
-just because they are normally not open to change.</p>
-
-<p>Students adapts very quickly to GNU/Linux (and for them being able
-to switch between different OS is a plus value); teachers and managers
-don't.</p>
-
-<p>We decided to move to Linux because students at our school have own
-laptop and we have the responsibility to keep the laptop ready to use;
-we were really unsatisfied with Microsoft since every Monday we had 20
-machine to fix for viral infections... With Linux this has been
-reduced to zero, since people installs almost only from official
-repositories. I think that our special needs brought us to Linux.
-Those who don't have such needs will hardly move to Linux.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Modalias_strings___a_practical_way_to_map__stuff__to_hardware.html">Modalias strings - a practical way to map "stuff" to hardware</a></div>
+ <div class="date">14th January 2013</div>
+ <div class="body"><p>While looking into how to look up Debian packages based on hardware
+information, to find the packages that support a given piece of
+hardware, I refreshed my memory regarding modalias values, and decided
+to document the details. Here are my findings so far, also available
+in
+<a href="http://anonscm.debian.org/viewvc/debian-edu/trunk/src/hw-support-handler/">the
+Debian Edu subversion repository</a>:
+
+<p><strong>Modalias decoded</strong></p>
+
+<p>This document try to explain what the different types of modalias
+values stands for. It is in part based on information from
+<URL: <a href="https://wiki.archlinux.org/index.php/Modalias">https://wiki.archlinux.org/index.php/Modalias</a> >,
+<URL: <a href="http://unix.stackexchange.com/questions/26132/how-to-assign-usb-driver-to-device">http://unix.stackexchange.com/questions/26132/how-to-assign-usb-driver-to-device</a> >,
+<URL: <a href="http://code.metager.de/source/history/linux/stable/scripts/mod/file2alias.c">http://code.metager.de/source/history/linux/stable/scripts/mod/file2alias.c</a> > and
+<URL: <a href="http://cvs.savannah.gnu.org/viewvc/dmidecode/dmidecode.c?root=dmidecode&view=markup">http://cvs.savannah.gnu.org/viewvc/dmidecode/dmidecode.c?root=dmidecode&view=markup</a> >.
+
+<p>The modalias entries for a given Linux machine can be found using
+this shell script:</p>
+
+<pre>
+find /sys -name modalias -print0 | xargs -0 cat | sort -u
+</pre>
+
+<p>The supported modalias globs for a given kernel module can be found
+using modinfo:</p>
+
+<pre>
+% /sbin/modinfo psmouse | grep alias:
+alias: serio:ty05pr*id*ex*
+alias: serio:ty01pr*id*ex*
+%
+</pre>
+
+<p><strong>PCI subtype</strong></p>
+
+<p>A typical PCI entry can look like this. This is an Intel Host
+Bridge memory controller:</p>
+
+<p><blockquote>
+pci:v00008086d00002770sv00001028sd000001ADbc06sc00i00
+</blockquote></p>
+
+<p>This represent these values:</p>
+
+<pre>
+ v 00008086 (vendor)
+ d 00002770 (device)
+ sv 00001028 (subvendor)
+ sd 000001AD (subdevice)
+ bc 06 (bus class)
+ sc 00 (bus subclass)
+ i 00 (interface)
+</pre>
+
+<p>The vendor/device values are the same values outputted from 'lspci
+-n' as 8086:2770. The bus class/subclass is also shown by lspci as
+0600. The 0600 class is a host bridge. Other useful bus values are
+0300 (VGA compatible card) and 0200 (Ethernet controller).</p>
+
+<p>Not sure how to figure out the interface value, nor what it
+means.</p>
+
+<p><strong>USB subtype</strong></p>
+
+<p>Some typical USB entries can look like this. This is an internal
+USB hub in a laptop:</p>
+
+<p><blockquote>
+usb:v1D6Bp0001d0206dc09dsc00dp00ic09isc00ip00
+</blockquote></p>
+
+<p>Here is the values included in this alias:</p>
+
+<pre>
+ v 1D6B (device vendor)
+ p 0001 (device product)
+ d 0206 (bcddevice)
+ dc 09 (device class)
+ dsc 00 (device subclass)
+ dp 00 (device protocol)
+ ic 09 (interface class)
+ isc 00 (interface subclass)
+ ip 00 (interface protocol)
+</pre>
+
+<p>The 0900 device class/subclass means hub. Some times the relevant
+class is in the interface class section. For a simple USB web camera,
+these alias entries show up:</p>
+
+<p><blockquote>
+usb:v0AC8p3420d5000dcEFdsc02dp01ic01isc01ip00
+<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic01isc02ip00
+<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic0Eisc01ip00
+<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic0Eisc02ip00
+</blockquote></p>
+
+<p>Interface class 0E01 is video control, 0E02 is video streaming (aka
