J est rolando a inscri o de participante e a chamada de atividades para a MiniDebConf Belo Horizonte 2024, que acontecer de 27 a 30 de abril no Campus Pampulha da UFMG. Este ano estamos ofertando bolsas de alimenta o, hospedagem e passagens para contribuidores(as) ativos(as) do Projeto Debian. Patroc nio: Para a realiza o da MiniDebConf, estamos buscando patroc nio financeiro de empresas e entidades. Ent o se voc trabalha em uma empresa/entidade (ou conhece algu m que trabalha em uma) indique o nosso plano de patroc nio para ela. L voc ver os valores de cada cota e os seus benef cios. Financiamento coletivo: Mas voc tamb m pode ajudar a realiza o da MiniDebConf por meio do nosso financiamento coletivo! Fa a uma doa o de qualquer valor e tenha o seu nome publicado no site do evento como apoiador(a) da MiniDebConf Belo Horizonte 2024. Mesmo que voc n o pretenda vir a Belo Horizonte para participar do evento, voc pode doar e assim contribuir para o mais importante evento do Projeto Debian no Brasil. Contato Qualquer d vida, mande um email para contato@debianbrasil.org.br Organiza o

Est aberta a inscri o de participantes e a chamada de atividades para a MiniDebConf Belo Horizonte 2024 e para o FLISOL - Festival Latino-americano de Instala o de Software Livre. Veja abaixo algumas informa es importantes: Data e local da MiniDebConf e do FLISOL A MiniDebConf acontecer de 27 a 30 de abril no Campus Pampulha da UFMG - Universidade Federal de Minas Gerais. No dia 27 (s bado) tamb m realizaremos uma edi o do FLISOL - Festival Latino-americano de Instala o de Software Livre, evento que acontece no mesmo dia em v rias cidades da Am rica Latina. Enquanto a MiniDebConf ter atividades focados no Debian, o FLISOL ter atividades gerais sobre Software Livre e temas relacionados como linguagem de programa o, CMS, administra o de redes e sistemas, filosofia, liberdade, licen as, etc. Inscri o gratuita e oferta de bolsas Voc j pode realizar a sua inscri o gratuita para a MiniDebConf Belo Horizonte 2024. A MiniDebConf um evento aberto a todas as pessoas, independente do seu n vel de conhecimento sobre Debian. O mais importante ser reunir a comunidade para celebrar um dos maiores projeto de Software Livre no mundo, por isso queremos receber desde usu rios(as) inexperientes que est o iniciando o seu contato com o Debian at Desenvolvedores(as) oficiais do projeto. Ou seja, est o todos(as) convidados(as)! Este ano estamos ofertando bolsas de hospedagem e passagens para viabilizar a vinda de pessoas de outras cidades que contribuem para o Projeto Debian. Contribuidores(as) n o oficiais, DMs e DDs podem solicitar as bolsas usando o formul rio de inscri o. Tamb m estamos ofertando bolsas de alimenta o para todos(as) os(as) participantes, mesmo n o contribuidores(as), e pessoas que moram na regi o de BH. Os recursos financeiros s o bastante limitados, mas tentaremos atender o m ximo de pedidos. Se voc pretende pedir alguma dessas bolsas, acesse este link e veja mais informa es antes de realizar a sua inscri o: A inscri o (sem bolsas) poder ser feita at a data do evento, mas temos uma data limite para o pedido de bolsas de hospedagem e passagens, por isso fique atento(a) ao prazo final: at 18 de fevereiro. Como estamos usando mesmo formul rio para os dois eventos, a inscri o ser v lida tanto para a MiniDebConf quanto para o FLISOL. Para se inscrever, acesse o site, v em Criar conta. Criei a sua conta (preferencialmente usando o Salsa) e acesse o seu perfil. L voc ver o bot o de Se inscrever. https://bh.mini.debconf.org Chamada de atividades Tamb m est aberta a chamada de atividades tanto para MiniDebConf quanto para o FLISOL. Para mais informa es, acesse este link. Fique atento ao prazo final para enviar sua proposta de atividade: at 18 de fevereiro. Contato Qualquer d vida, mande um email para contato@debianbrasil.org.br Organiza o

A great talk on SteamOS progress to effective boot loaders for atomic OS updates.How to produce something that will allow instant updates and instant fallbacks when updating a whole OS image - lots of explanation - and it's good when three or four people who are directly interested in problems and solutions round, for example, Secure Boot are in the room.Jessica Clarke on CHERI, Morello and security protections in hardware, software and programming hardware which has verifiable pointers and routines. A couple of flourishes which had the room breaking out in applause.Roberto Sanchez and Santiago Rincon on suggestions for LTS and ways forward. The presentation very clearly set out what LTS is, is not, and maybe should be.Last presentation of the day was from Ian Jackson on a potential change to git based working and tagging. Then lots of chasing around to get people out of the building. Thanks very much to the Arm personnel, especially the security staff who have been helpful throughout the day with getting us all in and out

Thanks to all involved with Arm, Codethink and Pexip for hosting and sponsorship without which this would not have been possible.

