Search Results: "jens"

13 March 2024

Russell Coker: The Shape of Computers

Introduction There have been many experiments with the sizes of computers, some of which have stayed around and some have gone away. The trend has been to make computers smaller, the early computers had buildings for them. Recently for come classes computers have started becoming as small as could be reasonably desired. For example phones are thin enough that they can blow away in a strong breeze, smart watches are much the same size as the old fashioned watches they replace, and NUC type computers are as small as they need to be given the size of monitors etc that they connect to. This means that further development in the size and shape of computers will largely be determined by human factors. I think we need to consider how computers might be developed to better suit humans and how to write free software to make such computers usable without being constrained by corporate interests. Those of us who are involved in developing OSs and applications need to consider how to adjust to the changes and ideally anticipate changes. While we can t anticipate the details of future devices we can easily predict general trends such as being smaller, higher resolution, etc. Desktop/Laptop PCs When home computers first came out it was standard to have the keyboard in the main box, the Apple ][ being the most well known example. This has lost popularity due to the demand to have multiple options for a light keyboard that can be moved for convenience combined with multiple options for the box part. But it still pops up occasionally such as the Raspberry Pi 400 [1] which succeeds due to having the computer part being small and light. I think this type of computer will remain a niche product. It could be used in a add a screen to make a laptop as opposed to the add a keyboard to a tablet to make a laptop model but a tablet without a keyboard is more useful than a non-server PC without a display. The PC as box with connections for keyboard, display, etc has a long future ahead of it. But the sizes will probably decrease (they should have stopped making PC cases to fit CD/DVD drives at least 10 years ago). The NUC size is a useful option and I think that DVD drives will stop being used for software soon which will allow a range of smaller form factors. The regular laptop is something that will remain useful, but the tablet with detachable keyboard devices could take a lot of that market. Full functionality for all tasks requires a keyboard because at the moment text editing with a touch screen is an unsolved problem in computer science [2]. The Lenovo Thinkpad X1 Fold [3] and related Lenovo products are very interesting. Advances in materials allow laptops to be thinner and lighter which leaves the screen size as a major limitation to portability. There is a conflict between desiring a large screen to see lots of content and wanting a small size to carry and making a device foldable is an obvious solution that has recently become possible. Making a foldable laptop drives a desire for not having a permanently attached keyboard which then makes a touch screen keyboard a requirement. So this means that user interfaces for PCs have to be adapted to work well on touch screens. The Think line seems to be continuing the history of innovation that it had when owned by IBM. There are also a range of other laptops that have two regular screens so they are essentially the same as the Thinkpad X1 Fold but with two separate screens instead of one folding one, prices are as low as $600US. I think that the typical interfaces for desktop PCs (EG MS-Windows and KDE) don t work well for small devices and touch devices and the Android interface generally isn t a good match for desktop systems. We need to invent more options for this. This is not a criticism of KDE, I use it every day and it works well. But it s designed for use cases that don t match new hardware that is on sale. As an aside it would be nice if Lenovo gave samples of their newest gear to people who make significant contributions to GUIs. Give a few Thinkpad Fold devices to KDE people, a few to GNOME people, and a few others to people involved in Wayland development and see how that promotes software development and future sales. We also need to adopt features from laptops and phones into desktop PCs. When voice recognition software was first released in the 90s it was for desktop PCs, it didn t take off largely because it wasn t very accurate (none of them recognised my voice). Now voice recognition in phones is very accurate and it s very common for desktop PCs to have a webcam or headset with a microphone so it s time for this to be re-visited. GPS support in laptops is obviously useful and can work via Wifi location, via a USB GPS device, or via wwan mobile phone hardware (even if not used for wwan networking). Another possibility is using the same software interfaces as used for GPS on laptops for a static definition of location for a desktop PC or server. The Interesting New Things Watch Like The wrist-watch [4] has been a standard format for easy access to data when on the go since it s military use at the end of the 19th century when the practical benefits beat the supposed femininity of the watch. So it seems most likely that they will continue to be in widespread use in computerised form for the forseeable future. For comparison smart phones have been in widespread use as pocket watches for about 10 years. The question is how will watch computers end up? Will we have Dick Tracy style watch phones that you speak into? Will it be the current smart watch functionality of using the watch to answer a call which goes to a bluetooth headset? Will smart watches end up taking over the functionality of the calculator watch [5] which was popular in the 80 s? With today s technology you could easily have a fully capable PC strapped to your forearm, would that be useful? Phone Like Folding phones (originally popularised as Star Trek Tricorders) seem likely to have a long future ahead of them. Engineering technology has only recently developed to the stage of allowing them to work the way people would hope them to work (a folding screen with no gaps). Phones and tablets with multiple folds are coming out now [6]. This will allow phones to take much of the market share that tablets used to have while tablets and laptops merge at the high end. I ve previously written about Convergence between phones and desktop computers [7], the increased capabilities of phones adds to the case for Convergence. Folding phones also provide new possibilities for the OS. The Oppo OnePlus Open and the Google Pixel Fold both have a UI based around using the two halves of the folding screen for separate data at some times. I think that the current user interfaces for desktop PCs don t properly take advantage of multiple monitors and the possibilities raised by folding phones only adds to the lack. My pet peeve with multiple monitor setups is when they don t make it obvious which monitor has keyboard focus so you send a CTRL-W or ALT-F4 to the wrong screen by mistake, it s a problem that also happens on a single screen but is worse with multiple screens. There are rumours of phones described as three fold (where three means the number of segments with two folds between them), it will be interesting to see how that goes. Will phones go the same way as PCs in terms of having a separation between the compute bit and the input device? It s quite possible to have a compute device in the phone form factor inside a secure pocket which talks via Bluetooth to another device with a display and speakers. Then you could change your phone between a phone-size display and a tablet sized display easily and when using your phone a thief would not be able to easily steal the compute bit (which has passwords etc). Could the watch part of the phone (strapped to your wrist and difficult to steal) be the active part and have a tablet size device as an external display? There are already announcements of smart watches with up to 1GB of RAM (same as the Samsung Galaxy S3), that s enough for a lot of phone functionality. The Rabbit R1 [8] and the Humane AI Pin [9] have some interesting possibilities for AI speech interfaces. Could that take over some of the current phone use? It seems that visually impaired people have been doing badly in the trend towards touch screen phones so an option of a voice interface phone would be a good option for them. As an aside I hope some people are working on AI stuff for FOSS devices. Laptop Like One interesting PC variant I just discovered is the Higole 2 Pro portable battery operated Windows PC with 5.5 touch screen [10]. It looks too thick to fit in the same pockets as current phones but is still very portable. The version with built in battery is $AU423 which is in the usual price range for low end laptops and tablets. I don t think this is the future of computing, but it is something that is usable today while we wait for foldable devices to take over. The recent release of the Apple Vision Pro [11] has driven interest in 3D and head mounted computers. I think this could be a useful peripheral for a laptop or phone but it won t be part of a primary computing environment. In 2011 I wrote about the possibility of using augmented reality technology for providing a desktop computing environment [12]. I wonder how a Vision Pro would work for that on a train or passenger jet. Another interesting thing that s on offer is a laptop with 7 touch screen beside the keyboard [13]. It seems that someone just looked at what parts are available cheaply in China (due to being parts of more popular devices) and what could fit together. I think a keyboard should be central to the monitor for serious typing, but there may be useful corner cases where typing isn t that common and a touch-screen display is of use. Developing a range of strange hardware and then seeing which ones get adopted is a good thing and an advantage of Ali Express and Temu. Useful Hardware for Developing These Things I recently bought a second hand Thinkpad X1 Yoga Gen3 for $359 which has stylus support [14], and it s generally a great little laptop in every other way. There s a common failure case of that model where touch support for fingers breaks but the stylus still works which allows it to be used for testing touch screen functionality while making it cheap. The PineTime is a nice smart watch from Pine64 which is designed to be open [15]. I am quite happy with it but haven t done much with it yet (apart from wearing it every day and getting alerts etc from Android). At $50 when delivered to Australia it s significantly more expensive than most smart watches with similar features but still a lot cheaper than the high end ones. Also the Raspberry Pi Watch [16] is interesting too. The PinePhonePro is an OK phone made to open standards but it s hardware isn t as good as Android phones released in the same year [17]. I ve got some useful stuff done on mine, but the battery life is a major issue and the screen resolution is low. The Librem 5 phone from Purism has a better hardware design for security with switches to disable functionality [18], but it s even slower than the PinePhonePro. These are good devices for test and development but not ones that many people would be excited to use every day. Wwan hardware (for accessing the phone network) in M.2 form factor can be obtained for free if you have access to old/broken laptops. Such devices start at about $35 if you want to buy one. USB GPS devices also start at about $35 so probably not worth getting if you can get a wwan device that does GPS as well. What We Must Do Debian appears to have some voice input software in the pocketsphinx package but no documentation on how it s to be used. This would be a good thing to document, I spent 15 mins looking at it and couldn t get it going. To take advantage of the hardware features in phones we need software support and we ideally don t want free software to lag too far behind proprietary software which IMHO means the typical Android setup for phones/tablets. Support for changing screen resolution is already there as is support for touch screens. Support for adapting the GUI to changed screen size is something that needs to be done even today s hardware of connecting a small laptop to an external monitor doesn t have the ideal functionality for changing the UI. There also seem to be some limitations in touch screen support with multiple screens, I haven t investigated this properly yet, it definitely doesn t work in an expected manner in Ubuntu 22.04 and I haven t yet tested the combinations on Debian/Unstable. ML is becoming a big thing and it has some interesting use cases for small devices where a smart device can compensate for limited input options. There s a lot of work that needs to be done in this area and we are limited by the fact that we can t just rip off the work of other people for use as training data in the way that corporations do. Security is more important for devices that are at high risk of theft. The vast majority of free software installations are way behind Android in terms of security and we need to address that. I have some ideas for improvement but there is always a conflict between security and usability and while Android is usable for it s own special apps it s not usable in a I want to run applications that use any files from any other applicationsin any way I want sense. My post about Sandboxing Phone apps is relevant for people who are interested in this [19]. We also need to extend security models to cope with things like ok google type functionality which has the potential to be a bug and the emerging class of LLM based attacks. I will write more posts about these thing. Please write comments mentioning FOSS hardware and software projects that address these issues and also documentation for such things.
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6 September 2023

