The July 2020 edition of the Communications of the ACM (CACM) had a front-page theme of “Domains-Specific Hardware Accelerators”, or DSAs. It contained two articles about the subject, one about an academic genomics accelerator, and one about the Google TPU. Hardware accelerators dedicated to particular types of computation are basically everywhere today, and an accepted part of the evolution of computers. The CACM articles have some good tidbits and points about how accelerators are designed and used today. At the same time, I also found a youtube talk about the first hardware accelerator, the IBM Stretch HARVEST, showing both contrasts with today as well as a remarkable continuity in concept.Continue reading “CACM on DSAs”
Last week was spent at the Design Automation Conference (DAC) in Las Vegas. I had a presentation and poster in the Designer/IP track about Clouds, Containers, and Virtual Platforms , and worked in the Intel Simulation Solutions booth at the show floor. The DAC was good as always, meeting many old friends in the industry as well as checking out the latest trends in EDA (hint: same trends as everywhere else). One particularly nice surprise was a book (the printed type, not the Vegas “book” that means something else entirely).Continue reading “DAC 2019 – Cloud, a Book, an Award, and More”
The Embedded World in Nürnberg is still going strong as the best tradeshow for “Embedded” in the world. This year, I spent time doing booth duty and gave a talk in the Conference part of the event. There was an unusual high number of old friends and business acquaintances around, and it was a great experience overall with many fruitful discussions and connections for the future. However, it seems that there is always something that goes slightly awry with my travel to the show…Continue reading “Embedded World 2019”
The Embedded World Exhibition and Conference 2019 is coming up in the last week of February. I will be there presenting a paper in the conference as well as demoing CoFluent in the Intel booth and some other miscellany. The paper “Shifting-Left Together – Enabling the Ecosystem with Virtual Platforms” is about how silicon vendors can (should) use virtual platforms to bring shift-left practices to their customers in addition to their own internal teams.Continue reading “Shifting Left Together at the Embedded World 2019”
There are some things in computing that seem “obviously” true and that “clearly” make it “impossible” to do some things. One example of this is the idea that you cannot go backwards in time from the current state of a program or computer system and recover previous state by just reversing the semantics of the instructions in the program. In particular, that you cannot take a core dump from a failed system and reverse-execute back from it – how could you? In order to do reverse debugging and reverse execution, you “have to” record the state at the first point in time that you want to be able to go back to, and then record all changes to the state. Turns out I was wrong, as shown by a recent Usenix OSDI paper.Continue reading “Microsoft REPT: You CAN Reverse from a Core Dump!”
DVCon Europe took place in München, Bayern, Germany, on October 24 and 25, 2018. Here are some notes from the conference, including both general observations and some details on a few papers that were really quite interesting. This is not intended as an exhaustive replay, just my personal notes on what I found interesting.
I have a documented love for keyboards with RGB lighting. So I was rather annoyed when one of my Corsair K65 keyboards suddenly seemed to lose its entire red color component. The keyboard is supposed to default to all-red color scheme with the WASD and arrow keys highlighted in white when no user is logged in to the machine it is connected to – but all of a sudden, it went all dark except a light-blue color on the “white” keys. I guessed it was just a random misconfiguration, but it turned out to be worse than that.
I work with virtual platforms and software simulation technology, and for us most simulation is done on standard servers, PCs, or latptops. Sometimes we connect up an FPGA prototype or emulator box to run some RTL, or maybe a real-world PCIe device, but most of the time a simulator is just another general-purpose computer with no special distinguishing properties. When connecting to the real world, it is simple standard things like Ethernet, serial ports, or USB.
There are other types of simulators in the world however – still based on computers running software, but running it somehow closer to the real world, and with actual physical connections to real hardware beyond basic Ethernet and USB. I saw a couple of nice examples of this at the Embedded World back in February, where full-height racks were basically “simulators”.
Back in 2004, the startup Virtutech built a crazy demo for the 2004 Embedded Systems Conference (ESC). Back then, ESC was the place to be, and Virtutech was there with a battery of demos to blast the competition. The most interesting demo from a technology perspective was the 1002-machine network, as described in an Intel Developer Zone blog post of mine.
I had the honor to have a scheduled talk at the Embedded World 2018 show in Nürnberg, right at the start of the show on Tuesday morning. Getting to Nürnberg for the Embedded World without paying a fortune for plane tickets is tricky due to all the other people flying down from Swedish embedded and tech firms at the same time. This year, I was lucky and I had managed to get a very convenient flight at a decent price. Leaving Stockholm in the afternoon around 14.00 on Monday, flying via Frankfurt and then on to Nürnberg, arriving in the early evening just in time for a nice Bavarian dinner. No stress, no late evenings on the U-Bahn into town. A good night’s sleep before getting up and getting to the show with plenty of time to set up for my talk. What could possibly go wrong?
I will be presenting an Exhibitor Forum talk at the Embedded World in Nürnberg next week, about how to get to Agile and small batches for embedded. Using simulation to get around the annoying hard aspect of hardware.
A while ago, I visited my Intel colleagues in Costa Rica and ran a workshop for university teachers and researchers, showing how Simics could be used in academia. I worked with a very smart and talented intern, Jose Fernando Molina, and after a rather long process I have published an interview with him on my Intel blog: https://software.intel.com/en-us/blogs/2017/12/05/windriver-simics-to-inspire-teachers-costarica
I have posted a two-part blog post to the public Intel Developer Zone blog, about the “Small Batches Principle” and how simulation helps us achieve it for complicated hardware-software systems. I found the idea of the “small batch” a very good way to frame my thinking about what it is that simulation really brings to system development. The key idea I want to get at is this:
[…] the small batches principle: it is better to do work in small batches than big leaps. Small batches permit us to deliver results faster, with higher quality and less stress.