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.

---

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.

Yang the cat bird

While Yang our cat tries to lure in unsuspecting birds on the bird feeder, I have been busy working on many things. First things first though, a big thank you to all that donated to my Internet bill. I was able to continue my work without interruption. KDE neon: A busy week in KDE neon as https://kde.org/announcements/plasma/5/5.27.9/ was released! We have it ready to update in User edition or if you would like to download the new ISO you can find it here: https://neon.kde.org/download I highly advise the User Edition as Unstable is volatile right now with Qt6 transition and ABI breakage. Which leads me to the next busy work for the week. Plasma 6 exploded breaking unstable desktops all over, including mine! A library changed and it was not backward compatible, so we had to rebuild the Qt6 $world to get Plasma and PIM functional again. I am happy to report it is all fixed now, but I cannot stress enough, if you don t want to chance broken things, please use the User Edition! I also continued the orange -> green build effort in making sure all our runtime dependencies are up to date. This fixes odd UI bugs and developers have all the build dependencies needed to build their applications. KDE Snaps: Several more 23.08.2 snaps have arrived in the snap store including the new to snaps Kamoso!

KDE snap Kamoso

I have an auto-connect request to the snap-store policy folks, but until it is approved please snap connect kamoso:camera :camera I have a pile of new MR s in for non release service applications and some fixes for issues found while testing. While this new workflow does take a bit longer waiting for approvals I like it much better as I am developing closer relationships with the application developers. I have made significant progress on the Kf6 ( Qt6 based ) content snap. I am about 90% complete. While this doesn t mean much for users yet, it will when KDE applications release their qt6 ports starting the next major release cycle. I will be ready! The last bit for snap work is I have almost completed my akonadi service snap. This will connect to all KDE PIM snaps so they share data. Akonadi is the background database that ties all the PIM applications together. Debian: This week I have worked on updates for several golang packages including charmbracelet/lipgloss charmbracelet/bubbles, and muesli-termenv. unfortunately I am stuck golang-github-aymanbagabas-go-osc52. The work is done in salsa but the maintainer has not uploaded. I have shot an email to the maintainer. I have also begun mentoring my first potential future DD! I reviewed his python-scienceplots and python-art which should land in Debian soon. Thanks for stopping by! As usual, if you can please spare some change, consider a donation. All proceeds go to surviving another day to work on cool things to land on your desktop! https://gofund.me/b8b69e54 <noscript><a href="https://liberapay.com/sgmoore/donate"><img alt="Donate using Liberapay" src="https://liberapay.com/assets/widgets/donate.svg" /></a></noscript> Donate

Official logo of DebConf23

Introduction DebConf23, the 24th annual Debian Conference, was held in India in the city of Kochi, Kerala from the 3rd to the 17th of September, 2023. Ever since I got to know about it (which was more than an year ago), I was excited to attend DebConf in my home country. This was my second DebConf, as I attended one last year in Kosovo. I was very happy that I didn t need to apply for a visa to attend. I got full bursary to attend the event (thanks a lot to Debian for that!) which is always helpful in covering the expenses, especially if the venue is a five star hotel :) For the conference, I submitted two talks. One was suggested by Sahil on Debian packaging for beginners, while the other was suggested by Praveen who opined that a talk covering broader topics about freedom in self-hosting services will be better, when I started discussing about submitting a talk about prav app project. So I submitted one on Debian packaging for beginners and the other on ideas on sustainable solutions for self-hosting. My friend Suresh - who is enthusiastic about Debian and free software - wanted to attend the DebConf as well. When the registration started, I reminded him about applying. We landed in Kochi on the 28th of August 2023 during the festival of Onam. We celebrated Onam in Kochi, had a trip to Wayanad, and returned to Kochi. On the evening of the 3rd of September, we reached the venue - Four Points Hotel by Sheraton, at Infopark Kochi, Ernakulam, Kerala, India.

Suresh and me celebrating Onam in Kochi.