Dirk Eddelbuettel: RcppInt64 0.0.1 on CRAN: New Package!

Happy to share that a new package RcppInt64 arrived on CRAN earlier today after a brief one-day inspection round. RcppInt64 collects some of the previous conversions between 64-bit integer values in R and C++, and regroups them in a single package. A single header is provided. It actually offers two interfaces: both a more standard as<>() converter from R values along with its companions wrap() to return to R, as well as more dedicated functions from and to . A key difficulty faced when supporting 64 bit integer payloads is that R has no proper type for it so the standard template-based approaches use by Rcpp do not apply. To carry 64 bit integers, the clever approach by Jens Oehlschl gel and his bit64 package is used. However, its use of a double to transport the int64 payload means we must take care to not uninentionally interpret the double variables as, well, double. So we use an simple S3 class in R, and check for it. With some care (as provided by these helper functions) this works well. The RcppInt64 packages contains both an example function, as well as an entire example package to demonstrate how to use these facilities in your package. We hope others will find this useful. If you like this or other open-source work I do, you can sponsor me at GitHub.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

19 November 2021

Evgeni Golov: A String is not a String, and that's Groovy!

Halloween is over, but I still have some nightmares to share with you, so sit down, take some hot chocolate and enjoy :) When working with Jenkins, there is almost no way to avoid writing Groovy. Well, unless you only do old style jobs with shell scripts, but y'all know what I think about shell scripts Anyways, Eric have been rewriting the jobs responsible for building Debian packages for Foreman to pipelines (and thus Groovy). Our build process for pull requests is rather simple:
  1. Setup sources - get the orig tarball and adjust changelog to have an unique version for pull requests
  2. Call pbuilder
  3. Upload the built package to a staging archive for testing
For merges, it's identical, minus the changelog adjustment. And if there are multiple packages changed in one go, it runs each step in parallel for each package. Now I've been doing mass changes to our plugin packages, to move them to a shared postinst helper instead of having the same code over and over in every package. This required changes to many packages and sometimes I'd end up building multiple at once. That should be fine, right? Well, yeah, it did build fine, but the upload only happened for the last package. This felt super weird, especially as I was absolutely sure we did test this scenario (multiple packages in one PR) and it worked just fine So I went on a ride though the internals of the job, trying to understand why it didn't work. This requires a tad more information about the way we handle packages for Foreman:
  • the archive is handled by freight
  • it has suites like buster, focal and plugins (that one is a tad special)
  • each suite has components that match Foreman releases, so 2.5, 3.0, 3.1, nightly etc
  • core packages (Foreman etc) are built for all supported distributions (right now: buster and focal)
  • plugin packages are built only once and can be used on every distribution
As generating the package index isn't exactly fast in freight, we tried not not run it too often. The idea was that when we build two packages for the same target (suite/version combination), we upload both at once and run import only once for both. That means that when we build Foreman for buster and focal, this results in two parallel builds and then two parallel uploads (as they end up in different suites). But if we build Foreman and Foreman Installer, we have four parallel builds, but only two parallel uploads, as we can batch upload Foreman and Installer per suite. Well, or so was the theory. The Groovy code, that was supposed to do this looked roughly like this: 
def packages_to_build = find_changed_packages()
def repos = [:]
packages_to_build.each   pkg ->
    suite = 'buster'
    component = '3.0'
    target = "$ suite -$ component "
    if (!repos.containsKey(target))  
        repos[target] = []
     
    repos[target].add(pkg)
 
do_the_build(packages_to_build)
do_the_upload(repos)
That's pretty straight forward, no? We create an empty Map, loop over a list of packages and add them to an entry in the map which we pre-create as empty if it doesn't exist. Well, no, the resulting map always ended with only having one element in each target list. And this is also why our original tests always worked: we tested with a PR containing changes to Foreman and a plugin, and plugins go to this special target we have So I started playing with the code (https://groovyide.com/playground is really great for that!), trying to understand why the heck it erases previous data. The first finding was that it just always ended up jumping into the "if map entry not found" branch, even though the map very clearly had the correct entry after the first package was added. The second one was weird. I was trying to minimize the reproducer code (IMHO always a good idea) and switched target = "$ suite -$ component " to target = "lol". Two entries in the list, only one jump into the "map entry not found" branch. What?! So this is clearly related to the fact that we're using String interpolation here. But hey, that's a totally normal thing to do, isn't it?! Admittedly, at this point, I was lost. I knew what breaks, but not why. Luckily, I knew exactly who to ask: Jens. After a brief "well, that's interesting", Jens quickly found the source of our griefs: Double-quoted strings are plain java.lang.String if there s no interpolated expression, but are groovy.lang.GString instances if interpolation is present.. And when we do repos[target] the GString target gets converted to a String, but when we use repos.containsKey() it remains a GString. This is because GStrings get converted to Strings, if the method wants one, but containsKey takes any Object while the repos[target] notation for some reason converts it. Maybe this is because using GString as Map keys should be avoided. We can reproduce this with simpler code: 
def map = [:]
def something = "something"
def key = "$ something "
map[key] = 1
println key.getClass()
map.keySet().each  println it.getClass()  
map.keySet().each  println it.equals(key) 
map.keySet().each  println it.equals(key as String)
Which results in the following output: 
class org.codehaus.groovy.runtime.GStringImpl
class java.lang.String
false
true
With that knowledge, the fix was to just use the same repos[target] notation also for checking for existence Groovy helpfully returns null which is false-y when it can't find an entry in a Map absent. So yeah, a String is not always a String, and it'll bite you!

