Recent blog entries for LaForge

Ten years anniversary of Openmoko

In 2006 I first visited Taiwan. The reason back then was Sean Moss-Pultz contacting me about a new Linux and Free Software based Phone that he wanted to do at FIC in Taiwan. This later became the Neo1973 and the Openmoko project and finally became part of both Free Software as well as smartphone history.

Ten years later, it might be worth to share a bit of a retrospective.

It was about building a smartphone before Android or the iPhone existed or even were announced. It was about doing things "right" from a Free Software point of view, with FOSS requirements going all the way down to component selection of each part of the electrical design.

Of course it was quite crazy in many ways. First of all, it was a bunch of white, long-nosed western guys in Taiwan, starting a company around Linux and Free Software, at a time where that was not really well-perceived in the embedded and consumer electronics world yet.

It was also crazy in terms of the many cultural 'impedance mismatches', and I think at some point it might even be worth to write a book about the many stories we experienced. The biggest problem here is of course that I wouldn't want to expose any of the companies or people in the many instances something went wrong. So probably it will remain a secret to those present at the time :/

In any case, it was a great project and definitely one of the most exciting (albeit busy) times in my professional career so far. It was also great that I could involve many friends and FOSS-compatriots from other projects in Openmoko, such as Holger Freyther, Mickey Lauer, Stefan Schmidt, Daniel Willmann, Joachim Steiger, Werner Almesberger, Milosch Meriac and others. I am happy to still work on a daily basis with some of that group, while others have moved on to other areas.

I think we all had a lot of fun, learned a lot (not only about Taiwan), and were working really hard to get the hardware and software into shape. However, the constantly growing scope, the [for western terms] quite unclear and constantly changing funding/budget situation and the many changes in direction have ultimately lead to missing the market opportunity. At the time the iPhone and later Android entered the market, it was too late for a small crazy Taiwanese group of FOSS-enthusiastic hackers to still have a major impact on the landscape of Smartphones. We tried our best, but in the end, after a lot of hype and publicity, it never was a commercial success.

What's more sad to me than the lack of commercial success is also the lack of successful free software that resulted. Sure, there were some u-boot and linux kernel drivers that got merged mainline, but none of the three generations of UI stacks (GTK, Qt or EFL based), nor the GSM Modem abstraction gsmd/libgsmd nor middleware (freesmartphone.org) has manage to survive the end of the Openmoko company, despite having deserved to survive.

Probably the most important part that survived Openmoko was the pioneering spirit of building free software based phones. This spirit has inspired pure volunteer based projects like GTA04/Openphoenux/Tinkerphone, who have achieved extraordinary results - but who are in a very small niche.

What does this mean in practise? We're stuck with a smartphone world in which we can hardly escape any vendor lock-in. It's virtually impossible in the non-free-software iPhone world, and it's difficult in the Android world. In 2016, we have more Linux based smartphones than ever - yet we have less freedom on them than ever before. Why?

  • the amount of hardware documentation on the processors and chipsets to day is typically less than 10 years ago. Back then, you could still get the full manual for the S3C2410/S3C2440/S3C6410 SoCs. Today, this is not possible for the application processors of any vendor
  • the tighter integration of application processor and baseband processor means that it is no longer possible on most phone designs to have the 'non-free baseband + free application processor' approach that we had at Openmoko. It might still be possible if you designed your own hardware, but it's impossible with any actually existing hardware in the market.
  • Google blurring the line between FOSS and proprietary code in the Android OS. Yes, there's AOSP - but how many features are lacking? And on how many real-world phones can you install it? Particularly with the Google Nexus line being EOL'd? One of the popular exceptions is probably Fairphone2 with it's alternative AOSP operating system, even though that's not the default of what they ship.
  • The many binary-only drivers / blobs, from the graphics stack to wifi to the cellular modem drivers. It's a nightmare and really scary if you look at all of that, e.g. at the binary blob downloads for Fairphone2 to get an idea about all the binary-only blobs on a relatively current Qualcomm SoC based design. That's compressed 70 Megabytes, probably as large as all of the software we had on the Openmoko devices back then...

