Intel Blog: Wind River Using Simics to Test IoT at Scale

intel sw small This really happened last week, but I was in the US for the DAC then.  I did another blog on Intel Software blog, about a white paper that Wind River put out about how they use Simics internally. The white paper is a really good set of examples of how Simics can be used for software development, test, and debug – regardless of how old or new the hardware is.  It also touches my favorite topic of IoT simulation and scaling up – Wind River is actually using Simics for 1000+ node tests of IoT software!   Read on at

Wind River Guest Blog: Interview with Sangeeta, a CoFluent user doing Software Modeling

Cofluent studioEven though I am now working for Intel, the nice folks at Wind River have let me do blogging on the Wind River blog as a guest anyway.  I first blogged about the fantastic world of simulators that I have found inside Intel, and now a longer technical piece has appeared on a use of Intel CoFluent Studio. I interviewed Sangeeta Ghangam at Intel, who used CoFluent Studio to model the behavior of a complex software load on a gateway, connected to a set of sensor nodes. It is rather different from the very concrete software execution I work on with Simics. Being able to model and estimate the performance and cost and size of systems before you go to the concrete implementation is an important part of software and systems architecture, and CoFluent offers a neat tool for that.

Read the full story on the Wind River blog!

Wind River Blog: Interview with Intel Users of Simics

Intel is a big Simics user, but most of the time Intel internal use of Simics is kept internal. However, we recently had the chance to interview Karthik Kumar and Thomas Willhalm of Intel about how they used Simics to interact with external companies and improve Intel hardware designs. The interview is found on the Wind River blog network.

It is also my last blog post written at Wind River; since January 18, I am working at Intel. I am working on ways to keep publishing texts about Simics and simulation, but the details are not yet clear.

Wind River Blog: Demo of the Lab Cloud Web API with Video

I just posted a short blog post on the Wind River blog, introducing a video demo of the Web API to Wind River Helix Lab Cloud. In the post and video, I show how the Lab Cloud Web API works. For someone familiar with REST-style APIs, this is probably baby-level, but for me and probably most of our user base, it is something new and a rather interesting style for an API. Thus, doing a video that shows the first few steps of authentication and getting things going seems like a good idea.


Wind River Blog: Using Lab Cloud to Communicate Hardware Setups to Software Developers

In a blog post at Wind River, I describe how the Wind River Helix Lab Cloud system can be used to communicate hardware design to software developers. The idea is that you upload a virtual platform to the cloud-based system, and then share it to the software developers. In this way, there is no need to install or build a virtual platform locally, and the sender has perfect control over access and updates. It is a realization of the hardware communication principles I presented in an earlier blog post on use cases for Lab Cloud.

But the past part is that the targets I talk about in the blog post and use in the video are available for anyone! Just register on Lab Cloud, and you can try your own threaded software and check how it scales on a simulated 8-core ARM!




Wind River Blog: Helix Lab Cloud – What’s is it good For?

There is a new post at my Wind River blog, about the new Wind River Helix Lab Cloud product that we launched for real last week. The Lab Cloud is a really cool way to expose Simics-style functionality, and my blog goes through some of the more prominent use cases for a simulator in the cloud. There a couple of demo videos linked from the blog, and I have also set up a Youtube playlist collecting the Simics demos and other videos that we have posted there. Quite a set over the past few years, actually!


Wind River Blog: Resolving Software Issues using Lab Cloud

hlc-temp-logoThere is a new post at my Wind River blog, about how I helped a colleague resolve a real problem using the preview version of the new Helix Lab Cloud system. The Lab Cloud right now is basically Simics behind a simplified web user interface, exposing the checkpointing and record-replay facilities in a very clear way.  You can also share your sessions for live interactions with other people, which is truly cool.

Wind River Blog: Fault Injection using Simics – with Video

I just added a new blog post on the Wind River blog, about how you do fault injection with Simics. This blog post covers the new fault injection framework we added in Simics 5, and the interesting things you can do when you add record and replay capabilities to spontaneous interactive work with Simics. There is also a Youtube demo video of the system in action.

Wind River Blog: Simics 5 is Out!

On June 30, Wind River (my job) released Simics 5, the latest version of Simics. I have been working with Simics since 2002 now, and the tool is still improving, adding new features, and adopting the current world. The announcement blog post provides an overview of the features of the new release, and we will be doing some additional in-depth posts later on.


Wind River Blog: Simics 5 Multicore Accelerator Explained

While I was on vacation, Wind River published a blog post I wrote about the new multicore accelerator feature of Simics 5. The post has some details on what we did, and some of the things we learnt about simulation performance.


