Category Archives: Work

Work stuff

Parallel Spaghetti Decode Challenge

At the embedded hacking event in GBG yesterday I organized a small contest for the attendees. I’ve done something similar several times before, so I wanted to make it a bit different this time to spice things up a bit. A straight-forward N questions in a row and then a puzzle to get the final question was too easy. I wanted to create a maze or a play-field that you would need to traverse somehow in order to reach the final goal. But it is hard to create a maze that you don’t immediately spot the way through or that you can somehow “cheat” and find the way in other means rather than to actually answer the questions and do right by using your skills… Then I realized that with just a couple of things added, I could fulfill my goals and still get a fun contest. So, let me start by taking you through the first slide that details the rules:

The contest rules

Ok, so to make the rules be a bit clearer we take a look at a simplified example play field so that we understand what we’re about to play on:

A small example play-field

A short summary:

  1. start on a green box
  2. follow the arrow in the direction that your answer to the question of the box leads you. There’s a compass rose there to help you remember the directions! 🙂
  3. each box you visit has a word associated with it, collect the words along the path
  4. when you reach the red box you’ve read the goal and you’re done
  5. then you re-arrange all the box words you’ve collected and create a final question
  6. answer that questions, the fastest to answer wins!

Everything clear? To help the participants, we had both the playfield and the associated questions printed out on two sheets of paper that we handed out together with a pen. The amount of data is just a bit too much to be able to show on a single screen and it may help to use a pen etc to remember the track you take and which words to remember etc. If you want to repeat the exact same situation, you do the same! I did a special black-and-white version of the playfield to make it more printer-friendly. You may want to fire this up in full resolution to get the best experience:

full-spaghetti-playfield-maze

The question sheet looks like this, but click it for the full PDF:

All questions for the challenge

I posted the answers and everything in a separate post!

Haxx turns 0x10

On October 17th 1997 we registered Haxx as a company. Today we’re 0x10 years old. We like hexadecimal numbers.

BirthdaycakeHaxx was founded before the first curl version was released.

It was before Google.

It was long before Firefox and Chrome and even before the Mozilla browser appeared.

Heck, a lot of things of today didn’t exist those 16 long years ago.

It was a different and in many ways simpler world back then, but I would say that we’ve manage quite good to keep with the times and we’ve progressed fine as a company and as individuals all since then.

Me, Björn and Linus are still going strong with more contacts, more customers and possibly more fun than ever.

Happy birthday to us!

Another embedded hacking day

enea We started off this second embedded hacking day (the first one being the one we had in October) when I sent out the invitation email on April 22nd asking people to sign up. We limited the number of participants to 40, and within two hours all seats had been taken! Later on I handed out more tickets so we ended up with 49 people on the list and interestingly enough only 13 of these were signed up for the previous event as well so there were quite a lot of newcomers.Daniel Stenberg, a penguin

Arrival

At 10 in the morning on Saturday June 1st, the first people had already arrived and more visitors were dropping in one by one. They would get a goodie-bag from our gracious host with t-shirt (it is the black one you can see me wearing on the penguin picture on the left), some information and a giveaway thing. This time we unfortunately did not have a single female among the attendees, but the all-male crowd would spread out in the room and find seating, power and switches to use. People brought their laptops and we soon could see a very wide range of different devices, development boards and early design ideas showing up on the tables. Blinking leds and cables everywhere. Exactly the way we like it!

A table full of hackers and equipment!

Giveaway

A USB wifi thing

We decided pretty early on the planning for this event that we wouldn’t give away a Raspberry Pi again like we did last time. Not that it was a bad thing to give away, it was actually just a perfect gift, but simply because we had already done that and wanted to do something else and we reasoned that by now a lot of this audience already have a Raspberry pi or similar device.

So, we then came up with a little device that could improve your Raspberry Pi or similar board: a USB wifi thing with Linux drivers so that you easily can add wifi capabilities to your toy projects!

And in order to provide something that you can actually hack on during the event, we decided to give away an Arduino Nano version. Unfortunately, the delivery gods were not with us or perhaps we had forgot to sacrifice the correct animal or something, so this second piece didn’t arrive in time. Instead we gathered people’s postal addresseAns and once the package arrives in a couple of days we will send it out to all attendees. Sort of a little bonus present afterwards. Not the ideal situation, but hey, we did our best and I think this is at least a decent work-around.

