My effort to improve transparency and confidence of public apt archives continues. I started to work on this in Apt Archive Transparency in which I mention the debdistget project in passing. Debdistget is responsible for mirroring index files for some public apt archives. I ve realized that having a publicly auditable and preserved mirror of the apt repositories is central to being able to do apt transparency work, so the debdistget project has become more central to my project than I thought. Currently I track Trisquel, PureOS, Gnuinos and their upstreams Ubuntu, Debian and Devuan. Debdistget download Release/Package/Sources files and store them in a git repository published on GitLab. Due to size constraints, it uses two repositories: one for the Release/InRelease files (which are small) and one that also include the Package/Sources files (which are large). See for example the repository for Trisquel release files and the Trisquel package/sources files. Repositories for all distributions can be found in debdistutils archives GitLab sub-group. The reason for splitting into two repositories was that the git repository for the combined files become large, and that some of my use-cases only needed the release files. Currently the repositories with packages (which contain a couple of months worth of data now) are 9GB for Ubuntu, 2.5GB for Trisquel/Debian/PureOS, 970MB for Devuan and 450MB for Gnuinos. The repository size is correlated to the size of the archive (for the initial import) plus the frequency and size of updates. Ubuntu s use of Apt Phased Updates (which triggers a higher churn of Packages file modifications) appears to be the primary reason for its larger size. Working with large Git repositories is inefficient and the GitLab CI/CD jobs generate quite some network traffic downloading the git repository over and over again. The most heavy user is the debdistdiff project that download all distribution package repositories to do diff operations on the package lists between distributions. The daily job takes around 80 minutes to run, with the majority of time is spent on downloading the archives. Yes I know I could look into runner-side caching but I dislike complexity caused by caching. Fortunately not all use-cases requires the package files. The debdistcanary project only needs the Release/InRelease files, in order to commit signatures to the Sigstore and Sigsum transparency logs. These jobs still run fairly quickly, but watching the repository size growth worries me. Currently these repositories are at Debian 440MB, PureOS 130MB, Ubuntu/Devuan 90MB, Trisquel 12MB, Gnuinos 2MB. Here I believe the main size correlation is update frequency, and Debian is large because I track the volatile unstable. So I hit a scalability end with my first approach. A couple of months ago I solved this by discarding and resetting these archival repositories. The GitLab CI/CD jobs were fast again and all was well. However this meant discarding precious historic information. A couple of days ago I was reaching the limits of practicality again, and started to explore ways to fix this. I like having data stored in git (it allows easy integration with software integrity tools such as GnuPG and Sigstore, and the git log provides a kind of temporal ordering of data), so it felt like giving up on nice properties to use a traditional database with on-disk approach. So I started to learn about Git-LFS and understanding that it was able to handle multi-GB worth of data that looked promising. Fairly quickly I scripted up a GitLab CI/CD job that incrementally update the Release/Package/Sources files in a git repository that uses Git-LFS to store all the files. The repository size is now at Ubuntu 650kb, Debian 300kb, Trisquel 50kb, Devuan 250kb, PureOS 172kb and Gnuinos 17kb. As can be expected, jobs are quick to clone the git archives: debdistdiff pipelines went from a run-time of 80 minutes down to 10 minutes which more reasonable correlate with the archive size and CPU run-time. The LFS storage size for those repositories are at Ubuntu 15GB, Debian 8GB, Trisquel 1.7GB, Devuan 1.1GB, PureOS/Gnuinos 420MB. This is for a couple of days worth of data. It seems native Git is better at compressing/deduplicating data than Git-LFS is: the combined size for Ubuntu is already 15GB for a couple of days data compared to 8GB for a couple of months worth of data with pure Git. This may be a sub-optimal implementation of Git-LFS in GitLab but it does worry me that this new approach will be difficult to scale too. At some level the difference is understandable, Git-LFS probably store two different Packages files around 90MB each for Trisquel as two 90MB files, but native Git would store it as one compressed version of the 90MB file and one relatively small patch to turn the old files into the next file. So the Git-LFS approach surprisingly scale less well for overall storage-size. Still, the original repository is much smaller, and you usually don t have to pull all LFS files anyway. So it is net win. Throughout this work, I kept thinking about how my approach relates to Debian s snapshot service. Ultimately what I would want is a combination of these two services. To have a good foundation to do transparency work I would want to have a collection of all Release/Packages/Sources files ever published, and ultimately also the source code and binaries. While it makes sense to start on the latest stable releases of distributions, this effort should scale backwards in time as well. For reproducing binaries from source code, I need to be able to securely find earlier versions of binary packages used for rebuilds. So I need to import all the Release/Packages/Sources packages from snapshot into my repositories. The latency to retrieve files from that server is slow so I haven t been able to find an efficient/parallelized way to download the files. If I m able to finish this, I would have confidence that my new Git-LFS based approach to store these files will scale over many years to come. This remains to be seen. Perhaps the repository has to be split up per release or per architecture or similar. Another factor is storage costs. While the git repository size for a Git-LFS based repository with files from several years may be possible to sustain, the Git-LFS storage size surely won t be. It seems GitLab charges the same for files in repositories and in Git-LFS, and it is around $500 per 100GB per year. It may be possible to setup a separate Git-LFS backend not hosted at GitLab to serve the LFS files. Does anyone know of a suitable server implementation for this? I had a quick look at the Git-LFS implementation list and it seems the closest reasonable approach would be to setup the Gitea-clone Forgejo as a self-hosted server. Perhaps a cloud storage approach a la S3 is the way to go? The cost to host this on GitLab will be manageable for up to ~1TB ($5000/year) but scaling it to storing say 500TB of data would mean an yearly fee of $2.5M which seems like poor value for the money. I realized that ultimately I would want a git repository locally with the entire content of all apt archives, including their binary and source packages, ever published. The storage requirements for a service like snapshot (~300TB of data?) is today not prohibitly expensive: 20TB disks are $500 a piece, so a storage enclosure with 36 disks would be around $18.000 for 720TB and using RAID1 means 360TB which is a good start. While I have heard about ~TB-sized Git-LFS repositories, would Git-LFS scale to 1PB? Perhaps the size of a git repository with multi-millions number of Git-LFS pointer files will become unmanageable? To get started on this approach, I decided to import a mirror of Debian s bookworm for amd64 into a Git-LFS repository. That is around 175GB so reasonable cheap to host even on GitLab ($1000/year for 200GB). Having this repository publicly available will make it possible to write software that uses this approach (e.g., porting debdistreproduce), to find out if this is useful and if it could scale. Distributing the apt repository via Git-LFS would also enable other interesting ideas to protecting the data. Consider configuring apt to use a local file:// URL to this git repository, and verifying the git checkout using some method similar to Guix s approach to trusting git content or Sigstore s gitsign. A naive push of the 175GB archive in a single git commit ran into pack size limitations: remote: fatal: pack exceeds maximum allowed size (4.88 GiB) however breaking up the commit into smaller commits for parts of the archive made it possible to push the entire archive. Here are the commands to create this repository: git init
git lfs install
git lfs track 'dists/**' 'pool/**'
git add .gitattributes
git commit -m"Add Git-LFS track attributes." .gitattributes
time debmirror --method=rsync --host ftp.se.debian.org --root :debian --arch=amd64 --source --dist=bookworm,bookworm-updates --section=main --verbose --diff=none --keyring /usr/share/keyrings/debian-archive-keyring.gpg --ignore .git .
git add dists project
git commit -m"Add." -a
git remote add origin git@gitlab.com:debdistutils/archives/debian/mirror.git
git push --set-upstream origin --all
for d in pool//; do
echo $d;
time git add $d;
git commit -m"Add $d." -a
git push
done The resulting repository size is around 27MB with Git LFS object storage around 174GB. I think this approach would scale to handle all architectures for one release, but working with a single git repository for all releases for all architectures may lead to a too large git repository (>1GB). So maybe one repository per release? These repositories could also be split up on a subset of pool/ files, or there could be one repository per release per architecture or sources. Finally, I have concerns about using SHA1 for identifying objects. It seems both Git and Debian s snapshot service is currently using SHA1. For Git there is SHA-256 transition and it seems GitLab is working on support for SHA256-based repositories. For serious long-term deployment of these concepts, it would be nice to go for SHA256 identifiers directly. Git-LFS already uses SHA256 but Git internally uses SHA1 as does the Debian snapshot service. What do you think? Happy Hacking!

Last week marked a major milestone for me: the AMD driver-specific color management properties reached the upstream linux-next! And to celebrate, I m happy to share the slides notes from my 2023 XDC talk, The Rainbow Treasure Map along with the individual recording that just dropped last week on youtube talk about happy coincidences!

Steam Deck Rainbow: Treasure Map & Magic Frogs While I may be bubbly and chatty in everyday life, the stage isn t exactly my comfort zone (hallway talks are more my speed). But the journey of developing the AMD color management properties was so full of discoveries that I simply had to share the experience. Witnessing the fantastic work of Jeremy and Joshua bring it all to life on the Steam Deck OLED was like uncovering magical ingredients and whipping up something truly enchanting. For XDC 2023, we split our Rainbow journey into two talks. My focus, The Rainbow Treasure Map, explored the new color features we added to the Linux kernel driver, diving deep into the hardware capabilities of AMD/Steam Deck. Joshua then followed with The Rainbow Frogs and showed the breathtaking color magic released on Gamescope thanks to the power unlocked by the kernel driver s Steam Deck color properties.

Packing a Rainbow into 15 Minutes I had so much to tell, but a half-slot talk meant crafting a concise presentation. To squeeze everything into 15 minutes (and calm my pre-talk jitters a bit!), I drafted and practiced those slides and notes countless times. So grab your map, and let s embark on the Rainbow journey together! Intro: Hi, I m Melissa from Igalia and welcome to the Rainbow Treasure Map, a talk about advanced color management on Linux with AMD/SteamDeck. Useful links: First of all, if you are not used to the topic, you may find these links useful.

1. XDC 2022 - I m not an AMD expert, but - Melissa Wen
2. XDC 2022 - Is HDR Harder? - Harry Wentland
3. XDC 2022 Lightning - HDR Workshop Summary - Harry Wentland
4. Color management and HDR documentation for FOSS graphics - Pekka Paalanen et al.
5. Cinematic Color - 2012 SIGGRAPH course notes - Jeremy Selan
6. AMD Driver-specific Properties for Color Management on Linux (Part 1) - Melissa Wen

Context: When we talk about colors in the graphics chain, we should keep in mind that we have a wide variety of source content colorimetry, a variety of output display devices and also the internal processing. Users expect consistent color reproduction across all these devices. The userspace can use GPU-accelerated color management to get it. But this also requires an interface with display kernel drivers that is currently missing from the DRM/KMS framework. Since April, I ve been bothering the DRM community by sending patchsets from the work of me and Joshua to add driver-specific color properties to the AMD display driver. In parallel, discussions on defining a generic color management interface are still ongoing in the community. Moreover, we are still not clear about the diversity of color capabilities among hardware vendors. To bridge this gap, we defined a color pipeline for Gamescope that fits the latest versions of AMD hardware. It delivers advanced color management features for gamut mapping, HDR rendering, SDR on HDR, and HDR on SDR. AMD/Steam Deck hardware: AMD frequently releases new GPU and APU generations. Each generation comes with a DCN version with display hardware improvements. Therefore, keep in mind that this work uses the AMD Steam Deck hardware and its kernel driver. The Steam Deck is an APU with a DCN3.01 display driver, a DCN3 family. It s important to have this information since newer AMD DCN drivers inherit implementations from previous families but aldo each generation of AMD hardware may introduce new color capabilities. Therefore I recommend you to familiarize yourself with the hardware you are working on. The AMD display driver in the kernel space: It consists of three layers, (1) the DRM/KMS framework, (2) the AMD Display Manager, and (3) the AMD Display Core. We extended the color interface exposed to userspace by leveraging existing DRM resources and connecting them using driver-specific functions for color property management. Bridging DC color capabilities and the DRM API required significant changes in the color management of AMD Display Manager - the Linux-dependent part that connects the AMD DC interface to the DRM/KMS framework. The AMD DC is the OS-agnostic layer. Its code is shared between platforms and DCN versions. Examining this part helps us understand the AMD color pipeline and hardware capabilities, since the machinery for hardware settings and resource management are already there. The newest architecture for AMD display hardware is the AMD Display Core Next. In this architecture, two blocks have the capability to manage colors:

• Display Pipe and Plane (DPP) - for pre-blending adjustments;
• Multiple Pipe/Plane Combined (MPC) - for post-blending color transformations.

Let s see what we have in the DRM API for pre-blending color management. DRM plane color properties: This is the DRM color management API before blending. Nothing! Except two basic DRM plane properties: color_encoding and color_range for the input colorspace conversion, that is not covered by this work. In case you re not familiar with AMD shared code, what we need to do is basically draw a map and navigate there! We have some DRM color properties after blending, but nothing before blending yet. But much of the hardware programming was already implemented in the AMD DC layer, thanks to the shared code. Still both the DRM interface and its connection to the shared code were missing. That s when the search begins! AMD driver-specific color pipeline: Looking at the color capabilities of the hardware, we arrive at this initial set of properties. The path wasn t exactly like that. We had many iterations and discoveries until reached to this pipeline. The Plane Degamma is our first driver-specific property before blending. It s used to linearize the color space from encoded values to light linear values. We can use a pre-defined transfer function or a user lookup table (in short, LUT) to linearize the color space. Pre-defined transfer functions for plane degamma are hardcoded curves that go to a specific hardware block called DPP Degamma ROM. It supports the following transfer functions: sRGB EOTF, BT.709 inverse OETF, PQ EOTF, and pure power curves Gamma 2.2, Gamma 2.4 and Gamma 2.6. We also have a one-dimensional LUT. This 1D LUT has four thousand ninety six (4096) entries, the usual 1D LUT size in the DRM/KMS. It s an array of drm_color_lut that goes to the DPP Gamma Correction block. We also have now a color transformation matrix (CTM) for color space conversion. It s a 3x4 matrix of fixed points that goes to the DPP Gamut Remap Block. Both pre- and post-blending matrices were previously gone to the same color block. We worked on detaching them to clear both paths. Now each CTM goes on its own way. Next, the HDR Multiplier. HDR Multiplier is a factor applied to the color values of an image to increase their overall brightness. This is useful for converting images from a standard dynamic range (SDR) to a high dynamic range (HDR). As it can range beyond [0.0, 1.0] subsequent transforms need to use the PQ(HDR) transfer functions. And we need a 3D LUT. But 3D LUT has a limited number of entries in each dimension, so we want to use it in a colorspace that is optimized for human vision. It means in a non-linear space. To deliver it, userspace may need one 1D LUT before 3D LUT to delinearize content and another one after to linearize content again for blending. The pre-3D-LUT curve is called Shaper curve. Unlike Degamma TF, there are no hardcoded curves for shaper TF, but we can use the AMD color module in the driver to build the following shaper curves from pre-defined coefficients. The color module combines the TF and the user LUT values into the LUT that goes to the DPP Shaper RAM block. Finally, our rockstar, the 3D LUT. 3D LUT is perfect for complex color transformations and adjustments between color channels. 3D LUT is also more complex to manage and requires more computational resources, as a consequence, its number of entries is usually limited. To overcome this restriction, the array contains samples from the approximated function and values between samples are estimated by tetrahedral interpolation. AMD supports 17 and 9 as the size of a single-dimension. Blue is the outermost dimension, red the innermost. As mentioned, we need a post-3D-LUT curve to linearize the color space before blending. This is done by Blend TF and LUT. Similar to shaper TF, there are no hardcoded curves for Blend TF. The pre-defined curves are the same as the Degamma block, but calculated by the color module. The resulting LUT goes to the DPP Blend RAM block. Now we have everything connected before blending. As a conflict between plane and CRTC Degamma was inevitable, our approach doesn t accept that both are set at the same time. We also optimized the conversion of the framebuffer to wire encoding by adding support to pre-defined CRTC Gamma TF. Again, there are no hardcoded curves and TF and LUT are combined by the AMD color module. The same types of shaper curves are supported. The resulting LUT goes to the MPC Gamma RAM block. Finally, we arrived in the final version of DRM/AMD driver-specific color management pipeline. With this knowledge, you re ready to better enjoy the rainbow treasure of AMD display hardware and the world of graphics computing. With this work, Gamescope/Steam Deck embraces the color capabilities of the AMD GPU. We highlight here how we map the Gamescope color pipeline to each AMD color block. Future works: The search for the rainbow treasure is not over! The Linux DRM subsystem contains many hidden treasures from different vendors. We want more complex color transformations and adjustments available on Linux. We also want to expose all GPU color capabilities from all hardware vendors to the Linux userspace. Thanks Joshua and Harry for this joint work and the Linux DRI community for all feedback and reviews. The amazing part of this work comes in the next talk with Joshua and The Rainbow Frogs! Any questions?

---

References:

1. Slides of the talk The Rainbow Treasure Map.
2. Youtube video of the talk The Rainbow Treasure Map.
3. Patch series for AMD driver-specific color management properties (upstream Linux 6.8v).
4. SteamDeck/Gamescope color management pipeline
5. XDC 2023 website.
6. Igalia website.

Did you hear the news? Firefox development is moving from Mercurial to Git. While the decision is far from being mine, and I was barely involved in the small incremental changes that ultimately led to this decision, I feel I have to take at least some responsibility. And if you are one of those who would rather use Mercurial than Git, you may direct all your ire at me. But let's take a step back and review the past 25 years leading to this decision. You'll forgive me for skipping some details and any possible inaccuracies. This is already a long post, while I could have been more thorough, even I think that would have been too much. This is also not an official Mozilla position, only my personal perception and recollection as someone who was involved at times, but mostly an observer from a distance. From CVS to DVCS From its release in 1998, the Mozilla source code was kept in a CVS repository. If you're too young to know what CVS is, let's just say it's an old school version control system, with its set of problems. Back then, it was mostly ubiquitous in the Open Source world, as far as I remember. In the early 2000s, the Subversion version control system gained some traction, solving some of the problems that came with CVS. Incidentally, Subversion was created by Jim Blandy, who now works at Mozilla on completely unrelated matters. In the same period, the Linux kernel development moved from CVS to Bitkeeper, which was more suitable to the distributed nature of the Linux community. BitKeeper had its own problem, though: it was the opposite of Open Source, but for most pragmatic people, it wasn't a real concern because free access was provided. Until it became a problem: someone at OSDL developed an alternative client to BitKeeper, and licenses of BitKeeper were rescinded for OSDL members, including Linus Torvalds (they were even prohibited from purchasing one). Following this fiasco, in April 2005, two weeks from each other, both Git and Mercurial were born. The former was created by Linus Torvalds himself, while the latter was developed by Olivia Mackall, who was a Linux kernel developer back then. And because they both came out of the same community for the same needs, and the same shared experience with BitKeeper, they both were similar distributed version control systems. Interestingly enough, several other DVCSes existed:

• SVK, a DVCS built on top of Subversion, allowing users to create local (offline) branches of remote Subversion repositories. It was also known for its powerful merging capabilities. I picked it at some point for my Debian work, mainly because I needed to interact with Subversion repositories.
• Arch (tla), later known as GNU arch. From what I remember, it was awful to use. You think Git is complex or confusing? Arch was way worse. It was forked as "Bazaar", but the fork was abandoned in favor of "Bazaar-NG", now known as "Bazaar" or "bzr", a much more user-friendly DVCS. The first release of Bzr actually precedes Git's by two weeks. I guess it was too new to be considered by Linus Torvalds for the Linux kernel needs.
• Monotone, which I don't know much about, but it was mentioned by Linus Torvalds two days before the initial Git commit of Git. As far as I know, it was too slow for the Linux kernel's needs. I'll note in passing that Monotone is the creation of Graydon Hoare, who also created Rust.
• Darcs, with its patch-based model, rather than the common snapshot-based model, allowed more flexible management of changes. This approach came, however, at the expense of performance.

