Search Results: "ana"

1 April 2023

Paul Wise: FLOSS Activities March 2023

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

Issues

Review

Administration
  • Debian QA services: disabled updating jessie as it was removed
  • Debian IRC: rescued #debian-s390x from inactive person
  • Debian servers: repair a /etc git repo
  • Debian wiki: unblock IP addresses, approve accounts

Communication
  • Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors The gensim, sptag, purple-discord, harmony work was sponsored. All other work was done on a volunteer basis.

31 March 2023

Scarlett Gately Moore: KDE Snaps! Many new releases, more to come.

I have been extremely busy the last 2 weeks churning out KDE snaps! All of the have been tested and released on AMD64 and Arm64 architectures. If you run into any problems please file bugs @ http://bugs.kde.org and feel free to assign me. Thanks!
KDE Krita snapKDE Krita snap
Krita Version 5.1.5 https://apps.kde.org/krita/
KDE Parley snapKDE Parley snap
Parley Version 22.12.3 https://apps.kde.org/parley/
KDE Kate snapKDE Kate snap
Kate Version 22.12.3 https://apps.kde.org/kate/
KDE Okular snapKDE Okular snap
Okular Version 22.12.3 https://apps.kde.org/okular/
KDE Haruna snapKDE Haruna snap
Haruna Version 0.10.3 https://apps.kde.org/haruna/
KDE Granatier snapKDE Granatier snap
Granatier Version 22.12.3 https://apps.kde.org/granatier/
KDE Gwenview snapKDE Gwenview snap
Gwenview Version 22.12.3 https://apps.kde.org/gwenview/
KDE Gcompris snapKDE Gcompris snap
GCompris-qt Version 3.2 https://apps.kde.org/gcompris/
KDE Bomber snapKDE Bomber snap
Bomber Version 22.12.3 https://apps.kde.org/bomber/
KDE Falkon snapKDE Falkon snap
Falkon Version 22.12.3 https://apps.kde.org/falkon/
KDE Ark snapKDE Ark snap
Ark Version 22.12.3 https://apps.kde.org/ark/
KDE Blinken snapKDE Blinken snap
Blinken Version 22.12.3 https://apps.kde.org/blinken/
KDE Bovo snapKDE Bovo Snap
Bovo Version 22.12.3 https://apps.kde.org/bovo/
KDE Atikulate snapKDE Atikulate snap
Artikulate Version 22.12.3 https://apps.kde.org/artikulate/ There are many more snaps coming your way! As usual, I hate to ask, but if you can spare anything we appreciate it, even if they are just kind words, thank you! https://gofund.me/d73342c3

30 March 2023

Jonathan McDowell: Buttering up my storage

(TL;DR: I ve been trying out btrfs in some places instead of ext4, I ve hit absolutely zero issues and there are a few features that make me plan to use it more.) Despite (or perhaps because of) working on storage products for a reasonable chunk of my career I have tended towards a conservative approach to my filesystems. By the time I came to Linux ext2 was well established, the move to ext3 was a logical one (the joys of added journalling for faster recovery after unclean shutdowns) and for a long time my default stack has been MD raid with LVM2 on top and then ext4 as the filesystem. I ve dabbled with other filesystems; I ran XFS for a while on my VDR machine, and also when I had a large tradspool with INN, but never really had a hard requirement for it. I ve ended up adminning a machine that had JFS in the past, largely for historical reasons, but don t really remember any issues (vague recollections of NFS problems but that might just have been NFS being NFS). However. ZFS has gathered itself a significant fan base and that makes me wonder about what it can offer and whether I want that. Firstly, let s be clear that I m never going to run a primary filesystem that isn t part of the mainline kernel. So ZFS itself is out, because I run Linux. So what do I want that I can t get with ext4? Firstly, I d like data checksumming. As storage gets larger there s a bigger chance of silent data corruption and while I have backups of the important stuff that doesn t help if you don t know you need to use them. Secondly, these days I have machines running containers, VMs, or with lots of source checkouts with a reasonable amount of overlap in their data. Disk space has got cheaper, but I d still like to be able to do some sort of deduplication of common blocks. So, I ve been trying out btrfs. When I installed my desktop I went with btrfs for / and /home (I kept /boot as ext4). The thought process was that this was a local machine (so easy access if it all went wrong) and I take regular backups (so if it all went wrong I could recover). That was a year and a half ago and it s been pretty dull; I mostly forget I m running btrfs instead of ext4. This is on a machine that tracks Debian testing, so currently on kernel 6.1 but originally installed with 5.10. So it seems modern btrfs is reasonably stable for a machine that isn t driven especially hard. Good start. The fact I forget what filesystem I m running points to the fact that I m not actually doing anything special here. I get the advantage of data checksumming, but not much else. 2 things spring to mind. Firstly, I don t do snapshots. Given I run testing it might be wiser if I did take a snapshot before every apt-get upgrade, and I have a friend who does just that, but even when I ve run unstable I ve never had a machine get itself into a state that I couldn t recover so I haven t spent time investigating. I note Ubuntu has apt-btrfs-snapshot but it doesn t seem to have any updates for years. The other thing I didn t do when I installed my desktop is take advantage of subvolumes. I m still trying to get my head around exactly what I want them for, but they provide a partial replacement for LVM when it comes to carving up disk space. Instead of the separate / and /home LVs I created I could have created a single LV that would have a single btrfs filesystem on it. / and /home would then be separate subvolumes, allowing me to snapshot each individually. Quotas can also be applied separately so there s still the potential to prevent one subvolume taking all available space. Encouraged by the lack of hassle with my desktop I decided to try moving my sbuild machine over to use btrfs for its build chroots. For Reasons this is a VM kindly hosted by a friend, rather than something local. To be honest these days I would probably go for local hosting, but it works and there s no strong reason to move. The point is it s remote, and so if migrating went wrong and I had to ask for assistance I d be bothering someone who s doing me a favour as it is. The build VM is, of course, running LVM, and there was luckily some free space available. I m reasonably sure the underlying storage involves spinning rust, so I did a laborious set of pvmove commands to make sure all the available space was at the start of the PV, and created a new btrfs volume there. I was advised that while btrfs-convert would do the job it was better to create a fresh filesystem where possible. This time I did create an initial root subvolume. Configuring up sbuild was then much simpler than I d expected. My setup originally started out as a set of tarballs for the chroots that would get untarred + used for the builds, which is pretty slow. Once overlayfs was mature enough I switched to that. I d had a conversation with Enrico about his nspawn/btrfs setup, but it turned out Russ Allbery had written an excellent set of instructions on sbuild with btrfs. I tweaked my existing setup based on his details, and I was in business. Each chroot is a separate subvolume - I don t actually end up having to mount them individually, but it means that only the chroot in use gets snapshotted. For example during a build the following can be observed:
# btrfs subvolume list /
ID 257 gen 111534 top level 5 path root
ID 271 gen 111525 top level 257 path srv/chroot/unstable-amd64-sbuild
ID 275 gen 27873 top level 257 path srv/chroot/bullseye-amd64-sbuild
ID 276 gen 27873 top level 257 path srv/chroot/buster-amd64-sbuild
ID 343 gen 111533 top level 257 path srv/chroot/snapshots/unstable-amd64-sbuild-328059a0-e74b-4d9f-be70-24b59ccba121
I was a little confused about whether I d got something wrong because the snapshot top level is listed as 257 rather than 271, but digging further with btrfs subvolume show on the 2 mounted directories correctly showed the snapshot had a parent equal to the chroot, not /. As a final step I ran jdupes via jdupes -1Br / to deduplicate things across the filesystem. It didn t end up providing a significant saving unfortunately - I guess there s a reasonable amount of change between Debian releases - but I think tried it on my desktop, which tends to have a large number of similar source trees checked out. There I managed to save about 5% on /home, which didn t seem too shabby. The sbuild setup has been in place for a couple of months now, and I ve run quite a few builds on it while preparing for the freeze. So I m fairly confident in the stability of the setup and my next move is to transition my local house server over to btrfs for its containers (which all run under systemd-nspawn). Those are generally running a Debian stable base so there should be a decent amount of commonality for deduping. I m not saying I m yet at the point where I ll default to btrfs on new installs, but I m definitely looking at it for situations where I think I can get benefits from deduplication, or being able to divide up disk space without hard partitioning space. (And, just to answer the worry I had when I started, I ve got nowhere near ENOSPC problems, but I believe they re handled much more gracefully these days. And my experience of ZFS when it got above 90% utilization was far from ideal too.)

Russell Coker: Links March 2023

Interesting paper about a plan for eugenics in dogs with an aim to get human equivalent IQ within 100 generations [1]. It gets a bit silly when the author predicts IQs of 8000+ as there will eventually be limits of what can fit in one head. But the basic concept is good. Interesting article about what happens inside a proton [2]. This makes some aspects of the Trisolar series and the Dragon s Egg series seem less implausible. Insightful article about how crypto-currencies really work [3]. Basically the vast majority of users trust some company that s outside the scope of most financial regulations to act as their bank. Surprisingly the author doesn t seem to identify such things as a Ponzi scheme. Bruce Schneier wrote an interesting blog post about AIs as hackers [4]. Cory Doctorow wrote an insightful article titled The Enshittification of TikTok which is about the enshittification of commercial Internet platforms in general [5]. We need more regulation of such things. Cat Valente wrote an insightful article titled Stop Talking to Each Other and Start Buying Things: Three Decades of Survival in the Desert of Social Media about the desire to profit from social media repeatedly destroying platforms [6]. This Onion video has a good point, I don t want to watch videos on news sites etc [7]. We need ad-blockers that can block video on all sites other than YouTube etc. Wired has an interesting article about the machines that still need floppy disks, including early versions of the 747 [8]. There are devices to convert the floppy drive interface to a USB storage device which are being used on some systems but which presumably aren t certified for a 747. The article says that 3.5 disks cost $1 each because they are rare that s still cheaper than when they were first released. Android Police has an interesting article about un-redacting information in PNG files [9]. It seems that some software on Pixel devices hasn t been truncating files when editing them, just writing the new data over top and some platforms (notably Discord) send the entire file wuthout parsing it (unlike Twitter for example which removes EXIF data to protect users). Then even though a PNG file is compressed from the later part of the data someone can deduce the earlier data. Teen Vogue has an insightful article about the harm that influencer parents do to their children [10]. Jonathan McDowell wrote a very informative blog post about his new RISC-V computer running Debian [11]. He says that it takes 10 hours to do a full Debian kernel build (compared to 14 minutes for my 18 core E5-2696) so it s about 2% the CPU speed of a high end 2015 server CPU which is pretty good for an embedded devivce. That is similar to some of the low end Thinkpads that were on sale in 2015. The Surviving Tomorrow site has an interesting article about a community where all property is community owned [12]. It s an extremist Christian group and the article is written by a slightly different Christian extremist, but the organisation is interesting. A technology positive atheist versions of this would be good. Bruce Schneier and Nathan E. Sanders co-wrote an insightful article about how AI could exploit the process of making laws [13]. We really need to crack down on political lobbying, any time a constitution is being amender prohibiting lobbying should be included. Anarcat wrote a very informative blog post about the Framework laptops that are designed to be upgraded by the user [14]. The motherboard can be replaced and there are cases designed so you can use the old laptop motherboard as an embedded PC. Before 2017 I would have been very interested in such a laptop. Now I ve moved to low power laptops and servers for serious compiles and a second-hand Thinkpad X1 Carbon costs less than a new Framework motherboard. But this will be a really good product for people with more demanding needs than mine. Pity they don t have a keyboard with the Thinkpad Trackpoint.

28 March 2023

Shirish Agarwal: Three Ancient Civilizations, Tesla, IMU and other things.

Three Ancient Civilizations I have been reading books for a long time but somehow I don t know how or when I realized that there are three medieval civilizations that time and again seem to fascinate the authors, either American or European. The three civilizations that do get mentioned every now and then are Egyptian, Greece and Roman and I have no clue as to why. Another two civilizations closely follow them, Mesopotian and Sumerian Civilizations. Why most of the authors irrespective of genre are mystified by these 5 civilizations is beyond me but they also conjure lot of imagination. Now if I was on the right side of 40, maybe 22-25 onwards and had the means or the opportunity or both, I would have gone and tried to learn as much as I can about these various civilizations. There is still a lot of enigma attached and it seems that the official explanations of how these various civilizations ended seems too good to be true or whatever. One of the more interesting points has been how Greece mythology were subverted and flipped to make Roman mythology. Apparently, many Greek gods have a Roman aspect and the qualities are opposite to the Greek aspect. I haven t learned the reason why it is so, yet. Apart from the Iziko Natural Museum in South Africa which did have its share of wonders (the whole South African experience was surreal) nowhere I have witnessed stuff from the above other than in Africa. The whole thing seemed just surreal. I could go on but as I don t know what is real and what is mythology when it comes to various cultures including whatever little I experienced in Africa.

Recent History Having said the above, I also find that many Indians somehow do not either know or are not interested in understanding recent history. I am talking of the time between 1800s and 1950 s. British apologist Mr. William Dalrymple in his book Anarchy has shared how the East Indian Company looted India and gave less than half back to the British. So where did the rest of the money go ? It basically went to the tax free havens around UK. That tale is very much similar as to how the Axis gold was used to have an entity called Switzerland from scratch. There have been books as well as couple of miniseries or two that document that fact. But for me this is not the real story, this is more of a side dish per-se. The real story perhaps is how the EU peace project was born. Because of Hitler s rise and the way World War 2 happened, the Allies knew that they couldn t subjugate Germany through another humiliation as they had after World War 1, who knows another Hitler might come. So while they did fine the Germans, they also helped them via the Marshall plan. Germany also realized that it had been warring with other European countries for over a thousand years as well as quite a few other countries. The first sort of treaty immediately in that regard was the Western Union Alliance . While on the face of it, it was a defense treaty between sovereign powers. Interestingly, as can be seen UK at that point in time wanted more countries to be part of the Treaty of Dunkirk. This was quickly followed 2 years later by the Treaty of London which made way for the Council of Europe to be formed. The reason I am sharing is because a lot of Indians whom I meet on SM do not know that UK was instrumental front and center for the formation of European Union (EU). Also they perhaps don t realize that after World War 2, UK was greatly diminished both financially and militarily. That is the reason it gave back its erstwhile colonies including India and other countries. If UK hadn t become a part of EU they would have been called the poor man of Europe as they had been called few hundred years ago. In fact, after Brexit, UK has been the only nation that has fallen on the dire times as much as it has. They have practically no food, supermarkets running out of veggies and whatnot. electricity sky-high as they don t want to curtail profits of the gas companies which in turn donate money to Tory coffers. Sadly, most of my brethen do not know that hence I have had to share it. The EU became a power in its own right due to Gravity model of trade. The U.S. is attempting the same thing and calls it near off-shoring.