25 April 2021

Antoine Beaupr : Lost article ideas

I wrote for LWN for about two years. During that time, I wrote (what seems to me an impressive) 34 articles, but I always had a pile of ideas in the back of my mind. Those are ideas, notes, and scribbles lying around. Some were just completely abandoned because they didn't seem a good fit for LWN. Concretely, I stored those in branches in a git repository, and used the branch name (and, naively, the last commit log) as indicators of the topic. This was the state of affairs when I left: 
remotes/private/attic/novena                    822ca2bb add letter i sent to novena, never published
remotes/private/attic/secureboot                de09d82b quick review, add note and graph
remotes/private/attic/wireguard                 5c5340d1 wireguard review, tutorial and comparison with alternatives
remotes/private/backlog/dat                     914c5edf Merge branch 'master' into backlog/dat
remotes/private/backlog/packet                  9b2c6d1a ham radio packet innovations and primer
remotes/private/backlog/performance-tweaks      dcf02676 config notes for http2
remotes/private/backlog/serverless              9fce6484 postponed until kubecon europe
remotes/private/fin/cost-of-hosting             00d8e499 cost-of-hosting article online
remotes/private/fin/kubecon                     f4fd7df2 remove published or spun off articles
remotes/private/fin/kubecon-overview            21fae984 publish kubecon overview article
remotes/private/fin/kubecon2018                 1edc5ec8 add series
remotes/private/fin/netconf                     3f4b7ece publish the netconf articles
remotes/private/fin/netdev                      6ee66559 publish articles from netdev 2.2
remotes/private/fin/pgp-offline                 f841deed pgp offline branch ready for publication
remotes/private/fin/primes                      c7e5b912 publish the ROCA paper
remotes/private/fin/runtimes                    4bee1d70 prepare publication of runtimes articles
remotes/private/fin/token-benchmarks            5a363992 regenerate timestamp automatically
remotes/private/ideas/astropy                   95d53152 astropy or python in astronomy
remotes/private/ideas/avaneya                   20a6d149 crowdfunded blade-runner-themed GPLv3 simcity-like simulator
remotes/private/ideas/backups-benchmarks        fe2f1f13 review of backup software through performance and features
remotes/private/ideas/cumin                     7bed3945 review of the cumin automation tool from WM foundation
remotes/private/ideas/future-of-distros         d086ca0d modern packaging problems and complex apps
remotes/private/ideas/on-dying                  a92ad23f another dying thing
remotes/private/ideas/openpgp-discovery         8f2782f0 openpgp discovery mechanisms (WKD, etc), thanks to jonas meurer
remotes/private/ideas/password-bench            451602c0 bruteforce estimates for various password patterns compared with RSA key sizes
remotes/private/ideas/prometheus-openmetrics    2568dbd6 openmetrics standardizing prom metrics enpoints
remotes/private/ideas/telling-time              f3c24a53 another way of telling time
remotes/private/ideas/wallabako                 4f44c5da talk about wallabako, read-it-later + kobo hacking
remotes/private/stalled/bench-bench-bench       8cef0504 benchmarking http benchmarking tools
remotes/private/stalled/debian-survey-democracy 909bdc98 free software surveys and debian democracy, volunteer vs paid work
Wow, what a mess! Let's see if I can make sense of this:

Attic Those are articles that I thought about, then finally rejected, either because it didn't seem worth it, or my editors rejected it, or I just moved on:
  • novena: the project is ooold now, didn't seem to fit a LWN article. it was basically "how can i build my novena now" and "you guys rock!" it seems like the MNT Reform is the brain child of the Novena now, and I dare say it's even cooler!
  • secureboot: my LWN editors were critical of my approach, and probably rightly so - it's a really complex subject and I was probably out of my depth... it's also out of date now, we did manage secureboot in Debian
  • wireguard: LWN ended up writing extensive coverage, and I was biased against Donenfeld because of conflicts in a previous project

Backlog Those were articles I was planning to write about next.
  • dat: I already had written Sharing and archiving data sets with Dat, but it seems I had more to say... mostly performance issues, beaker, no streaming, limited adoption... to be investigated, I guess?
  • packet: a primer on data communications over ham radio, and the cool new tech that has emerged in the free software world. those are mainly notes about Pat, Direwolf, APRS and so on... just never got around to making sense of it or really using the tech...
  • performance-tweaks: "optimizing websites at the age of http2", the unwritten story of the optimization of this website with HTTP/2 and friends
  • serverless: god. one of the leftover topics at Kubecon, my notes on this were thin, and the actual subject, possibly even thinner... the only lie worse than the cloud is that there's no server at all! concretely, that's a pile of notes about Kubecon which I wanted to sort through. Probably belongs in the attic now.

Fin Those are finished articles, they were published on my website and LWN, but the branches were kept because previous drafts had private notes that should not be published.

Ideas A lot of those branches were actually just an empty commit, with the commitlog being the "pitch", more or less. I'd send that list to my editors, sometimes with a few more links (basically the above), and they would nudge me one way or the other. Sometimes they would actively discourage me to write about something, and I would do it anyways, send them a draft, and they would patiently make me rewrite it until it was a decent article. This was especially hard with the terminal emulator series, which took forever to write and even got my editors upset when they realized I had never installed Fedora (I ended up installing it, and I was proven wrong!)

Stalled Oh, and then there's those: those are either "ideas" or "backlog" that got so far behind that I just moved them out of the way because I was tired of seeing them in my list.
  • stalled/bench-bench-bench benchmarking http benchmarking tools, a horrible mess of links, copy-paste from terminals, and ideas about benchmarking... some of this trickled out into this benchmarking guide at Tor, but not much more than the list of tools
  • stalled/debian-survey-democracy: "free software surveys and Debian democracy, volunteer vs paid work"... A long standing concern of mine is that all Debian work is supposed to be volunteer, and paying explicitly for work inside Debian has traditionally been frowned upon, even leading to serious drama and dissent (remember Dunc-Tank)? back when I was writing for LWN, I was also doing paid work for Debian LTS. I also learned that a lot (most?) Debian Developers were actually being paid by their job to work on Debian. So I was confused by this apparent contradiction, especially given how the LTS project has been mostly accepted, while Dunc-Tank was not... See also this talk at Debconf 16. I had hopes that this study would show the "hunch" people have offered (that most DDs are paid to work on Debian) but it seems to show the reverse (only 36% of DDs, and 18% of all respondents paid). So I am still confused and worried about the sustainability of Debian.