In this landscape, the major difference Git was making at the time was that it was blazing fast. Almost incredibly so, at least on Linux systems. That was less true on other platforms (especially Windows). It was a game-changer for handling large codebases in a smooth manner. Anyways, two years later, in 2007, Mozilla decided to move its source code not to Bzr, not to Git, not to Subversion (which, yes, was a contender), but to Mercurial. The decision "process" was laid down in two rather colorful blog posts. My memory is a bit fuzzy, but I don't recall that it was a particularly controversial choice. All of those DVCSes were still young, and there was no definite "winner" yet (GitHub hadn't even been founded). It made the most sense for Mozilla back then, mainly because the Git experience on Windows still wasn't there, and that mattered a lot for Mozilla, with its diverse platform support. As a contributor, I didn't think much of it, although to be fair, at the time, I was mostly consuming the source tarballs. Personal preferences Digging through my archives, I've unearthed a forgotten chapter: I did end up setting up both a Mercurial and a Git mirror of the Firefox source repository on alioth.debian.org. Alioth.debian.org was a FusionForge-based collaboration system for Debian developers, similar to SourceForge. It was the ancestor of salsa.debian.org. I used those mirrors for the Debian packaging of Firefox (cough cough Iceweasel). The Git mirror was created with hg-fast-export, and the Mercurial mirror was only a necessary step in the process. By that time, I had converted my Subversion repositories to Git, and switched off SVK. Incidentally, I started contributing to Git around that time as well. I apparently did this not too long after Mozilla switched to Mercurial. As a Linux user, I think I just wanted the speed that Mercurial was not providing. Not that Mercurial was that slow, but the difference between a couple seconds and a couple hundred milliseconds was a significant enough difference in user experience for me to prefer Git (and Firefox was not the only thing I was using version control for) Other people had also similarly created their own mirror, or with other tools. But none of them were "compatible": their commit hashes were different. Hg-git, used by the latter, was putting extra information in commit messages that would make the conversion differ, and hg-fast-export would just not be consistent with itself! My mirror is long gone, and those have not been updated in more than a decade. I did end up using Mercurial, when I got commit access to the Firefox source repository in April 2010. I still kept using Git for my Debian activities, but I now was also using Mercurial to push to the Mozilla servers. I joined Mozilla as a contractor a few months after that, and kept using Mercurial for a while, but as a, by then, long time Git user, it never really clicked for me. It turns out, the sentiment was shared by several at Mozilla. Git incursion In the early 2010s, GitHub was becoming ubiquitous, and the Git mindshare was getting large. Multiple projects at Mozilla were already entirely hosted on GitHub. As for the Firefox source code base, Mozilla back then was kind of a Wild West, and engineers being engineers, multiple people had been using Git, with their own inconvenient workflows involving a local Mercurial clone. The most popular set of scripts was moz-git-tools, to incorporate changes in a local Git repository into the local Mercurial copy, to then send to Mozilla servers. In terms of the number of people doing that, though, I don't think it was a lot of people, probably a few handfuls. On my end, I was still keeping up with Mercurial. I think at that time several engineers had their own unofficial Git mirrors on GitHub, and later on Ehsan Akhgari provided another mirror, with a twist: it also contained the full CVS history, which the canonical Mercurial repository didn't have. This was particularly interesting for engineers who needed to do some code archeology and couldn't get past the 2007 cutoff of the Mercurial repository. I think that mirror ultimately became the official-looking, but really unofficial, mozilla-central repository on GitHub. On a side note, a Mercurial repository containing the CVS history was also later set up, but that didn't lead to something officially supported on the Mercurial side. Some time around 2011~2012, I started to more seriously consider using Git for work myself, but wasn't satisfied with the workflows others had set up for themselves. I really didn't like the idea of wasting extra disk space keeping a Mercurial clone around while using a Git mirror. I wrote a Python script that would use Mercurial as a library to access a remote repository and produce a git-fast-import stream. That would allow the creation of a git repository without a local Mercurial clone. It worked quite well, but it was not able to incrementally update. Other, more complete tools existed already, some of which I mentioned above. But as time was passing and the size and depth of the Mercurial repository was growing, these tools were showing their limits and were too slow for my taste, especially for the initial clone. Boot to Git In the same time frame, Mozilla ventured in the Mobile OS sphere with Boot to Gecko, later known as Firefox OS. What does that have to do with version control? The needs of third party collaborators in the mobile space led to the creation of what is now the gecko-dev repository on GitHub. As I remember it, it was challenging to create, but once it was there, Git users could just clone it and have a working, up-to-date local copy of the Firefox source code and its history... which they could already have, but this was the first officially supported way of doing so. Coincidentally, Ehsan's unofficial mirror was having trouble (to the point of GitHub closing the repository) and was ultimately shut down in December 2013. You'll often find comments on the interwebs about how GitHub has become unreliable since the Microsoft acquisition. I can't really comment on that, but if you think GitHub is unreliable now, rest assured that it was worse in its beginning. And its sustainability as a platform also wasn't a given, being a rather new player. So on top of having this official mirror on GitHub, Mozilla also ventured in setting up its own Git server for greater control and reliability. But the canonical repository was still the Mercurial one, and while Git users now had a supported mirror to pull from, they still had to somehow interact with Mercurial repositories, most notably for the Try server. Git slowly creeping in Firefox build tooling Still in the same time frame, tooling around building Firefox was improving drastically. For obvious reasons, when version control integration was needed in the tooling, Mercurial support was always a no-brainer. The first explicit acknowledgement of a Git repository for the Firefox source code, other than the addition of the .gitignore file, was bug 774109. It added a script to install the prerequisites to build Firefox on macOS (still called OSX back then), and that would print a message inviting people to obtain a copy of the source code with either Mercurial or Git. That was a precursor to current bootstrap.py, from September 2012. Following that, as far as I can tell, the first real incursion of Git in the Firefox source tree tooling happened in bug 965120. A few days earlier, bug 952379 had added a mach clang-format command that would apply clang-format-diff to the output from hg diff. Obviously, running hg diff on a Git working tree didn't work, and bug 965120 was filed, and support for Git was added there. That was in January 2014. A year later, when the initial implementation of mach artifact was added (which ultimately led to artifact builds), Git users were an immediate thought. But while they were considered, it was not to support them, but to avoid actively breaking their workflows. Git support for mach artifact was eventually added 14 months later, in March 2016. From gecko-dev to git-cinnabar Let's step back a little here, back to the end of 2014. My user experience with Mercurial had reached a level of dissatisfaction that was enough for me to decide to take that script from a couple years prior and make it work for incremental updates. That meant finding a way to store enough information locally to be able to reconstruct whatever the incremental updates would be relying on (guess why other tools hid a local Mercurial clone under hood). I got something working rather quickly, and after talking to a few people about this side project at the Mozilla Portland All Hands and seeing their excitement, I published a git-remote-hg initial prototype on the last day of the All Hands. Within weeks, the prototype gained the ability to directly push to Mercurial repositories, and a couple months later, was renamed to git-cinnabar. At that point, as a Git user, instead of cloning the gecko-dev repository from GitHub and switching to a local Mercurial repository whenever you needed to push to a Mercurial repository (i.e. the aforementioned Try server, or, at the time, for reviews), you could just clone and push directly from/to Mercurial, all within Git. And it was fast too. You could get a full clone of mozilla-central in less than half an hour, when at the time, other similar tools would take more than 10 hours (needless to say, it's even worse now). Another couple months later (we're now at the end of April 2015), git-cinnabar became able to start off a local clone of the gecko-dev repository, rather than clone from scratch, which could be time consuming. But because git-cinnabar and the tool that was updating gecko-dev weren't producing the same commits, this setup was cumbersome and not really recommended. For instance, if you pushed something to mozilla-central with git-cinnabar from a gecko-dev clone, it would come back with a different commit hash in gecko-dev, and you'd have to deal with the divergence. Eventually, in April 2020, the scripts updating gecko-dev were switched to git-cinnabar, making the use of gecko-dev alongside git-cinnabar a more viable option. Ironically(?), the switch occurred to ease collaboration with KaiOS (you know, the mobile OS born from the ashes of Firefox OS). Well, okay, in all honesty, when the need of syncing in both directions between Git and Mercurial (we only had ever synced from Mercurial to Git) came up, I nudged Mozilla in the direction of git-cinnabar, which, in my (biased but still honest) opinion, was the more reliable option for two-way synchronization (we did have regular conversion problems with hg-git, nothing of the sort has happened since the switch). One Firefox repository to rule them all For reasons I don't know, Mozilla decided to use separate Mercurial repositories as "branches". With the switch to the rapid release process in 2011, that meant one repository for nightly (mozilla-central), one for aurora, one for beta, and one for release. And with the addition of Extended Support Releases in 2012, we now add a new ESR repository every year. Boot to Gecko also had its own branches, and so did Fennec (Firefox for Mobile, before Android). There are a lot of them. And then there are also integration branches, where developer's work lands before being merged in mozilla-central (or backed out if it breaks things), always leaving mozilla-central in a (hopefully) good state. Only one of them remains in use today, though. I can only suppose that the way Mercurial branches work was not deemed practical. It is worth noting, though, that Mercurial branches are used in some cases, to branch off a dot-release when the next major release process has already started, so it's not a matter of not knowing the feature exists or some such. In 2016, Gregory Szorc set up a new repository that would contain them all (or at least most of them), which eventually became what is now the mozilla-unified repository. This would e.g. simplify switching between branches when necessary. 7 years later, for some reason, the other "branches" still exist, but most developers are expected to be using mozilla-unified. Mozilla's CI also switched to using mozilla-unified as base repository. Honestly, I'm not sure why the separate repositories are still the main entry point for pushes, rather than going directly to mozilla-unified, but it probably comes down to switching being work, and not being a top priority. Also, it probably doesn't help that working with multiple heads in Mercurial, even (especially?) with bookmarks, can be a source of confusion. To give an example, if you aren't careful, and do a plain clone of the mozilla-unified repository, you may not end up on the latest mozilla-central changeset, but rather, e.g. one from beta, or some other branch, depending which one was last updated. Hosting is simple, right? Put your repository on a server, install hgweb or gitweb, and that's it? Maybe that works for... Mercurial itself, but that repository "only" has slightly over 50k changesets and less than 4k files. Mozilla-central has more than an order of magnitude more changesets (close to 700k) and two orders of magnitude more files (more than 700k if you count the deleted or moved files, 350k if you count the currently existing ones). And remember, there are a lot of "duplicates" of this repository. And I didn't even mention user repositories and project branches. Sure, it's a self-inflicted pain, and you'd think it could probably(?) be mitigated with shared repositories. But consider the simple case of two repositories: mozilla-central and autoland. You make autoland use mozilla-central as a shared repository. Now, you push something new to autoland, it's stored in the autoland datastore. Eventually, you merge to mozilla-central. Congratulations, it's now in both datastores, and you'd need to clean-up autoland if you wanted to avoid the duplication. Now, you'd think mozilla-unified would solve these issues, and it would... to some extent. Because that wouldn't cover user repositories and project branches briefly mentioned above, which in GitHub parlance would be considered as Forks. So you'd want a mega global datastore shared by all repositories, and repositories would need to only expose what they really contain. Does Mercurial support that? I don't think so (okay, I'll give you that: even if it doesn't, it could, but that's extra work). And since we're talking about a transition to Git, does Git support that? You may have read about how you can link to a commit from a fork and make-pretend that it comes from the main repository on GitHub? At least, it shows a warning, now. That's essentially the architectural reason why. So the actual answer is that Git doesn't support it out of the box, but GitHub has some backend magic to handle it somehow (and hopefully, other things like Gitea, Girocco, Gitlab, etc. have something similar). Now, to come back to the size of the repository. A repository is not a static file. It's a server with which you negotiate what you have against what it has that you want. Then the server bundles what you asked for based on what you said you have. Or in the opposite direction, you negotiate what you have that it doesn't, you send it, and the server incorporates what you sent it. Fortunately the latter is less frequent and requires authentication. But the former is more frequent and CPU intensive. Especially when pulling a large number of changesets, which, incidentally, cloning is. "But there is a solution for clones" you might say, which is true. That's clonebundles, which offload the CPU intensive part of cloning to a single job scheduled regularly. Guess who implemented it? Mozilla. But that only covers the cloning part. We actually had laid the ground to support offloading large incremental updates and split clones, but that never materialized. Even with all that, that still leaves you with a server that can display file contents, diffs, blames, provide zip archives of a revision, and more, all of which are CPU intensive in their own way. And these endpoints are regularly abused, and cause extra load to your servers, yes plural, because of course a single server won't handle the load for the number of users of your big repositories. And because your endpoints are abused, you have to close some of them. And I'm not mentioning the Try repository with its tens of thousands of heads, which brings its own sets of problems (and it would have even more heads if we didn't fake-merge them once in a while). Of course, all the above applies to Git (and it only gained support for something akin to clonebundles last year). So, when the Firefox OS project was stopped, there wasn't much motivation to continue supporting our own Git server, Mercurial still being the official point of entry, and git.mozilla.org was shut down in 2016. The growing difficulty of maintaining the status quo Slowly, but steadily in more recent years, as new tooling was added that needed some input from the source code manager, support for Git was more and more consistently added. But at the same time, as people left for other endeavors and weren't necessarily replaced, or more recently with layoffs, resources allocated to such tooling have been spread thin. Meanwhile, the repository growth didn't take a break, and the Try repository was becoming an increasing pain, with push times quite often exceeding 10 minutes. The ongoing work to move Try pushes to Lando will hide the problem under the rug, but the underlying problem will still exist (although the last version of Mercurial seems to have improved things). On the flip side, more and more people have been relying on Git for Firefox development, to my own surprise, as I didn't really push for that to happen. It just happened organically, by ways of git-cinnabar existing, providing a compelling experience to those who prefer Git, and, I guess, word of mouth. I was genuinely surprised when I recently heard the use of Git among moz-phab users had surpassed a third. I did, however, occasionally orient people who struggled with Mercurial and said they were more familiar with Git, towards git-cinnabar. I suspect there's a somewhat large number of people who never realized Git was a viable option. But that, on its own, can come with its own challenges: if you use git-cinnabar without being backed by gecko-dev, you'll have a hard time sharing your branches on GitHub, because you can't push to a fork of gecko-dev without pushing your entire local repository, as they have different commit histories. And switching to gecko-dev when you weren't already using it requires some extra work to rebase all your local branches from the old commit history to the new one. Clone times with git-cinnabar have also started to go a little out of hand in the past few years, but this was mitigated in a similar manner as with the Mercurial cloning problem: with static files that are refreshed regularly. Ironically, that made cloning with git-cinnabar faster than cloning with Mercurial. But generating those static files is increasingly time-consuming. As of writing, generating those for mozilla-unified takes close to 7 hours. I was predicting clone times over 10 hours "in 5 years" in a post from 4 years ago, I wasn't too far off. With exponential growth, it could still happen, although to be fair, CPUs have improved since. I will explore the performance aspect in a subsequent blog post, alongside the upcoming release of git-cinnabar 0.7.0-b1. I don't even want to check how long it now takes with hg-git or git-remote-hg (they were already taking more than a day when git-cinnabar was taking a couple hours). I suppose it's about time that I clarify that git-cinnabar has always been a side-project. It hasn't been part of my duties at Mozilla, and the extent to which Mozilla supports git-cinnabar is in the form of taskcluster workers on the community instance for both git-cinnabar CI and generating those clone bundles. Consequently, that makes the above git-cinnabar specific issues a Me problem, rather than a Mozilla problem. Taking the leap I can't talk for the people who made the proposal to move to Git, nor for the people who put a green light on it. But I can at least give my perspective. Developers have regularly asked why Mozilla was still using Mercurial, but I think it was the first time that a formal proposal was laid out. And it came from the Engineering Workflow team, responsible for issue tracking, code reviews, source control, build and more. It's easy to say "Mozilla should have chosen Git in the first place", but back in 2007, GitHub wasn't there, Bitbucket wasn't there, and all the available options were rather new (especially compared to the then 21 years-old CVS). I think Mozilla made the right choice, all things considered. Had they waited a couple years, the story might have been different. You might say that Mozilla stayed with Mercurial for so long because of the sunk cost fallacy. I don't think that's true either. But after the biggest Mercurial repository hosting service turned off Mercurial support, and the main contributor to Mercurial going their own way, it's hard to ignore that the landscape has evolved. And the problems that we regularly encounter with the Mercurial servers are not going to get any better as the repository continues to grow. As far as I know, all the Mercurial repositories bigger than Mozilla's are... not using Mercurial. Google has its own closed-source server, and Facebook has another of its own, and it's not really public either. With resources spread thin, I don't expect Mozilla to be able to continue supporting a Mercurial server indefinitely (although I guess Octobus could be contracted to give a hand, but is that sustainable?). Mozilla, being a champion of Open Source, also doesn't live in a silo. At some point, you have to meet your contributors where they are. And the Open Source world is now majoritarily using Git. I'm sure the vast majority of new hires at Mozilla in the past, say, 5 years, know Git and have had to learn Mercurial (although they arguably didn't need to). Even within Mozilla, with thousands(!) of repositories on GitHub, Firefox is now actually the exception rather than the norm. I should even actually say Desktop Firefox, because even Mobile Firefox lives on GitHub (although Fenix is moving back in together with Desktop Firefox, and the timing is such that that will probably happen before Firefox moves to Git). Heck, even Microsoft moved to Git! With a significant developer base already using Git thanks to git-cinnabar, and all the constraints and problems I mentioned previously, it actually seems natural that a transition (finally) happens. However, had git-cinnabar or something similarly viable not existed, I don't think Mozilla would be in a position to take this decision. On one hand, it probably wouldn't be in the current situation of having to support both Git and Mercurial in the tooling around Firefox, nor the resource constraints related to that. But on the other hand, it would be farther from supporting Git and being able to make the switch in order to address all the other problems. But... GitHub? I hope I made a compelling case that hosting is not as simple as it can seem, at the scale of the Firefox repository. It's also not Mozilla's main focus. Mozilla has enough on its plate with the migration of existing infrastructure that does rely on Mercurial to understandably not want to figure out the hosting part, especially with limited resources, and with the mixed experience hosting both Mercurial and git has been so far. After all, GitHub couldn't even display things like the contributors' graph on gecko-dev until recently, and hosting is literally their job! They still drop the ball on large blames (thankfully we have searchfox for those). Where does that leave us? Gitlab? For those criticizing GitHub for being proprietary, that's probably not open enough. Cloud Source Repositories? "But GitHub is Microsoft" is a complaint I've read a lot after the announcement. Do you think Google hosting would have appealed to these people? Bitbucket? I'm kind of surprised it wasn't in the list of providers that were considered, but I'm also kind of glad it wasn't (and I'll leave it at that). I think the only relatively big hosting provider that could have made the people criticizing the choice of GitHub happy is Codeberg, but I hadn't even heard of it before it was mentioned in response to Mozilla's announcement. But really, with literal thousands of Mozilla repositories already on GitHub, with literal tens of millions repositories on the platform overall, the pragmatic in me can't deny that it's an attractive option (and I can't stress enough that I wasn't remotely close to the room where the discussion about what choice to make happened). "But it's a slippery slope". I can see that being a real concern. LLVM also moved its repository to GitHub (from a (I think) self-hosted Subversion server), and ended up moving off Bugzilla and Phabricator to GitHub issues and PRs four years later. As an occasional contributor to LLVM, I hate this move. I hate the GitHub review UI with a passion. At least, right now, GitHub PRs are not a viable option for Mozilla, for their lack of support for security related PRs, and the more general shortcomings in the review UI. That doesn't mean things won't change in the future, but let's not get too far ahead of ourselves. The move to Git has just been announced, and the migration has not even begun yet. Just because Mozilla is moving the Firefox repository to GitHub doesn't mean it's locked in forever or that all the eggs are going to be thrown into one basket. If bridges need to be crossed in the future, we'll see then. So, what's next? The official announcement said we're not expecting the migration to really begin until six months from now. I'll swim against the current here, and say this: the earlier you can switch to git, the earlier you'll find out what works and what doesn't work for you, whether you already know Git or not. While there is not one unique workflow, here's what I would recommend anyone who wants to take the leap off Mercurial right now:

• Make sure git is installed. Chances are you already have it.
• Install git-cinnabar where mach bootstrap would install it.