Tesla, Investor Day Presentation, Toyota and Free Software The above brings it nicely about the Tesla Investor Day that happened couple of weeks back. The biggest news though was broken just 24 hours earlier when the governor of Monterrey] shared how Giga New Mexico would be happening and shared some site photographs. There have been bits of news on that off-and-on since then. Toyota meanwhile has been putting lot of anti-EV posters and whatnot. In fact, India seems to be mirroring Japan in a lot of ways, the only difference is Japan is still superior economically than India. I do sincerely hope that at least Japan can get out of its lost decades. I have asked privately if any of the Japanese translators would be willing to translate the anti-EV poster so we may all know.
Anti-EV poster by Toyota

Urinal outside UK Embassy About a week back few people chanting Khalistan entered the Indian Embassy and showed the flags. This was in the UK. Now in a retaliatory move against a friendly nation, we want to make a Urinal. after making a security downgrade for the Embassy. The pettiness being shown by Indian Govt. especially when it has very few friends. There are also plans to do the same for the U.S. and other embassies as well. I do not know when we will get common sense.

Holi Just a few weeks back, Holi happened. It used to be a sweet and innocent festival. But from the last few years, I have been hearing and seeing sexual harassment on the rise. In fact, saw quite a few lewd posts written to women on Holi or verge of Holi and also videos of the same. One of the most shameful incidents occurred with a Japanese tourist. She was not only sexually molested but also terrorized that if she were to report then she could be raped and murdered. She promptly left Delhi. Once it was reported in mass media, Delhi Police tried to show it was doing something. FWIW, Delhi s crime against women stats have been at record high and conviction at record low.

Ecommerce Rules being changed, logistics gonna be tough. Just today there have been changes in Ecommerce rules (again) and this is gonna be a pain for almost all companies big and small with the exception of Adani and Ambani. Almost all players including the Tatas have called them out. Of course, all such laws have been passed without debate. In such a scenario, small startups like these cannot hope to grow their business.

Inertial Measurement Unit or Full Body Tracking with cheap hardware. Apparently, a whole host of companies are looking at 3-D tracking using cheap hardware apparently known as IMU sensors. Sooner than later cheap 3-D glasses and IMU sensors should explode the 3-D market worldwide. There is a huge potential and upside to it and will probably overtake smartphones as well. But then the danger will be of our thoughts, ideas, nightmares etc. to be shared without our consent. The more we tap into a virtual world, what stops anybody from tapping into our brain and practically stealing our identity in more than one way. I dunno if there are any Debian people or FSF projects working on the above. Even Laws can only do so much, until and unless there are alternative places and ways it would be difficult to say the least

Jonathan Dowland: daily log

I was asked on the Fediverse1 to describe my $dayjob daily workflow. Blogging about it seemed like a good opportunity to take stock of my current setup. The core of my approach is to maintain a daily log, rather like an engineering Lab Book2. My number one tip for anyone starting a career in Software Engineering (or for that matter systems administration) is to keep a daily log of what you intended to do, what you actually did, what you changed, what changed as a consequence, etcetera. I've already written about the tools I use for that: vimwiki. They key drawback of that system is managing TODO lists. In Vimwiki, tasks look like this:
  * [ ] buy milk (still todo)
  * [X] clean the car (done)
These get dispersed or duplicated around different days/wiki pages. It's hard to get a current view of open (or otherwise relevant) tasks, and impractical to update many copies of the same task when its state changes (such as when it's done). The solution I've adopted for now is another Vim plugin, taskwiki, which synchronises tasks with Taskwarrior3, an external task-management tool. If I mark a task as "done", Taskwiki updates all references to that task to reflect the new state. I can also construct queries to list all tasks matching some criteria. I have a special Vimwiki page named "Backlog" which runs the query "all tasks tagged 'redhat' in state 'pending'" (Linked from the boilerplate at the top of every page I write, for quick access):
= Backlog   +redhat status:pending =
* [ ] buy milk (still todo)
...
Much like the base Vimwiki plugin, Taskwiki is very opinionated, and I've had to tame it by disabling several of its features. I've also hit a couple of mildly frustrating bugs (#368, #425). I might one day have a go at writing an alternative, simpler plugin in Lua (Neovim's native scripting language), but for now it works well enough and I don't have the time. There's very little in this current workflow for managing scheduling tasks, and that's probably where the focus should be for my next iterative improvement efforts. I think Taskwarrior, the underlying tool, has some good support for that. I'd particularly like some more visual approaches for managing the backlog, such as something Kanban-style.

  1. sorry I can't find who/the toot any more
  2. Analogous to an engineering lab book, but the analogy is not exact. I recently read a little bit about what Engineers are actually taught to do in a lab book, and it's quite a bit more narrowly-scoped than I realised. This slide-deck is interesting: https://www.training.nih.gov/assets/Lab_Notebook_508_(new).pdf
  3. I rarely use Taskwarrior directly yet, and so I haven't written about it independently of Taskwiki..

Mike Gabriel: UbuntuTouch Focal OTA-1 has been released

Yesterday, the UBports core developer team released Ubuntu Touch Focal OTA-1 (In fact, Raoul, Marius and I were in a conference call when Marius froze and said: the PR team already posted the release blog post; the post is out, but we haven't released yet... ahhhh... panic... Shall I?, Marius said, and we said: GO!!! This is why the release occurred in public five hours ahead of schedule. OMG.) For all the details, please study:
https://ubports.com/blog/ubports-news-1/post/ubuntu-touch-ota-1-focal-re... Credits Thanks to all the developers, other contributors and funding providers that helped to reach this massive milestone. I dare to drop some names here at the risk of forgetting others (I put them in alphanumerical order): Alan, Alfred, Brian, Christoffer, Daniel, Eline, Florian, Guido, Jami, Jonathan, Kugi, Lionel, Maciek, Mardy, Marius, Mike, Nigel, Nikita, Raoul, Ratchanan, Robert, Sergey. I have been involved in the development and release process over the past four years and I feel honoured to work with so many fine and genuine people on such a unique project. It is a pleasure to work with you guys!!! Also a big thanks to the UBports Foundation and its BoD for being the umbrella organisation of all Ubuntu Touch related initiatives. Consumer-Ready Ubuntu Touch is one of the very few Open Source projects that brings fourth a 100% FLOSS phone operating system. After using Ubuntu Touch myself for several months now, I can confirm that it is a consumer grade OS that can be used by non-tech people as a daily driver for mobile communications and connectivity. Go for it and try it out.

Matt Brown: Ventilation Monitoring: Ensuring every space has clean, fresh air

The importance of clean, fresh indoor air is one of the most tangible takeaways of the Covid-19 pandemic. In addition to being an effective risk mitigation strategy for reducing the spread of respiratory illnesses, clean, fresh air is necessary to enable effective cognitive performance. Monitoring indoor air quality is relatively easy to do, but traditionally has not been a key focus. I believe air quality monitoring should be accessible for any indoor space, and for highly occupied indoor spaces should be provided on a continuous basis. This post explores the need and an opportunity for a business that can accelerate the adoption of ventilation monitoring through the following topics:

The importance of indoor air quality Clean, fresh air is fundamental to life and health. That might sound obvious, but unfortunately being obvious is not enough to ensure the air we breathe is in fact always clean and healthy. Repeated studies have revealed that in many cases the air you re breathing at school, in the bus or at work and probably also at home falls well below the ideal of what clean, fresh air should be. Unclean air has potential long-term health impacts and has also been shown to lower cognitive performance impacting the ability to learn and work as well as increasing the risk of transmission of respiratory illnesses like Covid-19 and the flu. Ventilation (replacing old stale air with clean fresh air) is the most effective and economical method of improving and maintaining high indoor air quality. Most New Zealand buildings (including schools and houses) are designed to rely on manual ventilation (opening windows), while newer buildings, often including larger or commercial buildings may use mechanical ventilation involving fans and ducts. Mechanical ventilation including filtration may also be required in situations where the outdoor air is not clean and fresh such as in a city or next to a busy intersection.

Observing the invisible Overall air quality is a complex topic involving many contributing factors, many of which are invisible and not perceptible to us until well after adverse effects or irritation occur. This complexity and lack of visible signal is a large contributing factor to the ignorance and lack of attention towards indoor air quality that is prevalent in most buildings and indoor spaces today. Our attention is biased towards the risks that we can see, and this default bias has not been helped by hesitation and resistance to the idea that aerosol transmission and air quality is an important factor in preventing disease transmission that has only recently started to change. Zeynep Tufekci has a great overview that provides fascinating context for how an overreaction to the early incorrect theories of bad air and miasma causing disease contributed to aerosol transmission and air quality being incorrectly neglected for so long. Correcting this history of inattention to indoor air quality is going to take time and effort, but one significant step that we can take to help start the journey to ensuring all indoor spaces have clean, healthy air is to make the invisible part visible. The concentration of carbon dioxide (CO2) in a space is an incredibly effective and easy to measure proxy for the ventilation of a space. The atmospheric background level of CO2 is around 420 parts per million (ppm), while our exhaled breath has concentrations as high as 40,000 ppm. Without effective ventilation, one or more people breathing in an enclosed space will rapidly lead to an observable increase in CO2 concentration, which in turn provides a signal that the ventilation is insufficient and needs to be improved. Monitoring CO2 and improving ventilation is not a panacea for all possible air quality issues, but for the majority of buildings and indoor spaces, using CO2 as a proxy for ventilation and increasing ventilation when CO2 levels rise above recommended levels is a simple, effective and achievable approach that will deliver improvements in cognitive performance and reduction in the risk of disease transmission with few, if any, downsides or risks. See this Public Health Communication Centre briefing for a more detailed explanation.

Adding clean air to our hygiene practices We have well established expectations of hygiene for the food we eat and the water we drink and these expectations are codified in regulations that ensure those providing these services do so in a way that gives us confidence that we re not going to be at risk of illness. You may recall seeing food grade ratings prominently displayed on the walls of restaurants and cafes that you visit as an example of this. Why should the air we breathe be treated any differently? I think there is a strong argument that indoor air quality deserves regulation, both of the absolute quality of the air and ensuring that the practices and achieved air quality are clearly advertised and available. Ventilation monitoring via measurement of CO2 concentration provides an effective and achievable method that can be used to achieve this, and countries like Belgium and Japan are already starting to regulate indoor air quality. In the UK, the independent SAGE group of scientists has published Scores on the Doors , a proposal which demonstrates how CO2 monitoring can be helpful in providing information about the air quality of indoor spaces. Unfortunately there is no movement in any of these directions in New Zealand yet, and no sign that regulation or even a basic campaign to raise awareness of ventilation and air quality is even being planned. This is disappointing, but even if such work was planned, it would still require appropriate ventilation monitoring products and services to enable it, and while there are some options available, it is not a fully solved space yet.

Existing ventilation monitoring options Until recently the available offerings for ventilation monitoring have sat at two distinct ends of the price and quality spectrum:
  • Handheld air quality meters advertised as measuring CO2, but in reality reporting only an approximation. These meters do not contain actual CO2 sensors, and only approximate CO2 levels based on measurements of other components of the air. While cheap (often less than $100), these meters are not useful for providing reliable data that can be systematically used to assess and improve ventilation and should be avoided.
  • High-end building management systems (BMS), and industrial measurement products targeted at large buildings such as offices or commercial applications such as food production. These systems require specialist installation, often integrated with large whole-building air conditioning systems. These systems, if appropriately configured, can be a great solution for the types of buildings and spaces that can afford them, but by their nature and cost, they do not offer a solution for the majority of smaller buildings and indoor spaces where we tend to spend a lot of our time.
Over the last few years a growing number of companies have developed products that fit in between the unreliable air quality meters and the expensive BMS/industrial measurement products. Promising NZ-based options in this space include Air Suite, Tether and Monkeytronics. These products are wall mountable, resemble a smoke alarm and utilise a WiFi network to report their measurements to a supporting web service. Pricing varies between $200 and $300 ex GST per unit. Aranet, while not NZ based, provides a handheld monitor the Aranet4 Home, which is well regarded for quality and accuracy. Aranet4 Home devices are the most expensive in this space, retailing at $386 ex GST and offer a clunkier and less convenient set of connectivity options via a Bluetooth connection to an associated phone. To obtain similar reporting functionality to the other products requires upgrading to their Pro model and purchasing a separate base station at a combined cost of $1255 ex GST. Outside the commercial product offerings are a number of open source DIY options, which can be built by anyone with basic electronics knowledge. AirGradient is a leading example based in Thailand, and within New Zealand Oliver Seiler s CO2 Monitor provides similar functionality. These open source options have a parts cost in the $100-$150 range, depending on volume built and provide high-quality measurements via trusted CO2 sensors while also offering huge flexibility in terms of how they operate, interact with users and potential supporting web services.

An opportunity: Small businesses and organisations While a growing number of high-quality CO2 monitors has the potential to help drive increased adoption of ventilation monitoring, the plethora of small businesses and organisations that own, operate and manage many of the indoor spaces we visit on a day-to-day basis do not appear to be well served by these existing products. To deploy ventilation monitoring a small business or organisation needs to first become aware of the need or demand for it, and then have a simple and easy path to acquire and install the monitor and access the data. Little to no marketing or demand generation appears to be targeted towards this market from the existing businesses and tellingly, several of the products are not directly available for sale, requiring interaction with a salesperson to purchase. This indicates a focus on selling to larger customers who have a campus or portfolio of buildings and will purchase in larger quantities than the typical small business or organisation will. Small businesses and organisations are likely to occupy smaller buildings and spaces where manual ventilation is the prevalent method of improving and maintaining air quality. Maintaining clean, fresh air via manual ventilation requires the occupants of the space to receive an obvious and straightforward signal when action (opening windows, etc) is required. While the products above all tend to provide some form of local feedback and display in the room, the indication provided and notification of when to take action is less obvious and prominent than would be ideal in a situation where manual ventilation is being relied upon. Informally testing this opportunity with family and friends running small businesses over the last few months has resulted in promising feedback. One particular success story was the discovery of a fresh air duct on the air conditioning unit in a small office that had never been connected to the outside air and was simply recirculating air from the ceiling space back into an office! The resulting stuffiness and poor air quality had been noticed, but without the clear indication from the CO2 monitor that the air conditioning was actually making things worse, rather than better, the underlying issue had not been understood. With the issue fixed and the duct now connected, that business is now enjoying much more productive and healthy working conditions.