What do you think? So that's all I got. As people might have noticed here, I have much less time to write these days, but if there's any subject in there I should pick, what is the one that you would find most interesting? Oh! and I should mention that you can write to LWN! If you think people should know more about some Linux thing, you can get paid to write for it! Pitch it to the editors, they won't bite. The worst that can happen is that they say "yes" and there goes two years of your life learning to write. Because no, you don't know how to write, no one does. You need an editor to write. That's why this article looks like crap and has a smiley. :)

30 November 2020

Chris Lamb: Free software activities in November 2020

Here is my monthly update covering what I have been doing in the free software world during November 2020 (previous month):

Reproducible Builds One of the original promises of open source software is that distributed peer review and transparency of process results in enhanced end-user security. However, whilst anyone may inspect the source code of free and open source software for malicious flaws, almost all software today is distributed as pre-compiled binaries. This allows nefarious third-parties to compromise systems by injecting malicious code into ostensibly secure software during the various compilation and distribution processes. The motivation behind the Reproducible Builds effort is to ensure no flaws have been introduced during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised. The project is proud to be a member project of the Software Freedom Conservancy. Conservancy acts as a corporate umbrella allowing projects to operate as non-profit initiatives without managing their own corporate structure. If you like the work of the Conservancy or the Reproducible Builds project, please consider becoming an official supporter.
This month, I:
I also made the following changes to diffoscope:

Debian I performed the following uploads to the Debian Linux distribution this month: I also filed a release-critical bug against the minidlna package which could not be successfully purged from the system without reporting a cannot remove '/var/log/minidlna' error. (#975372)

Debian LTS This month I have worked 18 hours on Debian Long Term Support (LTS) and 12 hours on its sister Extended LTS project, including: You can find out more about the Debian LTS project via the following video:

2 September 2020

Kees Cook: security things in Linux v5.6

Previously: v5.5. Linux v5.6 was released back in March. Here s my quick summary of various features that caught my attention: WireGuard
The widely used WireGuard VPN has been out-of-tree for a very long time. After 3 1/2 years since its initial upstream RFC, Ard Biesheuvel and Jason Donenfeld finished the work getting all the crypto prerequisites sorted out for the v5.5 kernel. For this release, Jason has gotten WireGuard itself landed. It was a twisty road, and I m grateful to everyone involved for sticking it out and navigating the compromises and alternative solutions. openat2() syscall and RESOLVE_* flags
Aleksa Sarai has added a number of important path resolution scoping options to the kernel s open() handling, covering things like not walking above a specific point in a path hierarchy (RESOLVE_BENEATH), disabling the resolution of various magic links (RESOLVE_NO_MAGICLINKS) in procfs (e.g. /proc/$pid/exe) and other pseudo-filesystems, and treating a given lookup as happening relative to a different root directory (as if it were in a chroot, RESOLVE_IN_ROOT). As part of this, it became clear that there wasn t a way to correctly extend the existing openat() syscall, so he added openat2() (which is a good example of the efforts being made to codify Extensible Syscall arguments). The RESOLVE_* set of flags also cover prior behaviors like RESOLVE_NO_XDEV and RESOLVE_NO_SYMLINKS. pidfd_getfd() syscall
In the continuing growth of the much-needed pidfd APIs, Sargun Dhillon has added the pidfd_getfd() syscall which is a way to gain access to file descriptors of a process in a race-less way (or when /proc is not mounted). Before, it wasn t always possible make sure that opening file descriptors via /proc/$pid/fd/$N was actually going to be associated with the correct PID. Much more detail about this has been written up at LWN. openat() via io_uring
With my attack surface reduction hat on, I remain personally suspicious of the io_uring() family of APIs, but I can t deny their utility for certain kinds of workloads. Being able to pipeline reads and writes without the overhead of actually making syscalls is pretty great for performance. Jens Axboe has added the IORING_OP_OPENAT command so that existing io_urings can open files to be added on the fly to the mapping of available read/write targets of a given io_uring. While LSMs are still happily able to intercept these actions, I remain wary of the growing syscall multiplexer that io_uring is becoming. I am, of course, glad to see that it has a comprehensive (if out of tree ) test suite as part of liburing. removal of blocking random pool
After making algorithmic changes to obviate separate entropy pools for random numbers, Andy Lutomirski removed the blocking random pool. This simplifies the kernel pRNG code significantly without compromising the userspace interfaces designed to fetch cryptographically secure random numbers. To quote Andy, This series should not break any existing programs. /dev/urandom is unchanged. /dev/random will still block just after booting, but it will block less than it used to. See LWN for more details on the history and discussion of the series. arm64 support for on-chip RNG
Mark Brown added support for the future ARMv8.5 s RNG (SYS_RNDR_EL0), which is, from the kernel s perspective, similar to x86 s RDRAND instruction. This will provide a bootloader-independent way to add entropy to the kernel s pRNG for early boot randomness (e.g. stack canary values, memory ASLR offsets, etc). Until folks are running on ARMv8.5 systems, they can continue to depend on the bootloader for randomness (via the UEFI RNG interface) on arm64. arm64 E0PD
Mark Brown added support for the future ARMv8.5 s E0PD feature (TCR_E0PD1), which causes all memory accesses from userspace into kernel space to fault in constant time. This is an attempt to remove any possible timing side-channel signals when probing kernel memory layout from userspace, as an alternative way to protect against Meltdown-style attacks. The expectation is that E0PD would be used instead of the more expensive Kernel Page Table Isolation (KPTI) features on arm64. powerpc32 VMAP_STACK
Christophe Leroy added VMAP_STACK support to powerpc32, joining x86, arm64, and s390. This helps protect against the various classes of attacks that depend on exhausting the kernel stack in order to collide with neighboring kernel stacks. (Another common target, the sensitive thread_info, had already been moved away from the bottom of the stack by Christophe Leroy in Linux v5.1.) generic Page Table dumping
Related to RISCV s work to add page table dumping (via /sys/fs/debug/kernel_page_tables), Steven Price extracted the existing implementations from multiple architectures and created a common page table dumping framework (and then refactored all the other architectures to use it). I m delighted to have this because I still remember when not having a working page table dumper for ARM delayed me for a while when trying to implement upstream kernel memory protections there. Anything that makes it easier for architectures to get their kernel memory protection working correctly makes me happy. That s in for now; let me know if there s anything you think I missed. Next up: Linux v5.7.

2020, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

1 October 2017

Paul Wise: FLOSS Activities September 2017

Changes

Issues

Review

Administration
  • icns: merged patches
  • Debian: help guest user with access, investigate/escalate broken network, restart broken stunnels, investigate static.d.o storage, investigate weird RAID mails, ask hoster to investigate power issue,
  • Debian mentors: lintian/security updates & reboot
  • Debian wiki: merged & deployed patch, redirect DDTSS translator, redirect user support requests, whitelist email addresses, update email for accounts with bouncing email,
  • Debian derivatives census: merged/deployed patches
  • Debian PTS: debugged cron mails, deployed changes, reran scripts, fixed configuration file
  • Openmoko: debug reboot issue, debug load issues

Communication

Sponsors The samba bug was sponsored by my employer. All other work was done on a volunteer basis.

16 December 2016

Dirk Eddelbuettel: nanotime 0.0.1: New package for Nanosecond Resolution Time for R

R has excellent tools for dates and times. The Date and POSIXct classes (as well as the 'wide' representation in POSIXlt) are versatile, and a lot of useful tooling has been built around them. However, POSIXct is implemented as a double with fractional seconds since the epoch. Given the 53 bits accuracy, it leaves just a bit less than microsecond resolution. Which is good enough for most things. But more and more performance measurements, latency statistics, ... are now measured more finely, and we need nanosecond resolution. For which commonly an integer64 is used to represent nanoseconds since the epoch. And while R does not a native type for this, the bit64 package by Jens Oehlschl gel offers a performant one implemented as a lightweight S3 class. So this package uses this integer64 class, along with two helper functions for parsing and formatting, respectively, at nano-second resolution from the RcppCCTZ package which wraps the CCTZ library from Google. CCTZ is a modern C++11 library extending the (C++11-native) chrono type.