  $ mkdir -p ~/.mozbuild/git-cinnabar
  $ cd ~/.mozbuild/git-cinnabar
  $ curl -sOL https://raw.githubusercontent.com/glandium/git-cinnabar/master/download.py
  $ python3 download.py && rm download.py

• Add git-cinnabar to your PATH. Make sure to also set that wherever you keep your PATH up-to-date (.bashrc or wherever else).

  $ PATH=$PATH:$HOME/.mozbuild/git-cinnabar

• Enter your mozilla-central or mozilla-unified Mercurial working copy, we'll do an in-place conversion, so that you don't need to move your mozconfigs, objdirs and what not.
• Initialize the git repository from GitHub.

  $ git init
  $ git remote add origin https://github.com/mozilla/gecko-dev
  $ git remote update origin

• Switch to a Mercurial remote.

  $ git remote set-url origin hg::https://hg.mozilla.org/mozilla-unified
  $ git config --local remote.origin.cinnabar-refs bookmarks
  $ git remote update origin --prune

• Fetch your local Mercurial heads.

  $ git -c cinnabar.refs=heads fetch hg::$PWD refs/heads/default/*:refs/heads/hg/*

  This will create a bunch of hg/<sha1> local branches, not all relevant to you (some come from old branches on mozilla-central). Note that if you're using Mercurial MQ, this will not pull your queues, as they don't exist as heads in the Mercurial repo. You'd need to apply your queues one by one and run the command above for each of them.
  Or, if you have bookmarks for your local Mercurial work, you can use this instead:

  $ git -c cinnabar.refs=bookmarks fetch hg::$PWD refs/heads/*:refs/heads/hg/*

  This will create hg/<bookmark_name> branches.
• Now, make git know what commit your working tree is on.

  $ git reset $(git cinnabar hg2git $(hg log -r . -T ' node '))

  This will take a little moment because Git is going to scan all the files in the tree for the first time. On the other hand, it won't touch their content or timestamps, so if you had a build around, it will still be valid, and mach build won't rebuild anything it doesn't have to.

As there is no one-size-fits-all workflow, I won't tell you how to organize yourself from there. I'll just say this: if you know the Mercurial sha1s of your previous local work, you can create branches for them with:

$ git branch <branch_name> $(git cinnabar hg2git <hg_sha1>)

At this point, you should have everything available on the Git side, and you can remove the .hg directory. Or move it into some empty directory somewhere else, just in case. But don't leave it here, it will only confuse the tooling. Artifact builds WILL be confused, though, and you'll have to ./mach configure before being able to do anything. You may also hit bug 1865299 if your working tree is older than this post. If you have any problem or question, you can ping me on #git-cinnabar or #git on Matrix. I'll put the instructions above somewhere on wiki.mozilla.org, and we can collaboratively iterate on them. Now, what the announcement didn't say is that the Git repository WILL NOT be gecko-dev, doesn't exist yet, and WON'T BE COMPATIBLE (trust me, it'll be for the better). Why did I make you do all the above, you ask? Because that won't be a problem. I'll have you covered, I promise. The upcoming release of git-cinnabar 0.7.0-b1 will have a way to smoothly switch between gecko-dev and the future repository (incidentally, that will also allow to switch from a pure git-cinnabar clone to a gecko-dev one, for the git-cinnabar users who have kept reading this far). What about git-cinnabar? With Mercurial going the way of the dodo at Mozilla, my own need for git-cinnabar will vanish. Legitimately, this begs the question whether it will still be maintained. I can't answer for sure. I don't have a crystal ball. However, the needs of the transition itself will motivate me to finish some long-standing things (like finalizing the support for pushing merges, which is currently behind an experimental flag) or implement some missing features (support for creating Mercurial branches). Git-cinnabar started as a Python script, it grew a sidekick implemented in C, which then incorporated some Rust, which then cannibalized the Python script and took its place. It is now close to 90% Rust, and 10% C (if you don't count the code from Git that is statically linked to it), and has sort of become my Rust playground (it's also, I must admit, a mess, because of its history, but it's getting better). So the day to day use with Mercurial is not my sole motivation to keep developing it. If it were, it would stay stagnant, because all the features I need are there, and the speed is not all that bad, although I know it could be better. Arguably, though, git-cinnabar has been relatively stagnant feature-wise, because all the features I need are there. So, no, I don't expect git-cinnabar to die along Mercurial use at Mozilla, but I can't really promise anything either. Final words That was a long post. But there was a lot of ground to cover. And I still skipped over a bunch of things. I hope I didn't bore you to death. If I did and you're still reading... what's wrong with you? ;) So this is the end of Mercurial at Mozilla. So long, and thanks for all the fish. But this is also the beginning of a transition that is not easy, and that will not be without hiccups, I'm sure. So fasten your seatbelts (plural), and welcome the change. To circle back to the clickbait title, did I really kill Mercurial at Mozilla? Of course not. But it's like I stumbled upon a few sparks and tossed a can of gasoline on them. I didn't start the fire, but I sure made it into a proper bonfire... and now it has turned into a wildfire. And who knows? 15 years from now, someone else might be looking back at how Mozilla picked Git at the wrong time, and that, had we waited a little longer, we would have picked some yet to come new horse. But hey, that's the tech cycle for you.

TL;DR: This blog post explores the color capabilities of AMD hardware and how they are exposed to userspace through driver-specific properties. It discusses the different color blocks in the AMD Display Core Next (DCN) pipeline and their capabilities, such as predefined transfer functions, 1D and 3D lookup tables (LUTs), and color transformation matrices (CTMs). It also highlights the differences in AMD HW blocks for pre and post-blending adjustments, and how these differences are reflected in the available driver-specific properties. Overall, this blog post provides a comprehensive overview of the color capabilities of AMD hardware and how they can be controlled by userspace applications through driver-specific properties. This information is valuable for anyone who wants to develop applications that can take advantage of the AMD color management pipeline. Get a closer look at each hardware block s capabilities, unlock a wealth of knowledge about AMD display hardware, and enhance your understanding of graphics and visual computing. Stay tuned for future developments as we embark on a quest for GPU color capabilities in the ever-evolving realm of rainbow treasures.

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Operating Systems can use the power of GPUs to ensure consistent color reproduction across graphics devices. We can use GPU-accelerated color management to manage the diversity of color profiles, do color transformations to convert between High-Dynamic-Range (HDR) and Standard-Dynamic-Range (SDR) content and color enhacements for wide color gamut (WCG). However, to make use of GPU display capabilities, we need an interface between userspace and the kernel display drivers that is currently absent in the Linux/DRM KMS API. In the previous blog post I presented how we are expanding the Linux/DRM color management API to expose specific properties of AMD hardware. Now, I ll guide you to the color features for the Linux/AMD display driver. We embark on a journey through DRM/KMS, AMD Display Manager, and AMD Display Core and delve into the color blocks to uncover the secrets of color manipulation within AMD hardware. Here we ll talk less about the color tools and more about where to find them in the hardware. We resort to driver-specific properties to reach AMD hardware blocks with color capabilities. These blocks display features like predefined transfer functions, color transformation matrices, and 1-dimensional (1D LUT) and 3-dimensional lookup tables (3D LUT). Here, we will understand how these color features are strategically placed into color blocks both before and after blending in Display Pipe and Plane (DPP) and Multiple Pipe/Plane Combined (MPC) blocks. That said, welcome back to the second part of our thrilling journey through AMD s color management realm!

AMD Display Driver in the Linux/DRM Subsystem: The Journey In my 2022 XDC talk I m not an AMD expert, but , I briefly explained the organizational structure of the Linux/AMD display driver where the driver code is bifurcated into a Linux-specific section and a shared-code portion. To reveal AMD s color secrets through the Linux kernel DRM API, our journey led us through these layers of the Linux/AMD display driver s software stack. It includes traversing the DRM/KMS framework, the AMD Display Manager (DM), and the AMD Display Core (DC) [1]. The DRM/KMS framework provides the atomic API for color management through KMS properties represented by struct drm_property. We extended the color management interface exposed to userspace by leveraging existing resources and connecting them with driver-specific functions for managing modeset properties. On the AMD DC layer, the interface with hardware color blocks is established. The AMD DC layer contains OS-agnostic components that are shared across different platforms, making it an invaluable resource. This layer already implements hardware programming and resource management, simplifying the external developer s task. While examining the DC code, we gain insights into the color pipeline and capabilities, even without direct access to specifications. Additionally, AMD developers provide essential support by answering queries and reviewing our work upstream. The primary challenge involved identifying and understanding relevant AMD DC code to configure each color block in the color pipeline. However, the ultimate goal was to bridge the DC color capabilities with the DRM API. For this, we changed the AMD DM, the OS-dependent layer connecting the DC interface to the DRM/KMS framework. We defined and managed driver-specific color properties, facilitated the transport of user space data to the DC, and translated DRM features and settings to the DC interface. Considerations were also made for differences in the color pipeline based on hardware capabilities.

Exploring Color Capabilities of the AMD display hardware Now, let s dive into the exciting realm of AMD color capabilities, where a abundance of techniques and tools await to make your colors look extraordinary across diverse devices. First, we need to know a little about the color transformation and calibration tools and techniques that you can find in different blocks of the AMD hardware. I borrowed some images from [2] [3] [4] to help you understand the information.

Predefined Transfer Functions (Named Fixed Curves): Transfer functions serve as the bridge between the digital and visual worlds, defining the mathematical relationship between digital color values and linear scene/display values and ensuring consistent color reproduction across different devices and media. You can learn more about curves in the chapter GPU Gems 3 - The Importance of Being Linear by Larry Gritz and Eugene d Eon. ITU-R 2100 introduces three main types of transfer functions:

• OETF: the opto-electronic transfer function, which converts linear scene light into the video signal, typically within a camera.
• EOTF: electro-optical transfer function, which converts the video signal into the linear light output of the display.
• OOTF: opto-optical transfer function, which has the role of applying the rendering intent .

AMD s display driver supports the following pre-defined transfer functions (aka named fixed curves):

• Linear/Unity: linear/identity relationship between pixel value and luminance value;
• Gamma 2.2, Gamma 2.4, Gamma 2.6: pure power functions;
• sRGB: 2.4: The piece-wise transfer function from IEC 61966-2-1:1999;
• BT.709: has a linear segment in the bottom part and then a power function with a 0.45 (~1/2.22) gamma for the rest of the range; standardized by ITU-R BT.709-6;
• PQ (Perceptual Quantizer): used for HDR display, allows luminance range capability of 0 to 10,000 nits; standardized by SMPTE ST 2084.

These capabilities vary depending on the hardware block, with some utilizing hardcoded curves and others relying on AMD s color module to construct curves from standardized coefficients. It also supports user/custom curves built from a lookup table.

1D LUTs (1-dimensional Lookup Table): A 1D LUT is a versatile tool, defining a one-dimensional color transformation based on a single parameter. It s very well explained by Jeremy Selan at GPU Gems 2 - Chapter 24 Using Lookup Tables to Accelerate Color Transformations It enables adjustments to color, brightness, and contrast, making it ideal for fine-tuning. In the Linux AMD display driver, the atomic API offers a 1D LUT with 4096 entries and 8-bit depth, while legacy gamma uses a size of 256.

3D LUTs (3-dimensional Lookup Table): These tables work in three dimensions red, green, and blue. They re perfect for complex color transformations and adjustments between color channels. It s also more complex to manage and require more computational resources. Jeremy also explains 3D LUT at GPU Gems 2 - Chapter 24 Using Lookup Tables to Accelerate Color Transformations

CTM (Color Transformation Matrices): Color transformation matrices facilitate the transition between different color spaces, playing a crucial role in color space conversion.

HDR Multiplier: HDR multiplier is a factor applied to the color values of an image to increase their overall brightness.

AMD Color Capabilities in the Hardware Pipeline First, let s take a closer look at the AMD Display Core Next hardware pipeline in the Linux kernel documentation for AMDGPU driver - Display Core Next In the AMD Display Core Next hardware pipeline, we encounter two hardware blocks with color capabilities: the Display Pipe and Plane (DPP) and the Multiple Pipe/Plane Combined (MPC). The DPP handles color adjustments per plane before blending, while the MPC engages in post-blending color adjustments. In short, we expect DPP color capabilities to match up with DRM plane properties, and MPC color capabilities to play nice with DRM CRTC properties. Note: here s the catch there are some DRM CRTC color transformations that don t have a corresponding AMD MPC color block, and vice versa. It s like a puzzle, and we re here to solve it!

AMD Color Blocks and Capabilities We can finally talk about the color capabilities of each AMD color block. As it varies based on the generation of hardware, let s take the DCN3+ family as reference. What s possible to do before and after blending depends on hardware capabilities describe in the kernel driver by struct dpp_color_caps and struct mpc_color_caps. The AMD Steam Deck hardware provides a tangible example of these capabilities. Therefore, we take SteamDeck/DCN301 driver as an example and look at the Color pipeline capabilities described in the file: driver/gpu/drm/amd/display/dcn301/dcn301_resources.c

/* Color pipeline capabilities */
dc->caps.color.dpp.dcn_arch = 1; // If it is a Display Core Next (DCN): yes. Zero means DCE.
dc->caps.color.dpp.input_lut_shared = 0;
dc->caps.color.dpp.icsc = 1; // Intput Color Space Conversion  (CSC) matrix.
dc->caps.color.dpp.dgam_ram = 0; // The old degamma block for degamma curve (hardcoded and LUT).  Gamma correction  is the new one.
dc->caps.color.dpp.dgam_rom_caps.srgb = 1; // sRGB hardcoded curve support
dc->caps.color.dpp.dgam_rom_caps.bt2020 = 1; // BT2020 hardcoded curve support (seems not actually in use)
dc->caps.color.dpp.dgam_rom_caps.gamma2_2 = 1; // Gamma 2.2 hardcoded curve support
dc->caps.color.dpp.dgam_rom_caps.pq = 1; // PQ hardcoded curve support
dc->caps.color.dpp.dgam_rom_caps.hlg = 1; // HLG hardcoded curve support
dc->caps.color.dpp.post_csc = 1; // CSC matrix
dc->caps.color.dpp.gamma_corr = 1; // New  Gamma Correction  block for degamma user LUT;
dc->caps.color.dpp.dgam_rom_for_yuv = 0;
dc->caps.color.dpp.hw_3d_lut = 1; // 3D LUT support. If so, it's always preceded by a shaper curve. 
dc->caps.color.dpp.ogam_ram = 1; //  Blend Gamma  block for custom curve just after blending
// no OGAM ROM on DCN301
dc->caps.color.dpp.ogam_rom_caps.srgb = 0;
dc->caps.color.dpp.ogam_rom_caps.bt2020 = 0;
dc->caps.color.dpp.ogam_rom_caps.gamma2_2 = 0;
dc->caps.color.dpp.ogam_rom_caps.pq = 0;
dc->caps.color.dpp.ogam_rom_caps.hlg = 0;
dc->caps.color.dpp.ocsc = 0;
dc->caps.color.mpc.gamut_remap = 1; // Post-blending CTM (pre-blending CTM is always supported)
dc->caps.color.mpc.num_3dluts = pool->base.res_cap->num_mpc_3dlut; // Post-blending 3D LUT (preceded by shaper curve)
dc->caps.color.mpc.ogam_ram = 1; // Post-blending regamma.
// No pre-defined TF supported for regamma.
dc->caps.color.mpc.ogam_rom_caps.srgb = 0;
dc->caps.color.mpc.ogam_rom_caps.bt2020 = 0;
dc->caps.color.mpc.ogam_rom_caps.gamma2_2 = 0;
dc->caps.color.mpc.ogam_rom_caps.pq = 0;
dc->caps.color.mpc.ogam_rom_caps.hlg = 0;
dc->caps.color.mpc.ocsc = 1; // Output CSC matrix.

I included some inline comments in each element of the color caps to quickly describe them, but you can find the same information in the Linux kernel documentation. See more in struct dpp_color_caps, struct mpc_color_caps and struct rom_curve_caps. Now, using this guideline, we go through color capabilities of DPP and MPC blocks and talk more about mapping driver-specific properties to corresponding color blocks.

DPP Color Pipeline: Before Blending (Per Plane) Let s explore the capabilities of DPP blocks and what you can achieve with a color block. The very first thing to pay attention is the display architecture of the display hardware: previously AMD uses a display architecture called DCE

• Display and Compositing Engine, but newer hardware follows DCN - Display Core Next.

The architectute is described by: dc->caps.color.dpp.dcn_arch

AMD Plane Degamma: TF and 1D LUT Described by: dc->caps.color.dpp.dgam_ram, dc->caps.color.dpp.dgam_rom_caps,dc->caps.color.dpp.gamma_corr AMD Plane Degamma data is mapped to the initial stage of the DPP pipeline. It is utilized to transition from scanout/encoded values to linear values for arithmetic operations. Plane Degamma supports both pre-defined transfer functions and 1D LUTs, depending on the hardware generation. DCN2 and older families handle both types of curve in the Degamma RAM block (dc->caps.color.dpp.dgam_ram); DCN3+ separate hardcoded curves and 1D LUT into two block: Degamma ROM (dc->caps.color.dpp.dgam_rom_caps) and Gamma correction block (dc->caps.color.dpp.gamma_corr), respectively. Pre-defined transfer functions:

• they are hardcoded curves (read-only memory - ROM);
• supported curves: sRGB EOTF, BT.709 inverse OETF, PQ EOTF and HLG OETF, Gamma 2.2, Gamma 2.4 and Gamma 2.6 EOTF.

The 1D LUT currently accepts 4096 entries of 8-bit. The data is interpreted as an array of struct drm_color_lut elements. Setting TF = Identity/Default and LUT as NULL means bypass. References:

• [PATCH v3 04/32] drm/amd/display: add driver-specific property for plane degamma LUT
• [PATCH v3 05/32] drm/amd/display: add plane degamma TF driver-specific property
• [PATCH v3 19/32] drm/amd/display: add plane degamma TF and LUT support

AMD Plane 3x4 CTM (Color Transformation Matrix) AMD Plane CTM data goes to the DPP Gamut Remap block, supporting a 3x4 fixed point (s31.32) matrix for color space conversions. The data is interpreted as a struct drm_color_ctm_3x4. Setting NULL means bypass. References:

• [PATCH v3 30/32] drm/amd/display: add plane CTM driver-specific property
• [PATCH v3 31/32] drm/amd/display: add plane CTM support
• [PATCH v3 32/32] drm/amd/display: Add 3x4 CTM support for plane CTM

AMD Plane Shaper: TF + 1D LUT Described by: dc->caps.color.dpp.hw_3d_lut The Shaper block fine-tunes color adjustments before applying the 3D LUT, optimizing the use of the limited entries in each dimension of the 3D LUT. On AMD hardware, a 3D LUT always means a preceding shaper 1D LUT used for delinearizing and/or normalizing the color space before applying a 3D LUT, so this entry on DPP color caps dc->caps.color.dpp.hw_3d_lut means support for both shaper 1D LUT and 3D LUT. Pre-defined transfer function enables delinearizing content with or without shaper LUT, where AMD color module calculates the resulted shaper curve. Shaper curves go from linear values to encoded values. If we are already in a non-linear space and/or don t need to normalize values, we can set a Identity TF for shaper that works similar to bypass and is also the default TF value. Pre-defined transfer functions:

• there is no DPP Shaper ROM. Curves are calculated by AMD color modules. Check calculate_curve() function in the file amd/display/modules/color/color_gamma.c.
• supported curves: Identity, sRGB inverse EOTF, BT.709 OETF, PQ inverse EOTF, HLG OETF, and Gamma 2.2, Gamma 2.4, Gamma 2.6 inverse EOTF.