So the fun begun

In the big conference room next to the large common room, I said welcome to everyone at 11:00 before I handed over to Magnus from Xilinx to talk about Xilinx Zynq and combining ARM and FPGAs. Magnus Lindblad, Xilinx The crowd proved itself from the first minute and Magnus got a flood of questions immediately. Possibly it was also due to the lovely combo that Magnus is primarily a HW-guy while the audience perhaps was mostly SW-persons but with an interest in lowlevel stuff and HW and how to optimize embedded systems etc.

Audience listening to Magnus

After this initial talk, lunch was served.

Contest

I got lots of positive feedback the last time on the contest I made then, so I made one this time around as well and it was fun again. See my separate post on the contest details.

Flying

After the dust had settled and everyones’ pulses had started to go back to normal again after the contest, Björn Stenberg “took the stage” at 14:00 and educated us all in how you can use 7 Arduinos when flying an R/C plane.

Björn talks about open source flying

Björn Stenberg, a penguin

It seemed as if Björn’s talk really hit home among many people in the audience and there was much talking and extra interest in Björn’s large pile of electronics and “stuff” that he had brought with him to show off. The final video Björn showed during his talk can be found here.

Stuff to eat

Buns for the masses!People actually want to get something done too during a day like this so we can’t make it all filled up with talks. Enea provided candy, drinks and buns. And of course coffee and water during the entire day.

Even with buns and several coffee refills, I think people were slowly getting soft in their brains when the afternoon struck and to really make people wake up, we hit them with Erik Alapää’s excellent talk…

Aliasing in C and C++

Or as Erik specified the full title: “Aliasing in C99/C++11 and data transfer between hard real-time systems on modern RISC processors”…

Erik helped put the light on some sides of the C programming language that perhaps aren’t the most used or understood. How aliasing can be used and what pitfalls it can send us down into!

Erik Alapää on C aliasing

Kjell Ericson's blinking ledsPersonally I don’t really had a lot of time or comfort to get much done this day other than making sure everything ran smooth and that everyone was happy and the schedule was kept. My original hopes was to get some time to do some debugging on a few of my projects during the day but I failed that ambition…

We made sure to videofilm all the talks so we should hopefully be able to provide online versions of them later on.

Real-time Linux

I took the last speaker slot for the day. I think lots of brains were soft by then, and a few people had already started to drop off. I talked for a while generically about how the real-time problem (or perhaps low-latency) is being handled with Linux these days and explained a bit about PREEMPT_RT and full dynamic ticks and what the differences of the methods are.

Daniel Stenberg talks Real-time Linux

The end

At 20:00 we forced everyone out of the facilities. A small team of us grabbed a bite and a couple of beers to digest the day and to yap just a little bit more before we split up for the evening and took off home…

Thank you everyone who was there for making it another great event. Thank you all speakers for giving the event the extra brightness! Thank you Enea for sponsoring, hosting and providing all the goodies in such an elegant manner! It is indeed possible that we make a 3rd embedded hacking day in the future…

Meet Haxx at FOSDEM 2013

Keeping up with our fine tradition, we will be present at that huge open source conference called FOSDEM in Brussels Belgium at the beginning of February 2013. It will then become our… 4th (?) visit there. I don’t have any talk planned yet, but possibly I’ll suggest something later.

Fosdem is several thousand open source geeks in a massive scale conference with something like twenty different parallel tracks, where each room basically is organized and planned independently. There’s no registration and no entrance fee. I usually enjoy network and security related rooms and of course the embedded room, which unfortunately seems to be stuck in a very large room of the campus with the worst sound system and audio conditions…

I look forward to meet friends there and have a great time with open source talks and good Belgian beers at night! If you’ll be there too, let us know and we can meet up.

fosdem

this vs that and ssh through proxy

Taken from the web stats for daniel.haxx.se during September 2012. The top-10 search phrases used to end up on a page on this site:

  1. ssh proxy (198)
  2. curl vs wget (145)
  3. ftp vs http (92)
  4. wget vs curl (91)
  5. ssh through proxy (72)
  6. http vs ftp (67)
  7. curl wget (55)
  8. wget curl (53)
  9. http ftp (46)
  10. difference between ftp and http (45)

The top-3 most visited pages on my site during the same month were:

  1. SSH Through or Over Proxy (viewed 4800 times)
  2. curl vs Wget (viewed 3000 times)
  3. FTP vs HTTP (viewed 2300 times)

I guess this tells me something. I’m not sure what…

Three years of Haxx

Haxx logoAt October first, another full year of work at Haxx has been spent since I last summed up the past year (my previous posts about Haxx’s first year and second year). Three years working for Haxx full-time, and it has been another great year with lots of fun, challenges and us enjoying being independent.

During this year I ended my previous engagement with that large chip company and got a new assignment for the same customer both Björn and Linus were working for at the time. It has been a big adventure for me as I dove straight into unknown territories and I’ve spent my work days since then as a product manager, making an embedded Linux distribution. In this role I’ve travelled to US, China and South Korea during the year and I’m serving as a member of an advisory board in a related organization on behalf of my customer! I recently agreed to extending this contract to at least April 2013. Partly due to this new assignment I’ve not worked very much on foss-sthlm activities recently, but after the summer I’ve really made an effort to get this back up to speed.

Birthdaycake

Later during the year, Linus changed assignment to a new customer when we signed a sort of partnership contract with a leading global embedded software company and he then continued to do a whole series of little projects for them. After the summer Linus has grabbed a couple of curl related projects, partly still in progress.

Björn stuck around at the same customer during the entire year, and he’s been working as an engineer and developer in the team that actually makes the product I am a manager for.

Haxx towelThis year we made more Haxx merchandise. Towels, stickers and jackets have now been sent out in the world to make our name more visible in a few weird corners of the universe.

We visisted FSCONS 2011 and FOSDEM 2012, two really nice conferences for FOSS fans like us and we got to meet a lot of friends and like-minded people there.

We continue to see a demand on the market for highly skilled embedded developers, including embedded Linux and open source related activities. We wouldn’t mind extending our merry team, so we decided to document a list of requirements of what to have in order to get hired by us. So far not a single person has applied…

Snaxx 27

A pint of guinnessGoing strong after 12 years in the making. For the 27th time we’re gathering friends in the Stockholm Sweden area who are interested in technology, open source, beers, slightly inaccurate Monty Python quotes, reverse engineering electronics and similar very important topics. We might also have a beer or two and talk rubbish.

On October 31st 2012 we invite all and every of our tech oriented friends to visit

Snaxx-27

We figured the 27th time would be the perfect time to do something new, so we now host the information on the fine snaxx.se domain.

Travel for fun or profit

As a protocol geek I love working in my open source projects curl, libssh2, c-ares and spindly. I also participate in a few related IETF working groups around these protocols, and perhaps primarily I enjoy the HTTPbis crowd.

Meanwhile, I’m a consultant during the day and most of my projects and assignments involve embedded systems and primarily embedded Linux. The protocol part of my life tends to be left to get practiced during my “copious” amount of spare time – you know that time after your work, after you’ve spent time with your family and played with your kids and done the things you need to do at home to keep the household in a decent shape. That time when the rest of the family has gone to bed and you should too but if you did when would you ever get time to do that fun things you really want to do?

IETF has these great gatherings every now and then and they’re awesome places to just drown in protocol mumbo jumbo for several days. They’re being hosted by various cities all over the world so often I deem them too far away or too awkward to go to, also a lot because I rarely have any direct monetary gain or compensation for going but rather I’d have to do it as a vacation and pay for it myself.

IETF 83 is going to be held in Paris during March 25-30 and it is close enough for me to want to go and HTTPbis and a few other interesting work groups are having scheduled meetings. I really considered going, at least to meet up with HTTP friends.

Something very rare instead happened that prevents me from going there! My customer (for whom I work full-time since about six months and shall remain nameless for now) asked me to join their team and go visit the large embedded conference ESC in San Jose, California in the exact same week! It really wasn’ t a hard choice for me, since this is my job and being asked to do something because I’m wanted is a nice feeling and position – and they’re paying me to go there. It will also be my first time in California even though I guess I won’t get time to actually see much of it.

I hope to write a follow-up post later on about what I’m currently working with, once it has gone public.

I’m interviewed by foss-magasin

foss-magasin

Claes at foss-magasin.se asked a bunch of questions about me, my commitments within the FOSS community and related matters recently over email. This Swedish interview just now went public: Daniel Stenberg cURL, Rockbox och FOSS-Sthlm (dead link).

For my international friends who don’t understand the Swedish: I am quite happy with the questions and being allowed to answer them at this lengths etc, so I am considering doing a full translation of it and posting it at a later date.