Examples

Simple Parsing and Arithmetic 
R> x <- nanotime("1970-01-01T00:00:00.000000001+00:00")
R> print(x)
integer64
[1] 1
R> format(x)
[1] "1970-01-01T00:00:00.000000001+00:00"
R> cat("x+1 is: ")
x+1 is: R> x <- x + 1
R> print(x)
integer64
[1] 2
R> format(x)
[1] "1970-01-01T00:00:00.000000002+00:00"
R>

Vectorised 
R> options("width"=60)
R> v <- nanotime(Sys.time()) + 1:5
R> v
integer64
[1] 1481505724483583001 1481505724483583002
[3] 1481505724483583003 1481505724483583004
[5] 1481505724483583005
R> format(v)
[1] "2016-12-12T01:22:04.483583001+00:00"
[2] "2016-12-12T01:22:04.483583002+00:00"
[3] "2016-12-12T01:22:04.483583003+00:00"
[4] "2016-12-12T01:22:04.483583004+00:00"
[5] "2016-12-12T01:22:04.483583005+00:00"
R>

Use with zoo 
R> z <- zoo(cbind(A=1:5, B=5:1), v)
R> options("nanotimeFormat"="%d %b %H:%M:%E*S")  ## override default
R> z
                          A B
12 Dec 01:47:55.812513001 1 5
12 Dec 01:47:55.812513002 2 4
12 Dec 01:47:55.812513003 3 3
12 Dec 01:47:55.812513004 4 2
12 Dec 01:47:55.812513005 5 1
R>

Technical Details The bit64 package (by Jens Oehlschl gel) supplies the integer64 type used to store the nanosecond resolution time as (positive or negative) offsets to the epoch of January 1, 1970. The RcppCCTZ package supplies the formatting and parsing routines based on the (modern C++) library CCTZ from Google.

Status Version 0.0.1 has now been released. It works with some other packages, notably zoo and data.table. It (at least currently) requires RcppCCTZ to parse and format nanosecond resolution time objects from / to text --- and this package is on Linux and OS X only due to its use of system time zoneinfo. The requirement could be relaxed in the future by rewriting formating and parsing code. Contributions are welcome.

Installation The package is not yet on CRAN. Until it gets there, or to install the development versions, it can also be installed via a standard 
install.packages("RcppCCTZ")   # need 0.1.0 or later
remotes::install_github("eddelbuettel/nanotime")
If you prefer install.packages() (as I do), use the version from the ghrr drat: 
install.packages("drat")       # easier repo access + creation
drat:::add("ghrr")             # make it known
install.packages("nanotime")   # install it
If and when it gets to CRAN you will be able to do 
install.packages("nanotime")

Contact For questions or comments use the issue tracker off the GitHub repo.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

3 September 2016

Bits from Debian: New Debian Developers and Maintainers (July and August 2016)

The following contributors got their Debian Developer accounts in the last two months: The following contributors were added as Debian Maintainers in the last two months: Congratulations!

17 November 2015

Clint Adams: Things I am supposed to look into to mitigate the corrupt evil of Moxie Marlinspike

https://github.com/microg http://o9i.de/2015/10/23/howto-gmscore.html https://github.com/JavaJens/TextSecure https://fdroid.eutopia.cz/

13 September 2015

Russ Allbery: Accumulated haul

I haven't posted one of these in a while, but now that I'm finally caught up with writing reviews (although not posting them yet), I've been feeling about reading again. And of course the backlog always grows. Let's see if I can figure out what I've picked up since the last post. Catherine Asaro The Phoenix Code (sff)
Annie Bellet Justice Calling (sff)
Annie Bellet Murder of Crows (sff)
Annie Bellet Pack of Lies (sff)
Zen Cho Sorcerer to the Crown (sff)
J.J. Gribble Steel Victory (sff)
Judith L. Herman Trauma and Recovery (non-fiction)
Janis Ian & Mike Resnick Stars: The Anthology (sff anthology)
Megg Jensen Hidden (sff)
T. Kingfisher Bryony and Roses (sff)
T. Kingfisher The Seventh Bride (sff)
Nancy Kress Crossfire (sff)
Edmond Lau The Effective Engineer (non-fiction)
Yoon Ha Lee The Fox's Tower and Other Tales (sff collection)
Lozzi Roma Rome and the Vatican (non-fiction)
Elizabeth Lynn The Dancers of Arun (sff)
Elizabeth Lynn The Northern Girl (sff)
Rhonda Mason Empress Game (sff)
Vonda N. McIntyre Starfarers (sff)
Linda Nagata Memory (sff)
Jody Lynn Nye Strong Arm Tactics (sff)
Cat Rambo Near + Far (sff)
Kristine Kathryn Rusch The Diving Bundle (sff collection)
Kristine Kathryn Rusch Recovering Apollo 8 (sff)
L. Shelby Serendipity's Tide (sff)
L. Shelby Treachery's Harbor (sff)
L. Shelby Fealty's Shore (sff)
K.B. Spangler Digital Divide (sff)
Judith Tarr Forgotten Suns (sff)
Greg van Eekhout California Bones (sff) Hm, that's quite a lot. Most of it is various ebooks I picked up from various places, including a Humble Bundle. I've been impulse-buying a lot of stuff based on James Nicoll's reviews. The travel guide was a gift from a friend from a vacation in Italy.

2 July 2015

Petter Reinholdtsen: MakerCon Nordic videos now available on Frikanalen

Last oktober I was involved on behalf of NUUG with recording the talks at MakerCon Nordic, a conference for the Maker movement. Since then it has been the plan to publish the recordings on Frikanalen, which finally happened the last few days. A few talks are missing because the speakers asked the organizers to not publish them, but most of the talks are available. The talks are being broadcasted on RiksTV channel 50 and using multicast on Uninett, as well as being available from the Frikanalen web site. The unedited recordings are available on Youtube too. This is the list of talks available at the moment. Visit the Frikanalen video pages to view them. Part of the reason this took so long was that the scripts NUUG had to prepare a recording for publication were five years old and no longer worked with the current video processing tools (command line argument changes). In addition, we needed better audio normalization, which sent me on a detour to package bs1770gain for Debian. Now this is in place and it became a lot easier to publish NUUG videos on Frikanalen.

17 September 2014

NOKUBI Takatsugu: Met with a debian developer from Germany

Last weekend, I (knok), Hideki (henrich) and Yutaka (gniibe) met with John Paul Adrian Glaubitz (glaubitz). In the past, I had met with another Germany developer Jens Schmalzing (jensen) in Japan. He was a good guy, but unfortunately he gone in 2005. I had an old OpenPGP key with his sign. It is a record of his activity, but the key is weak nowaday (1024D), so I stop to use the key but don t issue revoke. Anyway glaubitz is also a good guy, and he loves old videogame console. gniibe gave him five DreamCast consoles. I bring him to SUPER POTATO, a old videogame shop. He bought some software for Virtual Boy. DebConf 2015 will hold in Germany, I want to go for it if I can.

19 March 2014

Jan Dittberner: CLT 2014 was great again

as in previous years we had a Debian booth at the Chemnitzer Linux-Tage it was as well organized as the years before and I enjoyed meeting a lot of great people from the Debian and free software communities as well as CAcert again. At our booth we presented the awesome work of Debian Installer translators in a BabelBox surrounded by xpenguins which attracted young as well as older passers-by. We got thanks for our work which I want to forward to the whole Debian community. A Debian user told us that he is able to use some PC hardware from the late 1990s that does not work with other desktop OSes anymore. We fed 3 kg of strategic jelly bear reserves as well as some packs of savoury snacks to our visitors. Alexander Wirt brought some T-Shirts, Stickers and Hoodies that we sold almost completely. We did some keysigning at the booth to help to get better keys into the Debian keyring and helped a prospective new Debian Developer to get a strong key signed to his FD approval. I also attended the Key signing party organized by Jens Kubieziel. Thanks to all people who helped at the booth:
  • Alexander Mundt
  • Alexander Wirt
  • Florian Baumann
  • Jan H rsch
  • Jan Wagner
  • Jonas Genannt
  • Rene Engelhard
  • Rhalina
  • Y Plentyn
Thanks to TMT for sponsoring the booth hardware.