The 1D LUT currently accepts 4096 entries of 8-bit. The data is interpreted as an array of struct drm_color_lut elements. When setting Plane Shaper TF (!= Identity) and LUT at the same time, the color module will combine the pre-defined TF and the custom LUT values into the LUT that s actually programmed. Setting TF = Identity/Default and LUT as NULL works as bypass. References:

• [PATCH v3 10/32] drm/amd/display: add plane shaper LUT and TF
• [PATCH v3 23/32] drm/amd/display: add plane shaper LUT support
• [PATCH v3 24/32] drm/amd/display: add plane shaper TF support

AMD Plane 3D LUT Described by: dc->caps.color.dpp.hw_3d_lut The 3D LUT in the DPP block facilitates complex color transformations and adjustments. 3D LUT is a three-dimensional array where each element is an RGB triplet. As mentioned before, the dc->caps.color.dpp.hw_3d_lut describe if DPP 3D LUT is supported. The AMD driver-specific property advertise the size of a single dimension via LUT3D_SIZE property. Plane 3D LUT is a blog property where the data is interpreted as an array of struct drm_color_lut elements and the number of entries is LUT3D_SIZE cubic. The array contains samples from the approximated function. Values between samples are estimated by tetrahedral interpolation The array is accessed with three indices, one for each input dimension (color channel), blue being the outermost dimension, red the innermost. This distribution is better visualized when examining the code in [RFC PATCH 5/5] drm/amd/display: Fill 3D LUT from userspace by Alex Hung:

+	for (nib = 0; nib < 17; nib++)  
+		for (nig = 0; nig < 17; nig++)  
+			for (nir = 0; nir < 17; nir++)  
+				ind_lut = 3 * (nib + 17*nig + 289*nir);
+
+				rgb_area[ind].red = rgb_lib[ind_lut + 0];
+				rgb_area[ind].green = rgb_lib[ind_lut + 1];
+				rgb_area[ind].blue = rgb_lib[ind_lut + 2];
+				ind++;
+			 
+		 
+	 

In our driver-specific approach we opted to advertise it s behavior to the userspace instead of implicitly dealing with it in the kernel driver. AMD s hardware supports 3D LUTs with 17-size or 9-size (4913 and 729 entries respectively), and you can choose between 10-bit or 12-bit. In the current driver-specific work we focus on enabling only 17-size 12-bit 3D LUT, as in [PATCH v3 25/32] drm/amd/display: add plane 3D LUT support:

+		/* Stride and bit depth are not programmable by API yet.
+		 * Therefore, only supports 17x17x17 3D LUT (12-bit).
+		 */
+		lut->lut_3d.use_tetrahedral_9 = false;
+		lut->lut_3d.use_12bits = true;
+		lut->state.bits.initialized = 1;
+		__drm_3dlut_to_dc_3dlut(drm_lut, drm_lut3d_size, &lut->lut_3d,
+					lut->lut_3d.use_tetrahedral_9,
+					MAX_COLOR_3DLUT_BITDEPTH);

A refined control of 3D LUT parameters should go through a follow-up version or generic API. Setting 3D LUT to NULL means bypass. References:

• [PATCH v3 09/32] drm/amd/display: add plane 3D LUT driver-specific properties
• [PATCH v3 25/32] drm/amd/display: add plane 3D LUT support

AMD Plane Blend/Out Gamma: TF + 1D LUT Described by: dc->caps.color.dpp.ogam_ram The Blend/Out Gamma block applies the final touch-up before blending, allowing users to linearize content after 3D LUT and just before the blending. It supports both 1D LUT and pre-defined TF. We can see Shaper and Blend LUTs as 1D LUTs that are sandwich the 3D LUT. So, if we don t need 3D LUT transformations, we may want to only use Degamma block to linearize and skip Shaper, 3D LUT and Blend. Pre-defined transfer function:

• there is no DPP Blend ROM. Curves are calculated by AMD color modules;
• supported curves: Identity, sRGB EOTF, BT.709 inverse OETF, PQ EOTF, HLG inverse OETF, and Gamma 2.2, Gamma 2.4, Gamma 2.6 EOTF.

The 1D LUT currently accepts 4096 entries of 8-bit. The data is interpreted as an array of struct drm_color_lut elements. If plane_blend_tf_property != Identity TF, AMD color module will combine the user LUT values with pre-defined TF into the LUT parameters to be programmed. Setting TF = Identity/Default and LUT to NULL means bypass. References:

• [PATCH v3 11/32] drm/amd/display: add plane blend
• [PATCH v3 27/32] drm/amd/display: add plane blend LUT and TF support

MPC Color Pipeline: After Blending (Per CRTC)

DRM CRTC Degamma 1D LUT The degamma lookup table (LUT) for converting framebuffer pixel data before apply the color conversion matrix. The data is interpreted as an array of struct drm_color_lut elements. Setting NULL means bypass. Not really supported. The driver is currently reusing the DPP degamma LUT block (dc->caps.color.dpp.dgam_ram and dc->caps.color.dpp.gamma_corr) for supporting DRM CRTC Degamma LUT, as explaning by [PATCH v3 20/32] drm/amd/display: reject atomic commit if setting both plane and CRTC degamma.

DRM CRTC 3x3 CTM Described by: dc->caps.color.mpc.gamut_remap It sets the current transformation matrix (CTM) apply to pixel data after the lookup through the degamma LUT and before the lookup through the gamma LUT. The data is interpreted as a struct drm_color_ctm. Setting NULL means bypass.

DRM CRTC Gamma 1D LUT + AMD CRTC Gamma TF Described by: dc->caps.color.mpc.ogam_ram After all that, you might still want to convert the content to wire encoding. No worries, in addition to DRM CRTC 1D LUT, we ve got a AMD CRTC gamma transfer function (TF) to make it happen. Possible TF values are defined by enum amdgpu_transfer_function. Pre-defined transfer functions:

• there is no MPC Gamma ROM. Curves are calculated by AMD color modules.
• supported curves: Identity, sRGB inverse EOTF, BT.709 OETF, PQ inverse EOTF, HLG OETF, and Gamma 2.2, Gamma 2.4, Gamma 2.6 inverse EOTF.

The 1D LUT currently accepts 4096 entries of 8-bit. The data is interpreted as an array of struct drm_color_lut elements. When setting CRTC Gamma TF (!= Identity) and LUT at the same time, the color module will combine the pre-defined TF and the custom LUT values into the LUT that s actually programmed. Setting TF = Identity/Default and LUT to NULL means bypass. References:

• [PATCH v3 12/32] drm/amd/display: add CRTC gamma TF driver-specific property
• [PATCH v3 15/32] drm/amd/display: add CRTC gamma TF support

Others

AMD CRTC Shaper and 3D LUT We have previously worked on exposing CRTC shaper and CRTC 3D LUT, but they were removed from the AMD driver-specific color series because they lack userspace case. CRTC shaper and 3D LUT works similar to plane shaper and 3D LUT but after blending (MPC block). The difference here is that setting (not bypass) Shaper and Gamma blocks together are not expected, since both blocks are used to delinearize the input space. In summary, we either set Shaper + 3D LUT or Gamma.

Input and Output Color Space Conversion There are two other color capabilities of AMD display hardware that were integrated to DRM by previous works and worth a brief explanation here. The DC Input CSC sets pre-defined coefficients from the values of DRM plane color_range and color_encoding properties. It is used for color space conversion of the input content. On the other hand, we have de DC Output CSC (OCSC) sets pre-defined coefficients from DRM connector colorspace properties. It is uses for color space conversion of the composed image to the one supported by the sink. References:

• [PATCH] amd/display/dc: Fix COLOR_ENCODING and COLOR_RANGE doing nothing for DCN20+
• [PATCH v6 00/13] Enable Colorspace connector property in amdgpu

The search for rainbow treasures is not over yet If you want to understand a little more about this work, be sure to watch Joshua and I presented two talks at XDC 2023 about AMD/Steam Deck colors on Gamescope:

• The rainbow treasure map: advanced color management on Linux with AMD/Steam Deck
• Rainbow Frogs: HDR + Color Management in Gamescope/SteamOS

In the time between the first and second part of this blog post, Uma Shashank and Chaitanya Kumar Borah published the plane color pipeline for Intel and Harry Wentland implemented a generic API for DRM based on VKMS support. We discussed these two proposals and the next steps for Color on Linux during the Color Management workshop at XDC 2023 and I briefly shared workshop results in the 2023 XDC lightning talk session. The search for rainbow treasures is not over yet! We plan to meet again next year in the 2024 Display Hackfest in Coru a-Spain (Igalia s HQ) to keep up the pace and continue advancing today s display needs on Linux. Finally, a HUGE thank you to everyone who worked with me on exploring AMD s color capabilities and making them available in userspace.

TL;DR: Color is a visual perception. Human eyes can detect a broader range of colors than any devices in the graphics chain. Since each device can generate, capture or reproduce a specific subset of colors and tones, color management controls color conversion and calibration across devices to ensure a more accurate and consistent color representation. We can expose a GPU-accelerated display color management pipeline to support this process and enhance results, and this is what we are doing on Linux to improve color management on Gamescope/SteamDeck. Even with the challenges of being external developers, we have been working on mapping AMD GPU color capabilities to the Linux kernel color management interface, which is a combination of DRM and AMD driver-specific color properties. This more extensive color management pipeline includes pre-defined Transfer Functions, 1-Dimensional LookUp Tables (1D LUTs), and 3D LUTs before and after the plane composition/blending.

---

The study of color is well-established and has been explored for many years. Color science and research findings have also guided technology innovations. As a result, color in Computer Graphics is a very complex topic that I m putting a lot of effort into becoming familiar with. I always find myself rereading all the materials I have collected about color space and operations since I started this journey (about one year ago). I also understand how hard it is to find consensus on some color subjects, as exemplified by all explanations around the 2015 online viral phenomenon of The Black and Blue Dress. Have you heard about it? What is the color of the dress for you? So, taking into account my skills with colors and building consensus, this blog post only focuses on GPU hardware capabilities to support color management :-D If you want to learn more about color concepts and color on Linux, you can find useful links at the end of this blog post.

Linux Kernel, show me the colors ;D DRM color management interface only exposes a small set of post-blending color properties. Proposals to enhance the DRM color API from different vendors have landed the subsystem mailing list over the last few years. On one hand, we got some suggestions to extend DRM post-blending/CRTC color API: DRM CRTC 3D LUT for R-Car (2020 version); DRM CRTC 3D LUT for Intel (draft - 2020); DRM CRTC 3D LUT for AMD by Igalia (v2 - 2023); DRM CRTC 3D LUT for R-Car (v2 - 2023). On the other hand, some proposals to extend DRM pre-blending/plane API: DRM plane colors for Intel (v2 - 2021); DRM plane API for AMD (v3 - 2021); DRM plane 3D LUT for AMD - 2021. Finally, Simon Ser sent the latest proposal in May 2023: Plane color pipeline KMS uAPI, from discussions in the 2023 Display/HDR Hackfest, and it is still under evaluation by the Linux Graphics community. All previous proposals seek a generic solution for expanding the API, but many seem to have stalled due to the uncertainty of matching well the hardware capabilities of all vendors. Meanwhile, the use of AMD color capabilities on Linux remained limited by the DRM interface, as the DCN 3.0 family color caps and mapping diagram below shows the Linux/DRM color interface without driver-specific color properties [*]: Bearing in mind that we need to know the variety of color pipelines in the subsystem to be clear about a generic solution, we decided to approach the issue from a different perspective and worked on enabling a set of Driver-Specific Color Properties for AMD Display Drivers. As a result, I recently sent another round of the AMD driver-specific color mgmt API. For those who have been following the AMD driver-specific proposal since the beginning (see [RFC][V1]), the main new features of the latest version [v2] are the addition of pre-blending Color Transformation Matrix (plane CTM) and the differentiation of Pre-defined Transfer Functions (TF) supported by color blocks. For those who just got here, I will recap this work in two blog posts. This one describes the current status of the AMD display driver in the Linux kernel/DRM subsystem and what changes with the driver-specific properties. In the next post, we go deeper to describe the features of each color block and provide a better picture of what is available in terms of color management for Linux.

The Linux kernel color management API and AMD hardware color capabilities Before discussing colors in the Linux kernel with AMD hardware, consider accessing the Linux kernel documentation (version 6.5.0-rc5). In the AMD Display documentation, you will find my previous work documenting AMD hardware color capabilities and the Color Management Properties. It describes how AMD Display Manager (DM) intermediates requests between the AMD Display Core component (DC) and the Linux/DRM kernel interface for color management features. It also describes the relevant function to call the AMD color module in building curves for content space transformations. A subsection also describes hardware color capabilities and how they evolve between versions. This subsection, DC Color Capabilities between DCN generations, is a good starting point to understand what we have been doing on the kernel side to provide a broader color management API with AMD driver-specific properties.

Why do we need more kernel color properties on Linux? Blending is the process of combining multiple planes (framebuffers abstraction) according to their mode settings. Before blending, we can manage the colors of various planes separately; after blending, we have combined those planes in only one output per CRTC. Color conversions after blending would be enough in a single-plane scenario or when dealing with planes in the same color space on the kernel side. Still, it cannot help to handle the blending of multiple planes with different color spaces and luminance levels. With plane color management properties, userspace can get a more accurate representation of colors to deal with the diversity of color profiles of devices in the graphics chain, bring a wide color gamut (WCG), convert High-Dynamic-Range (HDR) content to Standard-Dynamic-Range (SDR) content (and vice-versa). With a GPU-accelerated display color management pipeline, we can use hardware blocks for color conversions and color mapping and support advanced color management. The current DRM color management API enables us to perform some color conversions after blending, but there is no interface to calibrate input space by planes. Note that here I m not considering some workarounds in the AMD display manager mapping of DRM CRTC de-gamma and DRM CRTC CTM property to pre-blending DC de-gamma and gamut remap block, respectively. So, in more detail, it only exposes three post-blending features:

• DRM CRTC de-gamma: used to convert the framebuffer s colors to linear gamma;
• DRM CRTC CTM: used for color space conversion;
• DRM CRTC gamma: used to convert colors to the gamma space of the connected screen.

AMD driver-specific color management interface We can compare the Linux color management API with and without the driver-specific color properties. From now, we denote driver-specific properties with the AMD prefix and generic properties with the DRM prefix. For visual comparison, I bring the DCN 3.0 family color caps and mapping diagram closer and present it here again: Mixing AMD driver-specific color properties with DRM generic color properties, we have a broader Linux color management system with the following features exposed by properties in the plane and CRTC interface, as summarized by this updated diagram: The blocks highlighted by red lines are the new properties in the driver-specific interface developed by me (Igalia) and Joshua (Valve). The red dashed lines are new links between API and AMD driver components implemented by us to connect the Linux/DRM interface to AMD hardware blocks, mapping components accordingly. In short, we have the following color management properties exposed by the DRM/AMD display driver:

• Pre-blending - AMD Display Pipe and Plane (DPP):
  • AMD plane de-gamma: 1D LUT and pre-defined transfer functions; used to linearize the input space of a plane;
  • AMD plane CTM: 3x4 matrix; used to convert plane color space;
  • AMD plane shaper: 1D LUT and pre-defined transfer functions; used to delinearize and/or normalize colors before applying 3D LUT;
  • AMD plane 3D LUT: 17x17x17 size with 12 bit-depth; three dimensional lookup table used for advanced color mapping;
  • AMD plane blend/out gamma: 1D LUT and pre-defined transfer functions; used to linearize back the color space after 3D LUT for blending.
• Post-blending - AMD Multiple Pipe/Plane Combined (MPC):
  • DRM CRTC de-gamma: 1D LUT (can t be set together with plane de-gamma);
  • DRM CRTC CTM: 3x3 matrix (remapped to post-blending matrix);
  • DRM CRTC gamma: 1D LUT + AMD CRTC gamma TF; added to take advantage of driver pre-defined transfer functions;

Note: You can find more about AMD display blocks in the Display Core Next (DCN) - Linux kernel documentation, provided by Rodrigo Siqueira (Linux/AMD display developer) in a 2021-documentation series. In the next post, I ll revisit this topic, explaining display and color blocks in detail.

How did we get a large set of color features from AMD display hardware? So, looking at AMD hardware color capabilities in the first diagram, we can see no post-blending (MPC) de-gamma block in any hardware families. We can also see that the AMD display driver maps CRTC/post-blending CTM to pre-blending (DPP) gamut_remap, but there is post-blending (MPC) gamut_remap (DRM CTM) from newer hardware versions that include SteamDeck hardware. You can find more details about hardware versions in the Linux kernel documentation/AMDGPU Product Information. I needed to rework these two mappings mentioned above to provide pre-blending/plane de-gamma and CTM for SteamDeck. I changed the DC mapping to detach stream gamut remap matrixes from the DPP gamut remap block. That means mapping AMD plane CTM directly to DPP/pre-blending gamut remap block and DRM CRTC CTM to MPC/post-blending gamut remap block. In this sense, I also limited plane CTM properties to those hardware versions with MPC/post-blending gamut_remap capabilities since older versions cannot support this feature without clashes with DRM CRTC CTM. Unfortunately, I couldn t prevent conflict between AMD plane de-gamma and DRM plane de-gamma since post-blending de-gamma isn t available in any AMD hardware versions until now. The fact is that a post-blending de-gamma makes little sense in the AMD color pipeline, where plane blending works better in a linear space, and there are enough color blocks to linearize content before blending. To deal with this conflict, the driver now rejects atomic commits if users try to set both AMD plane de-gamma and DRM CRTC de-gamma simultaneously. Finally, we had no other clashes when enabling other AMD driver-specific color properties for our use case, Gamescope/SteamDeck. Our main work for the remaining properties was understanding the data flow of each property, the hardware capabilities and limitations, and how to shape the data for programming the registers - AMD color block capabilities (and limitations) are the topics of the next blog post. Besides that, we fixed some driver bugs along the way since it was the first Linux use case for most of the new color properties, and some behaviors are only exposed when exercising the engine. Take a look at the Gamescope/Steam Deck Color Pipeline[**], and see how Gamescope uses the new API to manage color space conversions and calibration (please click on the image for a better view): In the next blog post, I ll describe the implementation and technical details of each pre- and post-blending color block/property on the AMD display driver. * Thank Harry Wentland for helping with diagrams, color concepts and AMD capabilities. ** Thank Joshua Ashton for providing and explaining Gamescope/Steam Deck color pipeline. *** Thanks to the Linux Graphics community - explicitly Harry, Joshua, Pekka, Simon, Sebastian, Siqueira, Alex H. and Ville - to all the learning during this Linux DRM/AMD color journey. Also, Carlos and Tomas for organizing the 2023 Display/HDR Hackfest where we have a great and immersive opportunity to discuss Color & HDR on Linux.

Useful Links

1. Cinematic Color - 2012 SIGGRAPH course notes by Jeremy Selan: an introduction to color science, concepts and pipelines.
2. Color management and HDR documentation for FOSS graphics by Pekka Paalanen: documentation and useful links on applying color concepts to the Linux graphics stack.
3. HDR in Linux by Jeremy Cline: a blog post exploring color concepts for HDR support on Linux.
4. Methods for conversion of high dynamic range content to standard dynamic range content and vice-versa by ITU-R: guideline for conversions between HDR and SDR contents.
5. Using Lookup Tables to Accelerate Color Transformations by Jeremy Selan: Nvidia blog post about Lookup Tables on color management.
6. The Importance of Being Linear by Larry Gritz and Eugene d Eon: Nvidia blog post about gamma and color conversions.

