programming – Page 6 – Observations from Uppsala

Security Now on Hacking Vehicles – A Bit of Let-Down

The Security Now Podcast number 497 dealt with the topic of Vehicle Hacking. It was fairly interesting, if a bit too light on the really interesting thing which is what actually went on in the vechicle hack that was apparently demonstrated on US national television at some point earlier this year (I guess this CBS News transcript fits the description). It was still good to hear the guys from the Galois consulting firm (Lee Pike and Pat Hickey) talking about what they did. Sobering to realize just how little even a smart guy like Steve Gibson really knows about embedded systems and the reality of their programming. Embedded software really is pretty invisible in both a good way and a bad way.

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In Defense of Testing and Testers

opinion 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.

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Fortress Rochester

fortress rochester

In a dusty bookshelf at work I found an ancient tome of wisdom, long abandoned by its previous owner. I was pointed to it by a fellow explorer of the dark arts of computer system design as something that you really should read. The book was “Fortress Rochester”, written by Frank Soltis, and published in 2001.

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Single Programming Language? No Way! (For Real Work)

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.

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Speaking about Continuous Integration at the Embedded World Conference 2015

Embedded World 2015 Logo

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.

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.

Why DO Computers Fail?

tandem2

I just found and read an old text in the computer systems field, “Why Do Computers Fail and What Can Be Done About It?” , written by Jim Gray at Tandem Computers in 1985. It is a really nice overview of the issues that Tandem had encountered in their customer based, back in the early 1980s. The report is really a classic in the computer systems field, but I did not read it until now. Tandem was an early manufacturer of explicitly fault tolerant and highly reliable and available computers. In this technical report Jim Gray describes the basic principles of fault tolerance, and what kinds of faults happen in the field and that need to be tolerated.

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Microsoft Catapult – Real Interesting Research at Real Scale

At the ISCA 2014 conference (the biggest event in computer architecture research), a group of researchers from Microsoft Research presented a paper on their Catapult system. The full title of the paper is “A Reconfigurable Fabric for Accelerating Large-Scale Datacenter Services“, and it is about using FPGAs to accelerate search engine queries at datacenter scale. It has 23 authors, which is probably the most I have ever seen on an interesting paper. There are many things to be learnt from and discussed about this paper, and here are my thoughts on it.

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“The Mill” – It just might Work!

The Mill is a new general-purpose high-performance processor design from out-of-the-box computing (http://ootbcomp.com/). They claim to beat typical high-end out-of-order (OOO) designs like the Intel Haswell generation by crazy factors, such as being 2.3x faster while using 2.3x less power compared to a Haswell. All the while costing less. Ignoring the cost aspect, the power and performance numbers are truly impressive – especially for general code. How can they do something so much better than what we have today? For general code? That requires some serious innovation. With that perspective, I ask myself where the Mill is really significantly different from what we have seen before.

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Application Expectations built on Touch

windows8logo I recently made my first acquaintance with Windows 8, having bought a new Sony ultrabook for the family. Including a touch screen. The combination of the touch-based interface and the phone-like look of Windows 8 even on a PC has led me to think about the (unconscious) expectations that I have come to have on how systems behave and how services are accessed, from how smart phones and tablets have come to work in the past few years. In particular, where are web-based services going?

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The First 64-bit Phone

apple_A7_image

Apple just released their new iPhone 5s, where the biggest news is really the 64-bit processor core inside the new A7 SoC. Sixty four bits in a phone is a first, and it immediately raises the old question of just what 64 bits gives you. We saw this when AMD launched the Opteron and 64-bit x86 PC computing back in the early 2000’s, and in a less public market the same question was asked as 64-bit MIPS took huge chunks out of the networking processor market in the mid-2000s. It was never questioned in servers, however.

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I Planted a Bug for Myself to Find…

butterfly I have a silly demo program that I have been using for a few years to demonstrate the Simics Analyzer ability to track software programs as they are executing and plot which threads run where and when. This demo involves using that plot window to virtually draw text, in a way akin to how I used to make my old ZX Spectrum “draw” things in the border. But when I brought it up in a new setting it failed to run properly and actually starting hanging on me. Strange, but also quite funny when I realized that I had originally foreseen this very problem and consciously decided not to put in a fix for it… which now came back to bite me in a pretty spectacular way. But at least I did get an interesting bug to write about.

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Book Review: Debugging

Debugging – the 9 Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems by David Agans was published in 2002, based on several decades of practical experience in debugging embedded systems. Compared to the other debugging book I read this Summer, Debugging is much more a book for the active professional currently working on embedded products. It is more of a guidebook for the practitioner than a textbook for students that need to learn the basics.

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David May on Multicore: Heterogeneity not Needed

Via the EETimes, I found a very interesting talk by Bristol professor David May, presented at the 4^th Annual Bristol Multicore Challenge, in June of 2013. The talk can be found as a Youtube movie here, and the slides are available here. The EETimes focused on the idea to cut down ARM to be really RISC, but I think the more interesting part is Professor May’s observations on multicore computing in general, and the case for and against heterogeneity in (parallel) computers.

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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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