Hotel overview The hotel had 14 floors, and featured a swimming pool and gym (these were included in our package). The hotel gave us elevator access for only our floor, along with public spaces like the reception, gym, swimming pool, and dining areas. The temperature inside the hotel was pretty cold and I had to buy a jacket to survive. Perhaps the hotel was in cahoots with winterwear companies? :)

Four Points Hotel by Sheraton was the venue of DebConf23. Photo credits: Bilal

Photo of the pool. Photo credits: Andreas Tille.

View from the hotel window.

Meals On the first day, Suresh and I had dinner at the eatery on the third floor. At the entrance, a member of the hotel staff asked us about how many people we wanted a table for. I told her that it s just the two of us at the moment, but (as we are attending a conference) we might be joined by others. Regardless, they gave us a table for just two. Within a few minutes, we were joined by Alper from Turkey and urbec from Germany. So we shifted to a larger table but then we were joined by even more people, so we were busy adding more chairs to our table. urbec had already been in Kerala for the past 5-6 days and was, on one hand, very happy already with the quality and taste of bananas in Kerala and on the other, rather afraid of the spicy food :) Two days later, the lunch and dinner were shifted to the All Spice Restaurant on the 14th floor, but the breakfast was still served at the eatery. Since the eatery (on the 3rd floor) had greater variety of food than the other venue, this move made breakfast the best meal for me and many others. Many attendees from outside India were not accustomed to the spicy food. It is difficult for locals to help them, because what we consider mild can be spicy for others. It is not easy to satisfy everyone at the dining table, but I think the organizing team did a very good job in the food department. (That said, it didn t matter for me after a point, and you will know why.) The pappadam were really good, and I liked the rice labelled Kerala rice . I actually brought that exact rice and pappadam home during my last trip to Kochi and everyone at my home liked it too (thanks to Abhijit PA). I also wished to eat all types of payasams from Kerala and this really happened (thanks to Sruthi who designed the menu). Every meal had a different variety of payasam and it was awesome, although I didn t like some of them, mostly because they were very sweet. Meals were later shifted to the ground floor (taking away the best breakfast option which was the eatery).

This place served as lunch and dinner place and later as hacklab during debconf. Photo credits: Bilal

The excellent Swag Bag The DebConf registration desk was at the second floor. We were given a very nice swag bag. They were available in multiple colors - grey, green, blue, red - and included an umbrella, a steel mug, a multiboot USB drive by Mostly Harmless, a thermal flask, a mug by Canonical, a paper coaster, and stickers. It rained almost every day in Kochi during our stay, so handing out an umbrella to every attendee was a good idea.

Picture of the awesome swag bag given at DebConf23. Photo credits: Ravi Dwivedi

A gift for Nattie During breakfast one day, Nattie (Belgium) expressed the desire to buy a coffee filter. The next time I went to the market, I bought a coffee filter for her as a gift. She seemed happy with the gift and was flattered to receive a gift from a young man :)

Being a mentor There were many newbies who were eager to learn and contribute to Debian. So, I mentored whoever came to me and was interested in learning. I conducted a packaging workshop in the bootcamp, but could only cover how to set up the Debian Unstable environment, and had to leave out how to package (but I covered that in my talk). Carlos (Brazil) gave a keysigning session in the bootcamp. Praveen was also mentoring in the bootcamp. I helped people understand why we sign GPG keys and how to sign them. I planned to take a workshop on it but cancelled it later.

My talk My Debian packaging talk was on the 10th of September, 2023. I had not prepared slides for my Debian packaging talk in advance - I thought that I could do it during the trip, but I didn t get the time so I prepared them on the day before the talk. Since it was mostly a tutorial, the slides did not need much preparation. My thanks to Suresh, who helped me with the slides and made it possible to complete them in such a short time frame. My talk was well-received by the audience, going by their comments. I am glad that I could give an interesting presentation.

My presentation photo. Photo credits: Valessio

Visiting a saree shop After my talk, Suresh, Alper, and I went with Anisa and Kristi - who are both from Albania, and have a never-ending fascination for Indian culture :) - to buy them sarees. We took autos to Kakkanad market and found a shop with a great variety of sarees. I was slightly familiar with the area around the hotel, as I had been there for a week. Indian women usually don t try on sarees while buying - they just select the design. But Anisa wanted to put one on and take a few photos as well. The shop staff did not have a trial saree for this purpose, so they took a saree from a mannequin. It took about an hour for the lady at the shop to help Anisa put on that saree but you could tell that she was in heaven wearing that saree, and she bought it immediately :) Alper also bought a saree to take back to Turkey for his mother. Me and Suresh wanted to buy a kurta which would go well with the mundu we already had, but we could not find anything to our liking.