Pearls of Luthra Pearls of Luthra is the first book by Brian Jacques and I think I am going to be a fan of his work. This particular book you have to be wary of. While it is a beautiful book with quite a few illustrations, I have to warn that if you are somebody who feels hungry at the very mention of food, then you will be hungry throughout the book. There isn t a single page where food isn t mentioned and not just any kind of food, the kind of food that is geared towards sweet tooth. So if you fancy tarts or chocolates or anything sweet you will right at home. The book also touches upon various teas and wines and various liquors but food is where it shines in literally. The tale is very much like a Harry Potter adventure but isn t as dark as HP was. In fact, apart from one death and one ear missing rest of our heroes and heroines and there are quite a few. I don t want to give too much away as it s a book to be treasured.

Dahaad Dahaad (the roar) is Sonakshi Sinha s entry in OTT/Web Series. The stage is set somewhere in North India while the exploits are based on a real life person called Cyanide Mohan who killed 20 women between 2005-2009. In the web series however, the antagonist s crimes are done over a period of 12 years and has 29 women as his victims. Apart from that it s pretty much a copy of what was done by the person above. It s a melting pot of a series which quite a few stories enmeshed along with the main one. The main onus and plot of the movie is about women from lower economic and caste order whose families want them to be wed but cannot due to huge demands for dowry. Now in such a situation, if a person were to give them a bit of attention, promise marriage and ask them to steal a bit and come with him and whatever, they will do it. The same modus operandi was done by Cynaide Mohan. He had a car that was not actually is but used it show off that he s from a richer background, entice the women, have sex, promise marriage and in the morning after pill there will be cynaide which the women unwittingly will consume. This is also framed by the protagonist Sonakshi Sinha to her mother as her mother is also forcing her to get married as she is becoming older. She shows some of the photographs of the victims and says that while the perpetrator is guilty but so is the overall society that puts women in such vulnerable positions. AFAIK, that is still the state of things. In fact, there is a series called Indian Matchmaking that has all the snobbishness that you want. How many people could have a lifestyle like the ones shown in that, less than 2% of the population. It s actually shows like the above that make the whole thing even more precarious Apart from it, the show also shows prejudice about caste and background. I wouldn t go much into it as it s worth seeing and experiencing.

Tetris Tetris in many a ways is a story of greed. It s also a story of a lone inventor who had to wait almost 20 odd years to profit from his invention. Forbes does a marvelous job of giving some more background and foreground info. about Tetris, the inventor and the producer that went to strike it rich. It also does share about copyright misrepresentation happens but does nothing to address it. Could talk a whole lot but better to see the movie and draw your own conclusions. For me it was 4/5.

Discord Discord became Discord 2.0 and is a blank to me. A blank page. Can t do anything. First I thought it was a bug. Waited for a few days as sometimes webservices do fix themselves. But two weeks on and it still wasn t fixed then decided to look under. One of the tools in Firefox is Web Developer Tools ( CTRL+Shift+I) that tells you if an element of a page is not appearing or at least gives you a hint. To me it gave me the following
Content Security Policy: Ignoring 'unsafe-inline' within script-src or style-src: nonce-source or hash-source specified
Content Security Policy: The page s settings blocked the loading of a resource at data:text/css,%0A%20%20%20%20%20%20%20%2 ( style-src ). data:44:30
Content Security Policy: Ignoring 'unsafe-inline' within script-src or style-src: nonce-source or hash-source specified
TypeError: AudioContext is not a constructor 138875 https://discord.com/assets/cbf3a75da6e6b6a4202e.js:262 l https://discord.com/assets/f5f0b113e28d4d12ba16.js:1ed46a18578285e5c048b.js:241:118 What is being done is dom.webaudio.enabled being disabled in Firefox. Then on a hunch, searched on reddit and saw the following. Be careful while visiting the link as it s labelled NSFW although to my mind there wasn t anything remotely NSFW about it. They do mention using another tool AudioContext Fingerprint Defender which supposedly fakes or spoofs an id. As this add-on isn t tracked by Firefox privacy team it s hard for me to say anything positive or negative. So, in the end I stopped using discord as the alternative was being tracked by them Last but not the least, saw this about a week back. Sooner or later this had to happen as Elon tries to make money off Twitter.

In my three most recent posts, I went over the memoirs and biographies, classics and fiction books that I enjoyed the most in 2022. But in the last of my book-related posts for 2022, I'll be going over my favourite works of non-fiction. Books that just missed the cut here include Adam Hochschild's King Leopold's Ghost (1998) on the role of Leopold II of Belgium in the Congo Free State, Johann Hari's Stolen Focus (2022) (a personal memoir on relating to how technology is increasingly fragmenting our attention), Amia Srinivasan's The Right to Sex (2021) (a misleadingly named set of philosophic essays on feminism), Dana Heller et al.'s The Selling of 9/11: How a National Tragedy Became a Commodity (2005), John Berger's mindbending Ways of Seeing (1972) and Louise Richardson's What Terrorists Want (2006).

The Great War and Modern Memory (1975)
Wartime: Understanding and Behavior in the Second World War (1989) Paul Fussell Rather than describe the battles, weapons, geopolitics or big personalities of the two World Wars, Paul Fussell's The Great War and Modern Memory & Wartime are focused instead on how the two wars have been remembered by their everyday participants. Drawing on the memoirs and memories of soldiers and civilians along with a brief comparison with the actual events that shaped them, Fussell's two books are a compassionate, insightful and moving piece of analysis. Fussell primarily sets himself against the admixture of nostalgia and trauma that obscures the origins and unimaginable experience of participating in these wars; two wars that were, in his view, a "perceptual and rhetorical scandal from which total recovery is unlikely." He takes particular aim at the dishonesty of hindsight:

For the past fifty years, the Allied war has been sanitised and romanticised almost beyond recognition by the sentimental, the loony patriotic, the ignorant and the bloodthirsty. I have tried to balance the scales. [And] in unbombed America especially, the meaning of the war [seems] inaccessible.

The author does not engage in any of the customary rose-tinted view of war, yet he remains understanding and compassionate towards those who try to locate a reason within what was quite often senseless barbarism. If anything, his despondency and pessimism about the Second World War (the war that Fussell himself fought in) shines through quite acutely, and this is especially the case in what he chooses to quote from others:

"It was common [ ] throughout the [Okinawa] campaign for replacements to get hit before we even knew their names. They came up confused, frightened, and hopeful, got wounded or killed, and went right back to the rear on the route by which they had come, shocked, bleeding, or stiff. They were forlorn figures coming up to the meat grinder and going right back out of it like homeless waifs, unknown and faceless to us, like unread books on a shelf."

It would take a rather heartless reader to fail to be sobered by this final simile, and an even colder one to view Fussell's citation of such an emotive anecdote to be manipulative. Still, stories and cruel ironies like this one infuse this often-angry book, but it is not without astute and shrewd analysis as well, especially on the many qualitative differences between the two conflicts that simply cannot be captured by facts and figures alone. For example:

A measure of the psychological distance of the Second [World] War from the First is the rarity, in 1914 1918, of drinking and drunkenness poems.

Indeed so. In fact, what makes Fussell's project so compelling and perhaps even unique is that he uses these non-quantitive measures to try and take stock of what happened. After all, this was a war conducted by humans, not the abstract school of statistics. And what is the value of a list of armaments destroyed by such-and-such a regiment when compared with truly consequential insights into both how the war affected, say, the psychology of postwar literature ("Prolonged trench warfare, whether enacted or remembered, fosters paranoid melodrama, which I take to be a primary mode in modern writing."), the specific words adopted by combatants ("It is a truism of military propaganda that monosyllabic enemies are easier to despise than others") as well as the very grammar of interaction:

The Field Service Post Card [in WW1] has the honour of being the first widespread exemplary of that kind of document which uniquely characterises the modern world: the "Form". [And] as the first widely known example of dehumanised, automated communication, the post card popularised a mode of rhetoric indispensable to the conduct of later wars fought by great faceless conscripted armies.

And this wouldn't be a book review without argument-ending observations that:

Indicative of the German wartime conception [of victory] would be Hitler and Speer's elaborate plans for the ultimate reconstruction of Berlin, which made no provision for a library.

Our myths about the two world wars possess an undisputed power, in part because they contain an essential truth the atrocities committed by Germany and its allies were not merely extreme or revolting, but their full dimensions (embodied in the Holocaust and the Holodomor) remain essentially inaccessible within our current ideological framework. Yet the two wars are better understood as an abyss in which we were all dragged into the depths of moral depravity, rather than a battle pitched by the forces of light against the forces of darkness. Fussell is one of the few observers that can truly accept and understand this truth and is still able to speak to us cogently on the topic from the vantage point of experience. The Second World War which looms so large in our contemporary understanding of the modern world (see below) may have been necessary and unavoidable, but Fussell convinces his reader that it was morally complicated "beyond the power of any literary or philosophic analysis to suggest," and that the only way to maintain a na ve belief in the myth that these wars were a Manichaean fight between good and evil is to overlook reality. There are many texts on the two World Wars that can either stir the intellect or move the emotions, but Fussell's two books do both. A uniquely perceptive and intelligent commentary; outstanding.

Longitude (1995) Dava Sobel Since Man first decided to sail the oceans, knowing one's location has always been critical. Yet doing so reliably used to be a serious problem if you didn't know where you were, you are far more likely to die and/or lose your valuable cargo. But whilst finding one's latitude (ie. your north south position) had effectively been solved by the beginning of the 17th century, finding one's (east west) longitude was far from trustworthy in comparison. This book first published in 1995 is therefore something of an anachronism. As in, we readily use the GPS facilities of our phones today without hesitation, so we find it difficult to imagine a reality in which knowing something fundamental like your own location is essentially unthinkable. It became clear in the 18th century, though, that in order to accurately determine one's longitude, what you actually needed was an accurate clock. In Longitude, therefore, we read of the remarkable story of John Harrison and his quest to create a timepiece that would not only keep time during a long sea voyage but would survive the rough ocean conditions as well. Self-educated and a carpenter by trade, Harrison made a number of important breakthroughs in keeping accurate time at sea, and Longitude describes his novel breakthroughs in a way that is both engaging and without talking down to the reader. Still, this book covers much more than that, including the development of accurate longitude going hand-in-hand with advancements in cartography as well as in scientific experiments to determine the speed of light: experiments that led to the formulation of quantum mechanics. It also outlines the work being done by Harrison's competitors. 'Competitors' is indeed the correct word here, as Parliament offered a huge prize to whoever could create such a device, and the ramifications of this tremendous financial incentive are an essential part of this story. For the most part, though, Longitude sticks to the story of Harrison and his evolving obsession with his creating the perfect timepiece. Indeed, one reason that Longitude is so resonant with readers is that many of the tropes of the archetypical 'English inventor' are embedded within Harrison himself. That is to say, here is a self-made man pushing against the establishment of the time, with his groundbreaking ideas being underappreciated in his life, or dishonestly purloined by his intellectual inferiors. At the level of allegory, then, I am minded to interpret this portrait of Harrison as a symbolic distillation of postwar Britain a nation acutely embarrassed by the loss of the Empire that is now repositioning itself as a resourceful but plucky underdog; a country that, with a combination of the brains of boffins and a healthy dose of charisma and PR, can still keep up with the big boys. (It is this same search for postimperial meaning I find in the fiction of John le Carr , and, far more famously, in the James Bond franchise.) All of this is left to the reader, of course, as what makes Longitute singularly compelling is its gentle manner and tone. Indeed, at times it was as if the doyenne of sci-fi Ursula K. LeGuin had a sideline in popular non-fiction. I realise it's a mark of critical distinction to downgrade the importance of popular science in favour of erudite academic texts, but Latitude is ample evidence that so-called 'pop' science need not be patronising or reductive at all.

Closed Chambers: The Rise, Fall, and Future of the Modern Supreme Court (1998) Edward Lazarus After the landmark decision by the U.S. Supreme Court in *Dobbs v. Jackson Women's Health Organization that ended the Constitutional right to abortion conferred by Roe v Wade, I prioritised a few books in the queue about the judicial branch of the United States. One of these books was Closed Chambers, which attempts to assay, according to its subtitle, "The Rise, Fall and Future of the Modern Supreme Court". This book is not merely simply a learned guide to the history and functioning of the Court (although it is completely creditable in this respect); it's actually an 'insider' view of the workings of the institution as Lazurus was a clerk for Justice Harry Blackmun during the October term of 1988. Lazarus has therefore combined his experience as a clerk and his personal reflections (along with a substantial body of subsequent research) in order to communicate the collapse in comity between the Justices. Part of this book is therefore a pure history of the Court, detailing its important nineteenth-century judgements (such as Dred Scott which ruled that the Constitution did not consider Blacks to be citizens; and Plessy v. Ferguson which failed to find protection in the Constitution against racial segregation laws), as well as many twentieth-century cases that touch on the rather technical principle of substantive due process. Other layers of Lazurus' book are explicitly opinionated, however, and they capture the author's assessment of the Court's actions in the past and present [1998] day. Given the role in which he served at the Court, particular attention is given by Lazarus to the function of its clerks. These are revealed as being far more than the mere amanuenses they were hitherto believed to be. Indeed, the book is potentially unique in its the claim that the clerks have played a pivotal role in the deliberations, machinations and eventual rulings of the Court. By implication, then, the clerks have plaedy a crucial role in the internal controversies that surround many of the high-profile Supreme Court decisions decisions that, to the outsider at least, are presented as disinterested interpretations of Constitution of the United States. This is of especial importance given that, to Lazarus, "for all the attention we now pay to it, the Court remains shrouded in confusion and misunderstanding." Throughout his book, Lazarus complicates the commonplace view that the Court is divided into two simple right vs. left political factions, and instead documents an ever-evolving series of loosely held but strongly felt series of cabals, quid pro quo exchanges, outright equivocation and pure personal prejudices. (The age and concomitant illnesses of the Justices also appears to have a not insignificant effect on the Court's rulings as well.) In other words, Closed Chambers is not a book that will be read in a typical civics class in America, and the only time the book resorts to the customary breathless rhetoric about the US federal government is in its opening chapter:

The Court itself, a Greek-style temple commanding the crest of Capitol Hill, loomed above them in the dim light of the storm. Set atop a broad marble plaza and thirty-six steps, the Court stands in splendid isolation appropriate to its place at the pinnacle of the national judiciary, one of the three independent and "coequal" branches of American government. Once dubbed the Ivory Tower by architecture critics, the Court has a Corinthian colonnade and massive twenty-foot-high bronze doors that guard the single most powerful judicial institution in the Western world. Lights still shone in several offices to the right of the Court's entrance, and [ ]

Et cetera, et cetera. But, of course, this encomium to the inherent 'nobility' of the Supreme Court is quickly revealed to be a narrative foil, as Lazarus soon razes this dangerously na ve conception to the ground:

[The] institution is [now] broken into unyielding factions that have largely given up on a meaningful exchange of their respective views or, for that matter, a meaningful explication or defense of their own views. It is of Justices who in many important cases resort to transparently deceitful and hypocritical arguments and factual distortions as they discard judicial philosophy and consistent interpretation in favor of bottom-line results. This is a Court so badly splintered, yet so intent on lawmaking, that shifting 5-4 majorities, or even mere pluralities, rewrite whole swaths of constitutional law on the authority of a single, often idiosyncratic vote. It is also a Court where Justices yield great and excessive power to immature, ideologically driven clerks, who in turn use that power to manipulate their bosses and the institution they ostensibly serve.

Lazurus does not put forward a single, overarching thesis, but in the final chapters, he does suggest a potential future for the Court:

In the short run, the cure for what ails the Court lies solely with the Justices. It is their duty, under the shield of life tenure, to recognize the pathologies affecting their work and to restore the vitality of American constitutionalism. Ultimately, though, the long-term health of the Court depends on our own resolve on whom [we] select to join that institution.

Back in 1998, Lazurus might have had room for this qualified optimism. But from the vantage point of 2022, it appears that the "resolve" of the United States citizenry was not muscular enough to meet his challenge. After all, Lazurus was writing before Bush v. Gore in 2000, which arrogated to the judicial branch the ability to decide a presidential election; the disillusionment of Barack Obama's failure to nominate a replacement for Scalia; and many other missteps in the Court as well. All of which have now been compounded by the Trump administration's appointment of three Republican-friendly justices to the Court, including hypocritically appointing Justice Barrett a mere 38 days before the 2020 election. And, of course, the leaking and ruling in Dobbs v. Jackson, the true extent of which has not been yet. Not of a bit of this is Lazarus' fault, of course, but the Court's recent decisions (as well as the liberal hagiographies of 'RBG') most perforce affect one's reading of the concluding chapters. The other slight defect of Closed Chambers is that, whilst it often implies the importance of the federal and state courts within the judiciary, it only briefly positions the Supreme Court's decisions in relation to what was happening in the House, Senate and White House at the time. This seems to be increasingly relevant as time goes on: after all, it seems fairly clear even to this Brit that relying on an activist Supreme Court to enact progressive laws must be interpreted as a failure of the legislative branch to overcome the perennial problems of the filibuster, culture wars and partisan bickering. Nevertheless, Lazarus' book is in equal parts ambitious, opinionated, scholarly and dare I admit it? wonderfully gossipy. By juxtaposing history, memoir, and analysis, Closed Chambers combines an exacting evaluation of the Court's decisions with a lively portrait of the intellectual and emotional intensity that has grown within the Supreme Court's pseudo-monastic environment all while it struggles with the most impactful legal issues of the day. This book is an excellent and well-written achievement that will likely never be repeated, and a must-read for anyone interested in this ever-increasingly important branch of the US government.

Crashed: How a Decade of Financial Crises Changed the World (2018)
Shutdown: How Covid Shook the World's Economy (2021) Adam Tooze The economic historian Adam Tooze has often been labelled as an unlikely celebrity, but in the fourteen years since the global financial crisis of 2008, a growing audience has been looking for answers about the various failures of the modern economy. Tooze, a professor of history at New York's Columbia University, has written much that is penetrative and thought-provoking on this topic, and as a result, he has generated something of a cult following amongst economists, historians and the online left. I actually read two Tooze books this year. The first, Crashed (2018), catalogues the scale of government intervention required to prop up global finance after the 2008 financial crisis, and it characterises the different ways that countries around the world failed to live up to the situation, such as doing far too little, or taking action far too late. The connections between the high-risk subprime loans, credit default swaps and the resulting liquidity crisis in the US in late 2008 is fairly well known today in part thanks to films such as Adam McKay's 2015 The Big Short and much improved economic literacy in media reportage. But Crashed makes the implicit claim that, whilst the specific and structural origins of the 2008 crisis are worth scrutinising in exacting detail, it is the reaction of states in the months and years after the crash that has been overlooked as a result. After all, this is a reaction that has not only shaped a new economic order, it has created one that does not fit any conventional idea about the way the world 'ought' to be run. Tooze connects the original American banking crisis to the (multiple) European debt crises with a larger crisis of liberalism. Indeed, Tooze somehow manages to cover all these topics and more, weaving in Trump, Brexit and Russia's 2014 annexation of Crimea, as well as the evolving role of China in the post-2008 economic order. Where Crashed focused on the constellation of consequences that followed the events of 2008, Shutdown is a clear and comprehensive account of the way the world responded to the economic impact of Covid-19. The figures are often jaw-dropping: soon after the disease spread around the world, 95% of the world's economies contracted simultaneously, and at one point, the global economy shrunk by approximately 20%. Tooze's keen and sobering analysis of what happened is made all the more remarkable by the fact that it came out whilst the pandemic was still unfolding. In fact, this leads quickly to one of the book's few flaws: by being published so quickly, Shutdown prematurely over-praises China's 'zero Covid' policy, and these remarks will make a reader today squirm in their chair. Still, despite the regularity of these references (after all, mentioning China is very useful when one is directly comparing economic figures in early 2021, for examples), these are actually minor blemishes on the book's overall thesis. That is to say, Crashed is not merely a retelling of what happened in such-and-such a country during the pandemic; it offers in effect a prediction about what might be coming next. Whilst the economic responses to Covid averted what could easily have been another Great Depression (and thus showed it had learned some lessons from 2008), it had only done so by truly discarding the economic rule book. The by-product of inverting this set of written and unwritten conventions that have governed the world for the past 50 years, this 'Washington consensus' if you well, has yet to be fully felt. Of course, there are many parallels between these two books by Tooze. Both the liquidity crisis outlined in Crashed and the economic response to Covid in Shutdown exposed the fact that one of the central tenets of the modern economy ie. that financial markets can be trusted to regulate themselves was entirely untrue, and likely was false from the very beginning. And whilst Adam Tooze does not offer a singular piercing insight (conveying a sense of rigorous mastery instead), he may as well be asking whether we're simply going to lurch along from one crisis to the next, relying on the technocrats in power to fix problems when everything blows up again. The answer may very well be yes.