Next steps Many small businesses and organisations are likely to have poor air quality and opportunities for improvement similar to the example above that are waiting to be found and fixed, and the existing products available are neither focused or ideal for the needs of this market. I have spent some time over the past six months building a basic CO2 monitoring service that I have used to deploy ventilation monitoring to our local school, and a few other local businesses. There are a number of challenges that still need to be addressed in order to scale the business up, but I think there is a reasonable chance that I can build a viable business that offers an attractive and useful solution that would accelerate the deployment of ventilation monitoring for small businesses and organisations. In an upcoming post, I will explain the foundations of the service that I have built to date, the challenges that need to be overcome and how I plan to evolve the service from the current prototype into a sustainable, bootstrapped business.

kpcyrd: Writing a Linux executable from scratch with x86_64-unknown-none and Rust

I recently mentioned on the internet I did work in this direction and a friend of mine asked me to write a blogpost on this. I didn t blog for a long time (keeping all the goodness for myself hehe), so here we go. To set the scene, let s assume we want to make an exectuable binary for x86_64 Linux that s supposed to be extremely portable. It should work on both Debian and Arch Linux. It should work on systems without glibc like Alpine Linux. It should even work in a FROM scratch Docker container. In a more serious setting you would statically link musl-libc with your Rust program, but today we re in a silly-goofy mood so we re going to try to make this work without a libc. And we re also going to use Rust for this, more specifically the stable release channel of Rust, so this blog post won t use any nightly-only features that might still change/break. If you re using a Rust 1.0 version that was recent at the time of writing or later (>= 1.68.0 according to my computer), you should be able to try this at home just fine . This tutorial assumes you have no prior programming experience in any programming language, but it s going to involve some x86_64 assembly. If you already know what a syscall is, you ll be just fine. If this is your first exposure to programming you might still be able to follow along, but it might be a wild ride. If you haven t already, install rustup (possibly also available in your package manager, who knows?)
# when asked, press enter to confirm default settings
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs   sh
This is going to install everything you need to use Rust on Linux (this tutorial assumes you re following along on Linux btw). Usually it s still using a system linker (by calling the cc binary, and errors out if none is present), but instead we re going to use rustup to install an additional target:
rustup target add x86_64-unknown-none
I don t know if/how this is made available by Linux distributions, so I recommend following along with rust installed from rustup. Anyway, we re creating a new project with cargo, this creates a new directory that we can then change into (you might ve done this before):
cargo new hack-the-planet
cd hack-the-planet
There s going to be a file named Cargo.toml, we don t need to make any changes there, but the one that was auto-generated for me at the time of writing looks like this:
[package]
name = "hack-the-planet"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
There s a second file named src/main.rs, it s going to contain some pre-generated hello world, but we re going to delete it and create a new, empty file:
rm src/main.rs
touch src/main.rs
Alrighty, leaving this file empty is not valid but we re going to walk through the individual steps so we re going to try to build with an empty file first. At this point I would like to credit this chapter of a fasterthanli.me series and a blogpost by Philipp Oppermann, this tutorial is merely an 2023 update and makes it work with stable Rust. Let s run the build:
$ cargo build --release --target x86_64-unknown-none
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
error[E0463]: can't find crate for  std 
   
  = note: the  x86_64-unknown-none  target may not support the standard library
  = note:  std  is required by  hack_the_planet  because it does not declare  #![no_std] 
error[E0601]:  main  function not found in crate  hack_the_planet 
   
  = note: consider adding a  main  function to  src/main.rs 
Some errors have detailed explanations: E0463, E0601.
For more information about an error, try  rustc --explain E0463 .
error: could not compile  hack-the-planet  due to 2 previous errors
Since this doesn t use a libc (oh right, I forgot to mention this up to this point actually), this also means there s no std standard library. Usually the standard library of Rust still uses the system libc to do syscalls, but since we specify our libc as none this means std won t be available (use std::fs::rename won t work). There are still other functions we can use and import, for example there s core that s effectively a second standard library, but much smaller. To opt-out of the std standard library, we can put #![no_std] into src/main.rs:
#![no_std]
Running the build again:
$ cargo build --release --target x86_64-unknown-none
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
error[E0601]:  main  function not found in crate  hack_the_planet 
 --> src/main.rs:1:11
   
1   #![no_std]
              ^ consider adding a  main  function to  src/main.rs 
For more information about this error, try  rustc --explain E0601 .
error: could not compile  hack-the-planet  due to previous error
Rust noticed we didn t define a main function and suggest we add one. This isn t what we want though so we ll politely decline and inform Rust we don t have a main and it shouldn t attempt to call it. We re adding #![no_main] to our file and src/main.rs now looks like this:
#![no_std]
#![no_main]
Running the build again:
$ cargo build
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
error:  #[panic_handler]  function required, but not found
error: language item required, but not found:  eh_personality 
   
  = note: this can occur when a binary crate with  #![no_std]  is compiled for a target where  eh_personality  is defined in the standard library
  = help: you may be able to compile for a target that doesn't need  eh_personality , specify a target with  --target  or in  .cargo/config 
error: could not compile  hack-the-planet  due to 2 previous errors
Rust is asking us for a panic handler, basically I m going to jump to this address if something goes terribly wrong and execute whatever you put there . Eventually we would put some code there to just exit the program, but for now an infinitely loop will do. This is likely going to get stripped away anyway by the compiler if it notices our program has no code-branches leading to a panic and the code is unused. Our src/main.rs now looks like this:
#![no_std]
#![no_main]
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    loop  
 
Running the build again:
$ cargo build --release --target x86_64-unknown-none
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
    Finished release [optimized] target(s) in 0.16s
Neat, it worked! What happens if we run it?
$ target/x86_64-unknown-none/release/hack-the-planet
Segmentation fault (core dumped)
Oops. Let s try to disassemble it:
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Ok that looks pretty from scratch to me . The file contains no cpu instructions. Also note how our infinity loop is not present (as predicted).

Making a basic program and executing it Ok let s try to make a valid program that basically just cleanly exits. First let s try to add some cpu instructions and verify they re indeed getting executed. Lemme introduce, the INT 3 instruction in x86_64 assembly. In binary it s also known as the 0xCC opcode. It crashes our program in a slightly different way, so if the error message changes, we know it worked. The other tutorials use a #[naked] function for the entry point, but since this feature isn t stabilized at the time of writing we re going to use the global_asm! macro. Also don t worry, I m not going to introduce every assembly instruction individually. Our program now looks like this:
#![no_std]
#![no_main]
use core::arch::global_asm;
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    loop  
 
global_asm!  
    ".global _start",
    "_start:",
    "int 3"
 
Running the build again (ok basically from now on the build is always going to be expected to work unless I say otherwise):
$ cargo build --release --target x86_64-unknown-none
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
    Finished release [optimized] target(s) in 0.11s
Let s try to disassemble the binary again:
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Disassembly of section .text:
0000000000001210 <_start>:
    1210:	cc                   	int3
And sure enough, there s a cc instruction that was identified as int3. Let s try to run this:
$ target/x86_64-unknown-none/release/hack-the-planet
Trace/breakpoint trap (core dumped)
The error message of the crash is now slightly different because it s hitting our breakpoint cpu instruction. Funfact btw, if you run this in strace you can see this isn t making any system calls (aka not talking to the kernel at all, it just crashes):
$ strace -f ./hack-the-planet
execve("./hack-the-planet", ["./hack-the-planet"], 0x74f12430d1d8 /* 39 vars */) = 0
--- SIGTRAP  si_signo=SIGTRAP, si_code=SI_KERNEL, si_addr=NULL  ---
+++ killed by SIGTRAP (core dumped) +++
[1]    2796457 trace trap (core dumped)  strace -f ./hack-the-planet
Let s try to make a program that does a clean shutdown. To do this we inform the kernel with a system call that we may like to exit. We can get more info on this with man 2 exit and it defines exit like this:
[[noreturn]] void _exit(int status);
On Linux this syscall is actually called _exit and exit is implemented as a libc function, but we don t care about any of that today, it s going to do the job just fine. Also note how it takes a single argument of type int. In C-speak this means signed 32 bit , i32 in Rust. Next we need to figure out the syscall number of this syscall. These numbers are cpu architecture specific for some reason (idk, idc). We re looking these numbers up with ripgrep in /usr/include/asm/:
$ rg __NR_exit /usr/include/asm
/usr/include/asm/unistd_64.h
64:#define __NR_exit 60
235:#define __NR_exit_group 231
/usr/include/asm/unistd_x32.h
53:#define __NR_exit (__X32_SYSCALL_BIT + 60)
206:#define __NR_exit_group (__X32_SYSCALL_BIT + 231)
/usr/include/asm/unistd_32.h
5:#define __NR_exit 1
253:#define __NR_exit_group 252
Since we re on x86_64 the correct value is the one in unistd_64.h, 60. Also, on x86_64 the syscall number goes into the rax cpu register, the status argument goes in the rdi register. The return value of the syscall is going to be placed in the rax register after the syscall is done, but for exit the execution is never given back to us. Let s try to write 60 into the rax register and 69 into the rdi register. To copy into registers we re going to use the mov destination, source instruction to copy from source to destination. With these registers setup we can use the syscall cpu instruction to hand execution over to the kernel. Don t worry, there s only one more assembly instruction coming and for everything else we re going to use Rust. Our code now looks like this:
#![no_std]
#![no_main]
use core::arch::global_asm;
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    loop  
 
global_asm!  
    ".global _start",
    "_start:",
    "mov rax, 60",
    "mov rdi, 69",
    "syscall"
 
Build the binary, run it and print the exit code:
$ cargo build --release --target x86_64-unknown-none
$ target/x86_64-unknown-none/release/hack-the-planet; echo $?
69
Nice. Rust is quite literally putting these cpu instructions into the binary for us, nothing else.
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Disassembly of section .text:
0000000000001210 <_start>:
    1210:	48 c7 c0 3c 00 00 00 	mov    $0x3c,%rax
    1217:	48 c7 c7 45 00 00 00 	mov    $0x45,%rdi
    121e:	0f 05                	syscall
Running this with strace shows the program does exactly one thing.
$ strace -f ./hack-the-planet
execve("./hack-the-planet", ["./hack-the-planet"], 0x70699fe8c908 /* 39 vars */) = 0
exit(69)                                = ?
+++ exited with 69 +++

Writing Rust Ok but even though cpu instructions can be fun at times, I d rather not deal with them most of the time (this might strike you as odd, considering this blog post). Instead let s try to define a function in Rust and call into that instead. We re going to define this function as unsafe (btw none of this is taking advantage of the safety guarantees by Rust in case it wasn t obvious. This tutorial is mostly going to stick to unsafe Rust, but for bigger projects you can attempt to reduce your usage of unsafe to opt back into normal safe Rust), it also declares the function with #[no_mangle] so the function name is preserved as main and we can call it from our global_asm entry point. Lastely, when our program is started it s going to get the stack address passed in one of the cpu registers, this value is expected to be passed to our function as an argument. Our function declares ! as return type, which means it never returns:
#[no_mangle]
unsafe fn main(_stack_top: *const u8) -> !  
    // TODO: this is missing
 
This won t compile yet, we need to add our assembly for the exit syscall back in.
#[no_mangle]
unsafe fn main(_stack_top: *const u8) -> !  
    asm!(
        "syscall",
        in("rax") 60,
        in("rdi") 0,
        options(noreturn)
    );
 
This time we re using the asm! macro, this is a slightly more declarative approach. We want to run the syscall cpu instruction with 60 in the rax register, and this time we want the rdi register to be zero, to indicate a successful exit. We also use options(noreturn) so Rust knows it should assume execution does not resume after this assembly is executed (the Linux kernel guarantees this). We modify our global_asm! entrypoint to call our new main function, and to copy the stack address from rsp into the register for the first argument rdi because it would otherwise get lost forever:
global_asm!  
    ".global _start",
    "_start:",
    "mov rdi, rsp",
    "call main"
 
Our full program now looks like this:
#![no_std]
#![no_main]
use core::arch::asm;
use core::arch::global_asm;
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    loop  
 
global_asm!  
    ".global _start",
    "_start:",
    "mov rdi, rsp",
    "call main"
 
#[no_mangle]
unsafe fn main(_stack_top: *const u8) -> !  
    asm!(
        "syscall",
        in("rax") 60,
        in("rdi") 0,
        options(noreturn)
    );
 
After building and disassembling this the Rust compiler is slowly starting to do work for us:
$ cargo build --release --target x86_64-unknown-none
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Disassembly of section .text:
0000000000001210 <_start>:
    1210:	48 89 e7             	mov    %rsp,%rdi
    1213:	e8 08 00 00 00       	call   1220 <main>
    1218:	cc                   	int3
    1219:	cc                   	int3
    121a:	cc                   	int3
    121b:	cc                   	int3
    121c:	cc                   	int3
    121d:	cc                   	int3
    121e:	cc                   	int3
    121f:	cc                   	int3
0000000000001220 <main>:
    1220:	50                   	push   %rax
    1221:	b8 3c 00 00 00       	mov    $0x3c,%eax
    1226:	31 ff                	xor    %edi,%edi
    1228:	0f 05                	syscall
    122a:	0f 0b                	ud2
The mov and syscall instructions are still the same, but it noticed it can XOR the rdi register with itself to set it to zero. It s using x86 assembly language (the 32 bit variant of x86_64, that also happens to work on x86_64) to do so, that s why the register is refered to as edi in the disassembly. You can also see it s inserting a bunch of 0xCC instructions (for alignment) and Rust puts the opcodes 0x0F 0x0B at the end of the function to force an invalid opcode exception so the program is guaranteed to crash in case the exit syscall doesn t do it. This code still executes as expected:
$ strace -f ./hack-the-planet
execve("./hack-the-planet", ["./hack-the-planet"], 0x72dae7e5dc08 /* 39 vars */) = 0
exit(0)                                 = ?
+++ exited with 0 +++

Adding functions Ok we re getting closer but we aren t quite there yet. Let s try to write an exit function for our assembly that we can then call like a normal function. Remember that it takes a signed 32 bit integer that s supposed to go into rdi.
unsafe fn exit(status: i32) -> !  
    asm!(
        "syscall",
        in("rax") 60,
        in("rdi") status,
        options(noreturn)
    );
 
Actually, since this function doesn t take any raw pointers and any i32 is valid for this syscall we re going to remove the unsafe marker of this function. When doing this we still need to use unsafe within the function for our inline assembly.
fn exit(status: i32) -> !  
    unsafe  
        asm!(
            "syscall",
            in("rax") 60,
            in("rdi") status,
            options(noreturn)
        );
     
 
Let s call this function from our main, and also remove the infinity loop of the panic handler with a call to exit(1):
#![no_std]
#![no_main]
use core::arch::asm;
use core::arch::global_asm;
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    exit(1);
 
global_asm!  
    ".global _start",
    "_start:",
    "mov rdi, rsp",
    "call main"
 
fn exit(status: i32) -> !  
    unsafe  
        asm!(
            "syscall",
            in("rax") 60,
            in("rdi") status,
            options(noreturn)
        );
     
 
#[no_mangle]
unsafe fn main(_stack_top: *const u8) -> !  
    exit(0);
 
Running this still works, but interestingly the generated assembly didn t change at all:
$ cargo build --release --target x86_64-unknown-none
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Disassembly of section .text:
0000000000001210 <_start>:
    1210:	48 89 e7             	mov    %rsp,%rdi
    1213:	e8 08 00 00 00       	call   1220 <main>
    1218:	cc                   	int3
    1219:	cc                   	int3
    121a:	cc                   	int3
    121b:	cc                   	int3
    121c:	cc                   	int3
    121d:	cc                   	int3
    121e:	cc                   	int3
    121f:	cc                   	int3
0000000000001220 <main>:
    1220:	50                   	push   %rax
    1221:	b8 3c 00 00 00       	mov    $0x3c,%eax
    1226:	31 ff                	xor    %edi,%edi
    1228:	0f 05                	syscall
    122a:	0f 0b                	ud2
Rust noticed there s no need to make it a separate function at runtime and instead merged the instructions of the exit function directly into our main. It also noticed the 0 argument in exit(0) means rdi is supposed to be zero and uses the XOR optimization mentioned before. Since main is not calling any unsafe functions anymore we could mark it as safe too, but in the next few functions we re going to deal with file descriptors and raw pointers, so this is likely the only safe function we re going to write in this tutorial so let s just keep the unsafe marker.