Selfie with Anisa and Kristi. Photo credits: Anisa.

Cheese and Wine Party On the 11th of September we had the Cheese and Wine Party, a tradition of every DebConf. I brought Kaju Samosa and Nankhatai from home. Many attendees expressed their appreciation for the samosas. During the party, I was with Abhas and had a lot of fun. Abhas brought packets of paan and served them at the Cheese and Wine Party. We discussed interesting things and ate burgers. But due to the restrictive alcohol laws in the state, it was less fun compared to the previous DebConfs - you could only drink alcohol served by the hotel in public places. If you bought your own alcohol, you could only drink in private places (such as in your room, or a friend s room), but not in public places.

Me helping with the Cheese and Wine Party.

Party at my room Last year, Joenio (Brazilian) brought pastis from France which I liked. He brought the same alocholic drink this year too. So I invited him to my room after the Cheese and Wine party to have pastis. My idea was to have them with my roommate Suresh and Joenio. But then we permitted Joenio to bring as many people as he wanted and he ended up bringing some ten people. Suddenly, the room was crowded. I was having good time at the party, serving them the snacks given to me by Abhas. The news of an alcohol party at my room spread like wildfire. Soon there were so many people that the AC became ineffective and I found myself sweating. I left the room and roamed around in the hotel for some fresh air. I came back after about 1.5 hours - for most part, I was sitting at the ground floor with TK Saurabh. And then I met Abraham near the gym (which was my last meeting with him). I came back to my room at around 2:30 AM. Nobody seemed to have realized that I was gone. They were thanking me for hosting such a good party. A lot of people left at that point and the remaining people were playing songs and dancing (everyone was dancing all along!). I had no energy left to dance and to join them. They left around 03:00 AM. But I am glad that people enjoyed partying in my room.

This picture was taken when there were few people in my room for the party.

Sadhya Thali On the 12th of September, we had a sadhya thali for lunch. It is a vegetarian thali served on a banana leaf on the eve of Thiruvonam. It wasn t Thiruvonam on this day, but we got a special and filling lunch. The rasam and payasam were especially yummy.

Sadhya Thali: A vegetarian meal served on banana leaf. Payasam and rasam were especially yummy! Photo credits: Ravi Dwivedi.

Sadhya thali being served at debconf23. Photo credits: Bilal

Day trip On the 13th of September, we had a daytrip. I chose the daytrip houseboat in Allepey. Suresh chose the same, and we registered for it as soon as it was open. This was the most sought-after daytrip by the DebConf attendees - around 80 people registered for it. Our bus was set to leave at 9 AM on the 13th of September. Me and Suresh woke up at 8:40 and hurried to get to the bus in time. It took two hours to reach the venue where we get the houseboat. The houseboat experience was good. The trip featured some good scenery. I got to experience the renowned Kerala backwaters. We were served food on the boat. We also stopped at a place and had coconut water. By evening, we came back to the place where we had boarded the boat.

Group photo of our daytrip. Photo credits: Radhika Jhalani

A good friend lost When we came back from the daytrip, we received news that Abhraham Raji was involved in a fatal accident during a kayaking trip. Abraham Raji was a very good friend of mine. In my Albania-Kosovo-Dubai trip last year, he was my roommate at our Tirana apartment. I roamed around in Dubai with him, and we had many discussions during DebConf22 Kosovo. He was the one who took the photo of me on my homepage. I also met him in MiniDebConf22 Palakkad and MiniDebConf23 Tamil Nadu, and went to his flat in Kochi this year in June. We had many projects in common. He was a Free Software activist and was the designer of the DebConf23 logo, in addition to those for other Debian events in India.

A selfie in memory of Abraham.

We were all fairly shocked by the news. I was devastated. Food lost its taste, and it became difficult to sleep. That night, Anisa and Kristi cheered me up and gave me company. Thanks a lot to them. The next day, Joenio also tried to console me. I thank him for doing a great job. I thank everyone who helped me in coping with the difficult situation. On the next day (the 14th of September), the Debian project leader Jonathan Carter addressed and announced the news officially. THe Debian project also mentioned it on their website. Abraham was supposed to give a talk, but following the incident, all talks were cancelled for the day. The conference dinner was also cancelled. As I write, 9 days have passed since his death, but even now I cannot come to terms with it.