So yes, the smartphone world is much more restricted, locked-down and proprietary than it was back in the Openmoko days. If we had been more successful then, that world might be quite different today. It was a lost opportunity to make the world embrace more freedom in terms of software and hardware. Without single-vendor lock-in and proprietary obstacles everywhere.

Syndicated 2016-11-27 15:00:00 from LaForge's home page

Open Hardware miniPCIe WWAN modem USB breakout board released

There are plenty of cellular modems on the market in the mPCIe form factor.

Playing with such modems is reasonably easy, you can simply insert them in a mPCIe slot of a laptop or an embedded device (soekris, pc-engines or the like).

However, many of those modems actually export interesting singals like digital PCM audio or UART ports on some of the mPCIe pins, both in standard and in non-standard ways. Those signals are inaccessible in those embedded devices or in your laptop.

So I built a small break-out board which performs the basic function of exposing the mPCIe USB signals on a USB mini-B socket, providing power supply to the mPCIe modem, offering a SIM card slot at the bottom, and exposing all additional pins of the mPCIe header on a standard 2.54mm pitch header for further experimentation.

/images/mpcie-breakout-front.jpg

The design of the board (including schematics and PCB layout design files) is available as open hardware under CC-BY-SA license terms. For more information see http://osmocom.org/projects/mpcie-breakout/wiki

If you don't want to build your own board, fully assembled and tested boards are available from http://shop.sysmocom.de/products/minipcie-wwan-modem-usb-break-out-board

Syndicated 2016-11-24 23:00:00 from LaForge's home page

Open Hardware Multi-Voltage USB UART board released

During the past 16 years I have been playing a lot with a variety of embedded devices.

One of the most important tasks for debugging or analyzing embedded devices is usually to get access to the serial console on the UART of the device. That UART is often exposed at whatever logic level the main CPU/SOC/uC is running on. For 5V and 3.3V that is easy, but for ever more and more unusual voltages I always had to build a custom cable or a custom level shifter.

In 2016, I finally couldn't resist any longer and built a multi-voltage USB UART adapter.

This board exposes two UARTs at a user-selectable voltage of 1.8, 2.3, 2.5, 2.8, 3.0 or 3.3V. It can also use whatever other logic voltage between 1.8 and 3.3V, if it can source a reference of that voltage from the target embedded board.

/images/mv-uart-front.jpg

Rather than just building one for myself, I released the design as open hardware under CC-BY-SA license terms. Full schematics + PCB layout design files are available. For more information see http://osmocom.org/projects/mv-uart/wiki

In case you don't want to build it from scratch, ready-made machine assembled boards are also made available from http://shop.sysmocom.de/products/multi-voltage-usb-dual-uart

Syndicated 2016-11-24 23:00:00 from LaForge's home page

(East) European motorbike tour on 20y old BMW F650ST

For many years I've always been wanting to do some motrobike riding accross the Alps, but somehow never managed to do so. It seems when in Germany I've always been too busy - contrary to the many motorbike tours around and accross Taiwan which I did during my frequent holidays there.

This year I finally took the opportunity to combine visiting some friends in Hungary and Bavaria with a nice tour starting from Berlin over Prague and Brno (CZ), Bratislava (SK) to Tata and Budapeest (HU), further along lake Balaton (HU) towards Maribor (SI) and finally accross the Grossglockner High Alpine Road (AT) to Salzburg and Bavaria before heading back to Berlin.

It was eight fun (but sometimes long) days riding. For some strange turn of luck, not a single drop of rain was encountered during all that time, travelling accross six countries.

The most interesting parts of the tour were:

  • Along the Elbe river from Pirna (DE) to Lovosice (CZ). Beautiful scenery along the river valey, most parts of the road immediately on either side of the river. Quite touristy on the German side, much more pleaant and quiet on the Czech side.
  • From Mosonmagyarovar via Gyor to Tata (all HU). Very little traffic alongside road '1'. Beatutil scenery with lots of agriculture and forests left and right.
  • The Nothern coast of Lake Balaton, particularly from Tinany to Keszthely (HU). Way too many tourists and traffic for my taste, but still very impressive to realize how large/long that lake really is.
  • From Maribor to Dravograd (SI) alongside the Drau/Drav river valley.
  • Finally, of course, the Grossglockner High Alpine Road, which reminded me in many ways of the high mountain tours I did in Taiwan. Not a big surprise, given that both lead you up to about 2500 meters above sea level.

