Umberto Raimondi 's Blog

Upgrading the ATI drivers and configuring OpenCL in Ubuntu

Admin — Sun, 05 Sep 2010 22:00:49 +0000

I’m planning a series of post about OpenCL basics and its use ( simple kernels, smoke modelling with Navier-Stokes equation and usage with python) , but before that, a short post on upgrading drivers and basic environment configuration could be useful. Especially when done in conjunction with a kernel upgrade, the update of the ATI graphic drivers is a bit tricky.
Unlike CUDA or Stream, OpenCL library is CPU/GPU architecture-independent, so this will be the only post where you’ll read something limited to ATI card owners. We’ll use ATI Radeon 57xx logical schematics in the next post to understand how modern GPUs are structured internally but every consideration will also apply to GPUs from other vendors.

The recommended procedure to perform a driver update consists of three steps: uninstalling the old drivers, building custom .deb packages/installing them, build the initial configuration.
So, first of all, uninstall the drivers and delete the obsolete fglrx packages:

# sudo sh /usr/share/ati/fglrx-uninstall.sh
# sudo apt-get remove --purge fglrx_* xorg-driver-fglrx

Download from ati.com the latest drivers, generate .deb and install (using 10.04, same procedure applies to other *recent* builds):

# sh ati-driver-installer-10-8-x86.x86_64.run --buildpkg Ubuntu/lucid
# sudo dpkg -i fglrx*.deb

Initialize /etc/X11/xorg.conf (a backup is generated) and after this reboot/restart X:

# sudo aticonfig --initial -f

To verify that everything has gone as expected (this will display the current driver version):

# fglrxinfo

Regarding OpenCL environment configuration, the official ATI documentation does a good job, easy and fast installation. Get the Stream SDK and the OpenCL ICD configuration (new in 2.2) from the developer site and follow these steps.
Untar the SDK in a directory of your choice and add to your .bash_profile (or equivalent) these lines, customizing where needed:

export ATISTREAMSDKROOT=<...>/ati-stream-sdk-v2.2-lnx64
export LD_LIBRARY_PATH=$ATISTREAMSDKROOT/lib/x86_64:$LD_LIBRARY_PATH

Untar the ICD configuration archive (will put vendor-specific configuration files in /etc/OpenCL/vendors):

# cd /
# sudo tar xfz icd-registration.tgz

To verify the successful installation, reload your .bash_profile (source ~/.bash_profile) go to …/ati-stream-sdk-v2.2-lnx64/samples/opencl , compile the opencl samples with make and then:

.../ati-stream-sdk-v2.2-lnx64/samples/opencl/bin/x86_64# ./CLInfo

Verify that both CL_DEVICE_TYPE_CPU and CL_DEVICE_TYPE_GPU are present in the output.
As last test and if you want to qualitatively evaluate performance differences, try Mandelbrot with –device cpu and –device gpu.

Amazon AWS, Cloud Computing and economies of scale

Admin — Sat, 10 Apr 2010 15:21:44 +0000

A really interesting presentation given at MIX10 (Microsoft sponsored conference) by James Hamilton regarding Cloud computing and its implementation in Amazon Web Services.
After a brief introduction about the reasons why AWS is economically sustainable and why it was mandatory for Amazon considering the large amount of underutilized servers they had, he provides a sneak peek on how an Amazon Data Center is structured and what kind of problem them or anyone else building a “cloud” have to address (power/cooling/maximize utilization). Well worth one hour of your time. You’ll need Silverlight(win) or Moonlight(lnx/firefox) to play this one, if you don’t feel inclined to install it, go straight to the site and download the mp4 recording.

HTC Magic ADB USB driver install instructions

Admin — Mon, 06 Jul 2009 19:11:22 +0000

If you diligently followed the android driver install instruction from the Android Developer site but your HTC Magic is still discovered only as an “HTC Android Phone USB Device” and an unknown device named “ADB” because the driver contained in the last SDK ( android-sdk-windows-1.5_r2\usb_driver\x86\ ) is not recognized, follow these steps:

Open the Device Manager, select the ADB Device and open the Details tab. Look for “Device Instance Id”, it should be something like vid_0bb4&pid_0c0*.
If your * is not 2, these instructions will probably solve your issue.