Visiting Abraham s house On the 15th of September, the conference ran two buses from the hotel to Abraham s house in Kottayam (2 hours ride). I hopped in the first bus and my mood was not very good. Evangelos (Germany) was sitting opposite me, and he began conversing with me. The distraction helped and I was back to normal for a while. Thanks to Evangelos as he supported me a lot on that trip. He was also very impressed by my use of the StreetComplete app which I was using to edit OpenStreetMap. In two hours, we reached Abraham s house. I couldn t control myself and burst into tears. I went to see the body. I met his family (mother, father and sister), but I had nothing to say and I felt helpless. Owing to the loss of sleep and appetite over the past few days, I had no energy, and didn t think it was good idea for me to stay there. I went back by taking the bus after one hour and had lunch at the hotel. I withdrew my talk scheduled for the 16th of September.

A Japanese gift I got a nice Japanese gift from Niibe Yutaka (Japan) - a folder to keep papers which had ancient Japanese manga characters. He said he felt guilty as he swapped his talk with me and so it got rescheduled from 12th September to 16 September which I withdrew later.

Thanks to Niibe Yutaka (the person towards your right hand) from Japan (FSIJ), who gave me a wonderful Japanese gift during debconf23: A folder to keep pages with ancient Japanese manga characters printed on it. I realized I immediately needed that :)

This is the Japanese gift I received.

Group photo On the 16th of September, we had a group photo. I am glad that this year I was more clear in this picture than in DebConf22.

Click to enlarge

Volunteer work and talks attended I attended the training session for the video team and worked as a camera operator. The Bits from DPL was nice. I enjoyed Abhas presentation on home automation. He basically demonstrated how he liberated Internet-enabled home devices. I also liked Kristi s presentation on ways to engage with the GNOME community.

Bits from the DPL. Photo credits: Bilal

Kristi on GNOME community. Photo credits: Ravi Dwivedi.

Abhas' talk on home automation. Photo credits: Ravi Dwivedi.

I also attended lightning talks on the last day. Badri, Wouter, and I gave a demo on how to register on the Prav app. Prav got a fair share of advertising during the last few days.

I was roaming around with a QR code on my T-shirt for downloading Prav.

The night of the 17th of September Suresh left the hotel and Badri joined me in my room. Thanks to the efforts of Abhijit PA, Kiran, and Ananthu, I wore a mundu.

Me in mundu. Picture credits: Abhijith PA

I then joined Kalyani, Mangesh, Ruchika, Anisa, Ananthu and Kiran. We took pictures and this marked the last night of DebConf23.

Departure day The 18th of September was the day of departure. Badri slept in my room and left early morning (06:30 AM). I dropped him off at the hotel gate. The breakfast was at the eatery (3rd floor) again, and it was good. Sahil, Saswata, Nilesh, and I hung out on the ground floor.

From left: Nilesh, Saswata, me, Sahil. Photo credits: Sahil.

I had an 8 PM flight from Kochi to Delhi, for which I took a cab with Rhonda (Austria), Michael (Nigeria) and Yash (India). We were joined by other DebConf23 attendees at the Kochi airport, where we took another selfie.

Ruchika (taking the selfie) and from left to right: Yash, Joost (Netherlands), me, Rhonda

Joost and I were on the same flight, and we sat next to each other. He then took a connecting flight from Delhi to Netherlands, while I went with Yash to the New Delhi Railway Station, where we took our respective trains. I reached home on the morning of the 19th of September, 2023.

Joost and me going to Delhi. Photo credits: Ravi.

Big thanks to the organizers DebConf23 was hard to organize - strict alcohol laws, weird hotel rules, death of a close friend (almost a family member), and a scary notice by the immigration bureau. The people from the team are my close friends and I am proud of them for organizing such a good event. None of this would have been possible without the organizers who put more than a year-long voluntary effort to produce this. In the meanwhile, many of them had organized local events in the time leading up to DebConf. Kudos to them. The organizers also tried their best to get clearance for countries not approved by the ministry. I am also sad that people from China, Kosovo, and Iran could not join. In particular, I feel bad for people from Kosovo who wanted to attend but could not (as India does not consider their passport to be a valid travel document), considering how we Indians were so well-received in their country last year.

Note about myself I am writing this on the 22nd of September, 2023. It took me three days to put up this post - this was one of the tragic and hard posts for me to write. I have literally forced myself to write this. I have still not recovered from the loss of my friend. Thanks a lot to all those who helped me. PS: Credits to contrapunctus for making grammar, phrasing, and capitalization changes.