Looking for the Good War: American Amnesia and the Violent Pursuit of Happiness (2021) Elizabeth D. Samet Elizabeth D. Samet's Looking for the Good War answers the following question what would be the result if you asked a professor of English to disentangle the complex mythology we have about WW2 in the context of the recent US exit of Afghanistan? Samet's book acts as a twenty-first-century update of a kind to Paul Fussell's two books (reviewed above), as well as a deeper meditation on the idea that each new war is seen through the lens of the previous one. Indeed, like The Great War and Modern Memory (1975) and Wartime (1989), Samet's book is a perceptive work of demystification, but whilst Fussell seems to have been inspired by his own traumatic war experience, Samet is not only informed by her teaching West Point military cadets but by the physical and ontological wars that have occurred during her own life as well. A more scholarly and dispassionate text is the result of Samet's relative distance from armed combat, but it doesn't mean Looking for the Good War lacks energy or inspiration. Samet shares John Adams' belief that no political project can entirely shed the innate corruptions of power and ambition and so it is crucial to analyse and re-analyse the role of WW2 in contemporary American life. She is surely correct that the Second World War has been universally elevated as a special, 'good' war. Even those with exceptionally giddy minds seem to treat WW2 as hallowed:

It is nevertheless telling that one of the few occasions to which Trump responded with any kind of restraint while he was in office was the 75th anniversary of D-Day in 2019.

What is the source of this restraint, and what has nurtured its growth in the eight decades since WW2 began? Samet posits several reasons for this, including the fact that almost all of the media about the Second World War is not only suffused with symbolism and nostalgia but, less obviously, it has been made by people who have no experience of the events that they depict. Take Stephen Ambrose, author of Steven Spielberg's Band of Brothers miniseries: "I was 10 years old when the war ended," Samet quotes of Ambrose. "I thought the returning veterans were giants who had saved the world from barbarism. I still think so. I remain a hero worshiper." If Looking for the Good War has a primary thesis, then, it is that childhood hero worship is no basis for a system of government, let alone a crusading foreign policy. There is a straight line (to quote this book's subtitle) from the "American Amnesia" that obscures the reality of war to the "Violent Pursuit of Happiness." Samet's book doesn't merely just provide a modern appendix to Fussell's two works, however, as it adds further layers and dimensions he overlooked. For example, Samet provides some excellent insight on the role of Western, gangster and superhero movies, and she is especially good when looking at noir films as a kind of kaleidoscopic response to the Second World War:

Noir is a world ruled by bad decisions but also by bad timing. Chance, which plays such a pivotal role in war, bleeds into this world, too.

Samet rightfully weaves the role of women into the narrative as well. Women in film noir are often celebrated as 'independent' and sassy, correctly reflecting their newly-found independence gained during WW2. But these 'liberated' roles are not exactly a ringing endorsement of this independence: the 'femme fatale' and the 'tart', etc., reflect a kind of conditional freedom permitted to women by a post-War culture which is still wedded to an outmoded honour culture. In effect, far from being novel and subversive, these roles for women actually underwrote the ambient cultural disapproval of women's presence in the workforce. Samet later connects this highly-conditional independence with the liberation of Afghan women, which:

is inarguably one of the more palatable outcomes of our invasion, and the protection of women's rights has been invoked on the right and the left as an argument for staying the course in Afghanistan. How easily consequence is becoming justification. How flattering it will be one day to reimagine it as original objective.

Samet has ensured her book has a predominantly US angle as well, for she ends her book with a chapter on the pseudohistorical Lost Cause of the Civil War. The legacy of the Civil War is still visible in the physical phenomena of Confederate statues, but it also exists in deep-rooted racial injustice that has been shrouded in euphemism and other psychological devices for over 150 years. Samet believes that a key part of what drives the American mythology about the Second World War is the way in which it subconsciously cleanses the horrors of brother-on-brother murder that were seen in the Civil War. This is a book that is not only of interest to historians of the Second World War; it is a work for anyone who wishes to understand almost any American historical event, social issue, politician or movie that has appeared since the end of WW2. That is for better or worse everyone on earth.

In my two most recent posts, I listed the memoirs and biographies and followed this up with the non-fiction I enjoyed the most in 2021. I'll leave my roundup of 'classic' fiction until tomorrow, but today I'll be going over my favourite fiction. Books that just miss the cut here include Kingsley Amis' comic Lucky Jim, Cormac McCarthy's The Road (although see below for McCarthy's Blood Meridian) and the Complete Adventures of Tintin by Herg , the latter forming an inadvertently incisive portrait of the first half of the 20th century. Like ever, there were a handful of books that didn't live up to prior expectations. Despite all of the hype, Emily St. John Mandel's post-pandemic dystopia Station Eleven didn't match her superb The Glass Hotel (one of my favourite books of 2020). The same could be said of John le Carr 's The Spy Who Came in from the Cold, which felt significantly shallower compared to Tinker, Tailor, Soldier, Spy again, a favourite of last year. The strangest book (and most difficult to classify at all) was undoubtedly Patrick S skind's Perfume: The Story of a Murderer, and the non-fiction book I disliked the most was almost-certainly Beartown by Fredrik Bachman. Two other mild disappointments were actually film adaptions. Specifically, the original source for Vertigo by Pierre Boileau and Thomas Narcejac didn't match Alfred Hitchock's 1958 masterpiece, as did James Sallis' Drive which was made into a superb 2011 neon-noir directed by Nicolas Winding Refn. These two films thus defy the usual trend and are 'better than the book', but that's a post for another day.

A Wizard of Earthsea (1971) Ursula K. Le Guin How did it come to be that Harry Potter is the publishing sensation of the century, yet Ursula K. Le Guin's Earthsea is only a popular cult novel? Indeed, the comparisons and unintentional intertextuality with Harry Potter are entirely unavoidable when reading this book, and, in almost every respect, Ursula K. Le Guin's universe comes out the victor. In particular, the wizarding world that Le Guin portrays feels a lot more generous and humble than the class-ridden world of Hogwarts School of Witchcraft and Wizardry. Just to take one example from many, in Earthsea, magic turns out to be nurtured in a bottom-up manner within small village communities, in almost complete contrast to J. K. Rowling's concept of benevolent government departments and NGOs-like institutions, which now seems a far too New Labour for me. Indeed, imagine an entire world imbued with the kindly benevolence of Dumbledore, and you've got some of the moral palette of Earthsea. The gently moralising tone that runs through A Wizard of Earthsea may put some people off:

Vetch had been three years at the School and soon would be made Sorcerer; he thought no more of performing the lesser arts of magic than a bird thinks of flying. Yet a greater, unlearned skill he possessed, which was the art of kindness.

Still, these parables aimed directly at the reader are fairly rare, and, for me, remain on the right side of being mawkish or hectoring. I'm thus looking forward to reading the next two books in the series soon.

Blood Meridian (1985) Cormac McCarthy Blood Meridian follows a band of American bounty hunters who are roaming the Mexican-American borderlands in the late 1840s. Far from being remotely swashbuckling, though, the group are collecting scalps for money and killing anyone who crosses their path. It is the most unsparing treatment of American genocide and moral depravity I have ever come across, an anti-Western that flouts every convention of the genre. Blood Meridian thus has a family resemblance to that other great anti-Western, Once Upon a Time in the West: after making a number of gun-toting films that venerate the American West (ie. his Dollars Trilogy), Sergio Leone turned his cynical eye to the western. Yet my previous paragraph actually euphemises just how violent Blood Meridian is. Indeed, I would need to be a much better writer (indeed, perhaps McCarthy himself) to adequately 0utline the tone of this book. In a certain sense, it's less than you read this book in a conventional sense, but rather that you are forced to witness successive chapters of grotesque violence... all occurring for no obvious reason. It is often said that books 'subvert' a genre and, indeed, I implied as such above. But the term subvert implies a kind of Puck-like mischievousness, or brings to mind court jesters licensed to poke fun at the courtiers. By contrast, however, Blood Meridian isn't funny in the slightest. There isn't animal cruelty per se, but rather wanton negligence of another kind entirely. In fact, recalling a particular passage involving an injured horse makes me feel physically ill. McCarthy's prose is at once both baroque in its language and thrifty in its presentation. As Philip Connors wrote back in 2007, McCarthy has spent forty years writing as if he were trying to expand the Old Testament, and learning that McCarthy grew up around the Church therefore came as no real surprise. As an example of his textual frugality, I often looked for greater precision in the text, finding myself asking whether who a particular 'he' is, or to which side of a fight some two men belonged to. Yet we must always remember that there is no precision to found in a gunfight, so this infidelity is turned into a virtue. It's not that these are fair fights anyway, or even 'murder': Blood Meridian is just slaughter; pure butchery. Murder is a gross understatement for what this book is, and at many points we are grateful that McCarthy spares us precision. At others, however, we can be thankful for his exactitude. There is no ambiguity regarding the morality of the puppy-drowning Judge, for example: a Colonel Kurtz who has been given free license over the entire American south. There is, thank God, no danger of Hollywood mythologising him into a badass hero. Indeed, we must all be thankful that it is impossible to film this ultra-violent book... Indeed, the broader idea of 'adapting' anything to this world is, beyond sick. An absolutely brutal read; I cannot recommend it highly enough.

Bodies of Light (2014) Sarah Moss Bodies of Light is a 2014 book by Glasgow-born Sarah Moss on the stirrings of women's suffrage within an arty clique in nineteenth-century England. Set in the intellectually smoggy cities of Manchester and London, this poignant book follows the studiously intelligent Alethia 'Ally' Moberly who is struggling to gain the acceptance of herself, her mother and the General Medical Council. You can read my full review from July.

House of Leaves (2000) Mark Z. Danielewski House of Leaves is a remarkably difficult book to explain. Although the plot refers to a fictional documentary about a family whose house is somehow larger on the inside than the outside, this quotidian horror premise doesn't explain the complex meta-commentary that Danielewski adds on top. For instance, the book contains a large number of pseudo-academic footnotes (many of which contain footnotes themselves), with references to scholarly papers, books, films and other articles. Most of these references are obviously fictional, but it's the kind of book where the joke is that some of them are not. The format, structure and typography of the book is highly unconventional too, with extremely unusual page layouts and styles. It's the sort of book and idea that should be a tired gimmick but somehow isn't. This is particularly so when you realise it seems specifically designed to create a fandom around it and to manufacturer its own 'cult' status, something that should be extremely tedious. But not only does this not happen, House of Leaves seems to have survived through two exhausting decades of found footage: The Blair Witch Project and Paranormal Activity are, to an admittedly lesser degree, doing much of the same thing as House of Leaves. House of Leaves might have its origins in Nabokov's Pale Fire or even Derrida's Glas, but it seems to have more in common with the claustrophobic horror of Cube (1997). And like all of these works, House of Leaves book has an extremely strange effect on the reader or viewer, something quite unlike reading a conventional book. It wasn't so much what I got out of the book itself, but how it added a glow to everything else I read, watched or saw at the time. An experience.

Milkman (2018) Anna Burns This quietly dazzling novel from Irish author Anna Burns is full of intellectual whimsy and oddball incident. Incongruously set in 1970s Belfast during The Irish Troubles, Milkman's 18-year-old narrator (known only as middle sister ), is the kind of dreamer who walks down the street with a Victorian-era novel in her hand. It's usually an error for a book that specifically mention other books, if only because inviting comparisons to great novels is grossly ill-advised. But it is a credit to Burns' writing that the references here actually add to the text and don't feel like they are a kind of literary paint by numbers. Our humble narrator has a boyfriend of sorts, but the figure who looms the largest in her life is a creepy milkman an older, married man who's deeply integrated in the paramilitary tribalism. And when gossip about the narrator and the milkman surfaces, the milkman beings to invade her life to a suffocating degree. Yet this milkman is not even a milkman at all. Indeed, it's precisely this kind of oblique irony that runs through this daring but darkly compelling book.

The First Fifteen Lives of Harry August (2014) Claire North Harry August is born, lives a relatively unremarkable life and finally dies a relatively unremarkable death. Not worth writing a novel about, I suppose. But then Harry finds himself born again in the very same circumstances, and as he grows from infancy into childhood again, he starts to remember his previous lives. This loop naturally drives Harry insane at first, but after finding that suicide doesn't stop the quasi-reincarnation, he becomes somewhat acclimatised to his fate. He prospers much better at school the next time around and is ultimately able to make better decisions about his life, especially when he just happens to know how to stay out of trouble during the Second World War. Yet what caught my attention in this 'soft' sci-fi book was not necessarily the book's core idea but rather the way its connotations were so intelligently thought through. Just like in a musical theme and varations, the success of any concept-driven book is far more a product of how the implications of the key idea are played out than how clever the central idea was to begin with. Otherwise, you just have another neat Borges short story: satisfying, to be sure, but in a narrower way. From her relatively simple premise, for example, North has divined that if there was a community of people who could remember their past lives, this would actually allow messages and knowledge to be passed backwards and forwards in time. Ah, of course! Indeed, this very mechanism drives the plot: news comes back from the future that the progress of history is being interfered with, and, because of this, the end of the world is slowly coming. Through the lives that follow, Harry sets out to find out who is passing on technology before its time, and work out how to stop them. With its gently-moralising romp through the salient historical touchpoints of the twentieth century, I sometimes got a whiff of Forrest Gump. But it must be stressed that this book is far less certain of its 'right-on' liberal credentials than Robert Zemeckis' badly-aged film. And whilst we're on the topic of other media, if you liked the underlying conceit behind Stuart Turton's The Seven Deaths of Evelyn Hardcastle yet didn't enjoy the 'variations' of that particular tale, then I'd definitely give The First Fifteen Lives a try. At the very least, 15 is bigger than 7. More seriously, though, The First Fifteen Lives appears to reflect anxieties about technology, particularly around modern technological accelerationism. At no point does it seriously suggest that if we could somehow possess the technology from a decade in the future then our lives would be improved in any meaningful way. Indeed, precisely the opposite is invariably implied. To me, at least, homo sapiens often seems to be merely marking time until we can blow each other up and destroying the climate whilst sleepwalking into some crisis that might precipitate a thermonuclear genocide sometimes seems to be built into our DNA. In an era of cli-fi fiction and our non-fiction newspaper headlines, to label North's insight as 'prescience' might perhaps be overstating it, but perhaps that is the point: this destructive and negative streak is universal to all periods of our violent, insecure species.

The Goldfinch (2013) Donna Tartt After Breaking Bad, the second biggest runaway success of 2014 was probably Donna Tartt's doorstop of a novel, The Goldfinch. Yet upon its release and popular reception, it got a significant number of bad reviews in the literary press with, of course, an equal number of predictable think pieces claiming this was sour grapes on the part of the cognoscenti. Ah, to be in 2014 again, when our arguments were so much more trivial. For the uninitiated, The Goldfinch is a sprawling bildungsroman that centres on Theo Decker, a 13-year-old whose world is turned upside down when a terrorist bomb goes off whilst visiting the Metropolitan Museum of Art, killing his mother among other bystanders. Perhaps more importantly, he makes off with a painting in order to fulfil a promise to a dying old man: Carel Fabritius' 1654 masterpiece The Goldfinch. For the next 14 years (and almost 800 pages), the painting becomes the only connection to his lost mother as he's flung, almost entirely rudderless, around the Western world, encountering an array of eccentric characters. Whatever the critics claimed, Tartt's near-perfect evocation of scenes, from the everyday to the unimaginable, is difficult to summarise. I wouldn't label it 'cinematic' due to her evocation of the interiority of the characters. Take, for example: Even the suggestion that my father had close friends conveyed a misunderstanding of his personality that I didn't know how to respond it's precisely this kind of relatable inner subjectivity that cannot be easily conveyed by film, likely is one of the main reasons why the 2019 film adaptation was such a damp squib. Tartt's writing is definitely not 'impressionistic' either: there are many near-perfect evocations of scenes, even ones we hope we cannot recognise from real life. In particular, some of the drug-taking scenes feel so credibly authentic that I sometimes worried about the author herself. Almost eight months on from first reading this novel, what I remember most was what a joy this was to read. I do worry that it won't stand up to a more critical re-reading (the character named Xandra even sounds like the pharmaceuticals she is taking), but I think I'll always treasure the first days I spent with this often-beautiful novel.

Beyond Black (2005) Hilary Mantel Published about five years before the hyperfamous Wolf Hall (2004), Hilary Mantel's Beyond Black is a deeply disturbing book about spiritualism and the nature of Hell, somewhat incongruously set in modern-day England. Alison Harte is a middle-aged physic medium who works in the various towns of the London orbital motorway. She is accompanied by her stuffy assistant, Colette, and her spirit guide, Morris, who is invisible to everyone but Alison. However, this is no gentle and musk-smelling world of the clairvoyant and mystic, for Alison is plagued by spirits from her past who infiltrate her physical world, becoming stronger and nastier every day. Alison's smiling and rotund persona thus conceals a truly desperate woman: she knows beyond doubt the terrors of the next life, yet must studiously conceal them from her credulous clients. Beyond Black would be worth reading for its dark atmosphere alone, but it offers much more than a chilling and creepy tale. Indeed, it is extraordinarily observant as well as unsettlingly funny about a particular tranche of British middle-class life. Still, the book's unnerving nature that sticks in the mind, and reading it noticeably changed my mood for days afterwards, and not necessarily for the best.

The Wall (2019) John Lanchester The Wall tells the story of a young man called Kavanagh, one of the thousands of Defenders standing guard around a solid fortress that envelopes the British Isles. A national service of sorts, it is Kavanagh's job to stop the so-called Others getting in. Lanchester is frank about what his wall provides to those who stand guard: the Defenders of the Wall are conscripted for two years on the Wall, with no exceptions, giving everyone in society a life plan and a story. But whilst The Wall is ostensibly about a physical wall, it works even better as a story about the walls in our mind. In fact, the book blends together of some of the most important issues of our time: climate change, increasing isolation, Brexit and other widening societal divisions. If you liked P. D. James' The Children of Men you'll undoubtedly recognise much of the same intellectual atmosphere, although the sterility of John Lanchester's dystopia is definitely figurative and textual rather than literal. Despite the final chapters perhaps not living up to the world-building of the opening, The Wall features a taut and engrossing narrative, and it undoubtedly warrants even the most cursory glance at its symbolism. I've yet to read something by Lanchester I haven't enjoyed (even his short essay on cheating in sports, for example) and will be definitely reading more from him in 2022.

The Only Story (2018) Julian Barnes The Only Story is the story of Paul, a 19-year-old boy who falls in love with 42-year-old Susan, a married woman with two daughters who are about Paul's age. The book begins with how Paul meets Susan in happy (albeit complicated) circumstances, but as the story unfolds, the novel becomes significantly more tragic and moving. Whilst the story begins from the first-person perspective, midway through the book it shifts into the second person, and, later, into the third as well. Both of these narrative changes suggested to me an attempt on the part of Paul the narrator (if not Barnes himself), to distance himself emotionally from the events taking place. This effect is a lot more subtle than it sounds, however: far more prominent and devastating is the underlying and deeply moving story about the relationship ends up. Throughout this touching book, Barnes uses his mastery of language and observation to avoid the saccharine and the maudlin, and ends up with a heart-wrenching and emotive narrative. Without a doubt, this is the saddest book I read this year.