Disconnect your device and uninstall the two discovered devices (i used usbdeview but you can do it manually from the Device Manager).

Open with a text editor android-sdk-windows-1.5_r2\usb_driver\x86\android_usb.inf.
Replace all the vid_0bb4&pid_0c02 occurrences with vid_0bb4&pid_0c0* (e.g. vid_0bb4&pid_0c03).

Connect your phone and when asked for driver choose to specify manually a path and select android-sdk-windows-1.5_r2\usb_driver\x86\.

If the installation is successful, to verify that all is ok execute android-sdk-windows-1.5_r2\tools\adb devices, your phone should be listed in the device table.

Thanks to Wysie, for the full discussion see the original thread. After following this procedure even HTC Sync should work.

UPDATE: This procedure should likely work for HTC Hero, Touch and Samsung Galaxy too, just substitute where needed the “Device Instance Id” found at step 1.

UPDATE 4/10/10: Confirmed, this procedure still works for newer phones like the Desire, just use a correct Device Id.

Software development books for Christmas 2008

Admin — Tue, 23 Dec 2008 10:07:02 +0000

In a post on JavaLobby, Meera presents her TOP5 of technical books published in 2008.
I definitely agree with the first two: a new book from Robert C. Martin, the second edition of the great Effective Java.
I haven’t read yet the first one but i liked his “Agile Software Development” and the initial reviews are quite good.
The new edition of Effective Java contains 21 new items and presents 1.5 language features such as enum, generics and annotations and also updates items related to improved features e.g. items in the concurrency section.
If you are a software developer or if you know one, this time of the year is the right time to buy one of these books.
Let me add a few more titles, that even if not published in 2008 (or not technical) could be good gift ideas:

	*Java Puzzlers: Traps, Pitfalls and corner cases* Another book from the great Joshua Bloch based on the JavaOne’s serie of presentations, full of thought-provoking “puzzles” related to details or known bug of the Java language. Here is a video of one of the Joshua’s presentations:
	*C++ Common Knowledge: Essential Intermediate Programming* As the cover says : “What Every Professional C++ Programmer Needs to Know—Pared to Its Essentials So It Can Be Efficiently and Accurately Absorbed”. As an Effective Java for the C++ language, it uses the same itemized approach and it describes very clearly and with many examples what every C++ programmer should know. Perfect for anyone who needs to review the language skipping the basics.
	My job went to India In this book published in 2005 , Chad Fowler takes his experience with outsourcing in India as a starting point to give reasonable advices about IT carer development. Even if some of these could sound obvious (as reasonable advices usually are), the book is still an enjoyable reading and give you the opportunity to review the way you approach your job in IT and think about what could be improved. Highly recommended.
	Permutation City A post-cyberpunk sci-fi book by Greg Egan, full of clever ideas about AIs, future post-death scenarios and virtual reality.

DNS-323/CH3SNAS Packages recap

Admin — Mon, 15 Dec 2008 19:51:56 +0000

Here is a brief recap of the new packages i built for the DNS-323/321/343/CH3SNAS and available here (fonz funplug 0.5 is required):

Lynx 2.8.6: The textual web browser;
Alpine 2.0: Successor of Pine, textual mail reader;
Aria2 1.0: Multi-threaded file download, it should support also bittorrent.

UPDATE: Added Htop 0.8.3 , a nice top-like process manager with tree view and other goodies (simpler arrow navigation , easily accessible kill/nice).

As usual, you can install it using:
funpkg -i htop-0.8.3.tgz

DNS-323/CH3SNAS: A low cost NAS and embedded development

Admin — Sat, 13 Dec 2008 14:51:17 +0000

If you are looking for a low cost NAS you surely will come across with three devices: the Linksys NSLU2, the Iomega MyBook WE and the D-Link DNS-323 (or its sibling CH3SNAS pitcured on left).
Devices with similar functionality (all of them support Samba/FTP/ITunesServer/UPNPAVServer/etc…) and that in a similar fashion have been greatly extended thanks to the community. The NSLU2 with its custom firmware, linux distributions and the optware package repository, the MyBook WE with a first customized firmware and now with a full fledged community and the DNS-323/CH3SNAS with the fonz’s fun_plug and the huge amount of modifications that came after that.
Something similar to what always happens to devices based on FOSS and when the opportunity to enhance them is given to the community and something, in my opinion, that always boosts the “saleability” of such products, just think to the famous Linksys WRT54G.
I got my own Conceptronic CH3SNAS last year, and since then i enjoyed the progress made by the community and contributed my little share when possible.
You can now find all my DNS323/CH3SNAS binaries here. Feel free to try them and call for support if needed.