Finally, I have to say I've been very happy with the performancee of my 1996 model BMW F 650ST bike, who has coincidentially just celebrated its 20ieth anniversary. I know it's an odd bike design (650cc single-cylinder with two spark plugs, ignition coils and two carburetors) but consider it an acquired taste ;)

I've also published a map with a track log of the trip

In one month from now, I should be reporting from motorbike tours in Taiwan on the equally trusted small Yamaha TW-225 - which of course plays in a totally different league ;)

Syndicated 2016-08-16 14:00:00 from LaForge's home page

Going to attend Electromagnetic Field 2016

Based on some encouragement from friends as well as my desire to find more time again to hang out at community events, I decided to attend Electromagnetic Field 2016 held in Guildford, UK from August 5th through 7th.

As I typically don't like just attending an event without contributing to it in some form, I submitted a couple of talks / workshops, all of which were accepted:

  • An overview talk about the Osmocom project
  • A Workshop on running your own cellular network using OpenBSC and related Osmocom software
  • A Workshop on tracing (U)SIM card communication using Osmocom SIMtrace

I believe the detailed schedule is still in the works, as I haven't yet been able to find any on the event website.

Looking forward to having a great time at EMF 2016. After attending Dutch and German hacker camps for almost 20 years, let's see how the Brits go about it!

Syndicated 2016-07-23 14:00:00 from LaForge's home page

EC-GSM-IoT: Enhanced Coverage GSM for IoT

In private conversation, Holger mentioned EC-GSM-IoT to me, and I had to dig a bit into it. It was introduced in Release 13, but if you do a web search for it, you find surprisingly little information beyond press releases with absolutely zero information content and no "further reading".

The primary reason for this seems to be that the feature was called EC-EGPRS until the very late stages, when it was renamed for - believe it or not - marketing reasons.

So when searching for the right term, you actually find specification references and change requests in the 3GPP document archives.

I tried to get a very brief overview, and from what I could find, it is centered around GERAN extension in the following ways:

  • EC-EGPRS goal: Improve coverage by 20dB
    • New single-burst coding schemes
    • Blind Physical Layer Repetitions where bursts are repeated up to 28 times without feedback from remote end
      • transmitter maintains phase coherency
      • receiver uses processing gain (like incremental redundancy?)
    • New logical channel types (EC-BCCH, EC-PCH, EC-AGC, EC-RACH, ...)
    • New RLC/MAC layer messages for the EC-PDCH communication
  • Power Efficient Operation (PEO)
    • Introduction of eDRX (extended DRX) to allow for PCH listening intervals from minutes up to a hour
    • Relaxed Idle Mode: Important to camp on a cell, not best cell. Reduces neighbor cell monitoring requirements

In terms of required modifications to an existing GSM/EDGE implementation, there will be (at least):

  • changes to the PHY layer regarding new coding schemes, logical channels and burst scheduling / re-transmissions
  • changes to the RLC/MAC layer in the PCU to implement the new EC specific message types and procedures
  • changes to the BTS and BSC in terms of paging in eDRX

In case you're interested in more pointers on technical details, check out the links provided at https://osmocom.org/issues/1780

It remains to be seen how widely this will be adopted. Rolling this cange out on moderm base station hardware seems technicalyl simple - but it remains to be seen how many equipment makers implement it, and at what cost to the operators. But I think the key issue is whether or not the baseband chipset makers (Intel, Qualcomm, Mediatek, ...) will implement it anytime soon on the device side.

There are no plans on implementing any of this in the Osmocom stack as of now,but in case anyone was interested in working on this, feel free to contact us on the osmocom-net-gprs@lists.osmocom.org mailing list.

Syndicated 2016-07-23 10:00:00 from LaForge's home page

Deeper ventures into Ericsson (Packet) Abis

Some topics keep coming back, even a number of years after first having worked on them. And then you start to search online using your favorite search engine - and find your old posts on that subject are the most comprehensive publicly available information on the subject ;)

Back in 2011, I was working on some very basic support for Ericsson RBS2xxx GSM BTSs in OpenBSC. The major part of this was to find out the weird dynamic detection of the signalling timeslot, as well as the fully non-standard OM2000 protocol for OML. Once it reached the state of a 'proof-of-concept', work at this ceased and remained in a state where still lots of manual steps were involved in BTS bring-up.

