November 2013
Using Linux Network Namespaces for per processes routing
The use case for this article may seem a bit strange in year 2013 but I swear it’s real. I have a (relatively) fast connection but I have a traffic cap on it and a (really) slow one which is flat. I would like to run not interactive task like “aptitude safe-upgrade” on the slow one but the bulk of my connections should go through the fast one. The work is done on a Debian Wheezy system, check that the “ip” command is not too old and lacks network namespace support.
Linux Linux Desktop Namespaces Networking Routing Sysadmin
7 minutes
Linux benchmark on Xilinx Spartan-6 LX45 (SP605 evk)
I was asked to give at least a generic insight of “how fast” would Linux run in a Microblaze soft-CPU running on a Spartan-6 LX45 processor (specifically on the SP605 evaluation kit). Of course it has to be clear that the usage of such a processor/environment cannot focus on pure performance reasons, as you usually choose a FPGA for other reasons. For pure performance there are much better solutions (hardware based CPUs indeed) or if you need also the FPGA advantages processors with both a FPGA part and a hardware CPU, such as the Zynq family processors for example.
Linux Linux Drivers Linux Embedded Microblaze Nbench Petalinux Sp605 Spartan-6 Xilinx
2 minutes
April 2013
TOR+Privoxy minimal setup for DGN2200v3/MIPS architecture
In a previous article I talked about how to customize the Linux based WLAN+ADSL Netgear DGN2200v3 router and prepared various binary packages ready for the device. In this short article I’m offering a small full setup that can be run on this router (and many other compatible ones and in general on any MIPS+uClinux hardware setup) to be able to use easily the TOR network to browser anonymously. In this way all the users behind the router can easily achieve anonymous surfing.
Anonymizer Anonymous Surfing Dgn2200v3 Embedded Linux Linux Desktop Linux Embedded Mips Security Teaching Material The Onion Ring TOR Transparent Proxy
5 minutes
February 2013
Linux iMX23 audio loop (or using the iMX23 as an amplifier)
As usual when working with embedded systems every component saved seems like gold to the HW guys (no matter how much software hassles or future limitations this may cause!) and in this context lately I’ve been working on the idea to use the Freescale iMX23 processor, that was anyway present in the project for other needs, as an audio amplifier to pilot a small speaker with no special volume requirements. Basically the output of a GSM module (audio out) was connected to the MIC input of the iMX23 and then the output to the speaker, just with little strictly needed passive electronics in between. As by the datasheet the processor should be able to pull out till 1.9W at 4Ω and there were some interesting registers to play with, even if not documented so very clearly nor seemed to be used anyhow in the audio driver provided. The software base used was the LTIB based BSP provided by Freescale, including their kernel patches for a 2.6.31 kernel.
Audio BM_AUDIOOUT_TEST_ADCTODAC_LOOP Drivers Embedded Freescale Imx23 Linux Linux Drivers Linux Embedded Loopback Teaching Material
4 minutes
January 2013
pyargocat: Argo Navis Catalog manager in Python
pyargocat is a small simple Python script that can be used to program the catalogs of the Argo Navis Digital Telescope Computer from a machine with a recent Python interpreter installed using the RS232 cable that you can either buy or easily construct yourself. pyargocat can manage, that is insert to the device, all three types of catalogs in the device (asteroids, comets and user defined objects), report the number of objects present, report available space and delete previously flashed catalogs. It can be used on any machine with a Python >= 2.7 installed and it has been tested on Linux and Windows machines. The imported catalogs have to be in the standard format Argo Navis uses (please refeer to the Argo Navis manual for the details and for links to useful resources). As an example and as a possible useful addition for your advanced observing sessions you can download this sample file I created that I often use as a basis: fede-general.txt. (the file contains all the Abell planetaries, the complete ARP catalog of Peculiar galaxies, the Hickinson galaxy groups catalog, most of the PK Planetary Nebula catalog and a selection of particullar globular clusters such as the Palomars and Terzans). Also a comet database file is given as an example with the most interesting comet objects data at the time of writing: Comets.txt Download: pyargocat-0.1.tar.gz.
