I am going to the S4D conference for the third year in a row. This year, I have a paper on reverse debugging, reviewing the technology, products, and history of the idea. I will probably write a longer blog post after the conference, interesting things tend to come up.
I am going to be talking about how to transport bugs with virtual platform checkpoints, in the Software Tools track at the Embedded Conference Scandinavia, on October 3, 2012, in Stockholm (Sweden). The ECS is a nice event, and there are several tracks to choose from both on October 2 and October 3. In addition to the tracks, Jan Bosch from Chalmers is going to present a keynote that I am sure will be very entertaining (see my notes from a presentation he did in Göteborg last year).
I am scheduled to talk at the SiCS multicore day 2012 (like I did back in 2009 and 2008). The event takes palce on September 13, at SiCS in Kista. My topic will be on System-Level Debug – how we can make debuggers that work for big systems.
This year, the multicore day is part of a bigger Software Week event, which also covers cloud and internet of things. See you there!
There is a new post at my Wind River blog, about how Simics was used to kick-start the development of the 64-bit version of VxWorks. It is an interesting example of how to use a virtual platform as a model of something much simpler and gentler than actual hardware systems.
There is a new post at my Wind River blog, about the testing on an integrated software stack in simulation. I base the discussion on the very interesting report about the Toyota “unintended acceleration” problems and the deep investigation into the control software of the affected vehicles performed by a NASA team (!). The report covers a lot of different tools, but also notes that about the only thing not done was to integrate the complete software stack in simulation.
There is a new post at my Wind River blog, about how you can use a virtual platform to complete work faster. Not by making the virtual platform execution of target code faster, but by optimizing the way you work and taking advantage of the features of a virtual platform.
There is a new post at my Wind River blog, about iterative hardware-software interface design. It is a discussion with some examples of why hardware designers would do well to use virtual platforms to include software designers in the loop when designing new devices and their programming interfaces.
I have a fairly lengthy new blog post at my Wind River blog. This time, I interview Tennessee Carmel-Veilleux, a Canadian MSc student who have done some very smart things with Simics. His research is in IMA, Integrated Modular Avionics, and how to make that work on multicore.
I just found the blog of an old real-time researcher friend of mine, John Regehr at the University of Utah.
It is at http://blog.regehr.org/ and covers a range of embedded topics relevant to his academic research (which is more embedded that most).
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.
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.
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.
I have now torn down the Kindergarten Robot, as I wanted to build some other things. However, before tearing it down, I did take a few more movies of its critical functions.
Today I finally got to try my MEPROM-equipped Lego Mindstorms robot with a larger group of kids. As expected, this did not go quite as expected.
As discussed in my previous blog post about Kindergarten robots, I wanted to see if I can teach kids the core idea of programming. This project has now progressed to the point that I have a working prototype of a programmable robot.
Essentially, the robot is programmed by putting colored Lego bricks in a sequence on top of the robot. This should be accessible and direct enough to work with kids — and with no computer needed, just direct physical interaction with the system. For some reason, I think the extra level of abstraction from a screen to a robot is just an unnecessary obstacle at this level.
One of my little projects while on parental leave has been to play around with my Lego Mindstorms NXT 2.0 robotics kit. Apart from being fun for a serious dad like myself, I always had in mind how I could use it with kids to get them interested in technology.
When I was a PhD student in Uppsala back around 2000, we bought a pile of the Lego Mindstorms RCX kits, for use in real-time courses. Obviously, the students loved the opportunity to play with Lego (including the few females). What was less obvious and much more interesting was what happened when we brought in a bunch of children from a local kindergarten to visit — they really took a liking to our little yellow robots running around a classroom. They treated the robots as little animals, wondering what they were doing and why…
With that in mind, I decided to try to reprise this myself with my own son and his kindergarten friends. Last week, I took my robot kit with me and went to meet the kids.
In his most recent Embedded Bridge Newsletter, Gary Stringham describes a solution to a common read-modify-write race-condition hazard on device registers accessed by multiple software units in parallel. Some of the solutions are really neat!
I have seen the “write 1 clears” solution before in real hardware, but I was not aware of the other two variants. The idea of having a “write mask” in one half of a 32-bit word is really clever.
However, this got me thinking about what the fundamental issue here really is.
I just spotted a fun little application on Freescale’s homepage: an interactive demo of the fault tolerance functions of the MPC564XL dual-core microcontroller.
Past Tuesday, I attended the Freescale Design With Freescale (DWF) one-day technology event in Kista, Stockholm. This is a small-scale version of the big Freescale Technology Forum, and featured four tracks of talks running from the morning into the afternoon. All very technical, aimed at designing engineers.
Freescale has now released the collected, updated, and restyled book version of the article series on embedded multicore that I wrote last year together with Patrik Strömblad of Enea, and Jonas Svennebring, and John Logan of Freescale. The book covers the basics of multicore software and hardware, as well as operating systems issues and virtual platforms. Obviously, the virtual platform part was my contribution.
The call for paper for LCTES 2010 is now out, the deadline is October 3. If you have something to publish in the area of “Languages, Compilers, and Tools for Embedded Systems”, please consider it! I am on the program committee, and looking forward to reading some really good papers. I used to publish at the LCTES myself when I was doing my PhD… see my older publications if you are curious.
The conference itself will take place in Stockholm in April of 2010, as part of the Cyber-Physical Systems Week (CPSWeek) 2010.
When I started out doing computer science “for real” way back, the emphasis and a lot of the fun was in the basics of algorithms, optimizing code, getting complex trees and sorts and hashes right an efficient. It was very much about computing defined as processor and memory (with maybe a bit of disk or printing or user interface accessed at a very high level, and providing the data for the interesting stuff). However, as time has gone on, I have come to feel that this is almost too clean, too easy to abstract… and gone back to where I started in my first home computer, programming close to the metal.
Another Cadence guest blog entry, about the overall impact of virtual platforms on the interaction between hardware and software designers. Essentially, virtual platforms are a great tool to make software and hardware people talk to each other more, since it provides a common basis for understanding.
The EETimes article Multicore CPUs face slow road in comms piqued my interest. There is an interesting chart in there about just how slow more-than-one-core processors will be in penetrating a vaguely defined “comms” market place. I can believe that, but I think their comments on the PowerQUICC series require some commentary…
Frank Schirrmeister of Synopsys recently published a blog post called “Busting Virtual Platform Myths – Part 1: “Virtual Platforms are for application software only”. In it, he is refuting a claim by Eve that virtual platforms are for application-level software-development only, basically claiming that they are mostly for driver and OS development and citing some Synopsys-Virtio Innovator examples of such uses. In his view, most appication-software is being developed using host-compiled techniques. I want to add to this refutal by adding that application-software is surely a very important — and large — use case for virtual platforms.
This is a small Linux SMP programming tip, which I had a hard time finding documented clearly anywhere on the web. I guess people won’t find it here either, but with some luck some search engine will pick up on this.
Jack Ganssle wrote a column about the failure of multicore to scale, based on an article in IEEE Spectrum. He makes the following claim:
Now a study in IEEE Spectrum shows that even for the classic embarrassingly parallel problems like weather simulations multicore offers little benefit. The curve in that article is priceless. As the number of cores grow from two to 64 performance plummets by a factor of five. Additional processors nullify each other.
Call it the Nulticore Effect.