Mais uma edi o da Campus Party Brasil aconteceu na cidade de S o Paulo entre os dias 25 e 30 de Julho de 2023. Novamente a comunidade Debian Brasil se fez presente. Durante os dias no espa o disponibilizado, realizamos algumas atividades:
- Distribui o de brindes (adesivos, copos, cord o de crach );
- Mini oficina sobre como contribuir para a equipe de tradu o;
- Mini oficina sobre empacotamento;
- Assinatura de chaves;
- Informa es sobre o projeto; Durante todos os dias, havia sempre uma pessoa dispon vel para passar informa es sobre o que o Debian e as diversas formas de contribuir. Durante todo o evento, estimamos que ao menos 700 pessoas interagiram de alguma forma com nossa comunidade. Diversas pessoas, aproveitaram a oportunidade para aproveitar pelo excelente trabalho realizado pelo projeto no Debian 12 - Bookworm. Segue algumas fotos tiradas durante o evento!
Espa o da Comunidade no Evento.

Romulo, visitante do espa o com Daniel Lenharo.

Alguns brindes que estavam a disposi o do p blico.

Vis o do espa o.

Adesivo com a Arte de 30 anos feita pelo Jefferson.

Pessoal no espa o da comunidade.

Mini curso de empacotamento, realizado pelo Charles.

Pessoal que esteve envolvido nas atividades da comunidade.

Mais uma edi o da Campus Party Brasil aconteceu na cidade de S o Paulo entre os dias 25 e 30 de Julho de 2023. Novamente a comunidade Brasileira se fez presente. Durante os dias no espa o disponibilizado, realizamos algumas atividades:
- Distribui o de brindes (Adesivos, Copos, Cord o de crach );
- Mini oficina sobre como contribuir para a equipe de tradu o;
- Mini oficina sobre empacotamento;
- Informa es sobre o projeto; Durante todos os dias, havia sempre uma pessoa dispon vel para passar informa es sobre o que o Debian, formas de contribuir. Durante todo o evento, estimamos que ao menos 700 pessoas interagiram de alguma forma com nossa comunidade. Diversas pessoas, aproveitaram a oportunidade para aproveitar pelo excelente trabalho realizado pelo projeto no Debian 12 - Bookworm. Segue algumas fotos tiradas durante o evento!
Espa o da Comunidade no Evento.

Romulo, visitante do espa o com Daniel Lenharo.

Alguns brindes que estavam a disposi o do p blico.

Vis o do espa o.

Adesivo com a Arte de 30 anos feita pelo Jefferson.

Pessoal no espa o da comunidade.

Mini curso de empacotamento, realizado pelo Charles.

Pessoal que esteve envolvido nas atividades da comunidade.

No per odo de 25 a 27 de maio, Bras lia foi palco da MiniDebConf 2023. Esse encontro, composto por diversas atividades como palestras, oficinas, sprints, BSP (Bug Squashing Party), assinatura de chaves, eventos sociais e hacking, teve como principal objetivo reunir a comunidade e celebrar o maior projeto de Software Livre do mundo: o Debian. A MiniDebConf Bras lia 2023 foi um sucesso gra as participa o de todas e todos, independentemente do n vel de conhecimento sobre o Debian. Valorizamos a presen a tanto dos(as) usu rios(as) iniciantes que est o se familiarizando com o sistema quanto dos(as) desenvolvedores(as) oficiais do projeto. O esp rito de acolhimento e colabora o esteve presente em todos os momentos. As MiniDebConfs s o encontros locais organizados por membros do Projeto Debian, visando objetivos semelhantes aos da DebConf, por m em mbito regional. Ao longo do ano, eventos como esse ocorrem em diferentes partes do mundo, fortalecendo a comunidade Debian. Atividades A programa o da MiniDebConf foi intensa e diversificada. Nos dias 25 e 26 (quinta e sexta-feira), tivemos palestras, debates, oficinas e muitas atividades pr ticas. J no dia 27 (s bado), ocorreu o Hacking Day, um momento especial em que os(as) colaboradores(as) do Debian se reuniram para trabalhar em conjunto em v rios aspectos do projeto. Essa foi a vers o brasileira da Debcamp, tradi o pr via DebConf. Nesse dia, priorizamos as atividades pr ticas de contribui o ao projeto, como empacotamento de softwares, tradu es, assinaturas de chaves, install fest e a Bug Squashing Party.