Argo Navis Astronomy Linux Linux Desktop Python Science
3 minutes
How to cross-compile under Linux
Recently I’ve been asked by a few people how to crosscompile programs/packages under Linux. This happened especially after the article on customizing the DGN2200v3 (you can find here) but also for work reasons. In this article I’ll try to give some insights on this operation that is often feared, but is generally not a very hard task (yes I said generally: try for example crosscompiling something like the openjdk and you’ll understand what I mean!). This article will try to be generic but with some more examples on the DGN2200v3 crosscompilation and some ARM references. Get and install the right tools The first thing to do if of course to install on the system you are working (which is called host system) the tools that run on the host and will permit you to compile something for the target system you want to compile the programs for. This set of programming tools is usually refeered as a toolchain and contains various things: usually one or a few compilers, one or a few linkers, an assembler, various header files, little or a lot of libraries and other simillar tools. If you are lucky you may get also a debugger packed. All this tools of course are compiled to run on your host machine but produce binaries that run on the target. Depending on how the toolchain was created you may also find supplied with it some set of tools that are ready to be run on the target to help your crosscompilation adventure. This operation may be very easy if you somehow received the crosscompiler package ready (as for example the DGN2200v3 you just download it from the Netgear site or you collegue may have passed it to you) as you just have to unpack it somewhere and then refeer to it.
Arm Compile Cross Crosscompile Dgn2200v3 Embedded Linux Linux Desktop Linux Drivers Linux Embedded Mips
11 minutes
November 2012
Customizing your Netgear DGN2200v3
The Netgear DGN2200v3 is a nice low cost Wireless (802.11b/g/n) ADSL2+ router that can be quite easily found. It is a nice piece of hardware and features some interesting features, such an USB host port to connect and share a USB storage device, and expecially is easily customizable for users interested in having a powerfull generic device running a Linux embedded operating system. Note: this is a heavily “Work in Progress” page so please check it out here and there if you are interested in the topic! (last update 09th June 2014) First of all you can find the source tree for the router at Netgear site starting from their GPL Open Source Code for Programmers page. The package also contains a suitable toolchain uclibc-crosstools-gcc-4.4.2-1. Everything described in this page refeers to the “official” firmware V1.1.00.10_1.00.10 . It may also apply to future updates and to the beta version that Netgear started to distribute but it may require slight modifications. The next step to access to your router internals is to enable the telnet shell using the debug backdoor present in the firmware. It is easily done by accessing (we suppose 10.0.1.69 is your router IP address) the URL: http://10.0.1.69/setup.cgi?todo=debug This will enable telnet connections from your local network. Just login with your administrator credentials. Once you entered you can analyze the running system, briefly:
Custom Customizing Dgn2200 Dgn2200v3 Embedded Firmware Hacking Linux Linux Desktop Linux Embedded Mips Netgear Screen Torrent
87 minutes
December 2011
ftdispi, a library for interfacing SPI devices with FTDI based USB to JTAG dongles
ftdispi is a small library that can be used to interface SPI devices to FTDI based USB to JTAG interfaces. It is based on libus-1.0. It was tested with the Xverve Signalyzer (USB VID 0x0403, PID 0xbca0). Have a look at the included example testftdispi.c for usage instructions.
Drivers FTDI JTAG Linux Linux Drivers SPI USB
1 minute
December 2009
Eurotech CTR1474 Linux driver. This is a powerful PC/104 board for DVR applications. It features an JPEG2000 codec and TWA2835 video processor.
Driver DVR Eurotech Linux Linux Drivers Pc104
1 minute
October 2009
Using Slovenian characters on an Italian keyboard
An article on how to use Slovenian characters under a Linux/GNU/X11 system. (in Slovene)
Desktop I18N Linux Linux Desktop Slovene X11
1 minute
crosstool-ng for the Maverick Crunch processors
crosstool-ng for the Maverick Crunch processors. With the generated toolchain you can use the FPU unit in this line of processors to speed-up calculations.
Embedded Linux Linux Embedded Toolchain
1 minute
August 2008
How to build a Debian based embedded distribution
Mindeb, an embedded distribution from scratch based on Debian Etch. (in Italian)
Debian Embedded Italian Linux Linux Embedded
1 minute
December 2006
Serocco PEB/PEF 20532 Linux 2.6.12 driver
Serocco driver. Linux 2.6.12 device driver for the chip “Serocco PEB/PEF 20532”
Driver Linux Linux Drivers Serial
1 minute
October 2006
Hopeless, a system for building disk-less clusters
Hopeless, the description of a system for easy set-up of disk-less clusters, based on unionfs.
Clustering Hpc HPC And Clustering Linux Unionfs
1 minute
March 2001
Enjoying Computers, Discovering Linux
An article about the course based on the ECDL syllabus based on Linux and open-source tools organized for high-school teachers published on Linux Journal Online.
Ecdl Linux Linux Desktop Open Source Teaching Teaching Material
1 minute