Wind River Blog: Automating Targets with the Simics Agent

There is a new post at my Wind River blog, about the Simics Agent feature that we included in Simics last year. Took a while to get a blog out, as I had so many other things to write about. It was also nice to get a video demo out to accompany the post. The most interesting part about the Simics Agent to me is how much more convenient it is to script a target with an agent on the inside. Too bad that also changes the target software stack a bit — but I do think that that is OK most of the time. As always, the solution has to be designed with the end goal in mind, and there is no absolute right or wrong here. Read the blog post for more details!


Wind River Blog: The Trinity of Simulation

There is a new post at my Wind River blog, about the Trinity of Simulation – the computer, the system, and the world. It discusses how you build a really complete system model using not just a virtual platform like Simics, but you also integrate it with a model of the system the computer sits in, as well as the world around it. Like this:



Read more about it in the blog post, and all the older blog posts it links to!

Wind River Blog: An Interview with Andreas Buchwieser about Safety Standards and Simics

There is a new post at my Wind River blog, an interview with Andreas Buchwieser from the Wind River office in München. It discusses how Simics can be applied to the field of safety-critical systems, including helping test the software to get it certified. Really interesting, and in particular it is worth noting that qualifying tools in the IEC 61508 and ISO 26262 context is much easier than in DO-178B/C. The industrial family of safety standards have been created to allow for tools to help validate an application without forcing incredibly high demands on the development of those tools.


Wind River Blog: Internet-of-Things Massive Simulation using Simics

There is a new post at my Wind River blog, about how Simics is used to simulate large wireless networks for IoT (Internet-of-Things) applications.

It is funny for me to be back at the IoT game. A decade ago (time flies, doesn’t it?), at Virtutech, I and Johan Runeson took part in an EU research project on exactly this topic. Unfortunately, we had to back out of that project due to economic circumstances and failing management commitment, but we still learnt a few things that were relevant now that we are back in the IoT game. In particular, how to simulate wireless networks in a reasonable way in a transaction-level simulator. Thus, payback for the investment took 10 years to arrive, but it did arrive. To me, that underscores the need to be a bit speculative, take some risk, and try to explore the future.

Wind River Blog: Automatic Testing of Anything with Simics

There is a new post at my Wind River blog, about how you can use Simics to enable the automatic testing of pretty much any computer system (as long as we can put it inside a simulator). This is a natural follow-up to the earlier post about continuous integration with Simics and Simics-Simulink integrations — automated test runs is a mandatory and necessary part of all modern software development.

Wind River Blog: Simics-Simulink PIL Integration

There is a new post at my Wind River blog, about how we have made Simics work with the Simulink Processor-in-the-Loop (PIL). This was a pretty interesting project, with a lot going on behind the scenes to realize what looks deceptively simple on the surface. Read the Wind River blog post for the details!

Wind River Blog: Continuous Integration, in two versions

At the Wind River corporate blog, there is a blog post that I wrote about continuous integration and Simics. At the Elsevier Computer Science Connect blog, there is also a blog post about continuous integration and Simics that I wrote. These two texts are essentially the same, and I had the good fortune to get it posted in multiple places. The reason it is up at Elsevier is to help promote our soon-to-be-released book at about virtual platforms and simulation (and a little bit about Simics), and hopefully we will reach a larger audience with both messages: CI with Simics is a great idea, and the book is a great book to buy.



Wind River Blog: A Million Simics Runs (and lots of cool technology)

During my vacation, a blog post went up on the Wind River blog with an interview with Hyungmin Cho, a researcher at Stanford. Hyungmin has done some seriously heavy and cool work with Simics, using it together with a circuit-level simulator to investigate error resiliency in hardware devices, and how errors propagate from hardware into the software. As part of this process, he has setup an automated test system using Simics, and this system has done more than a million automated Simics runs. That is an insane number – I  have been using Simics for twelve years now, and if I had used it every day for all these years, I would have had to start 10 runs per hour, every hour of the day. It shows the power of automation along with parallel runs on clusters of machines – once the setup is automated, you can pour on the volume.

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Busy Writing a Book About Simics

once upon a time - squaredFor the past six months I have not been doing much blogging at all, neither here nor on the Wind River blog.  The reason is that I have been directing my writing energy into writing a text book about Simics together with Daniel Aarno at Intel.  Last year, Daniel and I worked on an Intel Technology Journal issue on Simics.  The ITJ issue was kind of a first step on the way to the book, collecting several articles about Simics usage at Intel and elsewhere.  The book itself will be much more of a detailed description of Simics and how it works and why it works the way it works.

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Intel Technology Journal on Simics

Simics_ITJ_180-wideThe September 2013 issue of the Intel Technology Journal (which actually arrived in December) is all about Simics. Daniel Aarno of Intel and I served as the content architects for the issue, which meant that we managed to contributed articles from various sources, and wrote an introductory article about Simics and its usage in general. It has taken a while to get this journal issue out, and now that it is done it feels just great! I am very happy about the quality of all the ten contributed articles, and reading the final versions of them actually taught me some new things you could do with Simics! I already wrote about the issue in a Wind River blog post, so in this my personal blog I want to be a little bit more, well, personal.