+camera), 0101 is audio control device and 0102 is audio streaming (aka
+microphone). Thus this is a camera with microphone included.</p>
+
+<p><strong>ACPI subtype</strong></p>
+
+<p>The ACPI type is used for several non-PCI/USB stuff. This is an IR
+receiver in a Thinkpad X40:</p>
+
+<p><blockquote>
+acpi:IBM0071:PNP0511:
+</blockquote></p>
+
+<p>The values between the colons are IDs.</p>
+
+<p><strong>DMI subtype</strong></p>
+
+<p>The DMI table contain lots of information about the computer case
+and model. This is an entry for a IBM Thinkpad X40, fetched from
+/sys/devices/virtual/dmi/id/modalias:</p>
+
+<p><blockquote>
+dmi:bvnIBM:bvr1UETB6WW(1.66):bd06/15/2005:svnIBM:pn2371H4G:pvrThinkPadX40:rvnIBM:rn2371H4G:rvrNotAvailable:cvnIBM:ct10:cvrNotAvailable:
+</blockquote></p>
+
+<p>The values present are</p>
+
+<pre>
+ bvn IBM (BIOS vendor)
+ bvr 1UETB6WW(1.66) (BIOS version)
+ bd 06/15/2005 (BIOS date)
+ svn IBM (system vendor)
+ pn 2371H4G (product name)
+ pvr ThinkPadX40 (product version)
+ rvn IBM (board vendor)
+ rn 2371H4G (board name)
+ rvr NotAvailable (board version)
+ cvn IBM (chassis vendor)
+ ct 10 (chassis type)
+ cvr NotAvailable (chassis version)
+</pre>
+
+<p>The chassis type 10 is Notebook. Other interesting values can be
+found in the dmidecode source:</p>
+
+<pre>
+ 3 Desktop
+ 4 Low Profile Desktop
+ 5 Pizza Box
+ 6 Mini Tower
+ 7 Tower
+ 8 Portable
+ 9 Laptop
+ 10 Notebook
+ 11 Hand Held
+ 12 Docking Station
+ 13 All In One
+ 14 Sub Notebook
+ 15 Space-saving
+ 16 Lunch Box
+ 17 Main Server Chassis
+ 18 Expansion Chassis
+ 19 Sub Chassis
+ 20 Bus Expansion Chassis
+ 21 Peripheral Chassis
+ 22 RAID Chassis
+ 23 Rack Mount Chassis
+ 24 Sealed-case PC
+ 25 Multi-system
+ 26 CompactPCI
+ 27 AdvancedTCA
+ 28 Blade
+ 29 Blade Enclosing
+</pre>
+
+<p>The chassis type values are not always accurately set in the DMI
+table. For example my home server is a tower, but the DMI modalias
+claim it is a desktop.</p>
+
+<p><strong>SerIO subtype</strong></p>
+
+<p>This type is used for PS/2 mouse plugs. One example is from my
+test machine:</p>
+
+<p><blockquote>
+serio:ty01pr00id00ex00
+</blockquote></p>
+
+<p>The values present are</p>
+
+<pre>
+ ty 01 (type)
+ pr 00 (prototype)
+ id 00 (id)
+ ex 00 (extra)
+</pre>
+
+<p>This type is supported by the psmouse driver. I am not sure what
+the valid values are.</p>
+
+<p><strong>Other subtypes</strong></p>
+
+<p>There are heaps of other modalias subtypes according to
+file2alias.c. There is the rest of the list from that source: amba,
+ap, bcma, ccw, css, eisa, hid, i2c, ieee1394, input, ipack, isapnp,
+mdio, of, parisc, pcmcia, platform, scsi, sdio, spi, ssb, vio, virtio,
+vmbus, x86cpu and zorro. I did not spend time documenting all of
+these, as they do not seem relevant for my intended use with mapping
+hardware to packages when new stuff is inserted during run time.</p>
+
+<p><strong>Looking up kernel modules using modalias values</strong></p>
+
+<p>To check which kernel modules provide support for a given modalias,
+one can use the following shell script:</p>
+
+<pre>
+ for id in $(find /sys -name modalias -print0 | xargs -0 cat | sort -u); do \
+ echo "$id" ; \
+ /sbin/modprobe --show-depends "$id"|sed 's/^/ /' ; \
+ done
+</pre>
+
+<p>The output can look like this (only the first few entries as the
+list is very long on my test machine):</p>
+
+<pre>
+ acpi:ACPI0003:
+ insmod /lib/modules/2.6.32-5-686/kernel/drivers/acpi/ac.ko
+ acpi:device:
+ FATAL: Module acpi:device: not found.
+ acpi:IBM0068:
+ insmod /lib/modules/2.6.32-5-686/kernel/drivers/char/nvram.ko
+ insmod /lib/modules/2.6.32-5-686/kernel/drivers/leds/led-class.ko
+ insmod /lib/modules/2.6.32-5-686/kernel/net/rfkill/rfkill.ko
+ insmod /lib/modules/2.6.32-5-686/kernel/drivers/platform/x86/thinkpad_acpi.ko
+ acpi:IBM0071:PNP0511:
+ insmod /lib/modules/2.6.32-5-686/kernel/lib/crc-ccitt.ko
+ insmod /lib/modules/2.6.32-5-686/kernel/net/irda/irda.ko
+ insmod /lib/modules/2.6.32-5-686/kernel/drivers/net/irda/nsc-ircc.ko
+ [...]
+</pre>
+
+<p>If you want to help implementing a system to let us propose what
+packages to install when new hardware is plugged into a Debian
+machine, please send me an email or talk to me on
+<a href="irc://irc.debian.org/%23debian-devel">#debian-devel</a>.</p>
+
+<p><strong>Update 2013-01-15:</strong> Rewrite "cat $(find ...)" to
+"find ... -print0 | xargs -0 cat" to make sure it handle directories
+in /sys/ with space in them.</p>
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