N meros da edi o Os n meros do evento impressionam e demonstram o envolvimento da comunidade com o Debian. Tivemos 236 inscritos(as), 20 palestras submetidas, 14 volunt rios(as) e 125 check-ins realizados. Al m disso, nas atividades pr ticas, tivemos resultados significativos, como 7 novas instala es do Debian GNU/Linux, a atualiza o de 18 pacotes no reposit rio oficial do projeto Debian pelos participantes e a inclus o de 7 novos contribuidores na equipe de tradu o. Destacamos tamb m a participa o da comunidade de forma remota, por meio de transmiss es ao vivo. Os dados anal ticos revelam que nosso site obteve 7.058 visualiza es no total, com 2.079 visualiza es na p gina principal (que contava com o apoio de nossos patrocinadores), 3.042 visualiza es na p gina de programa o e 104 visualiza es na p gina de patrocinadores. Registramos 922 usu rios(as) nicos durante o evento. No YouTube, a transmiss o ao vivo alcan ou 311 visualiza es, com 56 curtidas e um pico de 20 visualiza es simult neas. Foram incr veis 85,1 horas de exibi o, e nosso canal conquistou 30 novos inscritos(as). Todo esse engajamento e interesse da comunidade fortalecem ainda mais a MiniDebConf. Fotos e v deos Para revivermos os melhores momentos do evento, temos dispon veis fotos e v deos. As fotos podem ser acessadas em: https://deb.li/pbsb2023. J os v deos com as grava es das palestras est o dispon veis no seguinte link: https://deb.li/vbsb2023. Para manter-se atualizado e conectar-se com a comunidade Debian Bras lia, siga-nos em nossas redes sociais:

• Telegram: https://t.me/debianbrasilia
• Facebook: https://www.facebook.com/debianbrasiliaoficial
• Twitter: https://twitter.com/DebianBrasilia

Agradecimentos Gostar amos de agradecer profundamente a todos(as) os(as) participantes, organizadores(as), patrocinadores e apoiadores(as) que contribu ram para o sucesso da MiniDebConf Bras lia 2023. Em especial, expressamos nossa gratid o aos patrocinadores Ouro: Pencillabs, Globo, Policorp e Toradex Brasil, e ao patrocinador Prata, 4-Linux. Tamb m agradecemos Finatec e ao Instituto para Conserva o de Tecnologias Livres (ICTL) pelo apoio. A MiniDebConf Bras lia 2023 foi um marco para a comunidade Debian, demonstrando o poder da colabora o e do Software Livre. Esperamos que todas e todos tenham desfrutado desse encontro enriquecedor e que continuem participando ativamente das pr ximas iniciativas do Projeto Debian. Juntos, podemos fazer a diferen a!

Last year I purchased an e-bike upgrade kit for my mother in law. We decided to install it on a bicycle she originally bought back in the 80s, which I fixed and refurbished a couple of years ago and used until September 2022 when I bought myself a Dutch Cortina U4. When I used this bicycle, I installed a lightweight Shutter Precision dynamo hub and compatible lights, XLC at the front, B chel at the back. Unfortunately, since Swytch is a front wheel with a built-in electric motor, these lights don t have a dynamo to connect to anymore, and Swytch doesn t have a dedicated connector for lights. I tried asking the manufacturer for more documentation or schematics, but they refused to do so. Luckily, a Canadian member of the Pedelecs forum managed to reverse-engineer the Swytch connector pinouts, which gave me an idea on how to proceed. Unfortunately, that meant that I had to replace both lights, and by trial and error I found specific models that worked. Before the Axa lights, I also tried B chel s Tivoli e-bike light, but it didn t work because the voltage was too low:

B chel Tivoli light that didn t work

Once I knew what to do, the rest was super easy So, here we go:

1. Get a 3-pin (yellow) male connector with a cable, e.g. off AliExpress. Only two wires will be used, the white one is +4.2V (4-point-2, not 42!), the black one is earth. This will go into the throttle port. If you actually have a throttle, you need some sort of Y-splitter, but I don t, so this was not an issue for me. (However, I bought both sides (M and F), just to be sure.)

   Cable for the throttle port

2. Purchase an Axa 606 E6-48 front light. The 606 comes in two versions, for dynamos and e-bikes, use the one for e-bikes; despite being officially rated as 6 48V, these lights work quite well off 4.2V too.

   Axa 606 E6-48 light

3. Purchase an Axa Spark Steady rear light. This light works with both AC and DC (just like the 606, the official rating is 6 48V), and works off 4.2V without an issue.

   Axa Spark light

4. Wire lights up. I used tiny wire terminals to join the wires, but I m sure there are better options too. Insulate them well, make sure the red wire from the throttle connector is insulated too. I used a bunch of shrink tubes and black insulation tape. Since the voltage is not wildly different from what the dynamo hub produced (although AC, not DC), I was able to reuse the cable I had already routed to the rear carrier.
5. Lights go on automatically as soon as you touch the power button on the battery pack, and stay on until the battery pack is switched off completely. I was considering adding a handlebar switch, but since I lost the only one I had, I had to do without.

