Observations from Uppsala

I have a paper about “Transporting Bugs with Checkpoints” to be presented at the S4D (System, Software, SoC and Silicon Debug) conference in Southampton, UK, on September 15 and 16, 2010. The core concept presented is to leverage Simics checkpointing to capture and move a bug from the bug reporter to the responsible developer. It is a fairly simple idea, but getting it to work efficiently does require that some things are done right. See the longer Wind River blog posting about this topic for a few more details.

Past Friday, I posted a new blog post in my Wind River blog. It is an interview the PhD student Girish Venkatasubramanian from the University of Florida. He is doing research on virtual machines/hypervisors and how they can be implemented more efficiently by making fairly small changes to the architecture of memory management units.

Read more…

I listened to an interesting FLOSS Weekly interview with Adam Hall and Achim Hasenmuller of VirtualBox. For someone interested in virtual machines and hardware simulation, the interview was full of interested tidbits. I think the best part was the discussion on multiprocessing in Virtualbox.

Read more…

I just posted a blog post called “Shiny Old Hardware” at my Wind River blog. In it, I discuss why modeling old computer hardware to build virtual systems make sense. Virtual platforms are just not all about the next-generation stuff.

I recently read a couple of articles on multicore that felt a bit like jumping back in time. In IEEE Spectrum, David Patterson at Berkeley’s parallel computing lab brings up the issue of just how hard it is to program in parallel and that this makes the wholesale move to multicore into something like a “hail Mary pass” for the computer industry. In Computer World, Chris Nicols at NICTA in Australia asks what you will do with a hundred cores – implying that there is not much you can do today. While both articles make some good points, I also think they should be taken with a grain of salt. Things are better than they make them seem. Read more…

The recent news that Microsoft has taken out an ARM architectural license has caused a lot of speculation about just what this might mean. There are several quite well reasoned ideas around the web, and I have one idea of my own: sixty-four bits.

Read more…

There is a very interesting worm going around the world right now which is specifically targeting industrial control systems. According to Business Week, the worm is targeting a Siemens plant control system, probably with the intent to steal production secrets and maybe even information useful to create counterfeit products. This is the first instance I have seen of malware targeting the area of embedded systems. However, the actual systems targeted are not really embedded systems, but rather regular PCs running supervision and control software.

Read more…

Following on my previous posts about broken phone browsers, phones, and cars, here is another case of “why didn’t they catch this in testing?”

We recently got ourselves an iPod Touch, to entertain our oldest child on long trips. It is a brilliant device in many ways, I can understand why people love their iPhones (even though I am very happy with the very different style of the Blackberry phone that I was given by my employer). However, I have found one weird behavior in the music player that leaves me wondering how it got through into the shipping product.

Read more…

Continuing on the thread from my previous post about the testing of products that fail to find problems that become obvious to (some) users after a very short time, I just read an article (in Swedish) about how the famed Tesla roadster cars behaved when they were confronted with Scandinavian winters.

Read more…

Legoland is full of cool and interesting Lego models, built from millions and millions of Lego bricks. The creations don’t have too much in common with the standard Lego kits sold in stores. Rather, they are advanced uses of Lego bricks that look like something from the real world — especially at a distance. Up close, they are very blocky and not as smooth and polished as regular Lego models.

Essentially, they are voxel graphic representations that must be very hard to plan and execute.  The standard single-stud 1×1 Lego brick is their smallest unit, or maybe its 1/3 height flat version. Here are some examples that I photographed in Legoland during my visit this Summer.

Read more…

Another Summer vacation has come around, and as usual that causes a blog post or two on Summer tips and comments on places where I have been. This year, we went down to Denmark to visit the city of Billund, home to Legoland and Lalandia. Lalandia is an interesting mix of indoors activity center and camping village. We rented a house there for our vacation, and are overall very pleased with the place.

Read more…

I have a blog post called “When is Scripting Really Programming” up at the Wind River blog network. In that post, I discuss how scripting is really not clearly separated from “real programming” in the way I once believed it was… today, the line between higher-level programming languages and scripting languages look very thin in many cases. I illustrate with examples from Simics and its CLI and Python scripting systems.

The call for papers for the third annual Swedish Workshop on Multicore Computing (MCC10) is now out! MCC is a nice venue for multicore research about everything from computer design to software and debug. It is fairly informal, but still attracts some good papers and provides good discussions. It is not restricted to Swedish submissions, in 2009 there were several international participants. I gave a keynote talk about multicore and Simics at last year’s MCC, and for this year, I am on the program committee and looking forward to many great submissions to review!

I have another blog up at Wind River. This one is about multicore bugs that cannot happen on multithreaded systems, and is called True Concurrency is Truly Different (Again). It bounces from a recent interesting Windows security flaw into how Simics works with multicore systems.

I recently started using a new mobile phone, a Blackberry Bold 9700. I am a bit ambivalent on some of its design features, but it is certainly a very different device from the much more friendly SonyEricsson I had before. Like anybody would do, I have been playing around with it to see what it can do and what not (notable things not working: the “AppWorld” application store is not available in Sweden, YouTube videos do not play in any way that I can figure out).

And almost inevitably, as you play around with a complex modern piece of software (which is what most of the phone is, after all), you find some obvious things which are just plain broken. You wonder, “why didn’t they think of this”, and “how could this ever escape testing?” My current best example is that the built-in web browser does not render the pages from Blackberry’s own support knowledgebase.

Read more…