Printing text Ok let s try to do a quick hello world, to do this we re going to call the write syscall. Looking it up with man 2 write:
ssize_t write(int fd, const void buf[.count], size_t count);
The write syscall takes 3 arguments and returns a signed size_t. In Rust this is called isize. In C size_t is an unsigned integer type that can hold any value of sizeof(...) for the given platform, ssize_t can only store half of that because it uses one of the bits to indicate an error has occured (the first s means signed, write returns -1 in case of an error). The arguments for write are:
  • the file descriptor to write to. stdout is located on file descriptor 1.
  • a pointer/address to some memory.
  • the number of bytes that should be written, starting at the given address.
Let s also lookup the syscall number of write:
% rg __NR_write /usr/include/asm
/usr/include/asm/unistd_64.h
5:#define __NR_write 1
24:#define __NR_writev 20
/usr/include/asm/unistd_32.h
8:#define __NR_write 4
150:#define __NR_writev 146
/usr/include/asm/unistd_x32.h
5:#define __NR_write (__X32_SYSCALL_BIT + 1)
323:#define __NR_writev (__X32_SYSCALL_BIT + 516)
The value we re looking for is 1. Let s write our write function (heh).
unsafe fn write(fd: i32, buf: *const u8, count: usize) -> isize  
    let r0;
    asm!(
        "syscall",
        inlateout("rax") 1 => r0,
        in("rdi") fd,
        in("rsi") buf,
        in("rdx") count,
        lateout("rcx") _,
        lateout("r11") _,
        options(nostack, preserves_flags)
    );
    r0
 
Now that s a lot of stuff at once. Since this syscall is actually going to hand execution back to our program we need to let Rust know which cpu registers the syscall is writing to, so Rust doesn t attempt to use them to store data (that would be silently overwritten by the syscall). inlateout("raw") 1 => r0 means we re writing a value to the register and want the result back in variable r0. in("rdi") fd means we want to write the value of fd into the rdi register. lateout("rcx") _ means the Linux kernel may write to that register (so the previous value may get lost), but we don t want to store the value anywhere (the underscore acts as a dummy variable name). This doesn t compile just yet though
$ cargo build --release --target x86_64-unknown-none
   Compiling hack-the-planet v0.1.0 (/hack-the-planet)
error: incompatible types for asm inout argument
  --> src/main.rs:35:26
    
35           inlateout("rax") 1 => r0,
                              ^    ^^ type  isize 
                               
                              type  i32 
    
   = note: asm inout arguments must have the same type, unless they are both pointers or integers of the same size
error: could not compile  hack-the-planet  due to previous error
Rust has inferred the type of r0 is isize since that s what our function returns, but the type of the input value for the register was inferred to be i32. We re going to select a specific number type to fix this.
unsafe fn write(fd: i32, buf: *const u8, count: usize) -> isize  
    let r0;
    asm!(
        "syscall",
        inlateout("rax") 1isize => r0,
        in("rdi") fd,
        in("rsi") buf,
        in("rdx") count,
        lateout("rcx") _,
        lateout("r11") _,
        options(nostack, preserves_flags)
    );
    r0
 
We can now call our new write function like this:
write(1, b"Hello world\n".as_ptr(), 12);
We need to set the number of bytes we want to write explicitly because there s no concept of null-byte termination in the write system call, it s quite literally write the next X bytes, starting from this address . Our program now looks like this:
#![no_std]
#![no_main]
use core::arch::asm;
use core::arch::global_asm;
use core::panic::PanicInfo;
#[panic_handler]
fn panic(_info: &PanicInfo) -> !  
    exit(1);
 
global_asm!  
    ".global _start",
    "_start:",
    "mov rdi, rsp",
    "call main"
 
fn exit(status: i32) -> !  
    unsafe  
        asm!(
            "syscall",
            in("rax") 60,
            in("rdi") status,
            options(noreturn)
        );
     
 
unsafe fn write(fd: i32, buf: *const u8, count: usize) -> isize  
    let r0;
    asm!(
        "syscall",
        inlateout("rax") 1isize => r0,
        in("rdi") fd,
        in("rsi") buf,
        in("rdx") count,
        lateout("rcx") _,
        lateout("r11") _,
        options(nostack, preserves_flags)
    );
    r0
 
#[no_mangle]
unsafe fn main(_stack_top: *const u8) -> !  
    write(1, b"Hello world\n".as_ptr(), 12);
    exit(0);
 
Let s try to build and disassemble it:
$ cargo build --release --target x86_64-unknown-none
$ objdump -d target/x86_64-unknown-none/release/hack-the-planet
target/x86_64-unknown-none/release/hack-the-planet:     file format elf64-x86-64
Disassembly of section .text:
0000000000001220 <_start>:
    1220:	48 89 e7             	mov    %rsp,%rdi
    1223:	e8 08 00 00 00       	call   1230 <main>
    1228:	cc                   	int3
    1229:	cc                   	int3
    122a:	cc                   	int3
    122b:	cc                   	int3
    122c:	cc                   	int3
    122d:	cc                   	int3
    122e:	cc                   	int3
    122f:	cc                   	int3
0000000000001230 <main>:
    1230:	50                   	push   %rax
    1231:	48 8d 35 d5 ef ff ff 	lea    -0x102b(%rip),%rsi        # 20d <_start-0x1013>
    1238:	b8 01 00 00 00       	mov    $0x1,%eax
    123d:	ba 0c 00 00 00       	mov    $0xc,%edx
    1242:	bf 01 00 00 00       	mov    $0x1,%edi
    1247:	0f 05                	syscall
    1249:	b8 3c 00 00 00       	mov    $0x3c,%eax
    124e:	31 ff                	xor    %edi,%edi
    1250:	0f 05                	syscall
    1252:	0f 0b                	ud2
This time there are 2 syscalls, first write, then exit. For write it s setting up the 3 arguments in our cpu registers (rdi, rsi, rdx). The lea instruction subtracts 0x102b from the rip register (the instruction pointer) and places the result in the rsi register. This is effectively saying an address relative to wherever this code was loaded into memory . The instruction pointer is going to point directly behind the opcodes of the lea instruction, so 0x1238 - 0x102b = 0x20d. This address is also pointed out in the disassembly as a comment. We don t see the string in our disassembly but we can convert our 0x20d hex to 525 in decimal and use dd to read 12 bytes from that offset, and sure enough:
$ dd bs=1 skip=525 count=12 if=target/x86_64-unknown-none/release/hack-the-planet
Hello world
12+0 records in
12+0 records out
Execute our binary with strace also shows the new write syscall (and the bytes that are being written mixed up in the output).
$ strace -f ./hack-the-planet
execve("./hack-the-planet", ["./hack-the-planet"], 0x74493abe64a8 /* 39 vars */) = 0
write(1, "Hello world\n", 12Hello world
)           = 12
exit(0)                                 = ?
+++ exited with 0 +++
After running strip on it to remove some symbols the binary is so small, if you open it in a text editor it fits on a screenshot:

27 March 2023

Vincent Fourmond: QSoas version 3.2 is out

Version 3.2 of QSoas is out ! It is mostly a bug-fix release, fixing the computation mistake found in the eecr-relay wave shape fit, see the correction to our initial article in JACS. We strongly encourage all the users of the eecr-relay wave shape fit to upgrade, and, unfortunately, refit previously fitted data as the results might change. The other wave shape fits are not affected by the issue. New features In addition to this important bug fix, new possibilities have been added, including a way to make fits with partially global parameters using the new define-indexed-fit command, to pick the best parameters dataset-by-dataset within fit trajectories, but also a parameter space explorer trying all possible permutations of one or more sets of parameters, and the possibility to save the results of a command to a global ruby variable. There are a lot of other new features, improvements and so on, look for the full list there. About QSoas
QSoas is a powerful open source data analysis program that focuses on flexibility and powerful fitting capacities. It is released under the GNU General Public License. It is described in Fourmond, Anal. Chem., 2016, 88 (10), pp 5050 5052. Current version is 3.2. You can download for free its source code or precompiled versions for MacOS and Windows there. Alternatively, you can clone from the GitHub repository.