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Wind River Blog: Simics Networking (with Video Demo)

On the Wind River blog network, I have a short posting about network simulation with Simics. It points to the network demo video that we put up on Youtube a few weeks ago, along with some explanations of what is shown in the video. In short, we show a simple example of a network being simulated in Simics, along with some examples of what you can do with it.

Wind River Blog: Cyberphysical System Modeling with Simics

As an old embedded systems and real-time guy, I have always worked with computer systems that are in some way tied to their environment. Simics has often been used to model such computer systems, inside of customer organizations. Which makes it a bit hard to show… however, recently I have cooked up a demo showing Simics simulating a computer system alongside a physical system.

physics-3 I just put out a post on the Wind River blog, pointing to both a video of my own “water heater” demo and some other Youtube videos showing Simics integrated with simulations of the real world. A screenshot of my setup in action is shown on the side of this post.


Wind River Blog: Simics Modeling Video Demo

There is a new post at my Wind River blog, featuring a recently-posted video demo of device and systems modeling with Simics. In this video demo, we show an outline of the modeling flow used with Simics 4.8, using only the Eclipse interface. It is actually quite new that we can do this much modeling from within Eclipse; recent efforts in improving the Simics user experience are starting to pay off. As part of the product design team, it feels good to see how even quite small features can really improve the usability of the product.

It is also my first blog post on the recently renovated Wind River blog network. I like the new look of the corporate blog, even if I will have to go back and adjust some older blog images to account for the change from a dark to a light background.


Wind River Blog: UEFI on Simics

150px-Uefi_logo.svgSimics can run and debug UEFI BIOSes, and that is the topic of my latest blog at Wind River. UEFI is actually pretty interesting once you get to know it, and building a good debug experience for UEFI took a bit of work. Still, it was built as just another target for the standard uniform Simics debugger, which is not the way most other UEFI and BIOS debuggers are built. I guess in that in the past, debugging a BIOS required such specialized tools that it made sense to also build a custom specialized frontend for the  purpose. With a simulator as the backend, things do become simpler and more uniform, and Eclipse CDT is a actually a very good basis for a debugger for any kind of C and C++ code.

For more reading on UEFI itself, I can recommend the 2011 Intel Tech Journal on the topic.

Wind River Blog: Reverse Execution (not Debugging)

There is a new post at my Wind River blog, where I go back to the basics of reverse execution in Simics and what it can do. The post is not about reverse debugging, about which I have written quite a bit (see for example my series of blog posts: 1, 2, 3, 4, 5, 6), but about the core of reverse execution. I.e., moving the system state back in time in a variety of ways. There is an accompanying video  demo on Youtube.

Wind River Blog: Starting & Configuring Simics

There is a new post at my Wind River blog, about how Simics sessions are started and the mechanics of system setups in Simics. It also has a link to a Youtube video demonstrating various ways of starting Simics simulation sessions.

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Wind River Blog: System Editor Demo for Simics

There is a new post at my Wind River blog, with a video demo of the new Simics 4.8 System Editor function. Posts are coming out quite quickly now, with various aspects of Simics and in particular Simics 4.8 being highlighted. This particular feature is probably the biggest news in Simics 4.8 from a user interface perspective, as it allows you to (finally) inspect a target setup in a nice graphical tree view.

Wind River Blog: Collaborating with Recording Checkpoints

There is a new post at my Wind River blog, about how some new features in Simics 4.8 improve the collaboration power of Simics checkpoints. For the first time, Simics checkpoint can now carry a piece of history (slice of time), which also makes reverse execution and reverse debug work with checkpoints in a logical way.

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Wind River Blog: Simics 4.8 is Here

Simics 4.8 is finally released, and I put up a blog post explaining the most important news in this release. It is two years since we released Simics 4.6, so there is quite a bit of news in Simics 4.8 – even though lots of functionality has been released continuously into 4.6 over the past twenty four months. My personal favorite are the comments you can put on an execution and the stop log,  but then again, that might be because they have been a couple of pet ideas of mine so I am hardly an impartial judge. Everything else is also really good, and the engineering teams and marketing teams involved have put in a lot of effort into this release (as we do in all releases).


Wind River Blog: Visuality NQ CIFS Server on Simics

There is a new post at my Wind River blog, about how I ran a Windows file share server (CIFS) on a Simics-simulated VxWorks big-endian Power Architecture target. Something that just should work, given that the software in question is known to work in the real world. But still, pretty cool, and a bit eerie.