I heard about the DOOM Game Engine Black Book by Fabien Sanglard on the Hanselminutes podcast episode 666, and immediately ordered the book. It was a riveting read – at least for someone who likes technology and computer history like I do. The book walks through how the ID Software classic DOOM game from 1993 works and the tricks and techniques used to get sufficient performance out of the hardware of 1993. As background to how the software was written, the book contains a great description of the hardware design of IBM-compatible PCs, gaming consoles, and NeXT machines circa 1992-1994. It covers software design, game design, marketing, and how ID Software worked.Continue reading “DOOM Black Book – This is Brilliant!”
The US Defense Advanced Projects Agency (DARPA) ran a “Cyber Grand Challenge” in 2016, where automated cyber-attack and cyber-defense systems were pitted against each other to drive progress in autonomous cyber-security. The competition was run on physical computers (obviously), but Simics was used in a parallel flow to check that competitors’ programs were not trying to undermine the infrastructure of the competition rather than compete fairly inside the rules of the competition.Continue reading “Intel Blog Post: Simics in the DARPA Cyber Grand Challenge”
For the past couple of weeks, I have been using a Nokia 7.1 phone as my main phone while my main Sony phone has been off for repairs. My habit for quite a few years has been to use Sony “flagship” phones as my work phones (and way back, even Sony-Ericsson). The question this poses – how was it to use a theoretically far weaker “mid-range” phone instead of a flagship?Continue reading “Living with a Nokia 7.1 Phone”
For some reason, Microsoft has decided to hide some decidedly useful features in Windows 10 explorer behind the non-intuitive and rather unknown “shift-key + right-click” combination.Continue reading “Off-Topic: Windows Explorer Tip: Shift Right-Click”
I have tried yet another keyboard at home in my quest to find one that the rest of the family finds sufficiently silent – while still being nice to type on. While my fingers love the feeling of the super-clicky MX Blues in my K70 at work, it is not the best choice with other people in the same room, especially at home. Thus, my long-running quest for a keyboard with a nice feel but less noise. I started with a Matias Quiet, and when that broke I tried a Corsair RGB Silent Strafe with the rather expensive MX Silent switches. The “silent” was not sufficiently silent, though, bringing me to the latest keyboard I am trying: the Corsair K55 RGB.Continue reading “Off-Topic: The Corsair K55 Rather Silent Keyboard”
Running Simics inside a container is a topic that has come up several times in recent years. In a two-part Intel Developer Zone blog post, my colleague Mambwe Mumbwa and I discuss both some background on container technology, how and how well Simics can run inside of containers, and what you can with containerized Simicses. Overall, containers offer a very good alternative to virtual machines for running programs like Simics, and the tool ecosystem opens up some exciting new ways to manage Simics installations and simulation instances.
Update: this post was extended to link to both part 1 and part 2 of the blog.Continue reading “Intel Blog Posts: Running Simics in Containers”
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”
Late last year I was trying to do some machine learning work on my brand new Alienware 15 R4 gaming laptop. I had bought the laptop in order to have something portable with sufficient performance to actually do convolutional neural network (CNN) training and inference “on the road”. The GTX 1060 in the laptop is just as powerful as my home desktop machine, and should run Tensorflow and Keras well. I had the setup working on the desktop already, and copied the code over to the laptop. When trying to run the code the first time, I got some rather strange errors that I finally figured out meant that I was missing the CUDA toolkit. I downloaded CUDA version 10, installed, and the machine rebooted into the Windows 10 automatic repair mode.Continue reading “Windows 10 Reboot Loop – CUDA & Alienware”
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!”
A few weeks ago, I talked about temporal decoupling in virtual platforms at DVCon Europe 2018. I just posted some additional notes on the topic temporal decoupling on my Intel blog. In this new blog post, I discuss some more aspects of temporal decoupling, and how it affects simulation semantics. I also explain some of the clever techniques used to minimize the impact of temporal decoupling on the software running on the virtual target system.
Read the full text at as “Additional Notes on Temporal Decoupling“.
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.
Recently I stumbled on a nice piece called “Always Measure One Level Deeper” by John Ousterhout, from Communications of the ACM, July 2018. https://cacm.acm.org/magazines/2018/7/229031-always-measure-one-level-deeper/fulltext. The article is about performance analysis, and how important it is to not just look at the top-level numbers and easy-to-see aspects of a system, but to also go (at least) one level deeper to measure the components and subsystems that affect the overall system performance.