Simon Josefsson: OpenPGP master key on Nitrokey Start

I ve used hardware-backed OpenPGP keys since 2006 when I imported newly generated rsa1024 subkeys to a FSFE Fellowship card. This worked well for several years, and I recall buying more ZeitControl cards for multi-machine usage and backup purposes. As a side note, I recall being unsatisfied with the weak 1024-bit RSA subkeys at the time my primary key was a somewhat stronger 1280-bit RSA key created back in 2002 but OpenPGP cards at the time didn t support more than 1024 bit RSA, and were (and still often are) also limited to power-of-two RSA key sizes which I dislike. I had my master key on disk with a strong password for a while, mostly to refresh expiration time of the subkeys and to sign other s OpenPGP keys. At some point I stopped carrying around encrypted copies of my master key. That was my main setup when I migrated to a new stronger RSA 3744 bit key with rsa2048 subkeys on a YubiKey NEO back in 2014. At that point, signing other s OpenPGP keys was a rare enough occurrence that I settled with bringing out my offline machine to perform this operation, transferring the public key to sign on USB sticks. In 2019 I re-evaluated my OpenPGP setup and ended up creating a offline Ed25519 key with subkeys on a FST-01G running Gnuk. My approach for signing other s OpenPGP keys were still to bring out my offline machine and sign things using the master secret using USB sticks for storage and transport. Which meant I almost never did that, because it took too much effort. So my 2019-era Ed25519 key still only has a handful of signatures on it, since I had essentially stopped signing other s keys which is the traditional way of getting signatures in return. None of this caused any critical problem for me because I continued to use my old 2014-era RSA3744 key in parallel with my new 2019-era Ed25519 key, since too many systems didn t handle Ed25519. However, during 2022 this changed, and the only remaining environment that I still used my RSA3744 key for was in Debian and they require OpenPGP signatures on the new key to allow it to replace an older key. I was in denial about this sub-optimal solution during 2022 and endured its practical consequences, having to use the YubiKey NEO (which I had replaced with a permanently inserted YubiKey Nano at some point) for Debian-related purposes alone. In December 2022 I bought a new laptop and setup a FST-01SZ with my Ed25519 key, and while I have taken a vacation from Debian, I continue to extend the expiration period on the old RSA3744-key in case I will ever have to use it again, so the overall OpenPGP setup was still sub-optimal. Having two valid OpenPGP keys at the same time causes people to use both for email encryption (leading me to have to use both devices), and the WKD Key Discovery protocol doesn t like two valid keys either. At FOSDEM 23 I ran into Andre Heinecke at GnuPG and I couldn t help complain about how complex and unsatisfying all OpenPGP-related matters were, and he mildly ignored my rant and asked why I didn t put the master key on another smartcard. The comment sunk in when I came home, and recently I connected all the dots and this post is a summary of what I did to move my offline OpenPGP master key to a Nitrokey Start. First a word about device choice, I still prefer to use hardware devices that are as compatible with free software as possible, but the FST-01G or FST-01SZ are no longer easily available for purchase. I got a comment about Nitrokey start in my last post, and had two of them available to experiment with. There are things to dislike with the Nitrokey Start compared to the YubiKey (e.g., relative insecure chip architecture, the bulkier form factor and lack of FIDO/U2F/OATH support) but as far as I know there is no more widely available owner-controlled device that is manufactured for an intended purpose of implementing an OpenPGP card. Thus it hits the sweet spot for me.
Nitrokey Start
The first step is to run latest firmware on the Nitrokey Start for bug-fixes and important OpenSSH 9.0 compatibility and there are reproducible-built firmware published that you can install using pynitrokey. I run Trisquel 11 aramo on my laptop, which does not include the Python Pip package (likely because it promotes installing non-free software) so that was a slight complication. Building the firmware locally may have worked, and I would like to do that eventually to confirm the published firmware, however to save time I settled with installing the Ubuntu 22.04 packages on my machine:
$ sha256sum python3-pip*
ded6b3867a4a4cbaff0940cab366975d6aeecc76b9f2d2efa3deceb062668b1c  python3-pip_22.0.2+dfsg-1ubuntu0.2_all.deb
e1561575130c41dc3309023a345de337e84b4b04c21c74db57f599e267114325  python3-pip-whl_22.0.2+dfsg-1ubuntu0.2_all.deb
$ doas dpkg -i python3-pip*
...
$ doas apt install -f
...
$
Installing pynitrokey downloaded a bunch of dependencies, and it would be nice to audit the license and security vulnerabilities for each of them. (Verbose output below slightly redacted.)
jas@kaka:~$ pip3 install --user pynitrokey
Collecting pynitrokey
  Downloading pynitrokey-0.4.34-py3-none-any.whl (572 kB)
Collecting frozendict~=2.3.4
  Downloading frozendict-2.3.5-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (113 kB)
Requirement already satisfied: click<9,>=8.0.0 in /usr/lib/python3/dist-packages (from pynitrokey) (8.0.3)
Collecting ecdsa
  Downloading ecdsa-0.18.0-py2.py3-none-any.whl (142 kB)
Collecting python-dateutil~=2.7.0
  Downloading python_dateutil-2.7.5-py2.py3-none-any.whl (225 kB)
Collecting fido2<2,>=1.1.0
  Downloading fido2-1.1.0-py3-none-any.whl (201 kB)
Collecting tlv8
  Downloading tlv8-0.10.0.tar.gz (16 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: certifi>=14.5.14 in /usr/lib/python3/dist-packages (from pynitrokey) (2020.6.20)
Requirement already satisfied: pyusb in /usr/lib/python3/dist-packages (from pynitrokey) (1.2.1.post1)
Collecting urllib3~=1.26.7
  Downloading urllib3-1.26.15-py2.py3-none-any.whl (140 kB)
Collecting spsdk<1.8.0,>=1.7.0
  Downloading spsdk-1.7.1-py3-none-any.whl (684 kB)
Collecting typing_extensions~=4.3.0
  Downloading typing_extensions-4.3.0-py3-none-any.whl (25 kB)
Requirement already satisfied: cryptography<37,>=3.4.4 in /usr/lib/python3/dist-packages (from pynitrokey) (3.4.8)
Collecting intelhex
  Downloading intelhex-2.3.0-py2.py3-none-any.whl (50 kB)
Collecting nkdfu
  Downloading nkdfu-0.2-py3-none-any.whl (16 kB)
Requirement already satisfied: requests in /usr/lib/python3/dist-packages (from pynitrokey) (2.25.1)
Collecting tqdm
  Downloading tqdm-4.65.0-py3-none-any.whl (77 kB)
Collecting nrfutil<7,>=6.1.4
  Downloading nrfutil-6.1.7.tar.gz (845 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: cffi in /usr/lib/python3/dist-packages (from pynitrokey) (1.15.0)
Collecting crcmod
  Downloading crcmod-1.7.tar.gz (89 kB)
  Preparing metadata (setup.py) ... done
Collecting libusb1==1.9.3
  Downloading libusb1-1.9.3-py3-none-any.whl (60 kB)
Collecting pc_ble_driver_py>=0.16.4
  Downloading pc_ble_driver_py-0.17.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (2.9 MB)
Collecting piccata
  Downloading piccata-2.0.3-py3-none-any.whl (21 kB)
Collecting protobuf<4.0.0,>=3.17.3
  Downloading protobuf-3.20.3-cp310-cp310-manylinux_2_12_x86_64.manylinux2010_x86_64.whl (1.1 MB)
Collecting pyserial
  Downloading pyserial-3.5-py2.py3-none-any.whl (90 kB)
Collecting pyspinel>=1.0.0a3
  Downloading pyspinel-1.0.3.tar.gz (58 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: pyyaml in /usr/lib/python3/dist-packages (from nrfutil<7,>=6.1.4->pynitrokey) (5.4.1)
Requirement already satisfied: six>=1.5 in /usr/lib/python3/dist-packages (from python-dateutil~=2.7.0->pynitrokey) (1.16.0)
Collecting pylink-square<0.11.9,>=0.8.2
  Downloading pylink_square-0.11.1-py2.py3-none-any.whl (78 kB)
Collecting jinja2<3.1,>=2.11
  Downloading Jinja2-3.0.3-py3-none-any.whl (133 kB)
Collecting bincopy<17.11,>=17.10.2
  Downloading bincopy-17.10.3-py3-none-any.whl (17 kB)
Collecting fastjsonschema>=2.15.1
  Downloading fastjsonschema-2.16.3-py3-none-any.whl (23 kB)
Collecting astunparse<2,>=1.6
  Downloading astunparse-1.6.3-py2.py3-none-any.whl (12 kB)
Collecting oscrypto~=1.2
  Downloading oscrypto-1.3.0-py2.py3-none-any.whl (194 kB)
Collecting deepmerge==0.3.0
  Downloading deepmerge-0.3.0-py2.py3-none-any.whl (7.6 kB)
Collecting pyocd<=0.31.0,>=0.28.3
  Downloading pyocd-0.31.0-py3-none-any.whl (12.5 MB)
Collecting click-option-group<0.6,>=0.3.0
  Downloading click_option_group-0.5.5-py3-none-any.whl (12 kB)
Collecting pycryptodome<4,>=3.9.3
  Downloading pycryptodome-3.17-cp35-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (2.1 MB)
Collecting pyocd-pemicro<1.2.0,>=1.1.1
  Downloading pyocd_pemicro-1.1.5-py3-none-any.whl (9.0 kB)
Requirement already satisfied: colorama<1,>=0.4.4 in /usr/lib/python3/dist-packages (from spsdk<1.8.0,>=1.7.0->pynitrokey) (0.4.4)
Collecting commentjson<1,>=0.9
  Downloading commentjson-0.9.0.tar.gz (8.7 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: asn1crypto<2,>=1.2 in /usr/lib/python3/dist-packages (from spsdk<1.8.0,>=1.7.0->pynitrokey) (1.4.0)
Collecting pypemicro<0.2.0,>=0.1.9
  Downloading pypemicro-0.1.11-py3-none-any.whl (5.7 MB)
Collecting libusbsio>=2.1.11
  Downloading libusbsio-2.1.11-py3-none-any.whl (247 kB)
Collecting sly==0.4
  Downloading sly-0.4.tar.gz (60 kB)
  Preparing metadata (setup.py) ... done
Collecting ruamel.yaml<0.18.0,>=0.17
  Downloading ruamel.yaml-0.17.21-py3-none-any.whl (109 kB)
Collecting cmsis-pack-manager<0.3.0
  Downloading cmsis_pack_manager-0.2.10-py2.py3-none-manylinux1_x86_64.whl (25.1 MB)
Collecting click-command-tree==1.1.0
  Downloading click_command_tree-1.1.0-py3-none-any.whl (3.6 kB)
Requirement already satisfied: bitstring<3.2,>=3.1 in /usr/lib/python3/dist-packages (from spsdk<1.8.0,>=1.7.0->pynitrokey) (3.1.7)
Collecting hexdump~=3.3
  Downloading hexdump-3.3.zip (12 kB)
  Preparing metadata (setup.py) ... done
Collecting fire
  Downloading fire-0.5.0.tar.gz (88 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: wheel<1.0,>=0.23.0 in /usr/lib/python3/dist-packages (from astunparse<2,>=1.6->spsdk<1.8.0,>=1.7.0->pynitrokey) (0.37.1)
Collecting humanfriendly
  Downloading humanfriendly-10.0-py2.py3-none-any.whl (86 kB)
Collecting argparse-addons>=0.4.0
  Downloading argparse_addons-0.12.0-py3-none-any.whl (3.3 kB)
Collecting pyelftools
  Downloading pyelftools-0.29-py2.py3-none-any.whl (174 kB)
Collecting milksnake>=0.1.2
  Downloading milksnake-0.1.5-py2.py3-none-any.whl (9.6 kB)
Requirement already satisfied: appdirs>=1.4 in /usr/lib/python3/dist-packages (from cmsis-pack-manager<0.3.0->spsdk<1.8.0,>=1.7.0->pynitrokey) (1.4.4)
Collecting lark-parser<0.8.0,>=0.7.1
  Downloading lark-parser-0.7.8.tar.gz (276 kB)
  Preparing metadata (setup.py) ... done
Requirement already satisfied: MarkupSafe>=2.0 in /usr/lib/python3/dist-packages (from jinja2<3.1,>=2.11->spsdk<1.8.0,>=1.7.0->pynitrokey) (2.0.1)
Collecting asn1crypto<2,>=1.2
  Downloading asn1crypto-1.5.1-py2.py3-none-any.whl (105 kB)
Collecting wrapt
  Downloading wrapt-1.15.0-cp310-cp310-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl (78 kB)
Collecting future
  Downloading future-0.18.3.tar.gz (840 kB)
  Preparing metadata (setup.py) ... done
Collecting psutil>=5.2.2
  Downloading psutil-5.9.4-cp36-abi3-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl (280 kB)
Collecting capstone<5.0,>=4.0
  Downloading capstone-4.0.2-py2.py3-none-manylinux1_x86_64.whl (2.1 MB)
Collecting naturalsort<2.0,>=1.5
  Downloading naturalsort-1.5.1.tar.gz (7.4 kB)
  Preparing metadata (setup.py) ... done
Collecting prettytable<3.0,>=2.0
  Downloading prettytable-2.5.0-py3-none-any.whl (24 kB)
Collecting intervaltree<4.0,>=3.0.2
  Downloading intervaltree-3.1.0.tar.gz (32 kB)
  Preparing metadata (setup.py) ... done
Collecting ruamel.yaml.clib>=0.2.6
  Downloading ruamel.yaml.clib-0.2.7-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.manylinux_2_24_x86_64.whl (485 kB)
Collecting termcolor
  Downloading termcolor-2.2.0-py3-none-any.whl (6.6 kB)
Collecting sortedcontainers<3.0,>=2.0
  Downloading sortedcontainers-2.4.0-py2.py3-none-any.whl (29 kB)
Requirement already satisfied: wcwidth in /usr/lib/python3/dist-packages (from prettytable<3.0,>=2.0->pyocd<=0.31.0,>=0.28.3->spsdk<1.8.0,>=1.7.0->pynitrokey) (0.2.5)
Building wheels for collected packages: nrfutil, crcmod, sly, tlv8, commentjson, hexdump, pyspinel, fire, intervaltree, lark-parser, naturalsort, future
  Building wheel for nrfutil (setup.py) ... done
  Created wheel for nrfutil: filename=nrfutil-6.1.7-py3-none-any.whl size=898520 sha256=de6f8803f51d6c26d24dc7df6292064a468ff3f389d73370433fde5582b84a10
  Stored in directory: /home/jas/.cache/pip/wheels/39/2b/9b/98ab2dd716da746290e6728bdb557b14c1c9a54cb9ed86e13b
  Building wheel for crcmod (setup.py) ... done
  Created wheel for crcmod: filename=crcmod-1.7-cp310-cp310-linux_x86_64.whl size=31422 sha256=5149ac56fcbfa0606760eef5220fcedc66be560adf68cf38c604af3ad0e4a8b0
  Stored in directory: /home/jas/.cache/pip/wheels/85/4c/07/72215c529bd59d67e3dac29711d7aba1b692f543c808ba9e86
  Building wheel for sly (setup.py) ... done
  Created wheel for sly: filename=sly-0.4-py3-none-any.whl size=27352 sha256=f614e413918de45c73d1e9a8dca61ca07dc760d9740553400efc234c891f7fde
  Stored in directory: /home/jas/.cache/pip/wheels/a2/23/4a/6a84282a0d2c29f003012dc565b3126e427972e8b8157ea51f
  Building wheel for tlv8 (setup.py) ... done
  Created wheel for tlv8: filename=tlv8-0.10.0-py3-none-any.whl size=11266 sha256=3ec8b3c45977a3addbc66b7b99e1d81b146607c3a269502b9b5651900a0e2d08
  Stored in directory: /home/jas/.cache/pip/wheels/e9/35/86/66a473cc2abb0c7f21ed39c30a3b2219b16bd2cdb4b33cfc2c
  Building wheel for commentjson (setup.py) ... done
  Created wheel for commentjson: filename=commentjson-0.9.0-py3-none-any.whl size=12092 sha256=28b6413132d6d7798a18cf8c76885dc69f676ea763ffcb08775a3c2c43444f4a
  Stored in directory: /home/jas/.cache/pip/wheels/7d/90/23/6358a234ca5b4ec0866d447079b97fedf9883387d1d7d074e5
  Building wheel for hexdump (setup.py) ... done
  Created wheel for hexdump: filename=hexdump-3.3-py3-none-any.whl size=8913 sha256=79dfadd42edbc9acaeac1987464f2df4053784fff18b96408c1309b74fd09f50
  Stored in directory: /home/jas/.cache/pip/wheels/26/28/f7/f47d7ecd9ae44c4457e72c8bb617ef18ab332ee2b2a1047e87
  Building wheel for pyspinel (setup.py) ... done
  Created wheel for pyspinel: filename=pyspinel-1.0.3-py3-none-any.whl size=65033 sha256=01dc27f81f28b4830a0cf2336dc737ef309a1287fcf33f57a8a4c5bed3b5f0a6
  Stored in directory: /home/jas/.cache/pip/wheels/95/ec/4b/6e3e2ee18e7292d26a65659f75d07411a6e69158bb05507590
  Building wheel for fire (setup.py) ... done
  Created wheel for fire: filename=fire-0.5.0-py2.py3-none-any.whl size=116951 sha256=3d288585478c91a6914629eb739ea789828eb2d0267febc7c5390cb24ba153e8
  Stored in directory: /home/jas/.cache/pip/wheels/90/d4/f7/9404e5db0116bd4d43e5666eaa3e70ab53723e1e3ea40c9a95
  Building wheel for intervaltree (setup.py) ... done
  Created wheel for intervaltree: filename=intervaltree-3.1.0-py2.py3-none-any.whl size=26119 sha256=5ff1def22ba883af25c90d90ef7c6518496fcd47dd2cbc53a57ec04cd60dc21d
  Stored in directory: /home/jas/.cache/pip/wheels/fa/80/8c/43488a924a046b733b64de3fac99252674c892a4c3801c0a61