I've recently picked this topic up again, resulting in some work-in-progress code in http://git.osmocom.org/openbsc/log/?h=laforge/om2000-fsm

Beyond classic E1 based A-bis support, I've also been looking (again) at Ericsson Packet Abis. Packet Abis is their understanding of Abis over IP. However, it is - again - much further from the 3GPP specifications than what we're used to in the Osmocom universe. Abis/IP as we know consists of:

  • RSL and OML over TCP (inside an IPA multiplex)
  • RTP streams for the user plane (voice)
  • Gb over IP (NS over UDP/IP), as te PCU is in the BTS.

In the Ericsson world, they decided to taka a much lower-layer approach and decided to

  • start with L2TP over IP (not the L2TP over UDP that many people know from VPNs)
  • use the IETF-standardized Pseudowire type for HDLC but use a frame format in violation of the IETF RFCs
  • Talk LAPD over L2TP for RSL and OML
  • Invent a new frame format for voice codec frames called TFP and feed that over L2TP
  • Invent a new frame format for the PCU-CCU communication called P-GSL and feed that over L2TP

I'm not yet sure if we want to fully support that protocol stack from OpenBSC and related projects, but in any case I've extende wireshark to decode such protocol traces properly by

  • Extending the L2TP dissector with Ericsson specific AVPs
  • Improving my earlier pakcet-ehdlc.c with better understanding of the protocol
  • Implementing a new TFP dissector from scratch
  • Implementing a new P-GSL dissector from scratch

The resulting work can be found at http://git.osmocom.org/wireshark/log/?h=laforge/ericsson-packet-abis in case anyone is interested. I've mostly been working with protocol traces from RBS2409 so far, and they are decoded quite nicely for RSL, OML, Voice and Packet data. As far as I know, the format of the STN / SIU of other BTS models is identical.

Is anyone out there in possession of Ericsson RBS2xxx RBSs interested in collboration on either a Packet Abis implementation, or an inteface of the E1 or packet based CCU-PCU interface to OsmoPCU?

Syndicated 2016-07-16 10:00:00 from LaForge's home page

Recent public allegations against Jacob Appelbaum

In recent days, various public allegations have been brought forward against Jacob Appelbaum. The allegations rank from plagiarism to sexual assault and rape.

I find it deeply disturbing that the alleged victims are putting up the effort of a quite slick online campaign to defame Jakes's name, using a domain name consisting of only his name and virtually any picture you can find online of him from the last decade, and - to a large extent - hide in anonymity.

I'm upset about this not because I happen to know Jake personally for many years, but because I think it is fundamentally wrong to bring up those accusations in such a form.

I have no clue what is the truth or what is not the truth. Nor does anyone else who has not experienced or witnessed the alleged events first hand. I'd hope more people would think about that before commenting on this topic one way or another on Twitter, in their blogs, on mailing lists, etc. It doesn't matter what we believe, hypothesize or project based on a personal like or dislike of either the person accused or of the accusers.

We don't live in the middle ages, and we have given up on the pillory for a long time (and the pillory was used after a judgement, not before). If there was illegal/criminal behavior, then our societies have a well-established and respected procedure to deal with such: It is based on laws, legal procedure and courts.

So if somebody has a claim, they can and should seek legal support and bring those claims forward to the competent authorities, rather than starting what very easily looks like a smear campaign (whether it is one or not).

Please don't get me wrong: I have the deepest respect and sympathies for victims of sexual assault or abuse - but I also have a deep respect for the legal foundation our societies have built over hundreds of years, and it's principles including the human right "presumption of innocence".

No matter who has committed which type of crime, everyone deserve to receive a fair trial, and they are innocent until proven guilty.

I believe nobody deserves such a public defamation campaign, nor does anyone have the authority to sentence such a verdict, not even a court of law. The Pillory was abandoned for good reasons.