14 March 2014

Richard Hartmann: Git prize: Outstanding Contribution to Open Source/Linux/Free Software

In February, Linux Magazine contacted me, asking if I would be willing to accept the Linux New Media Award 2014 in the main category "Outstanding Contribution to Open Source/Linux/Free Software" on behalf of the Git community due to my involvement with evangelizing and vcsh. Needless to say, I was thrilled. I managed to poke Junio via someone at Google and he agreed. We also reached out within the German Git community and two maintainers of git submodule, Jens Lehmann and Heiko Voigt, joined in as well. While we didn't manage to hammer out interoperability issues of vcsh and git submodule due to time constraints and too much beer, we are planning to follow up on that. Git beat OpenStack, Python, and Ubuntu by a huge margin; sadly I don't have exact numbers (yet). More details and a rather crummy photo can be found in Linux Magazine's article. A video of the whole thing will uploaded to this page soonish. If it appears that we kept our "speech" very short, that was deliberate after the somewhat prolonged speeches beforehand ;) The aftershow event was nice even though the DJ refused to turn down the music down to tolerable levels; his reaction to people moving father away, and asking him to turn down the volume a bit, was to turn it up... Anyway, given the mix of people present during the award ceremony, very interesting discussions ensued. While I failed to convert Klaus Knopper to zsh and git, at least there's a chance that Cornelius Schuhmacher will start using vcsh and maybe even push for a separation of configuration and state in KDE. The most interesting tidbits of the evening were shared by Abhisek Devkota of cyanogenmod fame. Without spilling any secrets it's safe to say that the future of cyanogenmod is looking extremely bright and that there are surprises in the works which will have quite the impact. Last but not least, here's the physical prize: Glass trophy held by your's truly

27 February 2014

Simon Josefsson: Replicant 4.2 on Samsung S3

Since November 2013 I have been using Replicant on my Samsung S3 as an alternative OS. The experience has been good for everyday use. The limits (due to non-free software components) compared to a normal S3 (running vendor ROM or CyanogenMod) is lack of GPS/wifi/bluetooth/NFC/frontcamera functionality although it is easy to get some of that working again, including GPS, which is nice for my geocaching hobby. The Replicant software is stable for being an Android platform; better than my Nexus 7 (2nd generation) tablet which I got around the same time that runs an unmodified version of Android. The S3 has crashed around ten times in these four months. I ve lost track of the number of N7 crashes, especially after the upgrade to Android 4.4. I use the N7 significantly less than the S3, reinforcing my impression that Replicant is a stable Android. I have not had any other problem that I couldn t explain, and have rarely had to reboot the device. The Replicant project recently released version 4.2 and while I don t expect the release to resolve any problem for me, I decided it was time to upgrade and learn something new. I initially tried the official ROM images, and later migrated to using my own build of the software (for no particular reason other than that I could). Before the installation, I wanted to have a full backup of the phone to avoid losing data. I use SMS Backup+ to keep a backup of my call log, SMS and MMS on my own IMAP server. I use oandbackup to take a backup of all software and settings on the phone. I use DAVDroid for my contacts and calendar (using a Radicale server), and reluctantly still use aCal in order to access my Google Calendar (because Google does not implement RFC 5397 properly so it doesn t work with DAVDroid). Alas all that software is not sufficient for backup purposes, for example photos are still not copied elsewhere. In order to have a complete backup of the phone, I m using rsync over the android debug bridge (adb). More precisely, I connect the phone using a USB cable, push a rsyncd configuration file, start the rsync daemon on the phone, forward the TCP/IP port, and then launch rsync locally. The following commands are used: jas@latte:~$ cat rsyncd.conf
address 127.0.0.1
uid = root
gid = root
[root]
path = /
jas@latte:~$ adb push rsyncd.conf /extSdCard/rsyncd.conf
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
0 KB/s (57 bytes in 0.059s)
jas@latte:~$ adb root
jas@latte:~$ adb shell rsync --daemon --no-detach --config=/extSdCard/rsyncd.conf &
jas@latte:~$ adb forward tcp:6010 tcp:873
jas@latte:~$ sudo rsync -av --delete --exclude /dev --exclude /acct --exclude /sys --exclude /proc rsync://localhost:6010/root/ /root/s3-bup/
...
 Now feeling safe that I would not lose any data, I remove the SIM card from my phone (to avoid having calls, SMS or cell data interrupt during the installation) and follow the Replicant Samsung S3 installation documentation. Installation was straightforward. I booted up the newly installed ROM and familiarized myself with it. My first reaction was that the graphics felt a bit slower compared to Replicant 4.0, but it is hard to tell for certain. After installation, I took a quick rsync backup of the freshly installed phone, to have a starting point for future backups. Since my IMAP and CardDav/CalDav servers use certificates signed by CACert I first had to install the CACert trust anchors, to get SMS Backup+ and DAVDroid to connect. For some reason it was not sufficient to add only the root CACert certificate, so I had to add the intermediate CA cert as well. To load the certs, I invoke the following commands, selecting Install from SD Card when the menu is invoked (twice). adb push root.crt /sdcard/
adb shell am start -n "com.android.settings/.Settings\"\$\"SecuritySettingsActivity"
adb push class3.crt /sdcard/
adb shell am start -n "com.android.settings/.Settings\"\$\"SecuritySettingsActivity"
 I restore apps with oandbackup, and I select a set of important apps that I want restored with settings preserved, including aCal, K9, Xabber, c:geo, OsmAnd~, NewsBlur, Google Authenticator. I install SMS Backup+ from FDroid separately and configure it, SMS Backup+ doesn t seem to want to restore anything if the app was restored with settings using oandbackup. I install and configure the DAVdroid account with the server URL, and watch it populate my address book and calendar with information. After organizing the icons on the launcher screen, and changing the wallpaper, I m up and running with Replicant 4.2. This upgrade effort took me around two evenings to complete, with around half of the time consumed by exploring different ways to do the rsync backup before I settled on the rsync daemon approach. Compared to the last time, when I spent almost two weeks researching various options and preparing for the install, this felt like a swift process.
I spent some time researching how to get the various non-free components running. This is of course sub-optimal, and the Replicant project does not endorse non-free software. Alas there aren t any devices out there that meets my requirements and use only free software. Personally, I feel using a free core OS like Replicant and then adding some non-free components back is a better approach than using CyanogenMod directly, or (horror) the stock ROM. Even better is of course to not add these components back, but you have to decide for yourselves which trade-offs you want to make. The Replicant wiki has a somewhat outdated page on Samsung S3 firmware. Below are my notes for each component, which applies to Replicant 4.2 0001. You need to first prepare your device a bit using these commands, and it is a good idea to reboot the device after installing the files. adb root
adb shell mount -o rw,remount /system
adb shell mkdir /system/vendor/firmware
adb shell chmod 755 /system/vendor/firmware
 GPS: The required files are the same as for Replicant 4.0, and using the files from CyanogenMod 10.1.3 works fine. The following commands load them onto the device. Note that this will load code that will execute on your main CPU which is particularly bothersome. There seems to exist a number of different versions of these files, CyanogenMod have the same gpsd and gps.exynos4.so in version 10.1.3 and 10.2 but the libsecril-client.so differs between 10.1.3 and 10.2. All files differ from the files I got with my stock Samsung ROM on this device (MD5 checksums in my previous blog). I have not investigated how these versions differs or which of them should be recommended. I use the files from CyanogenMod 10.1.3 because it matches the Android version and because the files are easily available. adb push cm-10.1.3-i9300/system/bin/gpsd /system/bin/gpsd
adb shell chmod 755 /system/bin/gpsd
adb push cm-10.1.3-i9300/system/lib/hw/gps.exynos4.so /system/lib/hw/gps.exynos4.so
adb push cm-10.1.3-i9300/system/lib/libsecril-client.so /system/lib/libsecril-client.so
adb shell chmod 644 /system/lib/hw/gps.exynos4.so /system/lib/libsecril-client.so
 Bluetooth: Only one file has to be installed, apparently firmware loaded onto the Bluetooth chip. Cyanogenmod 10.1.3 and 10.2 contains identical files, which has a string in it BCM4334B0 37.4MHz Class1.5 Samsung D2 . The file I got with my stock ROM has a string in it BCM4334B0 37.4MHz Class1.5 Samsung M0 . I don t know the difference, although I have seen that D2 sometimes refers to the US version of a Samsung device. My device is the international version, but it seems to work anyway. adb push cm-10.1.3-i9300/system/bin/bcm4334.hcd /system/vendor/firmware/bcm4334.hcd
adb shell chmod 644 /system/vendor/firmware/bcm4334.hcd
 Front Camera: Two files has to be installed, apparently firmware loaded onto the Camera chip. CyanogenMod 10.1.3 and 10.2 contains identical files, which has a string in it [E4412 520-2012/08/30 17:35:56]OABH30 . The file I got with my stock ROM has a string in it [E4412 533-2012/10/06 14:38:46]OABJ06 . I don t know the difference. adb push cm-10.1.3-i9300/system/vendor/firmware/fimc_is_fw.bin /system/vendor/firmware/fimc_is_fw.bin
adb push cm-10.1.3-i9300/system/vendor/firmware/setfile.bin /system/vendor/firmware/setfile.bin
adb shell chmod 644 /system/vendor/firmware/fimc_is_fw.bin /system/vendor/firmware/setfile.bin
 NFC: I m happy that I got NFC to work, this was one of my main issues with Replicant 4.0 (see my earlier blog post). Only one file is needed, however CyanogenMod does not seem to distribute it so you have to get it from your stock ROM or elsewhere. The md5 of the file I have is b9364ba59de1947d4588f588229bae20 (and no I will not send it to you). I have tested it with the YubiKey NEO and the Yubico Authenticator app. adb push clockworkmod/blobs/ee6/7188ca465cf01dd355a92685a42361e113f886ef44e96d371fdaebf57acae /system/vendor/firmware/libpn544_fw.so
adb shell chmod 644 /system/vendor/firmware/libpn544_fw.so
 Wifi: I haven t gotten wifi to work, although I have not tried very hard. Loading the CyanogenMod firmwares makes my device find wireless networks, but when I try to authenticate (WPA-PSK2), I get failures. Possibly some other files has to be loaded as well. Update: This blog post has been updated since initial posting to use rsync over adb instead of USB tethering, and to mention that I got the ROM building to work. flattr this!