  Building wheel for lark-parser (setup.py) ... done
  Created wheel for lark-parser: filename=lark_parser-0.7.8-py2.py3-none-any.whl size=62527 sha256=3d2ec1d0f926fc2688d40777f7ef93c9986f874169132b1af590b6afc038f4be
  Stored in directory: /home/jas/.cache/pip/wheels/29/30/94/33e8b58318aa05cb1842b365843036e0280af5983abb966b83
  Building wheel for naturalsort (setup.py) ... done
  Created wheel for naturalsort: filename=naturalsort-1.5.1-py3-none-any.whl size=7526 sha256=bdecac4a49f2416924548cae6c124c85d5333e9e61c563232678ed182969d453
  Stored in directory: /home/jas/.cache/pip/wheels/a6/8e/c9/98cfa614fff2979b457fa2d9ad45ec85fa417e7e3e2e43be51
  Building wheel for future (setup.py) ... done
  Created wheel for future: filename=future-0.18.3-py3-none-any.whl size=492037 sha256=57a01e68feca2b5563f5f624141267f399082d2f05f55886f71b5d6e6cf2b02c
  Stored in directory: /home/jas/.cache/pip/wheels/5e/a9/47/f118e66afd12240e4662752cc22cefae5d97275623aa8ef57d
Successfully built nrfutil crcmod sly tlv8 commentjson hexdump pyspinel fire intervaltree lark-parser naturalsort future
Installing collected packages: tlv8, sortedcontainers, sly, pyserial, pyelftools, piccata, naturalsort, libusb1, lark-parser, intelhex, hexdump, fastjsonschema, crcmod, asn1crypto, wrapt, urllib3, typing_extensions, tqdm, termcolor, ruamel.yaml.clib, python-dateutil, pyspinel, pypemicro, pycryptodome, psutil, protobuf, prettytable, oscrypto, milksnake, libusbsio, jinja2, intervaltree, humanfriendly, future, frozendict, fido2, ecdsa, deepmerge, commentjson, click-option-group, click-command-tree, capstone, astunparse, argparse-addons, ruamel.yaml, pyocd-pemicro, pylink-square, pc_ble_driver_py, fire, cmsis-pack-manager, bincopy, pyocd, nrfutil, nkdfu, spsdk, pynitrokey
  WARNING: The script nitropy is installed in '/home/jas/.local/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed argparse-addons-0.12.0 asn1crypto-1.5.1 astunparse-1.6.3 bincopy-17.10.3 capstone-4.0.2 click-command-tree-1.1.0 click-option-group-0.5.5 cmsis-pack-manager-0.2.10 commentjson-0.9.0 crcmod-1.7 deepmerge-0.3.0 ecdsa-0.18.0 fastjsonschema-2.16.3 fido2-1.1.0 fire-0.5.0 frozendict-2.3.5 future-0.18.3 hexdump-3.3 humanfriendly-10.0 intelhex-2.3.0 intervaltree-3.1.0 jinja2-3.0.3 lark-parser-0.7.8 libusb1-1.9.3 libusbsio-2.1.11 milksnake-0.1.5 naturalsort-1.5.1 nkdfu-0.2 nrfutil-6.1.7 oscrypto-1.3.0 pc_ble_driver_py-0.17.0 piccata-2.0.3 prettytable-2.5.0 protobuf-3.20.3 psutil-5.9.4 pycryptodome-3.17 pyelftools-0.29 pylink-square-0.11.1 pynitrokey-0.4.34 pyocd-0.31.0 pyocd-pemicro-1.1.5 pypemicro-0.1.11 pyserial-3.5 pyspinel-1.0.3 python-dateutil-2.7.5 ruamel.yaml-0.17.21 ruamel.yaml.clib-0.2.7 sly-0.4 sortedcontainers-2.4.0 spsdk-1.7.1 termcolor-2.2.0 tlv8-0.10.0 tqdm-4.65.0 typing_extensions-4.3.0 urllib3-1.26.15 wrapt-1.15.0
jas@kaka:~$
Then upgrading the device worked remarkable well, although I wish that the tool would have printed URLs and checksums for the firmware files to allow easy confirmation.
jas@kaka:~$ PATH=$PATH:/home/jas/.local/bin
jas@kaka:~$ nitropy start list
Command line tool to interact with Nitrokey devices 0.4.34
:: 'Nitrokey Start' keys:
FSIJ-1.2.15-5D271572: Nitrokey Nitrokey Start (RTM.12.1-RC2-modified)
jas@kaka:~$ nitropy start update
Command line tool to interact with Nitrokey devices 0.4.34
Nitrokey Start firmware update tool
Platform: Linux-5.15.0-67-generic-x86_64-with-glibc2.35
System: Linux, is_linux: True
Python: 3.10.6
Saving run log to: /tmp/nitropy.log.gc5753a8
Admin PIN: 
Firmware data to be used:
- FirmwareType.REGNUAL: 4408, hash: ...b'72a30389' valid (from ...built/RTM.13/regnual.bin)
- FirmwareType.GNUK: 129024, hash: ...b'25a4289b' valid (from ...prebuilt/RTM.13/gnuk.bin)
Currently connected device strings:
Device: 
    Vendor: Nitrokey
   Product: Nitrokey Start
    Serial: FSIJ-1.2.15-5D271572
  Revision: RTM.12.1-RC2-modified
    Config: *:*:8e82
       Sys: 3.0
     Board: NITROKEY-START-G
initial device strings: [ 'name': '', 'Vendor': 'Nitrokey', 'Product': 'Nitrokey Start', 'Serial': 'FSIJ-1.2.15-5D271572', 'Revision': 'RTM.12.1-RC2-modified', 'Config': '*:*:8e82', 'Sys': '3.0', 'Board': 'NITROKEY-START-G' ]
Please note:
- Latest firmware available is: 
  RTM.13 (published: 2022-12-08T10:59:11Z)
- provided firmware: None
- all data will be removed from the device!
- do not interrupt update process - the device may not run properly!
- the process should not take more than 1 minute
Do you want to continue? [yes/no]: yes
...
Starting bootloader upload procedure
Device: Nitrokey Start FSIJ-1.2.15-5D271572
Connected to the device
Running update!
Do NOT remove the device from the USB slot, until further notice
Downloading flash upgrade program...
Executing flash upgrade...
Waiting for device to appear:
  Wait 20 seconds.....
Downloading the program
Protecting device
Finish flashing
Resetting device
Update procedure finished. Device could be removed from USB slot.
Currently connected device strings (after upgrade):
Device: 
    Vendor: Nitrokey
   Product: Nitrokey Start
    Serial: FSIJ-1.2.19-5D271572
  Revision: RTM.13
    Config: *:*:8e82
       Sys: 3.0
     Board: NITROKEY-START-G
device can now be safely removed from the USB slot
final device strings: [ 'name': '', 'Vendor': 'Nitrokey', 'Product': 'Nitrokey Start', 'Serial': 'FSIJ-1.2.19-5D271572', 'Revision': 'RTM.13', 'Config': '*:*:8e82', 'Sys': '3.0', 'Board': 'NITROKEY-START-G' ]
finishing session 2023-03-16 21:49:07.371291
Log saved to: /tmp/nitropy.log.gc5753a8
jas@kaka:~$ 
jas@kaka:~$ nitropy start list
Command line tool to interact with Nitrokey devices 0.4.34
:: 'Nitrokey Start' keys:
FSIJ-1.2.19-5D271572: Nitrokey Nitrokey Start (RTM.13)
jas@kaka:~$ 
Before importing the master key to this device, it should be configured. Note the commands in the beginning to make sure scdaemon/pcscd is not running because they may have cached state from earlier cards. Change PIN code as you like after this, my experience with Gnuk was that the Admin PIN had to be changed first, then you import the key, and then you change the PIN.
jas@kaka:~$ gpg-connect-agent "SCD KILLSCD" "SCD BYE" /bye
OK
ERR 67125247 Slut p  fil <GPG Agent>
jas@kaka:~$ ps auxww grep -e pcsc -e scd
jas        11651  0.0  0.0   3468  1672 pts/0    R+   21:54   0:00 grep --color=auto -e pcsc -e scd
jas@kaka:~$ gpg --card-edit
Reader ...........: 20A0:4211:FSIJ-1.2.19-5D271572:0
Application ID ...: D276000124010200FFFE5D2715720000
Application type .: OpenPGP
Version ..........: 2.0
Manufacturer .....: unmanaged S/N range
Serial number ....: 5D271572
Name of cardholder: [not set]
Language prefs ...: [not set]
Salutation .......: 
URL of public key : [not set]
Login data .......: [not set]
Signature PIN ....: forced
Key attributes ...: rsa2048 rsa2048 rsa2048
Max. PIN lengths .: 127 127 127
PIN retry counter : 3 3 3
Signature counter : 0
KDF setting ......: off
Signature key ....: [none]
Encryption key....: [none]
Authentication key: [none]
General key info..: [none]
gpg/card> admin
Admin commands are allowed
gpg/card> kdf-setup
gpg/card> passwd
gpg: OpenPGP card no. D276000124010200FFFE5D2715720000 detected
1 - change PIN
2 - unblock PIN
3 - change Admin PIN
4 - set the Reset Code
Q - quit
Your selection? 3
PIN changed.
1 - change PIN
2 - unblock PIN
3 - change Admin PIN
4 - set the Reset Code
Q - quit
Your selection? q
gpg/card> name
Cardholder's surname: Josefsson
Cardholder's given name: Simon
gpg/card> lang
Language preferences: sv
gpg/card> sex
Salutation (M = Mr., F = Ms., or space): m
gpg/card> login
Login data (account name): jas
gpg/card> url
URL to retrieve public key: https://josefsson.org/key-20190320.txt
gpg/card> forcesig
gpg/card> key-attr
Changing card key attribute for: Signature key
Please select what kind of key you want:
   (1) RSA
   (2) ECC
Your selection? 2
Please select which elliptic curve you want:
   (1) Curve 25519
   (4) NIST P-384
Your selection? 1
The card will now be re-configured to generate a key of type: ed25519
Note: There is no guarantee that the card supports the requested size.
      If the key generation does not succeed, please check the
      documentation of your card to see what sizes are allowed.
Changing card key attribute for: Encryption key
Please select what kind of key you want:
   (1) RSA
   (2) ECC
Your selection? 2
Please select which elliptic curve you want:
   (1) Curve 25519
   (4) NIST P-384
Your selection? 1
The card will now be re-configured to generate a key of type: cv25519
Changing card key attribute for: Authentication key
Please select what kind of key you want:
   (1) RSA
   (2) ECC
Your selection? 2
Please select which elliptic curve you want:
   (1) Curve 25519
   (4) NIST P-384
Your selection? 1
The card will now be re-configured to generate a key of type: ed25519
gpg/card> 
jas@kaka:~$ gpg --card-edit
Reader ...........: 20A0:4211:FSIJ-1.2.19-5D271572:0
Application ID ...: D276000124010200FFFE5D2715720000
Application type .: OpenPGP
Version ..........: 2.0
Manufacturer .....: unmanaged S/N range
Serial number ....: 5D271572
Name of cardholder: Simon Josefsson
Language prefs ...: sv
Salutation .......: Mr.
URL of public key : https://josefsson.org/key-20190320.txt
Login data .......: jas
Signature PIN ....: not forced
Key attributes ...: ed25519 cv25519 ed25519
Max. PIN lengths .: 127 127 127
PIN retry counter : 3 3 3
Signature counter : 0
KDF setting ......: on
Signature key ....: [none]
Encryption key....: [none]
Authentication key: [none]
General key info..: [none]
jas@kaka:~$ 
Once setup, bring out your offline machine and boot it and mount your USB stick with the offline key. The paths below will be different, and this is using a somewhat unorthodox approach of working with fresh GnuPG configuration paths that I chose for the USB stick.
jas@kaka:/media/jas/2c699cbd-b77e-4434-a0d6-0c4965864296$ cp -a gnupghome-backup-masterkey gnupghome-import-nitrokey-5D271572
jas@kaka:/media/jas/2c699cbd-b77e-4434-a0d6-0c4965864296$ gpg --homedir $PWD/gnupghome-import-nitrokey-5D271572 --edit-key B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
gpg (GnuPG) 2.2.27; Copyright (C) 2021 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Secret key is available.
sec  ed25519/D73CF638C53C06BE
     created: 2019-03-20  expired: 2019-10-22  usage: SC  
     trust: ultimate      validity: expired
[ expired] (1). Simon Josefsson <simon@josefsson.org>
gpg> keytocard
Really move the primary key? (y/N) y
Please select where to store the key:
   (1) Signature key
   (3) Authentication key
Your selection? 1
sec  ed25519/D73CF638C53C06BE
     created: 2019-03-20  expired: 2019-10-22  usage: SC  
     trust: ultimate      validity: expired
[ expired] (1). Simon Josefsson <simon@josefsson.org>
gpg> 
Save changes? (y/N) y
jas@kaka:/media/jas/2c699cbd-b77e-4434-a0d6-0c4965864296$ 
At this point it is useful to confirm that the Nitrokey has the master key available and that is possible to sign statements with it, back on your regular machine:
jas@kaka:~$ gpg --card-status
Reader ...........: 20A0:4211:FSIJ-1.2.19-5D271572:0
Application ID ...: D276000124010200FFFE5D2715720000
Application type .: OpenPGP
Version ..........: 2.0
Manufacturer .....: unmanaged S/N range
Serial number ....: 5D271572
Name of cardholder: Simon Josefsson
Language prefs ...: sv
Salutation .......: Mr.
URL of public key : https://josefsson.org/key-20190320.txt
Login data .......: jas
Signature PIN ....: not forced
Key attributes ...: ed25519 cv25519 ed25519
Max. PIN lengths .: 127 127 127
PIN retry counter : 3 3 3
Signature counter : 1
KDF setting ......: on
Signature key ....: B1D2 BD13 75BE CB78 4CF4  F8C4 D73C F638 C53C 06BE
      created ....: 2019-03-20 23:37:24
Encryption key....: [none]
Authentication key: [none]
General key info..: pub  ed25519/D73CF638C53C06BE 2019-03-20 Simon Josefsson <simon@josefsson.org>
sec>  ed25519/D73CF638C53C06BE  created: 2019-03-20  expires: 2023-09-19
                                card-no: FFFE 5D271572
ssb>  ed25519/80260EE8A9B92B2B  created: 2019-03-20  expires: 2023-09-19
                                card-no: FFFE 42315277
ssb>  ed25519/51722B08FE4745A2  created: 2019-03-20  expires: 2023-09-19
                                card-no: FFFE 42315277
ssb>  cv25519/02923D7EE76EBD60  created: 2019-03-20  expires: 2023-09-19
                                card-no: FFFE 42315277
jas@kaka:~$ echo foo gpg -a --sign gpg --verify
gpg: Signature made Thu Mar 16 22:11:02 2023 CET
gpg:                using EDDSA key B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
gpg: Good signature from "Simon Josefsson <simon@josefsson.org>" [ultimate]
jas@kaka:~$ 
Finally to retrieve and sign a key, for example Andre Heinecke s that I could confirm the OpenPGP key identifier from his business card.
jas@kaka:~$ gpg --locate-external-keys aheinecke@gnupg.com
gpg: key 1FDF723CF462B6B1: public key "Andre Heinecke <aheinecke@gnupg.com>" imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   2  signed:   7  trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1  valid:   7  signed:  64  trust: 7-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2023-05-26
pub   rsa3072 2015-12-08 [SC] [expires: 2025-12-05]
      94A5C9A03C2FE5CA3B095D8E1FDF723CF462B6B1
uid           [ unknown] Andre Heinecke <aheinecke@gnupg.com>
sub   ed25519 2017-02-13 [S]
sub   ed25519 2017-02-13 [A]
sub   rsa3072 2015-12-08 [E] [expires: 2025-12-05]
sub   rsa3072 2015-12-08 [A] [expires: 2025-12-05]
jas@kaka:~$ gpg --edit-key "94A5C9A03C2FE5CA3B095D8E1FDF723CF462B6B1"
gpg (GnuPG) 2.2.27; Copyright (C) 2021 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
pub  rsa3072/1FDF723CF462B6B1
     created: 2015-12-08  expires: 2025-12-05  usage: SC  
     trust: unknown       validity: unknown
sub  ed25519/2978E9D40CBABA5C
     created: 2017-02-13  expires: never       usage: S   
sub  ed25519/DC74D901C8E2DD47
     created: 2017-02-13  expires: never       usage: A   
The following key was revoked on 2017-02-23 by RSA key 1FDF723CF462B6B1 Andre Heinecke <aheinecke@gnupg.com>
sub  cv25519/1FFE3151683260AB
     created: 2017-02-13  revoked: 2017-02-23  usage: E   
sub  rsa3072/8CC999BDAA45C71F
     created: 2015-12-08  expires: 2025-12-05  usage: E   
sub  rsa3072/6304A4B539CE444A
     created: 2015-12-08  expires: 2025-12-05  usage: A   
[ unknown] (1). Andre Heinecke <aheinecke@gnupg.com>
gpg> sign
pub  rsa3072/1FDF723CF462B6B1
     created: 2015-12-08  expires: 2025-12-05  usage: SC  
     trust: unknown       validity: unknown
 Primary key fingerprint: 94A5 C9A0 3C2F E5CA 3B09  5D8E 1FDF 723C F462 B6B1
     Andre Heinecke <aheinecke@gnupg.com>
This key is due to expire on 2025-12-05.
Are you sure that you want to sign this key with your
key "Simon Josefsson <simon@josefsson.org>" (D73CF638C53C06BE)
Really sign? (y/N) y
gpg> quit
Save changes? (y/N) y
jas@kaka:~$ 
This is on my day-to-day machine, using the NitroKey Start with the offline key. No need to boot the old offline machine just to sign keys or extend expiry anymore! At FOSDEM 23 I managed to get at least one DD signature on my new key, and the Debian keyring maintainers accepted my Ed25519 key. Hopefully I can now finally let my 2014-era RSA3744 key expire in 2023-09-19 and not extend it any further. This should finish my transition to a simpler OpenPGP key setup, yay!