Changes

• myrepos: webcheckout considers https URLs as anonymous, switch URLs from http to https and fall back on terminal tools when X11 is gone
• fdupes: NUL separator option
• whohas: add more TODO sites
• apt: more flexibility in APT::Periodic interval options
• foxtrotgps: fix maps-for-free.com, httpsify website links (1, 2) and remove website comment
• lm-sensors: workaround RRD format inflexibility
• check-all-the-things: terminal fixes (1, 2, 3), Perl fixes (1, 2, 3, 4, 5, 6), grep fixes, more key checks, wrapping fixes (1, 2), release (1, 2) and TODO items for chap/Devel::Plumber
• youtube-dl: video downloader list
• devscripts: add support for running aptitude to chdist, add support for cgit URLs to debcheckout and fix issues when $HOME is unset (1, 2)
• Spelling:
  • codespell: sort dictionary, explot(ing), menue(s), mimimise, intall, cas, overrided, icluding, pleaes, interract(ing), interracts, deffered, upsteram, componet(s), depracated, annoncement, settting, pasword, post-morten, converion, verifyied and achive
  • lintian: explot(ing), menue(s), mimimise, intall, cas, icluding, interract(ing), interracts, deffered, upsteram, componet(s), depracated, annoncement, adminstration, inappropiate, pasword, post-morten and verifyied
• Debian wiki: Andrewsomething/Fonts/PackagingPolicy, AptitudeTodo, AudioVideo, BogdanPurcareata/PluggableAptBackend, BTS/NewcomerTag, DebianColombia (Eventos, MiniDebconf2017), DebianEdu/Status/Stretch, DebianEvents/br, (2017/MiniDebconfCuritiba), Debian_GNU/kFreeBSD/Jessie, DebianIndia/PackagingSessions, DebianInstaller/Qemu, DebianKernel/UserspaceTools, DebianMentorsFaq, DebianOnHandhelds/OpenPandora, DebianPackage (es, fr, ru, sv), DebianReleaseFAQ, DebianRepository (Setup), DebianScience/Debci, DebianSingleSignOn, DebianWomen/Projects/NewbieTasks, Derivatives/Census (QA, AstraLinux, CumulusLinux, CumulusLinux, Kali, Netrunner, Parsix, Tanglu, TurnKeyLinux, Ubuntu, Wazo), FreedomBox/LeavingTheCloud, fr (genisoimage, Quota), hal, Hardware/Wanted, HelpDebian (FAQ (it), TODO), how-can-i-help, (Ideas, fr), HP/ProLiant, Init, (fr), Initrd, (fr), InstallingDebianOn, (InstallingDebianOn/HP/EliteBook 820 G1, Razer/BladeStealth, it/Init, it/Initrd, Mempo/mempo-deb/tar, motd, (it, fr), MulheresBrasil (1, 2), MultimediaFetchingTools (1, 2), Packaging/BinaryPackage, PaulWise/InterestingSoftware, ReproducibleBuilds (BuildinfoInfrastructure, History), ru/ReposRelease, SecureApt, ServicesSSL (1, 2), SHA-1, Statistics, SuitesAndReposExtension, SystemBuildTools, Teams (Publicity, ReleaseTeam/ReleaseCheckList), UntrustedDebs, VideoDownloaders and WebBrowsers
• Debian wiki theme: remove last editor info
• Debian website: fix encoding issues, fix year issues and fix DPL update issue (1, 2)
• Debian mirrors: fix encoding issues
• Debian security tracker: encuentro embeds youtube-dl and add mediawiki issues (1, 2)
• Debian derivatives census: workaround apt issue with stretch, reduce max patch size to 5 MiB, document how to get large patches, ignore safe debian/changelog symlinks and add FIXMEs
• Debian Planets: Add Wazo, BunsenLabs RSS feed update, https for blog feeds and new Cumulus Linux/Netrunner logos
• Debian package uploads: python-debianbts, poppler, cruft, clamav-unofficial-sigs, config-package-dev, libarchive, talloc, tevent, libconfig-crontab-perl 1.42-1~bpo7+1 & 1.42-1~bpo8+1, openchange and check-all-the-things
• Debian puppet: switch from deprecated function, drop custom update-ca-certificates on stretch (1, 2) and support syslog-ng 3.8
• Debian meta-packages: www.d.o stretch updates and qa.d.o vcswatch deps
• Debian LDAP UI: use TLS for direct LDAP access
• Debian publicity: prefer verification to SHA-1
• Debian release: add latest two release updates
• Debian PTS: switch from gift to newcomer tags

Issues

• Crashes in remmina, liferea (1, 2) and diffoscope
• Non-distributable files in Ubuntu
• Debian testing migration unblocks of check-all-the-things
• Debian Policy violation in muttdown
• Move crash-whitepaper from Debian non-free to main
• Normal issues in needrestart (1, 2), liferea and git-crecord
• Features in needrestart, github-backup, systemctl, android-permissions, reprepro, freerdp, git-crecord (1, 2, 3), Debian manual pages, Debian sources browser, Debian Maintainer Dashboard and dman
• New versions of pyvmomi
• Typos in fenrir
• Code copy in encuentro
• Race conditions in git-hub
• Terminal handling in needrestart
• Bogus home directory handling in how-can-i-help, ruby, bash, dash and busybox sh
• CodePlex closing checks for lintian and duck
• Missing hashes in Ubuntu
• Weird spaces in evolution
• Verbosity in apt
• Security issue in nagstamon and a CSS injection attack elsewhere
• Minor issues in reportbug and debsources (1, 2)

Review

• Spam: reported 5 Debian bug reports and 246 Debian mailing list posts
• Debian wiki: RecentChanges for the month
• Debian packages: reviewed openscap-daemon, gsignond, qt5ct and sponsored open-ath9k-htc-firmware
• Debian screenshots:
  • approved 4pane, amiwm, btrfs-heatmap, cenon.app, desmume, fonts-atarismall, fonts-goudybookletter, fonts-junicode, fonts-ocr-a, fonts-ocr-b, gnome-paint, grafx2, higan (2), lm-sensors, lshw-gtk, mediathekview, mrboom, munin-plugins-btrfs, nano, openlugaru, project-x, protracker, software-properties-gtk (2), termit, torbrowser-launcher, wmaker, w-scan, caveexpress (2), telegram-desktop (2), gtimelog, taglog, gtimer, osmose-emulator (2), rox-filer, fonts-blankenburg, topcat, balsa (2), gnome-multi-writer (4), colorize, wine, mate-menu and mate-tweak
  • deleted osmose-emulator (6 screenshots of non-free games)
  • rejected xserver-xorg-video-amdgpu (drivers have no UI), eom (includes image of offensive historical figure), synaptic (includes non-free background image), osmose-emulator (6 screenshots of non-free games) and libomxil-bellagio0-components-xvideo (borked upload)
  • approved deletion of xserver-xephyr (includes image of non-free OS), perforate (image of the homepage) and openvas/lv2core (not screenshots)
  • rejected deletion of vkeybd (junk in reason field)

Administration

• Debian systems: quiet a logrotate warning, investigate issue with DNSSEC and alioth, deploy fix on our first stretch buildd, restore alioth git repo after history rewrite, investigate iptables segfaults on buildd and investigate time issues on a NAS
• Debian derivatives census: delete patches over 5 MiB, re-enable the service
• Debian wiki: investigate some 403 errors, fix alioth KGB config, deploy theme changes, close a bogus bug report, ping 1 user with bouncing email, whitelist 9 email addresses and whitelist 2 domains
• Debian QA: deploy my changes
• Debian mentors: security upgrades and service restarts
• Openmoko: debug mailing list issue, security upgrades and reboots

Communication

• Invite Wazo to the Debian derivatives census
• Welcome ubilinux, Wazo and Roopa Prabhu (of Cumulus Linux) to the Debian derivatives census
• Discuss HP/ProLiant wiki page with HPE folks
• Inform git history rewriter about the git mailmap feature

Sponsors The libconfig-crontab-perl backports and pyvmomi issue were sponsored by my employer. All other work was done on a volunteer basis.

Before starting, have to say hindsight as they say is always 20/20. I was moaning about my 6/7 hour trip few blog posts back but now came to know about the 17.5 hr. flights (17.5x800km/hr=14000 km.) which are happening around me. I would say I was whining about nothing seeing those flights. I can t even imagine how people would feel in those flights. Six hours were too much in the tin-can, thankfully though I was in the aisle seat. In 14 hours most people would probably give to Air rage . I just saw an excellent article on the subject. I also came to know that seat-selection and food on a long-haul flights are a luxury, hence that changes the equation quite a bit as well. So on these facts, it seems Qatar Airways treated me quite well as I was able to use both those options. Disclaimer My knowledge about birds/avian is almost non-existent, Hence feel free to correct me if I do go wrong anywhere. Coming back to earth literally , I will have to share a bit of South Africa as that is part and parcel of what I m going to share next. Also many of the pictures shared in this particular blog post belong to KK who has shared them with me with permission to share it with the rest of the world. When I was in South Africa, in the first couple of days as well as what little reading of South African History I had read before travelling, had known that the Europeans, specifically the Dutch ruled on South Africa for many years. What was shared to me in the first day or two that Afrikaans is mostly spoken by Europeans still living in South Africa, some spoken by the coloured people as well. This tied in with the literature I had already read. The Wikipedia page shares which language is spoken by whom and how the demographics play out if people are interested to know that. One of the words or part of the word for places we came to know is bosch as is used in many a places. Bosch means wood or forest. After this we came to know about many places which were known as somethingbosch which signified to us that area is or was a forest. On the second/third day Chirayu (pictured, extreme left) shared the idea of going to Eagle Encounters. Other people pictured in the picture are yours truly, some of the people from GSOC, KK is in the middle, the driver Leonard something who took us to Eagle Encounters on the right (pictured extreme right). Update I was informed that it was a joint plan between Chirayu and KK. They also had some other options planned which later got dropped by the wayside. It was supposed to be somewhat near, (Spier, Stellenbosch). While I was not able to able to see/figure out where Eagle Encounters is on Openstreetmap, somebody named Firefishy added Spier to OSM few years back. So thank you for that Firefishy so I can at least pin-point a closer place. I didn t see/know/try to figure out about the place as Chirayu said it s a zoo . I wasn t enthusiastic as much as I had been depressed by most zoos in India, while you do have national reserves/Parks in India where you see animals in their full glory. I have been lucky to been able to seen Tadoba and Ranthambore National parks and spend some quality time (about a week) to have some idea as to what can/happens in forests and people living in the buffer-zones but those stories are for a different day altogether. I have to say I do hope to be part of the Ranthambore experience again somewhere in the future, it really is a beautiful place for flora and fauna and fortunately or unfortunately this is the best time apart from spring, as you have the game of mist/fog and animals . North India this time of the year is something to be experienced. I wasn t much enthused as zoos in India are claustrophobic for animals and people both. There are small cages and you see and smell the shit/piss of the animals, generally not a good feeling. Chirayu shared with us also the possibility of being able to ride of Segways and range of bicycles which relieved me so that in case we didn t enjoy the zoo we would enjoy the Segway at least and have a good time (although it would have different expenses than the ones at Eagle Encounters). My whole education about what a zoo could be was turned around at Eagle Encounters as it seems to be somewhere between a zoo and what I know as national parks where animals roam free. We purchased the tickets and went in, the first event/happening was Eagle Encounters itself. Our introduction to the place started by two beautiful volunteer/trainers who were in charge of all the birds in the Eagle Encounters vicinity. The introduction started by every one of us who came for the Eagle Encounter show to wear a glove and to have/hold one of the pair of snowy owls to sit on the glove. That picture is of a family who was part of our show. Before my turn came, I was a little apprehensive/worried about holding a Owl -period. To my surprise, they were so soft and easy-going, I could hardly feel the weight on my hand. While the trainer/volunteers were constantly feeding them earthworm-bits (I didn t ask, just guessing) and we were all happy as they along with the visitors were constantly playing and interacting with the birds, sharing with us the life-cycle of the snowy Owl. It s only then I understood why in the Harry Potter Universe, the owl plays such an important part. They seem to be a nice, curious, easy-going, proud creatures which fits perfectly in the HP Universe. In hind-sight I should have videod the whole experience as the trainer/volunteer showed a battery of owls, eagles, vultures, Hawks (different birds of prey) what have you. I have to confess my knowledge of birds is and was non-existent. Vulture, One of the larger birds we saw at the Eagle Encounters show. Some of the birds could be dangerous, especially in the wild. That was the other Volunteer-Trainer who was showing off the birds. I especially liked the t-shirt she was wearing. The shop at Eagle Encounters had whole lot of them, they were a bit expensive and just not my size Tidbit Just a few years ago, it was a shocker to me to know/realize that what commonly goes/known in the country as a parrot by most people is actually a Parakeet. As can be seen in the article linked, they are widely distributed in India. While I was young, I used to see the rose-ringed parakeets quite a bit around but nowadays due to probably pollution and other factors, they are noticeably less. They are popular as pets in India. I don t know what Pollito would think about that, don t think he would think good. As I cannot differentiate between Hawk, Vulture, Eagle, etc. I would safely say a Bird of Prey as that was what he was holding. This photo was taken after the event was over where we all were curious to know about the volunteer/trainer, their day job and what it meant for them to be taking care of these birds. Update KK has shared with me what those specific birds are called, so in case the names or species are wrong, please take the truck with her and not me. While I don t remember the name of the trainer/volunteer, among other things it was shared that the volunteers/trainers aren t paid enough and they never have enough funds to take care of all the birds who come to them. Where the picture was shot (both this and earlier) was sort of open-office. If you look closely, you will see that there are names of the birds, for instance, people who loved LOTR would easily see Gandalf . that board lists how much food (probably in grams) did the bird eat in a day and week. While it was not shared, I m sure there would be a lot of paperwork, studies to get the birds as well as possible. From a computer science perspective, there seemed to be lot of potential for avian and big-data professionals to do lot of computer modelling and analysis and give more insight into the rehabilitation efforts so the process could be more fine-tuned, efficient and economic perhaps. This is how we saw the majority of the birds. Most of them had a metal/plastic string which was tied to small artificial branches as the one above. I forgot to share a very important point. Eagle Encounters is not a zoo but a Rehabilitation Centre. While the cynic/skeptic part of me tried to not feel or see the before and after pictures of the birds bought to the rehabilitation centre, the caring part was moved to see most of the birds being treated with love and affection. From our conversations with the Volunteer-Trainer it emerged that every week they had to turn away lots of birds due to space constraints. It is only the most serious/life-threatening cases for which they could provide care in a sustainable way they would keep. Some of the birds who were in the cages were large, airy. I wouldn t say clean as what little I read before as well later is that birds shit enormously so cleaning cages is quite an effort. Most of the cages and near those artificial branches there were placards of people who were sponsoring a bird or two to look after them. From what was shared, many of the birds who came had been abused in many ways. Some of them had their bones crushed or/and other cruel ways. As I had shared that I had been wonderfully surprised by seeing birds come so close to me and most of my friends, I felt rage about those who had treated the birds in such evil, bad ways. What was shared with us that while they try to heal the birds as much as possible, it is always suspect how well the birds would survive on their own in nature, hence many of these birds would go to the sponsor or to some other place when they are well. If you look at the picture closely, maybe look at the higher resolution photo in the gallery, you will see that both the birds have been adopted by two different couples. The birds as the name tag shows are called Secretaries . The Secretaries make a typical sound which is similar to the sound made by old typewriters. Just as woodpeckers make Morse Code noises when they are pecking with their beaks on trees, something similar to the sound of keys emitted by Old Remington typewriters when clicked on was done by the Secretaries. This is one of the birds in one of the few cages. If you see a higher-resolution picture of the earlier picture, the one which has Secretaries . Also as can be seen in the picture, there is wood-working happening and they are trying to expand the Rehabilitation Centre. All in all, an excursion which was supposed to be for just an hour, extended to something like 3 odd hours. KK shot more than a 1000 odd pictures while trying to teach/converse in Malyalam to some of the birds. She shot well over 1000 photos which would have filled something like 30 odd traditional photo albums. Jaminy (KK s partner-in-crime) used her selfie stick to desired effect, taking pictures with most of the birds as one does with celebrities. I had also taken some but most of them were over-exposed as was new to mobile photography at that time, still am but mostly it works. That is the lake we discovered/saw after coming back from Eagle Encounters. We had good times. Lastly, a virtual prize distribution ceremony a. Chirayu and KK A platinum trophy for actually thinking and pitching the place in the first place. b. Shirish and Deven Bansod Metal cups for not taking more than 10 minutes to freshen up and be back after hearing the plan to go to Eagle Encounters. c. All the girls/women Spoons for actually making it to the day. All the girls took quite sometime to freshen up, otherwise it might have been possible to also experience the Segways, who knows. All-in-all an enjoyable day spent in being part of Eagle Encounters .
Filed under: Miscellenous Tagged: #Birds of Prey, #Debconf16, #Eagle Encounters, #Rehabilitation, #South African History, #Stellenbosch

A longish blog post, please bear, a second part of the blog post would be published in few days from now. My fixed visa finally arrived, yeah But this story doesn t start here, it starts about a year back. While I have been contributing to Debian in my free time over the years, and sometimes paid time as well, I had never thought of going overseas as the experiences I knew from friends and relatives, it isn t easy to get all the permissions and paperwork done to say the least (bureaucracy @ work). But last year, when Debconf 15 was being launched, there are/were 2-3 friends of mine who are studying, doing their Ph.D. in some computer/web stuff, living in Germany currently that they goaded me to apply. The first few times I gave some standard excuses, but when they kept on for a while, just to shut them up I applied to the debconf team applying for food, accommodation and travel sponsorship. I didn t have high hopes as there obviously are many more talented peers around me who understand FOSS and Debian at a much more fundamental, philosophical as well as technical level than me. Much to my surprise though, about a month (and around two or three weeks just before the event was about to take place) I got the bursary/sponsorships for food, accommodation as well as travel. I was unsure that the remaining time was enough to get a visa hence declined that time around. That whole episode gave me the confidence that perhaps my application would be accepted if I applied again. Using my previous years understanding, decided to give it a shot again as this would also enable me to get a feel of visa bureaucracy as well as gain a bit of novice understanding about what factors go in choosing a flight and believe me the latter part proved to be pretty confusing. While the visa business seems easy, the form at least is easy and what they ask, it can be troublesome as far as visa-processing process is concerned. It took a better part of the month to get the visa which I needed. The in-between time is and can be a bit stressful as you have committed funds for travel i.e. the airline tickets and are in a limbo as you didn t know that if the visa is cancelled for some reason, your tickets would be refunded or not. A little history is needed and hopefully is helpful for anybody who s applying for a short-stay Visa in South Africa. Exactly, A month and day back I had applied for visa. The visa I had applied for is 17 days as the flights within my budget was for those days only. The visa I got was for 10 days only which was ending in the middle of the conference. I tried many avenues to get information and was told that I needed to write a correction letter telling/sharing the information about the correct time period and dates in BOLD with a heavier weight/point which is what I did and gave to VFS office without any further payment on my part. It took a bit more time than the first time around but the consulate co-operated. While I can understand the oversight as they probably get more visas requests along with special and urgent requests so such occurrences can happen. I am and was happy that there was a recourse rather than starting from scratch which probably would have made me more anxious due to the first experience . Apparently I was lucky that I had done with Qatar Airways as later came to know that there are other airways which don t refund money even after visa rejection . This information I got to know pretty late in the game otherwise I wouldn t have been much stressed. As had committed knew had to go the whole hog and whatever barriers are there, have overcome at least as far as the visa part/process is concerned. Now after few days, will probably start to worry about the actual travel, part nervousness, part excitement, nervousness as it will be an alien land, am obese so traveling economy on 787-8 and 777-300 ER will be tricky. The 787-8 will probably be a rough ride as it s a 9 hr. journey and the seat are a mere 18 , the cattle class as shared by one of our esteemed politicians. This blame has to do with Boeing 787 rather than anybody else. Hopefully, if there is a next time, would make better choices. Anyways,have selected an aisle seat so that will be able to walk every hr. or so to get the circulation in legs going as leg room in economy is not much from my domestic air travel experiences. If I do survive the travel, then will see South Africa and try to get some free time and explore South Africa and try to figure out how are they able to get one and half time tourists while we get around half figure for a whole year even though we are bigger (area-wise) to South Africa. I did find something positive for us as well, it s not all doldrums all around. Now, I had been thinking about if I know any South African music and movies. I had explored djembe while growing up in teens but other than that, not much. The only music I have heard is Harry Belafonte . So I hope to bring some Indian movies and music with me so that people if they have not explored Bollywood as well as Indian classical music could explore some of it, of course it will be pale imitation of what Sawai Gandharva Music Festival for instance gives. I also hope to hear and get some music and movies to learn more about South Africa.
Filed under: Miscellenous Tagged: #bollywood, #Debconf Germany 2015, #Debconf South Africa 2016, #Debconf15, #Debconf16, #djembe, #South-African consulate, music, tourism, visa