Syndicated 2016-06-06 10:00:00 from LaForge's home page

Nuand abusing the term "Open Source" for non-free Software

Back in late April, the well-known high-quality SDR hardware company Nuand published a blog post about an Open Source Release of a VHDL ADS-B receiver.

I was quite happy at that time about this, and bookmarked it for further investigation at some later point.

Today I actually looked at the source code, and more by coincidence noticed that the LICENSE file contains a license that is anything but Open Source: The license is a "free for evaluation only" license, and it is only valid if you run the code on an actual Nuand board.

Both of the above are clearly not compatible with any of the well-known and respected definitions of Open Source, particularly not the official Open Source Definition of the Open Source Initiative.

I cannot even start how much this makes me upset. This is once again openwashing, where something that clearly is not Free or Open Source Software is labelled and marketed as such.

I don't mind if an author chooses to license his work under a proprietary license. It is his choice to do so under the law, and it generally makes such software utterly unattractive to me. If others still want to use it, it is their decision. However, if somebody produces or releases non-free or proprietary software, then they should make that very clear and not mis-represent it as something that it clearly isn't!

Open-washing only confuses everyone, and it tries to market the respective company or product in a light that it doesn't deserve. I believe the proper English proverb is to adorn oneself with borrowed plumes.

I strongly believe the community must stand up against such practise and clearly voice that this is not something generally acceptable or tolerated within the Free and Open Source software world. It's sad that this is happening more frequently, like recently with OpenAirInterface (see related blog post).

I will definitely write an e-mail to Nuand management requesting to correct this mis-representation. If you agree with my posting, I'd appreciate if you would contact them, too.

Syndicated 2016-06-01 10:00:00 from LaForge's home page

Keynote at Black Duck Korea Open Source Conference

I've been giving a keynote at the Black Duck Korea Open Source Conference yesterday, and I'd like to share some thoughts about it.

In terms of the content, I spoke about the fact that the ultimate goal/wish/intent of free software projects is to receive contributions and for all of the individual and organizational users to join the collaborative development process. However, that's just the intent, and it's not legally required.

Due to GPL enforcement work, a lot of attention has been created over the past ten years in the corporate legal departments on how to comply with FOSS license terms, particularly copyleft-style licenses like GPLv2 and GPLv3. However,

License compliance ensures the absolute bare legal minimum on engaging with the Free Software community. While that is legally sufficient, the community actually wants to have all developers join the collaborative development process, where the resources for development are contributed and shared among all developers.

So I think if we had more contribution and a more fair distribution of the work in developing and maintaining the related software, we would not have to worry so much about legal enforcement of licenses.

However, in the absence of companies being good open source citizens, pulling out the legal baton is all we can do to at least require them to share their modifications at the time they ship their products. That code might not be mergeable, or it might be outdated, so it's value might be less than we would hope for, but it is a beginning.

Now some people might be critical of me speaking at a Black Duck Korea event, where Black Duck is a company selling (expensive!) licenses to proprietary tools for license compliance. Thereby, speaking at such an event might be seen as an endorsement of Black Duck and/or proprietary software in general.

Honestly, I don't think so. If you've ever seen a Black Duck Korea event, then you will notice there is no marketing or sales booth, and that there is no sales pitch on the conference agenda. Rather, you have speakers with hands-on experience in license compliance either from a community point of view, or from a corporate point of view, i.e. how companies are managing license compliance processes internally.

Thus, the event is not a sales show for proprietary software, but an event that brings together various people genuinely interested in license compliance matters. The organizers very clearly understand that they have to keep that kind of separation. So it's actually more like a community event, sponsored by a commercial entity - and that in turn is true for most technology conferences.

So I have no ethical problems with speaking at their event. People who know me, know that I don't like proprietary software at all for ethical reasons, and avoid it personally as far as possible. I certainly don't promote Black Ducks products. I promote license compliance.

Let's look at it like this: If companies building products based on Free Software think they need software tools to help them with license compliance, and they don't want to develop such tools together in a collaborative Free Software project themselves, then that's their decision to take. To state using words of Rosa Luxemburg:

Freedom is always the freedom of those who think different

I may not like that others want to use proprietary software, but if they think it's good for them, it's their decision to take.

Syndicated 2016-05-27 01:00:00 from LaForge's home page

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