Jonathan Dowland: Imaging Optical Media, Part 3: Figuring out disc contents

Too many years ago, I started (but did not finish) a series of blog posts on the topic of Imaging Optical Media. I was writing it as I was figuring out the process to use whilst importing my own piles of home-made CD-Rs and DVD-Rs to a more suitable storage. Back in 2018 Antoine Beaupr blogged about being inspired by my article series to sort out his optical media collection, and wrote up his notes so far. This inspired me (in 2018!) to change the approach for writing up what I'd been doing. Instead of a series of blog posts, I've dumped all the material I have written in one place: imaging discs. I've also reduced the scope somewhat, deciding that "Organising the extracted files" is a large enough (and orthogonal) topic to deserve its own page (if I ever write anything about it). The "new" material is really two unfinished blog posts: ?figuring out disc contents and ?Retrying damaged/degraded discs. I post them now in the hope that they are useful despite being unfinished.

26 March 2023

Emanuele Rocca: EFI and Secure Boot Notes

To create a bootable EFI drive to use with QEMU, first make a disk image and create a vfat filesystem on it.
$ dd if=/dev/zero of=boot.img bs=1M count=512
$ sudo mkfs.vfat boot.img
By default, EFI firmwares boot a specific file under /efi/boot/. The name of such file depends on the architecture: for example, on 64 bit x86 systems it is bootx64.efi, while on ARM it is bootaa64.efi.
Copy /usr/lib/grub/x86_64-efi/monolithic/grubx64.efi from package grub-efi-amd64-bin to /efi/boot/bootx64.efi on the boot image, and that should be enough to start GRUB.
# mount boot.img /mnt/
# mkdir -p /mnt/efi/boot/
# cp /usr/lib/grub/x86_64-efi/monolithic/grubx64.efi /mnt/efi/boot/bootx64.efi
# umount /mnt/
Now get the x86 firmware from package ovmf and start qemu:
$ cp /usr/share/OVMF/OVMF_CODE.fd /tmp/code.fd
$ qemu-system-x86_64 -drive file=/tmp/code.fd,format=raw,if=pflash -cdrom boot.img
GRUB looks fine, but it would be good to have a kernel to boot. Let s add one to boot.img.
# mount boot.img /mnt
# cp vmlinuz-6.1.0-7-amd64 /mnt/vmlinuz
# umount /mnt/
Boot with qemu again, but this time pass -m 1G. The default amount of memory is not enough to boot.
$ qemu-system-x86_64 -drive file=/tmp/code.fd,format=raw,if=pflash -cdrom boot.img -m 1G
At the grub prompt, type the following to boot:
grub> linux /vmlinuz
grub> boot
The kernel will start and reach the point of trying to mount the root fs. This is great but it would now be useful to have some sort of shell access in order to look around. Let s add an initrd!
# mount boot.img /mnt
# cp initrd.img-6.1.0-7-amd64 /mnt/initrd
# umount /mnt/
There s the option of starting qemu in console, let s try that out. Start qemu with -nographic, and append console=ttyS0 to the kernel command line arguments.
$ qemu-system-x86_64 -drive file=/tmp/code.fd,format=raw,if=pflash -cdrom boot.img -m 1G -nographic
grub> linux /vmlinuz console=ttyS0
grub> initrd /initrd
grub> boot
If all went well we are now in the initramfs shell. We can now run commands! At this point we can see that the system has Secure boot disabled:
(initramfs) dmesg   grep secureboot
[    0.000000] secureboot: Secure boot disabled
In order to boot with Secure boot, we need:
  • a signed shim, grub, and kernel
  • the right EFI variables for Secure boot
The package shim-signed provides a shim signed with Microsoft s key, while grub-efi-amd64-signed has GRUB signed with Debian s key.
The signatures can be shown with sbverify --list:
$ sbverify --list /usr/lib/shim/shimx64.efi.signed
warning: data remaining[823184 vs 948768]: gaps between PE/COFF sections?
signature 1
image signature issuers:
 - /C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/CN=Microsoft Corporation UEFI CA 2011
image signature certificates:
 - subject: /C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/CN=Microsoft Windows UEFI Driver Publisher
   issuer:  /C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/CN=Microsoft Corporation UEFI CA 2011
 - subject: /C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/CN=Microsoft Corporation UEFI CA 2011
   issuer:  /C=US/ST=Washington/L=Redmond/O=Microsoft Corporation/CN=Microsoft Corporation Third Party Marketplace Root
Similarly for GRUB and the kernel:
$ sbverify --list /usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed
signature 1
image signature issuers:
 - /CN=Debian Secure Boot CA
image signature certificates:
 - subject: /CN=Debian Secure Boot Signer 2022 - grub2
   issuer:  /CN=Debian Secure Boot CA
$ sbverify --list /mnt/vmlinuz
signature 1
image signature issuers:
 - /CN=Debian Secure Boot CA
image signature certificates:
 - subject: /CN=Debian Secure Boot Signer 2022 - linux
   issuer:  /CN=Debian Secure Boot CA
Let s use the signed shim and grub in the boot image:
# mount boot.img /mnt
# cp /usr/lib/shim/shimx64.efi.signed /mnt/efi/boot/bootx64.efi
# cp /usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed /mnt/efi/boot/grubx64.efi
# umount /mnt
And start QEMU with the appropriate EFI variables for Secure boot:
$ cp /usr/share/OVMF/OVMF_VARS.ms.fd /tmp/vars.fd
$ qemu-system-x86_64 -drive file=/tmp/code.fd,format=raw,if=pflash -drive file=/tmp/vars.fd,format=raw,if=pflash -cdrom boot.img -m 1G -nographic
We can double-check in the firmware settings if Secure boot is indeed enabled. At the GRUB prompt, type fwsetup:
grub> fwsetup
Check under "Device Manager" "Secure Boot Configuration" that "Attempt Secure Boot" is selected, then boot from GRUB as before. If all went well, the kernel should confirm that we have booted with Secure boot:
(initramfs) dmesg   grep secureboot
[    0.000000] secureboot: Secure boot enabled

25 March 2023

Gunnar Wolf: Four days to fix a simple configuration bug

Phew! Today, after four days of combing through code I am unfamiliar with, I was finally able to change my expression. I m finally at the part of my PhD work where I am tasked with implementing the protocol I claim improves from the current situation. I wrote a script to deploy the infrastructure I need for the experiment, and was not expecting any issues I am not (yet) familiar with the Go language (in which the Hockeypuck key server is developed), but I have managed to install it several times, and it holds no terrible surprises anymore for me. Or so I think. So, how come it s possible the five servers in my laboratory network don t gossip to each other? The logs don t show anything clear Only a sucession of this:
hockeypuck[5295]: time="2023-03-24T00:00:28-06:00" level=error msg="recon with :0 failed" error="[ /srv/hockeypuck/packaging/src/gopkg.in/hockeypuck/conflux.v2/recon/gossip.go:109:    dial tcp :0: connect: connection refused ]" label="gossip :11370"
hockeypuck[5295]: time="2023-03-24T00:00:28-06:00" level=info msg="waiting 27s for next gossip attempt" label="gossip :11370"
And while tcp :0: connect: connection refused sounds fishy It took me too long to find the reasons. But, at least, along the way I decided to find my errors by debugging the code, rather than by rebuilding the laboratory and random-stabbing at the configuration. And yes, finally I came to my senses, and found out my silly mistake was to have my configuration read:
[hockeypuck.conflux.recon.partner.10.0.3.13]
httpAddr="10.0.3.13:11371"
reconAddr="10.0.3.13:11370"
where it should have read:
[hockeypuck.conflux.recon.partner.10-0-3-13]
httpAddr="10.0.3.13:11371"
reconAddr="10.0.3.13:11370"
Because, of course, TOML would find no child declarations for hockeypuck.conflux.recon.partner.10 (as the following period makes the rest of the entry an entirely distinct one from what I thought I specified). Anyway, this made me at least: Now Why am I posting this? Not only because I feel very happy and wanted to share my a-ha moment, but also because I m sure this time that seems that I mindlessly spent poking at Go without knowing the basics will be somehow rewarded I have to learn bits of the language anyway, so it s time well spent. Or so I hope. (oh, and the funny spectacles? I am not sure, but I believe them to have been property of my grandfather or great-grandfather when they came from Europe, in 1947 or in 1928 respectively. One glasspiece is sadly lost, but other than that, I love them!)

Gunnar Wolf: Now that we are talking about kernel building... What about firebuild?

After my last post, B lint (who prompted it with his last post) suggested I should do a hybrid test of his tests and my extremes. He suggested I should build the Linux kernel using my Raspberry Pi 4 (8GB model), but using the Firebuild build accelerator. Before going any further: I must make clear that while Firebuild is freely redistributable, it is not made available under a free license. It is free for personal use or commercial trial, but otherwise requires licensing. B lint managed to build a Linux kernel in just over 8 seconds. So, how did my test go? My previous experiment, using -j 4, built Linux in ~100 minutes; this was about a year ago, and I m now building linux 6.1, so I timed this again. To get a baseline, I built my kernel from a just-unpacked tree, just as usual:
# cd /usr/src/linux-source-6.1
# make clean
# make defconfig
# time make -j4
(...)
real    117m30.588s
user    392m41.434s
sys     52m2.556s
Of course, having all of the object files built makes the rebuild process quite faster (this is still done without firebuild). I understand calling make defconfig without cleaning does not change much, but I saw it often referenced in firebuild s docs, so I m leaving it:
# time make -j 4
(...)
real    0m43.822s
user    1m36.577s
sys     0m40.805s
Then, I did a first run using firebuild. Firebuild is a caching build optimizer, so the first run will naturally be somewhat slower (but if you often rebuild your kernel, it should be seen as an investment). Now, in the Raspberry Pi, that uses a slow SD card interface for its storage It is a heavy investment. The first time I built with firebuild, it meant almost a 100% build time hit:
# cd /usr/src/linux-source-6.1
# make clean
# make defconfig
# time firebuild make -j 4
(...)
real    212m58.647s
user    391m49.080s
sys     81m10.758s
Not only that; I am using a fairly decent and big 32GB card, but this is quite a big price to pay in such a limited system!
# du -sh .cache/firebuild/
4.2G    .cache/firebuild/
I did a build without cleaning the build directory, using firebuild, and it does help although not by so much as in higher performance systems:
# cd /usr/src/linux-source-6.1
# make clean
# make defconfig
# time firebuild make -j 4
(...)
real    68m6.621s
user    98m32.514s
sys     31m41.643s
So, it built in roughly 65% of the time it would take to build regularly. And what about rebuilding without cleaning?
# make defconfig
# time firebuild make -j 4
(...)
real    1m11.872s
user    2m5.807s
sys     1m46.178s
In this case, using firebuild worked roughly 30% slower than not using it. I guess the high number of file ops inside .cache/firebuild are to blame, as in the case of the media I m using, those are quite expensive; make went its way basically checking date stamps between *.c and *.o (yes, very roughly), and while running under firebuild, I suppose each of these meant an extra lookup inside the cache. So Experiment requested, experiment performed!

Russ Allbery: Review: Thief of Time

Review: Thief of Time, by Terry Pratchett
Series: Discworld #26
Publisher: Harper
Copyright: May 2001
Printing: August 2014
ISBN: 0-06-230739-8
Format: Mass market
Pages: 420
Thief of Time is the 26th Discworld novel and the last Death novel, although he still appears in subsequent books. It's the third book starring Susan Sto Helit, so I don't recommend starting here. Mort is the best starting point for the Death subseries, and Reaper Man provides a useful introduction to the villains. Jeremy Clockson was an orphan raised by the Guild of Clockmakers. He is very good at making clocks. He's not very good at anything else, particularly people, but his clocks are the most accurate in Ankh-Morpork. He is therefore the logical choice to receive a commission by a mysterious noblewoman who wants him to make the most accurate possible clock: a clock that can measure the tick of the universe, one that a fairy tale says had been nearly made before. The commission is followed by a surprise delivery of an Igor, to help with the clock-making. People who live in places with lots of fields become farmers. People who live where there is lots of iron and coal become blacksmiths. And people who live in the mountains near the Hub, near the gods and full of magic, become monks. In the highest valley are the History Monks, founded by Wen the Eternally Surprised. Like most monks, they take apprentices with certain talents and train them in their discipline. But Lobsang Ludd, an orphan discovered in the Thieves Guild in Ankh-Morpork, is proving a challenge. The monks decide to apprentice him to Lu-Tze the sweeper; perhaps that will solve multiple problems at once. Since Hogfather, Susan has moved from being a governess to a schoolteacher. She brings to that job the same firm patience, total disregard for rules that apply to other people, and impressive talent for managing children. She is by far the most popular teacher among the kids, and not only because she transports her class all over the Disc so that they can see things in person. It is a job that she likes and understands, and one that she's quite irate to have interrupted by a summons from her grandfather. But the Auditors are up to something, and Susan may be able to act in ways that Death cannot. This was great. Susan has quickly become one of my favorite Discworld characters, and this time around there is no (or, well, not much) unbelievable romance or permanently queasy god to distract. The clock-making portions of the book quickly start to focus on Igor, who is a delightful perspective through whom to watch events unfold. And the History Monks! The metaphysics of what they are actually doing (which I won't spoil, since discovering it slowly is a delight) is perhaps my favorite bit of Discworld world building to date. I am a sucker for stories that focus on some process that everyone thinks happens automatically and investigate the hidden work behind it. I do want to add a caveat here that the monks are in part a parody of Himalayan Buddhist monasteries, Lu-Tze is rather obviously a parody of Laozi and Daoism in general, and Pratchett's parodies of non-western cultures are rather ham-handed. This is not quite the insulting mess that the Chinese parody in Interesting Times was, but it's heavy on the stereotypes. It does not, thankfully, rely on the stereotypes; the characters are great fun on their own terms, with the perfect (for me) balance of irreverence and thoughtfulness. Lu-Tze refusing to be anything other than a sweeper and being irritatingly casual about all the rules of the order is a classic bit that Pratchett does very well. But I also have the luxury of ignoring stereotypes of a culture that isn't mine, and I think Pratchett is on somewhat thin ice. As one specific example, having Lu-Tze's treasured sayings be a collection of banal aphorisms from a random Ankh-Morpork woman is both hilarious and also arguably rather condescending, and I'm not sure where I landed. It's a spot-on bit of parody of how a lot of people who get very into "eastern religions" sound, but it's also equating the Dao De Jing with advice from the Discworld equivalent of a English housewife. I think the generous reading is that Lu-Tze made the homilies profound by looking at them in an entirely different way than the woman saying them, and that's not completely unlike Daoism and works surprisingly well. But that's reading somewhat against the grain; Pratchett is clearly making fun of philosophical koans, and while anything is fair game for some friendly poking, it still feels a bit weird. That isn't the part of the History Monks that I loved, though. Their actual role in the story doesn't come out of the parody. It's something entirely native to Discworld, and it's an absolute delight. The scene with Lobsang and the procrastinators is perhaps my favorite Discworld set piece to date. Everything about the technology of the History Monks, even the Bond parody, is so good. I grew up reading the Marvel Comics universe, and Thief of Time reminds me of a classic John Byrne or Jim Starlin story, where the heroes are dumped into the middle of vast interdimensional conflicts involving barely-anthropomorphized cosmic powers and the universe is revealed to work in ever more intricate ways at vastly expanding scales. The Auditors are villains in exactly that tradition, and just like the best of those stories, the fulcrum of the plot is questions about what it means to be human, what it means to be alive, and the surprising alliances these non-human powers make with humans or semi-humans. I devoured this kind of story as a kid, and it turns out I still love it. The one complaint I have about the plot is that the best part of this book is the middle, and the end didn't entirely work for me. Ronnie Soak is at his best as a supporting character about three quarters of the way through the book, and I found the ending of his subplot much less interesting. The cosmic confrontation was oddly disappointing, and there's a whole extended sequence involving chocolate that I think was funnier in Pratchett's head than it was in mine. The ending isn't bad, but the middle of this book is my favorite bit of Discworld writing yet, and I wish the story had carried that momentum through to the end. I had so much fun with this book. The Discworld novels are clearly getting better. None of them have yet vaulted into the ranks of my all-time favorite books there's always some lingering quibble or sagging bit but it feels like they've gone from reliably good books to more reliably great books. The acid test is coming, though: the next book is a Rincewind book, which are usually the weak spots. Followed by The Last Hero in publication order. There is no direct thematic sequel. Rating: 8 out of 10

22 March 2023

Bits from Debian: New Debian Developers and Maintainers (January and February 2023)

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!