Yeah, another book finished in Japanese, the third Harry Potter book, Prisoner of Azkaban. Took me quite some time, but thanks to a good Kobo ebook reader and my own enriched dictionary reading is getting more and more fun, even if the book is in Japanese.
I guess I don t have to tell the story of the book, as it is sufficiently well known. Just a good recommendation to students k of Japanese (at a bit higher level) get some books you like and start reading, the sooner the better. And read on an ebook reader with a good dictionary. This way your Japanese will improve quickly. My next book will be , as I think I actually prefer the original (English) Harry Potter, and want to read Japanese authors in Japanese. Now if Murakami would only allow to have Japanese ebooks of his works

Let's see if I can scrounge through all of my now-organized directories of ebooks and figure out what I haven't recorded here yet. At least the paper books make that relatively easy, since I don't shelve them until I post them. (Yeah, yeah, I should actually make a database.) Hugh Aldersey-Williams Periodic Tales (nonfiction)
Sandra Ulbrich Almazan SF Women A-Z (nonfiction)
Radley Balko Rise of the Warrior Cop (nonfiction)
Peter V. Brett The Warded Man (sff)
Lois McMaster Bujold Gentleman Jole and the Red Queen (sff)
Fred Clark The Anti-Christ Handbook Vol. 2 (nonfiction)
Dave Duncan West of January (sff)
Karl Fogel Producing Open Source Software (nonfiction)
Philip Gourevitch We Wish to Inform You That Tomorrow We Will Be Killed With Our Families (nonfiction)
Andrew Groen Empires of EVE (nonfiction)
John Harris @ Play (nonfiction)
David Hellman & Tevis Thompson Second Quest (graphic novel)
M.C.A. Hogarth Earthrise (sff)
S.L. Huang An Examination of Collegial Dynamics... (sff)
S.L. Huang & Kurt Hunt Up and Coming (sff anthology)
Kameron Hurley Infidel (sff)
Kevin Jackson-Mead & J. Robinson Wheeler IF Theory Reader (nonfiction)
Rosemary Kirstein The Lost Steersman (sff)
Rosemary Kirstein The Language of Power (sff)
Merritt Kopas Videogames for Humans (nonfiction)
Alisa Krasnostein & Alexandra Pierce (ed.) Letters to Tiptree (nonfiction)
Mathew Kumar Exp. Negatives (nonfiction)
Ken Liu The Grace of Kings (sff)
Susan MacGregor The Tattooed Witch (sff)
Helen Marshall Gifts for the One Who Comes After (sff collection)
Jack McDevitt Coming Home (sff)
Seanan McGuire A Red-Rose Chain (sff)
Seanan McGuire Velveteen vs. The Multiverse (sff)
Seanan McGuire The Winter Long (sff)
Marc Miller Agent of the Imperium (sff)
Randal Munroe Thing Explainer (graphic nonfiction)
Marguerite Reed Archangel (sff)
J.K. Rowling Harry Potter: The Complete Collection (sff)
K.J. Russell Tides of Possibility (sff anthology)
Robert J. Sawyer Starplex (sff)
Bruce Schneier Secrets & Lies (nonfiction)
Mike Selinker (ed.) The Kobold Game to Board Game Design (nonfiction)
Douglas Smith Chimerascope (sff collection)
Jonathan Strahan Fearsome Journeys (sff anthology)
Nick Suttner Shadow of the Colossus (nonfiction)
Aaron Swartz The Boy Who Could Change the World (essays)
Caitlin Sweet The Pattern Scars (sff)
John Szczepaniak The Untold History of Japanese Game Developers I (nonfiction)
John Szczepaniak The Untold History of Japanese Game Developers II (nonfiction)
Jeffrey Toobin The Run of His Life (nonfiction)
Hayden Trenholm Blood and Water (sff anthology)
Coen Teulings & Richard Baldwin (ed.) Secular Stagnation (nonfiction)
Ursula Vernon Book of the Wombat 2015 (graphic nonfiction)
Ursula Vernon Digger (graphic novel) Phew, that was a ton of stuff. A bunch of these were from two large StoryBundle bundles, which is a great source of cheap DRM-free ebooks, although still rather hit and miss. There's a lot of just fairly random stuff that's been accumulating for a while, even though I've not had a chance to read very much. Vacation upcoming, which will be a nice time to catch up on reading.

I have just released a wastly improved new version of the Kobo Japanese Dictionary Enhancer. It allows you to enhance the Kobo Japanese dictionary with English translations. The new version provides now 326064 translated entries, which covers most non-compound words, including Hiragana. In my daily life reading Harry Potter and some other books in Japanese, I haven t found many untranslated words by now. Please head over to the main page of the project for details and download instructions. If you need my help in creating the updated dictionary, please feel free to contact me. Enjoy.

I implemented <? support (including <?php ) script embedding support for *.inc in MirWebseite today; the specific syntax was explicitely requested by Natureshadow. Ugh. My own hacking activities are progressing, even if slowly. I do some other interesting, funny, social, beneficial, etc. stuff in between, though. I ll even have to get some of my DD buddies to sponsor me some QA uploads of packages I formerly maintained, whereever changes are queued up such as better old-format repo compatibility in cvs(GNU) Though some of the stuff I do at work is currently done only there sorry. Also: prepare to be fully enlightened about just what evil (nice picture) Docker is. I especially liked the comparison of containers to a herd of cattle, mere numbers, replaceable, whereas VMs are cats, each with their individual name, lovely petted each day, etc. ObHint: Some may have noticed I do have a Twitter account now. I do not really use it much. I got it because I wanted to rant at someone who only gave Twitter as means to contact them (a European company running a lottery for USA citizens only). But I found one nice thing: @HourlyCats (though @FacesPics and @BahnAnsagen are funny too, and the Postillon anyway). The internet is there for cat content, anyway.
Ahem. Do not contact me there, use IRC, more specifically, the Freenode network, and possibly memoserv to mirabilos instead, I can t fit things into 140 chars, that s just ridiculous. Also, don t follow me. It may contain rants, it s NSFW, and I m not censoring there. As I said: I do not use it. So should you. (But kudos for having a mostly functional fallback site (the mobile one), which even works in PocketIE (Windows Mobile) and Opera 9, though not so much lynx(1) ) odc (from #!/bin/mksh on IRC) is hacking support to use mksh instead of GNU bash for bootstrapping pkgsrc (e.g. on Solaris). Nice! Good luck! propos mksh(1), dear Debian armel and armhf buildd maintainer colleagues, pretty please with strawberries and chocolate ice on top (I just had that on waffles at my favourite ice salon, so I may be biased), do like s390x and update your chroots and wanna-build give-back mksh, as we requested, so the privacy fix makes it into jessie. Thanks in advance! Oh, and Y_Plentyn and I both have been putting more and updated packages into my APT repository. XTaran held a talk at CLT 2015 mentioning it maybe I should write up some docs about how to use it for which purposes (e.g. how to avoid systemd but not get the other packages from it, or how to use it with systemd (trivial but has to be stated, it s freedom of choice after all), etc.)? Besides decent fanfiction (the stories in the Uzumaki Naruto universe seem, on average, to be much longer than those in the Harry Potter one), the weather is becoming good, so I ve already been enjoying going out for some geocaching and will have the bike fixed at the shop RSN (it suffers a bit each winter, as it stands outside, since our basement is mouldy, which is worse than a bit of rust IMHO) to get more activity in. Also planning to head to the GPS Maze in Mainz and, besides what time FrOSCon (including preparation) allows, heading to DebConf for a while.

Jo and I just got back from our massive holiday in Australia. We had an awesome time overall, fitting in lots of stuff in 4 weeks. Time for a quick write-up and some photos! We flew into Sydney, then straight onto Uluru for the obligatory sunset and sunrise viewings. We didn't climb the Rock, both for sensitivity reasons and (to be more honest!) it looked way too much like hard work in 40-plus degree heat. Coach over to Alice Springs, where we had a very quick look around before taking the Ghan train down to Adelaide. The train was fun for a day, and we got to see a lot of desert. In Adelaide, we had a look around the city (lovely colonial feel!) and got a couple of evenings in fun comedy shows at the Fringe. Great fun! On to Tasmania, where we did a quick (3 days) run around the island by car: into Hobart, up the east coast. Stopped in Swansea (a nice version!) for some heavenly Devonshire teas, then on up to Grindelwald near Launceston. Visited Trowunna Wildlife Park to see (and cuddle!) lots of local animals, which was amazing - Jo's favourite day of the holiday. Then on to Queenstown and drive back down to Hobart past some impossibly beautiful views around Cradle Mountain. Tassie's gorgeous - like the best bits of Scotland, Wales and Cornwall but with even fewer people and better weather. Next, on to Sydney for Harry and Cath's wedding. We stayed up in Chatswood. Not knowing anything about the area beforehand, we were a little surprised to basically find ourselves back in Hong Kong! We spent most of the weekend catching up with friends from the wedding group, and the wedding itself was at Quarantine Station, overlooking the harbour. It couldn't have been a more perfect location / weather / view for our friends' big day! We squeezed in a couple of the open-top bus tours of Sydney on the Sunday, but got caught in the horrendous storm that hit and ended up sheltering downstairs under cover on the bus. I'm told Bondi is lovely, but it all looked grey from the bus. :-P Down to Melbourne on the train (bit of a wasted day, in hindsight), where we wandered around the city quite a bit. Caught up with an old friend who lives there for a day, and we did a wine tour up the Yarra Valley which was fun too. Up to Port Douglas, where we headed out to the Reef for my highlight of the holiday: a snorkelling tour with some local marine experts who showed us the local flora and fauna. We also visited a local Aboriginal cultural centre, skyrail and scenic railway around Kuranda village. Down to Hervey Bay and a 1-day tour of Fraser Island - an amazing place in combination with quite a thrill-ride experience just being driven around on the sand tracks. Finally, down to Brisbane where we wandered around and visited both the Lone Pine Koala Sanctuary (more cuddles!) and the Gold Coast. Then the long flights home. Whew! We're knackered now. We knew we could't fit everything in, but we're glad we travelled all over and got tastes of almost everything. Now we can work out where we want to spend more time on our future visit(s). We'll definitely want to head over and see Perth and some of WA next time, and definitely more time in Tasmania, Sydney and Adelaide.

Since there's a discussion of packaging software for Debian that uses Git upstream on Planet Debian right now, I wanted to weigh in and advocate for my current workflow for this situation, which I'm quite fond of. It's worth noting that I'm also upstream for quite a few of the packages I maintain, all in Git, and I use (almost) exactly the same structure for packaging my own software as for packaging anyone else's. So I have some experience with both sides of this. First off, I completely agree with Joey: if upstream is already using Git, there's no reason not to base the Debian packaging on the upstream repository, and many, many reasons to do so. One of the biggest advantages is that when repositories share a common basis and have been regularly merged, you can easily cherry-pick commits, which is wonderful for security releases and situations where you need a quick bug fix from an unreleased upstream branch. I make very heavy use of this when packaging OpenAFS. I do, however, like to base the Debian packaging on the released tarball, if for no other reason than that's the artifact that other people can more easily confirm. Yes, you can do the same thing with a Git tag, but the tarball is what upstream considers a release, so if one is available, I think it makes the most sense to base the packaging on it. I do this even for my own software. Thankfully, it's not that difficult to do both. Sam Hartman was the one who showed me this technique, and (after I used a manual script for some time for a couple of packages) Guido G nther incorporated the support into git-import-orig. The key idea is to still import the tarball into the upstream branch, but instead of making that import a simple commit, you make it a merge commit referencing the upstream release tag or commit from their Git repository. This means that you still get the exact contents of the release tarball on the upstream branch (and pristine-tar works as normal), but that branch is also based on the full upstream line of development. Therefore, so is your packaging branch (master or what have you) since you merge upstream into it. You can then charry-pick and take advantage of all of the normal Git features when following upstream development. This is dead simple to do with git-import-orig. Just add the upstream repository as a remote for your Git repository, make sure it's up to date with git fetch and you have the upstream tags, and then pass the flag --upstream-vcs-tag <tag> to git-import-orig whenever importing the upstream release tarball. git-import-orig will handle the construction of the merge commit for you and everything will just work, exactly like it normally does with git-buildpackage except with a more complete history. This support was added in git-buildpackage 0.6.0~git20120324, so it's available in unstable and testing. (I was going to update my notes on Debian packaging with Git to include this information before posting this, but I see that it will require some restructuring and quite a few changes to that document and I don't have time tonight. Hopefully soon.)

...at least, if you are into fan fictions and Harry Potter. I love fan fictions, and I'll shamelessly admit that I like Harry Potter too, but I usually avoid crossovers. That is because however interesting and exciting is - in theory - to have your favourite characters from different fandoms together, it often ends bad. So, it's a public duty of every fanfic reader to recommend good crossovers, if they stumble upon them. Here are some I found recently (all the quotes are from the stories' summaries).

• Not Quite A Maia (Harry Potter x Lord of the Rings)

  "Middle Earth has a problem: Gandalf the Grey is AWOL in Time & Space after destroying the Balrog of Khazad-d m. But who will take his place in the Quest to defeat the Dark Lord Sauron? Not who you think..."

  This is a very well written fic, and one of the best HP/LOTR crossover I've ever read. Bonus points for not featuring main characters of HP-verse (someone else will have to save the day in Middle Earth, not the usual Golden Trio). And if there are some minor glitches in the plot (especially in the last chapters), the author has undoubtedly a knack for hilarious situations. If you can read through Augusta's chapters without laughing out loud you are not human. Really.
• Evil Be Thou My Good (Harry Potter x Hellraiser)

  "Nine years ago Vernon Dursley brought home a certain puzzle box. His nephew managed to open it, changing his destiny. Now, in the midst of Voldemort's second rise, Harry Potter has decided to recreate the Lament Configuration... and open it... again."

  Even if I am a notorious addicted to horror and b-movies (and more so to horror b-movies) I've never seen Hellraiser. But you don't have to, to enjoy this story. It's well written, it explains the backstory for the Hellraiser universe (or at least what you need to know about it) and features a refreshing Dark!Harry. The only thing I didn't like is a slightly OOC (Out Of Character) Voldemort, who's described in canon as intelligent and cunning and here seems to me a bit gullible. But apart from that, the story is worth a read.
• That Which Holds The Image (Harry Potter x Doctor Who).

  "Harry Potter faces a boggart that doesn't turn into a Dementor or even Voldermort, but into a horror from his childhood. Now the boggart isn't even a boggart anymore. There's no imitation. That which holds the image of an Angel, becomes itself an Angel."

  I have a soft spot for the Weeping Angels. They are pure evil genius. If you don't know what I'm talking about stop reading now and go watch Doctor Who episode 3x10 "Blink". It's really a masterpiece. So Weeping Angels in Potterverse would be awesome even if the plot of this story weren't as good as actually is. The only thing to make it better would be to have 10th Doctor instead of 11th. But then, you can't have everything, I guess.

If you read any of these and want to talk about it or if you have more crossovers to recommend, drop me a mail. For more fan fiction recommendations, I suggest you to check this detailed index on tvtropes.org.

For those who are not aware, The Archers is a soap opera about rural life, broadcast on BBC Radio 4. Its website has recently been revamped. Unfortunately, I appear to be served the mobile version when I visit the front page (in all of Chromium, Iceweasel and Epiphany on Debian - admittedly not the most mainstream of browsers). BBC Mobile is doing some over-zealous useragent sniffing, it seems. Also amusing: there's a "Who's Who" database of Archers characters, and several of them share the birthday "1st Jan 1970". There was I thinking that Harry Mason and Fallon Rogers had a 15 year age gap... but no. This will be as a result of the underlying database storing values in Unix time, and having a default value of "0". An explanation of Unix time popped up in an episode of The Infinite Monkey Cage the other week, which was nice to hear.

My fellow Republicans and I got a nice early Diwali present on Tuesday. ~65 seats in the House ~6 in the senate, ~18 governorships and control of ~20 state legislatures. (Some races haven't been formally called yet.) A few disappointments though. no majority in the Senate and Harry Reid and Barney Frank were not defeated. Still overall its an election to celebrate. Here are a few thoughts. The Election System Is An Embarassment Once again there are several races where the outcome is in doubt because of technical problems with voting. Whatever politics we have, can we agree that it is damn stupid that we still can't get something as simple as counting ballots right? Prediction: The 2012 Republican presidential candidate will come from the Tea Party. While I may be a Republican, I am also a Cosmopolitan East Coast Elitist so the Tea Party didn't move me much. There were a couple of cases (NY and DE atleast) where their candidates were subpar and cost us victory but the best of the new Republicans also came out of this movement. I would rather vote for one of them than Romney, Huckabee, McCain, Gingrich etc. (With the exception of Sarah Palin who is just too polarizing I'm afraid.) The Tea Party itself will subside in a few years as all populist movements do. (Ask the Hope'n'changers.) Young People Are Dumb Part of leftist mythology is the idea that one day "the kids" are going to rise up against the mean old corporate overlords. It ain't going to happen. There was a huge upsurge in first time voters in 2008 but that was because Obama was a novelty act not because they had suddenly discovered the merits of Keynesianism. Now Obama is old and busted so they won't vote anymore. (Not until they have kids and a mortgage sometime in the future.) They'll spend time make cool ironic signs for the Rally to Promote Comedy Central but even the prospect of legalizing pot won't get them to the polling booths in sufficient numbers to defeat the oldies. Why? Because young people are dumb. Prediction: War With Iran If you're President Obama what do you do now? Bipartisanship? Yeah right. Look at what happened to Rep. Cao of Louisiana, the only Republican to vote for Obamacare and one of only two GOP congressmen to lose on Tuesday. Obama actively campaigned for his challenger. Any of the new Republicans who try and compromise with the President will end up under the bus sooner or later as they well know. The President could go full retard with the socialism (progressivism, liberalism whatever. It's all the same.) All his initiatives will be shot down but he can claim to be a martyr to the party of No. (Who will be joined in the Senate by Lieberman and whatever centrist Democrats who are up for reelection in 2012.) But this seems to be the path to a one-term presidency to me. Maybe that's what he wants. He could retire comfortably to the deanship of some Ivy League law school and make a lucrative killing on the rubber chicken circuit. But lets assume he wants to get back in the White House in 2012. One way to get back in touch with the voters is to start getting serious about foreign policy which has either been a joke (Remember the reset button?) a travesty or just copied from the Bush administration. In particular the Obama administration has completely failed in stopping Iran from gaining nuclear technology, sponsoring terrorism in Iraq, Afghanistan and Lebanon, and oppressing its own people. War with Iran would enhance his standing with Conservatives (hey it works for me!) most liberals would go along with it and the extreme Code Pink type loonies can safely be ignored. I say it happens before November 2012.