I read some news (ExtremeTech, Techcrunch) about how “smart” wifi-connected locks sold by Lockstate got bricked by an automatic over-the-network update. This sounds bad – but it is bad for a good reason. I think the company should be lauded for actually having the ability – and laughed out for royally botching it.
Today, when developing embedded control systems, it is standard practice to test control algorithms against some kind of “world model”, “plant model” or “environment simulator”.
Using a simulated control system or a virtual platform running the actual control system code, connected to the world model lets you test the control system in a completely virtual and simulated environment (see for example my Trinity of Simulation blog post from a few years ago). This practice of simulating the environment for a control computer is long-standing in the aerospace field in particular, and I have found that it goes back at least to the Apollo program.
Doing continuous integration and continuous delivery for embedded systems is not necessarily all that easy. You need to get tools in place to support automatic testing, and free yourself from unneeded hardware dependencies. Based on an inspiring talk by Mike Long from Norway, I have a piece on how simulation helps with embedded CI and CD on my Software Evangelist blog on the Intel Developer Zone.
I have a two-part series (one, two) on testing posted on my Software Evangelist blog on the Intel Developer Zone. This is a long piece where I get back to the interesting question of how you test things and the fact that testing is not just the same as development. I call the posts Mindset and Toolset
It is really sad that the European Space Agency (ESA) lost their Schiaparelli lander last year, as we will miss out on a lot of Mars science. From a software engineering and testing perspective, the story of why the landing failed rather instructive, though. It gets down to how software can be written and tested to deal with unexpected inputs in unexpected circumstances. I wrote a piece about this on my blog at the Intel Developer Zone.
The SiCS Multicore Day took place last week, for the tenth year in a row! It is still a very good event to learn about multicore and computer architecture, and meet with a broad selection of industry and academic people interested in multicore in various ways. While multicore is not bright shiny new thing it once was, it is still an exciting area of research – even if much of the innovation is moving away from the traditional field of making a bunch of processor cores work together, towards system-level optimizations. For the past few years, SiCS has had to good taste to publish all the lectures online, so you can go to their Youtube playlist and see all the talks for free, right now!
UndoDB is an old player in the reverse debugging market, and have kept at it for ten years. Last year, they released the Live Recorder record-replay function. Most recently, they have showed an integration between the recorder function and Jenkins, where the idea is that you record failing runs in your CI system and replay them on the developer’s machine. Demo video is found on Youtube, see https://www.youtube.com/watch?v=ap8552P5vss.
A long time ago, when I was a PhD student at Uppsala University, I supervised a few Master’s students at the company CC-Systems, in some topics related to the simulation of real-time distributed computer systems for the purpose of software testing. One of the students, Magnus Nilsson, worked on a concept called “Time-Accurate Simulation”, where we annotated the source code of a program with the time it would take to execute (roughly) on the its eventual hardware platform. It was a workable idea at the time that we used for the simulation of distributed CAN systems. So, I was surprised and intrigued when I saw the same idea pop up in a paper written last year – only taken to the next level (or two) and used for detailed hardware design!
Continue reading “Time-Accurate Simulation Revisited – 15 years later”
Thanks to the good folks at Vector Software, I was pointed to a conference recording on Youtube, from the Google Test Automation Conference (GTAC) 2015 (Youtube video). The recording covers quite a few talks, but at around 4 hours 38 minutes, Brian Gogan describes the testing used for the Chromecast product. This offers a very cool insight into how networked consumer systems are being tested at Google. Brian labels the Chromecast as an “Internet of Things” device*, and pitches his talk as being about IoT testing. While I might disagree about his definition of IoT, he is definitely right that the techniques presented are applicable to IoT systems, or at least individual devices.
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!
I have a long-standing interested in debugging in general and reverse debugging in particular and the related idea of record-replay debug (see a series of blog posts I did a few years ago on the topic: history 1, history 2, history 3, S4D report, updates, Simics reverse execution, and then Lab Cloud record/replay). Recently, I found out that Undo Software, one of the pioneers in the field, had released a product called “Live Recorder“. So I went to check it out by reading their materials and comparing it to what we have seen before.
I have been thinking about the role and prestige of testing for the past several years. Many things I have read and things companies have done indicate that “testing” is something that is considered a bit passe and old-school. Testers are dead weight that get into the way of releases, and they are unproductive barnacles that slow development down. Testers can all be replaced by automatic testing put in place by brilliant developers. The creative developer types are the guys with the status anyway. I might be exaggerating, but there is an issue here. I think we need to be acknowledge that testers are a critical part of the software quality puzzle, and that testing is not just something developers can do with one hand tied behind their back.
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!
Last year, I concluded a programming project at work that clearly demonstrated that real programming tasks tend to involve multiple languages. I once made a remark to a journalist that there is a zoo of languages inside all real products, and my little project provided a very clear example of this. The project, as discussed previously, was to build an automated integration between a simple Simics target system and the Simulink processor-in-the-loop code testing system. In the course of this project, I used six or seven languages (depending on how you count), three C compilers, and three tools. Eight different compilers were involved in total.
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.
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.
I am going to be speaking at the 2015 Embedded World Conference in Nürnberg, Germany. My talk is about Continuous Integration for embedded systems, and in particular how to enable it using simulation technology such as Simics.
My talk is at 16.00 to 16.30, in session 03/II, Software Quality I – Design & Verification Methods.