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Writing Wireshark Plugins in C

tags: n900, wireshark, phonet, isi, c 2010-10-05 02:38 by sre

After some time writing the phonet dissector for wireshark in lua I noticed the disadvantages:

So I tried the C interface. I found the basic structure for plugins pretty fast in their documentation and thought about some design changes in the plugin:

Writing Wireshark Plugins

tags: n900, debian, wireshark, lua, phonet, isi 2010-08-26 01:10 by sre

In the last days I finally got some bits out of the Nokia N900’s modem on Debian without any properitary tools. For now it’s just the following information:

manufacturer: "Nokia"
model: "Nokia N900"
revision: "V ICPR82_10w08 25-02-10 RX-51 (c) Nokia"

But the most difficult part is probably done. My next plan was to get the modem connect to a mobile network, which requires an unlocked SIM card. Unfortunately ofono does not yet support SIM cards with PINs. Thus I had to find another way to get out how to perform this task.

Another Debian on N900 Update

tags: n900, debian, enlightenment 2010-08-15 17:47 by sre

First of all the Debian on N900 page moved to https://elektranox.org/n900. Now about the recent changes:

Highpoint rr272x driver on a cutting-edge system

tags: highpoint, rr272x, debian, linux, kernel, udev 2010-07-25 14:34 by sre

I had lots of fun with my server the last days. Apart from broken memory, a mainboard with weird behaviour and defect SATA cables I tried to use my RocketRaid 2720. There is currently no support for this piece of hardware in the mainline kernel (PCI device ID: [1103:2720]), even though there is an ‘mvsas’ driver, which is supposed to support the chip used by the rr272x series.

But one can download an ‘Open Source’ driver from Highpoint’s webpage and precompiled kernel modules for Debian’s 2.6.26 kernel. FYI even using their precompiled module with Debian stable and 2.6.26 kernel I got lots of problems, which are inherited to the updated system. I will talk about these in another blog entry.

After trying the precompiled kernel module I tried their ‘Open Source’ driver. First of all: it’s not Open Source. There is some sourcecode, which builds some code using their *.o precompiled blob. This is the same as the NVIDIA driver and definitively not Open Source. Next I tried to use the compiled kernel module under Debian squeeze with 2.6.32 and the result was a nice kernel crash once a disk is connected. After hours of testing I figured out, that it’s not a problem of the updated kernel, but a problem of the updated udev.

One can use the driver running even 2.6.34 as long as one uses the udev from Debian stable (125). There is one drawback though: /proc/scsi/rr272x_1x is not created by the driver then (so the CLI is not working).

The problem is: new software (e.g. cryptsetup from testing) depends on libudev0, which does not exist in Debian stable. The libudev0 from Debian squeeze depends on udev 158, so one can’t install it from there either. I ended up using udev from Debian stable and libudev0 from Debian unstable. The remaining system is a normal Debian testing (squeeze). I suggest to add a Pin for udev to apt’s preferences:

$ cat /etc/apt/preferences

Package: udev
Pin: release a=stable
Pin-Priority: 1000

I reported this to HighPoint using their WebSupport as #4659. So far I got told, that there are more users with the problems (what a coincidence…) and that they notified their engineering team.

the fatal ways of the sheevaplug

tags: hardware 2010-07-17 19:56 by lhw

It’s been about 10 month now since I ordered 7 SheevaPlugs, a plug sized computer, from GlobalScale. Everything ran smoothly for the next months till about 2 weeks ago when it suddenly became unresponsive and spammed the network with packages slowing down my other clients. A few more days later and it broke down completly with a blinking green LED. As it turned out this was already the second dead SheevaPlug after the one sre got back then.

After just about 1 minute search you will find the following thread on plugcomputer.org, the official forums: Is my sheevaplug dead ???. After reading the thread for a while it was obviously the power supply units fault. Seeing some of the pictures its a miracle that thing worked in the first place. The average lifetime of the PSU is about 9 month according to the thread. NewIt.co.uk the british GlobalScale reseller even offers the PSU as single product nowadays.

I first thought about buying on of those but then I probably would have gotten the same faulty PSU again. So I tried locating the defect parts on my one. I replaced an electrolytic capacitor and checked the output under stress with a 12cm fan, which seemed to work. But not when connected to the SheevaPlug which seems to suck that PSU to its uppermost limit. So there were more faulty parts which I couldn’t locate beneath all that brownish/blackish glue.

In the end I removed the internal openframe PSU and connected it to an cheap external power supply. As board connector the plug from an old PC case speaker fits perfectly.

And here some pictures of the now again working SheevaPlug: