Tuesday 22 December 2009

Time off

I have the time over Christmas off, partly because I needed some distance from work but mostly because the children need looking after while their schools are on break.

Usually switching off from the work mindset is hard for me and I end up "helping" anyway. Not this time...come last Friday at quitting time I was gone. I was apparently in desperate need of this break and spending time with the kids has been great.

It has also been snowing! I used to love the snow when I was a kid and watching the boys build a snowman and have a snowball fight brought back good memories. It somehow has less amusement value when you are older and have to go to work in it and deal with all the problems with transport induces in the UK. Did I mention I was off work? ;-) I had a great time with them...and got a very cold neck.

I have also managed to solve the cat box problem. Turns out it was not the boxes, their placement or type. It seems they wanted three to choose from! They now have three boxes in which to sprawl and they use the original two in the original locations...just as long as they have the option of a third they are happy.

Now I have unwound sufficiently I am looking at tackling some Open source projects of my own which I have been neglecting. I am planning on finishing my whether station recording software and feeding my observations to the weather underground. Possibly doing some more work on Netsurf and maybe even fixing some RC bugs for Debian.

Thursday 17 December 2009

What is it with embedded computing?

Last week I was given a development board for a system on chip (SoC) we were looking at using. All i had to do was ensure I could get a reasonable, supportable, bootloader and Linux kernel running on it.

Now I am a fairly competent engineer, I have worked with the ARM processors and SoC for many years. It should not therefor take me four days of almost continuous frustration to get a bootloader and kernel onto a system, but it has.

Firstly the system arrives and we look it over, the hardware design is not exactly elegant but seems like it will get the job done. That is at least a step up from several previous offerings which have been just plain broken. So I power it up and it boots into Fedora core 8, possibly not my first OS choice for a diskless system, but it does work.

Perhaps its worth mentioning that my experience with doing any Open Source development has caused me to have a severe aversion to software which is not upstream, especially kernels. The effort required to run your own patch series and keep it up to date is nothing short of Herculean.

Let us be honest, how many developers do you know who are talented enough to generate good code and patient enough to separately maintain it over a long period of time? I shall not belabor this point as others have repeatedly made it for me in much more eloquent ways. Lets us just say from my point of view. Upstream - good. Long term forks - bad.

With this in mind, the solutions Simtec develop are always with a view to our customers being able to simply download and use the standard upstream software wherever possible. Here is where the story stops being smooth and becomes a rant.

The system was running 2.6.22, one that was patched all which ways. "maybe they just shipped an old kernel" I thought. I opened the CD they provided and...oh, OK its just zips and tarballs of the binaries and source they used (actually that in itself is a minor miracle with a lot of vendors right now - see the almost continuous stream of copyright infringement litigation from the FSF) but sill stuck back in July 2007.

So i did teh normal thing, entered the URL printed on the outside of the box and went looking for the updates. No dice, just the same old stuff. So I contacted the company and recived the news that no there were no updates, that was what was published for the device, thats what I could have.

My initial reaction was of tired resignation...this would not be my first SoC port (probably around the fifth or sixth!) So I responded with cd linux-2.6;git checkout master;git pull and went to see what I could see. and lo and behold, there in the kernel, was full support for not only the SoC but for the other version of the very board I had.

Fortunately after mentioning this on IRC my giraffe loving friend. pointed me at the correct community git tree to find the tiny patch required to support my board.

So the vendor was not only shipping old code but actively dissuading customers from even looking for new stuff, which it turns out was mainline anyway! To add to this somewhere along the lines the company name on the box and contact information has changed and...well confusion reigned.

Right Plain sailing from here on? not quite...that would have been too easy. So you can build a mainline kernel...but you cannot boot it. you guessed it the bootloader they ship on the board is ancient, specifically a u-boot fork from December 2005. Having finally figured out how this was going to go, I went to the uboot repo, pulled the latest and built it for my target. And then I needed to upgrade the u-boot and joy of joys bricked the system.

Fortunately the system has a integrated FDTI serial/JTAG port so re-writing the flash should be as simple as running openOCD configured correctly. Of course this did not work...in the end I resorted to running their binary built versions from the CD (tarfile inside a zip inside a tarfile...whatever) and wrote their original image back to the board...which worked.

Long story short, next day I discover that i need a magic different uboot target (make u-boot.kwb for those that care) write this with the binary openocd build and...success
From then on its all been a bit anticlimactic and straightforward and I now have a system capable of starting a kernel over the network and a root fs on network, disc or flash.

My main complaint from all of this is what the hell are vendors doing shipping crap like this? Why do they all insist on taking a dreadful code drop from the SoC manufacturer when they first brought the part up and shipping that prototype junk until the part reaches the end of its life?!?

All the usual excuses about support etc. will come out, but seriously, you recive *no* support from vendors unless you pay for it and even then they will simply tell you whats on the CD is "it". Btw the diff for u-boot to support this board is larger than the original sources and the 2.6.22 is attacked with a 65MB diff which cannot be good.

The Open Source option is continuously innovating and improving, producing ever better software...but the embedded world seems to be forever stuck shipping crap. Is this just me? Does anyone have any solutions? Or am I stuck with this until I change profession?

Monday 14 December 2009

Two pussies, one box

Our household contains two felis catus. These evil creatures (sorry I repeat myself, I already mentioned they were cats) are not sweet kittens, they are grumpy old animals who spend the majority of their lives sleeping indoors and rarely venturing out.

Historically they have had free reign of the house and slept wherever it suited them but with the arrival of the children they were confined to the lower half of the house and provided simple cardboard boxes in which they can reside completely undisturbed.

All well and good you might say and indeed this has produced happy cats for the last eight years. however I recently caused a great deal of discord in the household by providing new boxes never imagining this could possibly cause as much trouble as it has. Currently the two of them are attempting to occupy a single box and win some form of passive aggressive fight for occupancy.

This has been going on for a month now and shows no sign of easing. I do wonder what I need to do to aleviate this situation before it results in a full blown outbreak of evil. Any ideas?

Friday 4 December 2009

Where did that that go?

Wow. OK, so its a week later and the time seems to have vanished.

I did get bored of getting nowhere with open source projects though, so last night I went back to the Netsurf browser and fixed a pile of bugs. It is nice to have commit rights to a project where they actually appreciate your contributions.

Most of the week I have been the only person working at Simtec (only other person about was a director in for a couple of days) so I was supposed to answer all inquiries and support etc. but perversely its been almost silent. Seems no one wants anything doing just before Christmas which suits me just fine ;-)

Friday 27 November 2009

Here comes the weekend

Well that was an unproductive week. Maybe I can do something interesting over the weekend? Nope, looks like I get to run around after the kids and do household chores.

Fortunately the interweb is here to entertain you! I am sure most of you have already seen it but the Muppets doing bohemian rhapsody is fun. The Nottingham university scientists explaining the small hotrod collider is amusing and two girls, one uke is safe for work.

Unfortunately there have been other happenings this week which are not so amusing, the extensive flooding in parts of the UK has caused many people a great deal of harm and in one case a policeman, protecting others, was swept to his death from a collapsing bridge.

Unfortunately due to a confluence of events I will not be able to attend the Bug Squashing Party (BSP) in Cambridge this weekend as I had originally intended. I do hope to be able to contribute some work on Sunday from here.

Thursday 26 November 2009

Sometimes it don't come easy, sometimes it don't come at all

My work sometimes causes me to have reason to change small things in open source projects which I then have to submit for consideration upstream. Often this is as simple as providing a patch on the relevant mailing list and moving on.

Sometimes however the change is larger and I really would like to see the feature or bug fix accepted by the project. I am fortunate that my employer is enlightened enough to not only accept this but actively encourage participation in open source communities.

Most of the time the patches are accepted, with changes or updates, in a reasonable timescale. Certainly for kernel work I have got used to a submission/accept time measured in hours!

On occasion the change gets dropped on the floor or missed and you have to resubmit (even if its just to get told its uninteresting and to go away ;-). Unfortunately there are a small number of projects where getting something merged is an experience in frustration.

The particular project which has caused me the most trouble along these lines is Qemu. Daniel and I did the work to support the Samsung ARM based 2410 and 2440 System on Chip (SoC) and a couple of boards they were used on. Of course we then presented the patch to the Qemu mailing list. That was in November...No, not this year, or even last, we are talking 2006!

Unsurprisingly there were numerous issues with our first cut, we improved the patches and resubmitted them and received absolutely no feedback. Eventually we provoked the maintainer to respond, we took his feedback into account and resubmitted. After a year of so of this Daniel got bored and gave up.

Being a complete idiot and apparently sucker for punishment I decided to re-try. I completely restructured the port and started by just trying to get the absolute minimal core changed accepted. It took some time to provoke a response (oh and they altered RCS which meant I had to change my submission again, but they did change to git so that is acceptable ;-)

Earlier this year resulted in my all time favorite maintainer response. Eventually I managed to find out he actually objected to the patch because the SoC we were using actually required a slightly different processor capability set (the emulation is ARMv5 by default and the SoC in question is ARM v4te, hey I had not noticed any practical difference, and Qemu is an emulator not a simulator...but OK)

Remember this is the first time this objection has been raised in 30months of patch submission. Fine, I create a patch which adds V4te emulation and submit that. I eventually get a response, to which my reply is a little frustrated I will admit.

I have since resubmitted the patch with the corner cases fixed, it has been ignored, and I never have received a reply to my direct questions. On this three year anniversary of the original submission I am simply going to give up, something I detest doing.

I am one of those dull people that finishes what he starts, that is pretty much my role in Simtec these days, ensuring stuff we start gets finished or at least drawing the line and calling it complete. To end up with a complete failure offends my personal values.

Now please do not think I hold any ill feelings towards anyone concerned, open source maintainers perform their roles without pay and, by extension, without responsibility to anyone but themselves. I am sure people are too busy to care about the itch I wanted scratched and that overall their project has not really lost all that much by not having me as a contributor.

I know I could have forked the project, or maintained my own tree or any number of other technical solutions but at the end of 1,100 days I have finally exhausted my enthusiasm and can move on. Speaking of which, time to resubmit a kbuild change which got dropped ;-)

Tuesday 24 November 2009

Getting things done

It seems that despite having a very important work deadline today I am destined to be interrupted every five minutes. Unfortunately I need to concentrate to get this done. And while i managed to get "in the zone" earlier, now I cannot string two words together.

This seems to be a recurring theme recently, my productivity is horribly low because I get interrupted all the time for "can you just" jobs. I turn the phone ringer off and hide my email window and I get called on my mobile and get asked why don't you answer your phone?

Its not so much the time lost to answering the specific query or doing the job but more my context switch time to restore to my previous task becomes huge. Somehow my switching time is absolutely non linear and today it has become so large I have decided to dump state altogether.

Because I know I have to do the school run soon and the interruptions continue I have abandoned the critical task altogether for now in the hope I can get back to it fresh. Do others get this I wonder? or is it a personal fault I should strive to fix? I know I used to be able to deal with this sort of thing with much less trouble, maybe I am getting less flexible as I age?

Fortunately (umm, you know what I mean) the Entropy Key software has some cleanups required which is an easy job and does not matter if I get interrupted so I do have a productive task to complete.

Oh speaking of the entropy key Niel blogged something silly I created the other day. I had a senior moment and filked the children's nursery rhyme "If You're happy and you know it" slapping some guitar chords on it.

It seems I cannot simply leave well enough alone and last Friday night (with the help of Mark Hymers) I made it a whole lot worse. I present to you the score of "If you're happy with your ekey, blog your praise" for piano and guitar. In fact I wrote this out in rosegarden so it can be turned into a midi file etc. all the source files are available. It is released under a CC license so I suppose someone could put the lyrics back to the proper nursery rhyme and use it for something less tacky.

Monday 23 November 2009

Fitting Everything In

Recently I have been having issues fitting everything I want to do into the time available.

As my kids grow up they always seem to need to be taken someplace or picked up from an activity and that is on top of the daily school run. I recently worked out I spend over eight hours a week, a whole five hundred minutes, taking them to and fro.

Now do not get me wrong, I actually enjoy spending time with my children and we do talk and interact during these occasions but it is hardly a stimulating activity walking to school or being driven to a club.

Add to that my job and its traveling requirements and assuming I want to sleep, eat etc. and all of a sudden I discover I have about forty hours left in a week to share between my family and hobbies.

Anyone with kids knows they are a wonderful time sink :-) and of course the family home often needs something doing. All of a sudden I realize why I feel like I often end up having to trade sleep for my hobbies!

As I get older I find I still have the same number of ideas for projects but the realization that even if I find the time to start something I am unlikely to be able to devote the resources to finishing it. Being one of life's boring people who like to finish a project they start (ok at least make something useful) this means I tend not to start new things too often.

All of this has lead me to become very careful about how I spend my free time and on what. It means my personal involvement in software projects like Debian and the Linux kernel is nowhere near the level I might like. Similarly my music practice (or absolute lack thereof) causes my teacher to get snippy with me.

As you can imagine starting something like a blog when I do not have enough time for what I am already doing is something of a challenge for me and may indeed falter. However I shall give it a chance as I feel a need for public place to share all those small things which I would probably put on my personal website if I had time to work on it ;-)