After this long preamble about opensource and NASes, let’s talk briefly about Linux and embedded development.
There are many ways to start learning Linux for those who come from a MSWindows background such as installing a random distribution, maybe on a virtual machine, and so on…
But what the DNS323 and similar devices give you is the opportunity to get a taste of what embedded development is.
The hardware platform reminds what you could find in your average pocket-pc and is good enough for this use: a Marvell SoC with an ARM926Tj at 500Mhz and 64Mb of RAM.
Don’t limit your experience to installing a different UPnP AV Server or the latest Transmission/mldonkey, try to compile some software yourself and experiment.
Browse the WIKI to discover what a toolchain is, how you can cross-compile software for different CPUs (in this case an ARM926) on a x86 host and which are the main differences among glibc and libraries like uclibc, eglibc, etc…
This post should contain enough pointers for you to start .

Google: The early days

Admin — Fri, 12 Sep 2008 20:19:45 +0000

In handwritten letters it said, “Google World Headquarters”.

Ubergizmo publishes this touching interview from 1998 and this reminds me of the great book “The Search” by John Battelle , a vivid and detailed description of the search market in the pre-bubble era (plus some chapters with debatable content about the future of the search engine and the search market in general).
Maybe it’s the right time to start “Founders at Work” or to buy the recent “Once You’re Lucky, Twice You’re Good”.
All Books about great people and successful ventures, someone should really write something similar to Banvard’s Folly (GREAT book with awesome stories) set in the bubble era, possibly non following the Startup.com documentary lousy approach…

SUN Spot

Admin — Sun, 03 Aug 2008 09:27:36 +0000

Open-source electronics platforms for rapid prototyping have already been around for a while, i can think of Arduino board but surely there are more of them.
The low cost, the wide variety of inputs/outputs, the ability to interact with sensors ot to control motors, the ease of use and the community, make these platforms a perfect fit for hobbyist’s and artist’s projects.
Regarding the ease of use, Arduino can be programmed in a c-like language ( additional straightforward libraries to access the board’s functions are provided ) and has a development environment based on the famous Processing.
And now, SUN Spot.

I’ve spotted the video embedded below on the googletechtalks youtube channel.

The platform developed by SUN Laboratories seems awesome:

Completely open source (hardware/software)

180 MHz 32 bit ARM920T core (with jazelle?) - 512K RAM/4M Flash

2.4 GHz IEEE 802.15.4 radio with integrated antenna

USB interface (host?)

2G/6G 3-axis accelerometer

Temperature sensor

Light sensor

8 tri-color LEDs

6 analog inputs

2 momentary switches

5 general purpose I/O pins and 4 high current output pins

100 mt max distance between Spots (more info on this on the sunspotworld.com forum, the devices together form a meshed network, so multiple stations can be used to extend the network civerage, but the maximum distance between two spots seems limited to that)

Missing agps and only 4mb flash you say? Looks like someone already built a custom gps module and SD module for their projects. Some new addons have been shown at JavaOne2008.

The SUN Spot can be programmed enterely in Java, and has a development platform based on NetBeans (Eclipse can also be used).
Refer to the embedded video for some example projects. Above all, watch @00:21 for the cool Sun Blackbox monitoring project.
It comes in a developer kit with 1 Spot base station and 2 standard Spots for under $700, a kit that reminds me of the early openmoko developers kit.
The two things that i found most intriguing are the ability to upload new “software packages” wirelessly (in this presentation is done through a management interface, could this be done dinamically using the java api provided?) and the way the meshed wireless network formed by Spots is managed (i should take a look at this sooner or later).
Additional videos about Sun Spot and projects based on it can be found on youtube.