I recently asked myself the question of just how many Powerpoint files I had on my work laptop and on my home machines. It turns out that it was pretty easy to figure that out using Windows Powershell, with some commands I found on a random website.
Last weekend, the yearly Flygdag (Airshow) of the Swedish Armed Forces took place in Uppsala at Ärna. Huge crowds, but it was still easy to get a good view of the aerial displays that took place. In this blog post, I just wanted to share a few photos.
During this year’s vacation trips, we sampled an unusual number of ice cream places around Sweden & Europe. Here are some notes on a few places we visited and where I took the time to actually take some photographs…
Thanks to a tip from “Derek” on a previous blog post about a replay debugger from 1995, I was made aware of the reverse execution ability that was available in the Borland Turbo Debugger version 3.0 from 1992! This is the oldest commercial instance of “reverse” that I have found (so far), and definitely one of the oldest incarnations of the idea overall. Thanks to Google and the Internet, I managed to find a scanned copy of the manual of the product, which provided some additional information. Note that the debugger only does reverse execution, but not reverse debugging since you cannot run in reverse to stop at a breakpoint.
Bengt Werner was one of the first people to work on the simulator that would become Simics, way back in 1992. On my Intel Blog, I published an interview with Bengt a while back where we discuss the early days of Simics and the original product vision and use cases.
Last month, I (together with my family and some friends) tried the virtual reality (VR) experience that has been created for the museum in Gamla Uppsala. VR is used to let people explore the area around Gamla Uppsala, experiencing what it looked like back in the year 650 AD. 650 AD is in the middle of the Vendeltid era (before the Viking age which is typically considered to start around the year 800). At this point in time, Gamla Uppsala had been an important religious and political center for a long time. The big burial mounds that dominate the landscape to this day were already old by then, having built in the 500s.
I have a new blog post up at the Intel Developer Zone, this time about the Simics “fulprompt”. Every software team has its legends about spectacular mistakes, crazy users, and customer calls with strange questions. The Simics “fulprompt” is one example of this from the early days of Simics. It was a prompt that appeared where no prompt would normally appear, right in the middle of executing an instruction. As such, it was an ugly hack… and for Swedes who were around in the 1990s, the only name for a ugly hack is a fulhack.
I just found a story about Undo software that was rather interesting from a strategic perspective. “Patient capital from CIC gives ‘time travelling’ company Undo space to pivot“, from the BusinessWeekly in the UK. The article describes a change from selling to individual developers, towards selling to enterprises. This is an important business change, but it also marks I think a technology thinking shift: from single-session debug to record-replay.
Injecting faults into systems and subjecting them to extreme situations at or beyond their nominal operating conditions is an important part of making sure they keep working even when things go bad. It was realized very early in the history of Simics (and the same observation had been made by other virtual platform and simulator providers) that using a virtual platform makes it much easier to provide cheap, reliable, and repeatable fault injection for software testing. In an Intel Developer Zone (IDZ) blog post, I describe some early cases of fault injection with Simics.
The Matias Quiet keyboard that I have been using for a couple of years recently gave up the ghost. The Enter key broke off and it seemed kind of unreliable in the USB department too – sometimes not activating when attached to a laptop, and sometimes just disappearing. I had got complaints about it being a little noisy still, despite being a lot quieter than a standard ALPS-style Matias keyboard. The replacement I got was a Corsair Strafe RGB Silent. I am rather fond of Corsair keyboards and mice, and this variant sounded promising.
Earlier this week, I attended a Google IO Extended event in Stockholm. It was really nice event organized by Google to extended the reach of Google IO across the globe and those of us who would not be able to attend live. The main event was watching the IO keynote live, but before it started we had some good team games (my team did so-so I must admit) and talks on WebRTC and real-time communications using standard web technology rather than custom plugins. Watching a keynote like this live in a theatre setting gives a different experience from just reading about it post-facto or watching it on your own where it is easy to be distracted (which is something that was addressed in the keynote…).
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.
Show like the Embedded World are full of vendors vying for attention and wanting to get their name onto your mind, desk, or appearance. This is the giveaway game: what can you hand out that will make people get a good and long-lasting impression of your company?
I have just released a new blog post on my Intel Developer Zone blog, about how Simics runs
large huge workloads. I look back at the kinds of workloads that ran on Simics back in 1998 when the product first went commercial, and then look at some current examples running on Simics. This is the first post in a series intended to celebrate 20 years of Simics as a commercial product.