Russ Allbery: Review: The Kaiju Preservation Society

Review: The Kaiju Preservation Society, by John Scalzi
Publisher: Tor
Copyright: 2022
ISBN: 0-7653-8913-4
Format: Kindle
Pages: 264
As this novel opens, Jamie Gray, our first-person narrator, is working for the business side of a startup food delivery service named f dm d. He's up for his six month performance review and has some great ideas for how to improve the company's market standing going into pandemic lockdown. His boss has other ideas: Jamie at the bottom of the corporate ladder, delivering food door-to-door. Tom is working for a semi-secret organization with a last-minute, COVID-induced worker shortage. He needs someone who can lift things. Jamie used to go to some of the same parties, can lift things, and is conveniently available. And that's how Jamie ends up joining the Kaiju Preservation Society, because it turns out the things that need lifting are in a different dimension. This book was so bad. I think this may be the worst-written novel at a technical level that I have read since I started writing book reviews. It's become trendy in some circles to hate Scalzi, so I want to be clear that I normally get along fine with his writing. Scalzi is an unabashedly commercial writer of light, occasionally humorous popcorn SF. It's not great literature, and he's unlikely to write a new favorite novel, but his books are easy to read and reliably deliver a few hours of comfortable entertainment. The key word is "reliably"; Scalzi doesn't have a lot of dynamic range, but you know what you're getting and can decide to read him when that matches your mood. When I give a book a bad review, it's usually because I found the ideas deeply unpleasant (genocidal theology, for instance, or creepy voyeuristic sexism). That's not the problem here. The ideas are fine: a variation on the Jurassic Park setup but with kaiju and less commercialism, an everyman narrator to look at everything for the reader, a few assholes thrown in to provide some conflict sure, sign me up, sounds like the kind of light entertainment I expect from a Scalzi novel. The excuse for interdimensional portals was clever (and consistent with kaiju story themes), and the biological handwaving created a lot of good story hooks. The material for a fun novel is all present. The problem, instead, is that this book was not finished. It's the bare skeleton of a story with almost-nonexistent characters and plot, stuck in a novel-shaped box and filled in with repetitive banter and dad jokes of the approximate consistency of styrofoam packing material. When I complain about the characterization, I fear people who haven't read the book won't understand what I mean. He's always had dialogue quirks that tend to show up in all of his characters and make them sound similar. I noticed this in other books, but it wasn't a big deal. The characterization problems in this book are a big deal. I can identify four characters, total, from the entire novel: the first-person protagonist, the villain, the pilot, and the woman who does the forest floor safety training. None of those characters are memorable or interesting, but at least they're somewhat distinct. Apart from them, you could write a computer program that randomly selected character names for each dialogue line and I wouldn't be able to tell the difference. I have never given up on character identity and started ignoring all the dialogue tags in a book before. Everyone says the same thing, makes the same jokes, has the same emotional reactions, and has the same total lack of interiority or distinguishing characteristics. The only way I can imagine telling the characters apart is if you memorized the association between names and professions, and I have no idea why you'd bother. The descriptions are, if anything, worse. Scalzi is not a heavily descriptive author, but usually he gives me something to hang my imagination on. You would think that if you were writing a book about kaiju one where kaiju are quite actively involved in the story, fighting, roaring, menacing, being central to the plot you would describe a kaiju at some point during the novel. They're visually impressive giant monsters! This is an inherently visual story genre! And at no point in this entire novel does Scalzi ever describe a kaiju in any detail. Not once! The most we get is that one has tentacles and a sort of eye spot. And sometimes there are wings. There are absolutely no overall impressions, comparisons, attempts to sketch what the characters are seeing, nothing. Or, for another example, consider the base, the place where the characters live for most of the story and where much of the dialogue happens. Here is the sum total of all sensory information I can recall about the characters' home: it has stairs, and there's a plant in Jamie's room. (The person who left the plant, who never appears on screen, gets more characterization in two pages than anyone else gets in the whole novel.) What does the base look like from the outside? The inside? How many stories does it have? What are the common spaces like? What does it smell like? Does it feel institutional, or welcoming, or dirty, or sparkling? How long does it take to get from one end of it to the other? Does it make weird noises at night? I have no impressions of this place whatsoever. Maybe a few of these things were mentioned in passing and I missed them, but that's because the narrator of this book never describes his surroundings in detail, stops to look at something eye-catching, thinks about how he feels about a place, or otherwise gives the reader any meaningful emotional engagement with the spaces around him. And it's not like this story was instead stuffed with action. There is barely a novelette's worth of plot and most of that is predictable: the setup, the initial confrontation, the discovery of the evil plan, the final confrontation. For most of the book, nothing of any consequence happens. It's just endless pages of vaguely bantering dialogue between totally indistinguishable characters while Jamie repeats "I lift things." (That was funny the first couple of times; by the fifth time, the funny wore off.) The climax, when it finally happens, is mostly monologuing and half-hearted repartee that is cringeworthy and vaguely embarrassing for everyone involved. I don't really blame Scalzi for this book. I wish he had realized that it was half-baked at best and needed some major revisions, but the author's note at the end makes it clear that the process of bringing this book into the world was a train wreck. It was written in two months, in a rush, after Scalzi had already missed a deadline for a different book that failed to come together. Life happens, and in 2020 and early 2021 a whole lot of life was happening. The tone of the author's note is vaguely apologetic; I think Scalzi realizes at some level that this is not his best work. The person I do blame is Patrick Nielsen Hayden, Scalzi's editor, who is a multiple-Hugo-award-winning book editor and the managing editor of science fiction at Tor and absolutely should have known better. It was his responsibility to look at this book and say "this is not ready yet"; this is part of the function of the traditional publishing apparatus. This could have been a good book. The ideas and the hook were there; it just needed some actual substance in the middle and a whole lot of character work. Instead, he was the one who made the decision to publish the book in this state. But, well, the joke's on me, because The Kaiju Preservation Society sold a ton of copies, got nominated for several awards, won an Alex Award, and made Amazon's best of 2022 list, so I guess this was a brilliant publishing decision and the book was everything it needed to be? Maybe I'm just bad at reading and have no sense of humor? I have no explanation; I am truly and completely baffled. There are books that I don't like but that have obvious merits for people who are not me. There are styles of writing that I don't like and other people do. But I would have sworn this book was objectively unfinished and half-assed at a craft and construction level, in ways that don't depend as much on personal taste. I recommend quietly forgetting it was ever published and waiting for a better Scalzi novel, but it has a 4.04 star rating on Goodreads with nearly 32,000 reviews, so what do I know. Anyway, I was warned that I wasn't going to like this book and I read it anyway for silly reasons because I figured it was a Scalzi novel and how bad could it be, really. I brought this on myself, and I at least got the fun of ranting about it. Apparently this book found its people and they got a lot of joy out of it, and good for them. Rating: 2 out of 10

21 March 2023

B lint R czey: Building the Linux kernel in under 10 seconds with Firebuild

Russell published an interesting post about his first experience with Firebuild accelerating refpolicy s and the Linux kernel s build. It turned out a few small tweaks could accelerate the builds even more, crossing the 10 second barrier with Linux s build.
Build performance with 18 cores The Linux kernel s build time is a widely used benchmark for compilers, making it a prime candidate to test a build accelerator as well. In the first run on Russell s 18 core test system the observed user+sys CPU time was cut by 44% with an actual increase in wall clock time which was quite unusual. Firebuild performed much better than that in prior tests. To replicate the results I ve set up a clean Debian Bookworm VM on my machine:
lxc launch images:debian/bookworm  vm -c limits.cpu=18 -c limits.memory=16GB bookworm-vm
Compiling Linux 6.1.10 in this clean Debian VM showed build times closer to what I expected to see, ~72% less wall clock time and ~97% less user+sys CPU time:
$ make defconfig && time make bzImage -j18
real	1m31.157s
user	20m54.256s
sys	2m25.986s
$ make defconfig && time firebuild make bzImage -j18
# first run:
real	2m3.948s
user	21m28.845s
sys	4m16.526s
# second run
real	0m25.783s
user	0m56.618s
sys	0m21.622s
There are multiple differences between Russell s and my test system including having different CPUs (E5-2696v3 vs. virtualized Ryzen 5900X) and different file systems (BTRFS RAID-1 vs ext4), but I don t think those could explain the observed mismatch in performance. The difference may be worth further analysis, but let s get back to squeezing out more performance from Firebuild. Firebuild was developed on Ubuntu. I was wondering if Firebuild was faster there, but I got only slightly better build times in an identical VM running Ubuntu 22.10 (Kinetic Kudu):
$ make defconfig && time make bzImage -j18
real	1m31.130s
user	20m52.930s
sys	2m12.294s
$ make defconfig && time firebuild make bzImage -j18
# first run:
real	2m3.274s
user	21m18.810s
sys	3m45.351s
# second run
real	0m25.532s
user	0m53.087s
sys	0m18.578s
The KVM virtualization certainly introduces an overhead, thus builds must be faster in LXC containers. Indeed, all builds are faster by a few percents:
$ lxc launch ubuntu:kinetic kinetic-container
...
$ make defconfig && time make bzImage -j18
real	1m27.462s
user	20m25.190s
sys	2m13.014s
$ make defconfig && time firebuild make bzImage -j18
# first run:
real	1m53.253s
user	21m42.730s
sys	3m41.067s
# second run
real	0m24.702s
user	0m49.120s
sys	0m16.840s
# Cache size:    1.85 GB
Apparently this ~72% reduction in wall clock time is what one should expect by simply prefixing the build command with firebuild on a similar configuration, but we should not stop here. Firebuild does not accelerate quicker commands by default to save cache space. This howto suggests letting firebuild accelerate all commands including even "sh by passing "-o 'processes.skip_cache = []' to firebuild.
Accelerating all commands in this build s case increases cache size by only 9%, and increases the wall clock time saving to 91%, not only making the build more than 10X faster, but finishing it in less than 8 seconds, which may be a new world record!:
$ make defconfig && time firebuild -o 'processes.skip_cache = []' make bzImage -j18
# first run:
real	1m54.937s
user	21m35.988s
sys	3m42.335s
# second run
real	0m7.861s
user	0m15.332s
sys	0m7.707s
# Cache size:    2.02 GB
There are even faster CPUs on the market than this 5900X. If you happen to have access to one please leave a comment if you could go below 5 seconds! Scaling to higher core counts and comparison with ccache Russell raised the very valid point about Firebuild s single threaded supervisor being a bottleneck on high core systems and comparison to ccache also came up in comments. Since ccache does not have a central supervisor it could scale better with more cores, but let s see if ccache could go below 10 seconds with the build times
firebuild -o processes.skip_cache = [] and ccache scaling to 24 cores
Well, no. The best time time for ccache is 18.81s, with -j24. Both firebuild and ccache keep gaining from extra cores up to 8 cores, but beyond that the wall clock time improvements diminish. The more interesting difference is that firebuild s user and sys time is basically constant from -j1 to -j24 similarly to ccache s user time, but ccache s sys time increases linearly or exponentially with the number of used cores. I suspect this is due to the many parallel ccache processes performing file operations to check if cache entries could be reused, while in firebuild s case the supervisor performs most of that work not requiring in-kernel synchronization across multiple cores. It is true, that the single threaded firebuild supervisor is a bottleneck, but the supervisor also implements a central filesystem cache, thus checking if a command s cache entry can be reused can be implemented with much fewer system calls and much less user space hashing making the architecture more efficient overall than ccache s. The beauty of Firebuild is not being faster than ccache, but being faster than ccache with basically no hard-coded information about how C compilers work. It can accelerate any other compiler or program that generates deterministic output from its input, just by observing what they did in their prior runs. It is like having ccache for every compiler including in-house developed ones, and also for random slow scripts.

20 March 2023

Russ Allbery: Review: The Star Fraction

Review: The Star Fraction, by Ken MacLeod
Series: Fall Revolution #1
Publisher: Orbit
Copyright: 1995
Printing: 2001
ISBN: 1-85723-833-8
Format: Trade paperback
Pages: 341
Ken MacLeod is a Scottish science fiction writer who has become amusingly famous for repeatedly winning the libertarian Prometheus Award despite being a (somewhat libertarian-leaning) socialist. The Star Fraction is the first of a loose series of four novels about future solar system politics and was nominated for the Clarke Award (as well as winning the Prometheus). It was MacLeod's first novel. Moh Kohn is a mercenary, part of the Felix Dzerzhinsky Workers' Defence collective. They're available for hire to protect research labs and universities against raids from people such as animal liberationists and anti-AI extremists (or, as Moh calls them, creeps and cranks). As The Star Fraction opens, he and his smart gun are protecting a lab against an attack. Janis Taine is a biologist who is currently testing a memory-enhancing drug on mice. It's her lab that is attacked, although it isn't vandalized the way she expected. Instead, the attackers ruined her experiment by releasing the test drug into the air, contaminating all of the controls. This sets off a sequence of events that results in Moh, Janis, and Jordon Brown, a stock trader for a religious theocracy, on the run from the US/UN and Space Defense. I had forgotten what it was like to read the uncompromising old-school style of science fiction novel that throws you into the world and explains nothing, leaving it to the reader to piece the world together as you go. It's weirdly fun, but I'm either out of practice or this was a particularly challenging example of the genre. MacLeod throws a lot of characters at you quickly, including some that have long and complicated personal histories, and it's not until well into the book that the pieces start to cohere into a narrative. Even once that happens, the relationship between the characters and the plot is unobvious until late in the book, and comes from a surprising direction. Science fiction as a genre is weirdly conservative about political systems. Despite the grand, futuristic ideas and the speculation about strange alien societies, the human governments rarely rise to the sophistication of a modern democracy. There are a lot of empires, oligarchies, and hand-waved libertarian semi-utopias, but not a lot of deep engagement with the speculative variety of government systems humans have proposed. The rare exceptions therefore get a lot of attention from those of us who find political systems fascinating. MacLeod has a reputation for writing political SF in that sense, and The Star Fraction certainly delivers. Moh (despite the name of his collective, which is explained briefly in the book) is a Trotskyist with a family history with the Fourth International that is central to the plot. The setting is a politically fractured Britain full of autonomous zones with wildly different forms of government, theoretically ruled by a restored monarchy. That monarchy is opposed by the Army of the New Republic, which claims to be the legitimate government of the United Kingdom and is considered by everyone else to be terrorists. Hovering in the background is a UN entirely subsumed by the US, playing global policeman over a chaotic world shattered by numerous small-scale wars. This satisfyingly different political world is a major plus for me. The main drawback is that I found the world-building and politics more interesting than the characters. It's not that I disliked them; I found them enjoyably quirky and odd. It's more that so much is happening and there are so many significant characters, all set in an unfamiliar and unexplained world and often divided into short scenes of a few pages, that I had a hard time keeping track of them all. Part of the point of The Star Fraction is digging into their tangled past and connecting it up with the present, but the flashbacks added a confused timeline on top of the other complexity and made it hard for me to get lost in the story. The characters felt a bit too much like puzzle pieces until the very end of the book. The technology is an odd mix with a very 1990s feel. MacLeod is one of the SF authors who can make computers and viruses believable, avoiding the cyberpunk traps, but AI becomes relevant to the plot and the conception of AI here feels oddly retro. (Not MacLeod's fault; it's been nearly 30 years and a lot has changed.) On-line discussion in the book is still based on newsgroups, which added to the nostalgic feel. I did like the eventual explanation for the computing part of the plot, though; I can't say much while avoiding spoilers, but it's one of the more believable explanations for how a technology could spread in a way required for the plot that I've read. I've been planning on reading this series for years but never got around to it. I enjoyed my last try at a MacLeod series well enough to want to keep reading, but not well enough to keep reading immediately, and then other books happened and now it's been 19 years. I feel similarly about The Star Fraction: it's good enough (and in a rare enough subgenre of SF) that I want to keep reading, but not enough to keep reading immediately. We'll see if I manage to get to the next book in a reasonable length of time. Followed by The Stone Canal. Rating: 6 out of 10

Next.

Previous.