11 November 2013

Simon Josefsson: Using Replicant on Samsung Galaxy S III

For the last half-year I have used CyanogenMod on an Nexus 4 as my main phone. Recently the touch functionality stopped working on parts of the display, and the glass on the back has started to crack. It seems modern phones are not built to last. For comparison, before the N4 I used a Nokia N900 for around 3 years without any hardware damages (in my drawer now, still working). A few weeks ago I started looking for a replacement. My experience with CyanogenMod had been good, but the number of proprietary blobs on the N4 concerned me. Finding something better wasn t easy though, so I m documenting my experience here. My requirements were, briefly, that I wanted a phone that I could buy locally that had a free software community around it that produced a stable environment. I have modest requirements for things I wouldn t give up on: telephony, data connection (3G), email (IMAP+SMTP), chat (XMPP), and a web browser. I like the philosophy and openness around the Firefox OS but the more I have read about it, it seems unlikely that it would deliver what I need today. In particular none of the devices capable of running Firefox OS appealed to me, and the state of email reading seemed unclear. I m sure I ll revisit Firefox OS as an alternative for me in the future.

As I had been happy with CyanogenMod, but concerned about its freeness, it felt natural to move on and test the more free software friendly project Replicant. Replicant only supports a small number of devices. After talking with people in the #replicant IRC channel, it seemed the Samsung S3 would be a decent choice for me. The Samsung S2 would have worked as well, but it cost almost as much as the S3 where I looked. Despite the large number of Samsung S3 devices out there, it seems the prices even for used devices are high (around 2500 SEK in Sweden, ~380 USD). I ended up buying a brand new one for 3200 SEK (~500 USD) which felt expensive, especially after recalling the recent $199 sale for Nexus 4. Noticing that brand new Nexus 4 devices are still over 3000 SEK in Sweden comforted me a bit. I would have preferred a more robust phone, like the CAT B15, but the state of free software OSes on them seem unclear and I wanted something stable. So, enough about the background, let s get started. Building and installing Replicant on the device was straight forward. I followed the Replicant Samsung S3 Build instructions to build my own images. The only issue I had was that I had not set JAVA_HOME and the defaults were bad; make sure to set JAVA_HOME before building. I built everything on my Lenovo X201 running Debian Wheezy, with OpenJDK 6 as the Java implementation. Installing the newly built firmware was easy, I just followed the installation process documentation. I made sure to take a clockworkmod backup to an external SD card before wiping the old system. To get a really clean new device, I also re-formated /sdcard inside clockworkmod; I noticed there were some traces left of the old system there. I spent about one week testing various configurations before settling on something I could use daily. A fair amount of time was spent looking into backup and restore options for Android devices. My idea was that I would take a backup of the apps I ran on the N4 and transfer them to the S3. The Android Debug Bridge (adb) has a backup/restore command, however it (intentionally) ignores apps marked as allowBackup=false which a number of apps has. It doesn t seem possible to override that settings so much for the freedom to backup your own device. I then discovered oandbackup. It can backup your entire system, saving each app (together with associated data) into a separate directory, for simple review and inspection before restore. You can do batch backups and batch restore. I couldn t get it to automatically restore things, though, which would be neat for really automated re-installations (there is an open issue about this feature). After noticing that some apps did not like being moved from the N4 (running Android 4.2) to the S3 (running 4.0), I ended up installing most apps from scratch on a freshly installed Replicant. I use oandbackup to the external SD card so that I can quickly restore my phone. For backup/restore of SMS/MMS and Call Log, I use SMS Backup+ against my own IMAP server. Camera pictures are synced manually using adb when I am connected to my laptop. There is a number of apps that deserve to be mentioned because they are what I use on a daily basis. All of them come via the free software market F-Droid. For email (IMAP/SMTP), I use K-9 Mail which is feature rich but still easy to use. For chat, I use Xabber. I use NewsBlur s free software app to read RSS flows. For two-factor authentication, I use Google Authenticator. I haven t evaluated different PDF viewers, but the first one I tried (APV PDF Viewer) has worked fine so far. Handling a a synchronized address book and calendar deserve its own blog post because it is a challenging topic, but briefly, I m currently using a combination of aCal and DAVdroid. Finally, since Replicant is still work in progress, some words about stability and notes on what doesn t work. This is probably the most interesting part if you are considering running Replicant on an S3 yourself. Overall system stability is flawless, I hadn t had any crash or problem with the fundamental functionality (telephony, 3G, Camera). People have said graphics feels a bit laggy, but I cannot compare with the stock ROM and it doesn t get in the way of daily use. First some notes about non-free aspects: Some other observations: I am quite happy with the setup so far, and I will continue to use it as my primary phone. flattr this!

21 October 2013

Petter Reinholdtsen: A Raspberry Pi based batman-adv Mesh network node

The last few days I have been experimenting with the batman-adv mesh technology. I want to gain some experience to see if it will fit the Freedombox project, and together with my neighbors try to build a mesh network around the park where I live. Batman-adv is a layer 2 mesh system ("ethernet" in other words), where the mesh network appear as if all the mesh clients are connected to the same switch. My hardware of choice was the Linksys WRT54GL routers I had lying around, but I've been unable to get them working with batman-adv. So instead, I started playing with a Raspberry Pi, and tried to get it working as a mesh node. My idea is to use it to create a mesh node which function as a switch port, where everything connected to the Raspberry Pi ethernet plug is connected (bridged) to the mesh network. This allow me to hook a wifi base station like the Linksys WRT54GL to the mesh by plugging it into a Raspberry Pi, and allow non-mesh clients to hook up to the mesh. This in turn is useful for Android phones using the Serval Project voip client, allowing every one around the playground to phone and message each other for free. The reason is that Android phones do not see ad-hoc wifi networks (they are filtered away from the GUI view), and can not join the mesh without being rooted. But if they are connected using a normal wifi base station, they can talk to every client on the local network. To get this working, I've created a debian package meshfx-node and a script build-rpi-mesh-node to create the Raspberry Pi boot image. I'm using Debian Jessie (and not Raspbian), to get more control over the packages available. Unfortunately a huge binary blob need to be inserted into the boot image to get it booting, but I'll ignore that for now. Also, as Debian lack support for the CPU features available in the Raspberry Pi, the system do not use the hardware floating point unit. I hope the routing performance isn't affected by the lack of hardware FPU support. To create an image, run the following with a sudo enabled user after inserting the target SD card into the build machine: 
% wget -O build-rpi-mesh-node \
    https://raw.github.com/petterreinholdtsen/meshfx-node/master/build-rpi-mesh-node
% sudo bash -x ./build-rpi-mesh-node > build.log 2>&1
% dd if=/root/rpi/rpi_basic_jessie_$(date +%Y%m%d).img of=/dev/mmcblk0 bs=1M
%
Booting with the resulting SD card on a Raspberry PI with a USB wifi card inserted should give you a mesh node. At least it does for me with a the wifi card I am using. The default mesh settings are the ones used by the Oslo mesh project at Hackeriet, as I mentioned in an earlier blog post about this mesh testing. The mesh node was not horribly expensive either. I bought everything over the counter in shops nearby. If I had ordered online from the lowest bidder, the price should be significantly lower:
SupplierModelNOK
TeknikkmagasinetRaspberry Pi model B349.90
TeknikkmagasinetRaspberry Pi type B case99.90
LefdalJensen Air:Link 25150295.-
Clas OhlsonKingston 16 GB SD card199.-
Total cost943.80
Now my mesh network at home consist of one laptop in the basement connected to my production network, one Raspberry Pi node on the 1th floor that can be seen by my neighbor across the park, and one play-node I use to develop the image building script. And some times I hook up my work horse laptop to the mesh to test it. I look forward to figuring out what kind of latency the batman-adv setup will give, and how much packet loss we will experience around the park. :)

4 July 2012

Michael Banck: 4 Jul 2012

Update on computational chemistry packages in Debian

For many years, me and the Debichem team maintained two computational chemistry packages, first MPQC and later PSI3. In recent years however, two respected quantum chemistry codes have been open sourced and are now available in Debian: ACESIII and NWChem. Make no mistake, those are not recently started codes or some Ph.D.'s pet-project but state-of-the-art projects targeted at massively parallel supercomputers and developed at the University of Florida's Quantum Chemistry Project (QTP) in the case of ACESIII and at Pacific Northwest National Laboratory (PNNL) for NWChem.

While ACESIII has a somewhat narrow focus on Coupled-Cluster (unfortunately, the current version does not yet implement analytic gradients for the "golden standard" CCSD(T) method) and Multi-Body Perturbation Theory methods, NWChem is a very versatile package supporting a variety of molecular quantum chemistry methods (including Density Functional Theory (DFT)), as well as periodic plane-wave electronic structure and (ab-initio and classical) molecular dynamics. At this point, NWChem probably covers 90% of all use cases for routine computational chemistry compared to the popular non-free codes Gaussian and GAMESS, while likely exhibiting superior parallel scaling at least compared to Gaussian.

Over the last year, I have packaged and integrated NWChem and ACESIII for Debian, and they are now both in testing. Furthermore, I have recently overhauled the packaging of MPQC and enabled parallel execution via MPI. Further, both MPQC and PSI will see updated versions (MPQC3 and PSI4) in the near future with significant increased functionality, including some unique (at least among open source codes) features like Symmetry-Adapted Perturbation Theory (SAPT) for PSI4 and general explicitly correlated corrections ([2]f12) for MPQC3. Unfortunately, they both did not get released in time for the wheezy freeze.

On the periodic/plane-wave front, I have also packaged and uploaded Quantum ESPRESSO (formerly PwSCF), a set of plane-wave programs, and I have been working with lafur Jens Sigur sson to get the latest Abinit release packaged. The nanoscale-physics team is also targeting further periodic ab-initio packages like BigDFT and Octopus, but those as well did not land in time for the freeze.

Finally, I also packaged and uploaded CP2K, a well-engineered and versatile periodic plane-wave/pseudo-potential code which focuses on state-of-the-art ab-initio Molecular Dynamics (AIMD) using Density Functional Theory. Some of the authors have recently published a paper reporting linear scaling benchmark calculations on a system with a million atoms using almost 50,000 CPU cores.

All of the above mentioned packages are included either in the molecular ab-initio or the periodic ab-initio Debichem tasks.

11 October 2011

Thomas Koch: Gemeinsam f r globalen Wandel

english abstract: call to assembly on October 15th in Constance (Germany).

ATTAC Konstanz und www.echte-demokratie-jetzt.de laden ein zur Versammlung "Gemeinsam f r globalen Wandel" am 15. Oktober 2011 um 15:10 Uhr auf die Marktst tte (in Bankenn he)
  • United for global change
  • Wir sind die 99%!
  • Wir zahlen nicht f r Eure Krise!
  • Echte Demokratie jetzt!
Weltweit gehen an diesem Tag Menschen auf die Stra e, um dar ber ins Gespr ch zu kommen, in welcher Gesellschaft sie leben wollen. Mit ihnen gemeinsam emp ren wir uns dar ber, dass heute die Interessen von Banken und Konzernen vielfach ber die Interessen der Menschen gestellt werden, und die Kluft zwischen Arm und Reich immer gr er wird. Wir sehen uns durch Politik und Wirtschaft nicht mehr repr sentiert und wollen selbst f r grundlegende Ver nderungen eintreten. Wir engagieren uns f r neue Wege aus der Krise, jenseits von Parteien, Gewerkschaften und anderen Gruppeninteressen.Dar ber wollen wir auch in Konstanz auf der Marktst tte miteinander reden. Zur Information, wie sich Menschen in anderen L ndern f r ihre Anliegen einsetzen, wird es einen Informationsstand ber die Protestbewegungen in Spanien, Griechenland, Israel, Chile und den USA geben.Weitere Informationen:

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