Front light

Rear light

The side effect of using the Axa Spark at the rear is that it has a capacitor inside and keeps going for a couple more minutes after the battery pack is off I haven t decided whether that s a benefit or a drawback

The Brazilian translation team debian-l10n-portuguese realizou a primeira oficina de 2023 em fevereiro, com timos resultados:

• A oficina foi direcionada para iniciantes, usando o DDTP/DDTSS.
• Dois dias de oficina m o-na-massa via Jitsi.
• Nos dias seguintes, continuidade dos trabalho de tradu o de forma independente, com o suporte da equipe.
• Quantidade de pessoas inscritos(as): 29
• Novos(as) contribuidores(as) no DDPT/DDTSS: 22
• Tradu es dos(as) novos(as) participantes: 175
• Revis es dos(as) novos(as) participantes : 261

Nosso foco era completar as descri es dos 500 pacotes mais populares (popcon). Apesar de n o termos conseguido chegar 100% do ciclo de tradu o, grande parte dessas descri es est o em andamento e com um pouco mais de trabalho estar o dispon veis comunidade. Agrade o aos( s) participantes pelas contribui es. As oficinas foram bem movimentadas e, muito al m das tradu es em si, conversamos sobre diversas faces da comunidade Debian. Esperamos ter ajudado aos( s) iniciantes a contribuir com o projeto de maneira frequente. Agrade o em especial ao Charles (charles) que ministrou um dos dias da oficina, ao Paulo (phls) que sempre est a dando uma for a, e ao Fred Maranh o pelo seu incans vel trabalho no DDTSS. Equipe de tradu o do portugu s do Brasil

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

Changes

• colord: update link
• ArchiveBot: add gitweb ignoreset
• gensim: gitignore generated file, fix docs build, update links
• duck: add indicators (1 2)
• Debian QA services: drop jessie, convert errors to SQL commands, handle timeouts
• Debian BTS usertags: fix BSP, porter, rebootstrap, Python 3 tags
• Debian package uploads: purple-discord (1 2), sptag (1 2)
• Debian wiki pages: CrossGrading, Hardware/Wanted, InstructionSelection, OrganicMaps, Ports (loong64), PortsDocs/CreateDebianInstallerImages, Services (dpkg (IRC bot) factoid search, judd (IRC bot)), SummerOfCode2023
• FOSSjobs wiki pages: Resources

Issues

• Broken links in Debian Portfolio Service (sent privately), debian-security-support
• Incorrectly versioned dependencies in firefox-esr
• New maintainer needed for purple-discord, harmony
• Conffile removal needed in pylint
• Outdated embedded code copy in gensim
• Expired certificate in ca-certificates

Review

• Spam: reported 2 Debian bug reports and 14 Debian mailing list posts
• Debian wiki: RecentChanges for the month
• Debian BTS usertags: changes for the month
• Debian screenshots:
  • approved alpine android-file-transfer apt atop audacity boinc-manager boomaga buku changetrack cmatrix cpufetch dpkg drkonqi dte easyeffects eog evince f3d freecell-solver-bin fzy gedit ghostwriter gimp gimp-help-en gmlive gnome-calculator gnome-chess gnome-disk-utility gnome-feeds gnome-firmware gnome-logs gnome-mahjongg gnome-mines gnome-shell-extension-dash-to-panel gnome-shell-extension-freon gnome-shell-extension-prefs gnome-shell-extension-weather gnome-software gnome-sudoku gnome-text-editor gufw hwloc iagno im-config inkscape kamoso kde-config-systemd liblatex-table-perl libreoffice libreoffice-base libreoffice-calc libreoffice-draw libreoffice-help-en-us libreoffice-impress libreoffice-numbertext libreoffice-style-breeze libreoffice-style-colibre libreoffice-writer minder most nautilus nmon nvtop opensnitch pageedit pdfgrep pinpoint pipx planner plasma-welcome procps qalc qrterminal rtl-433 spacebar spek stockfish syncthingtray-kde-plasma systemd-resolved systray-mdstat uefitool vim-motif webext-privacy-badger webext-ublock-origin-firefox xapers zim
  • rejected lighttpd-modules-ldap (medical photo?), webext-debianbuttons (accidental), mkdocs (random web page), wallstreet (truncated), qrencode (output not UI), cgpt (bug report?), fluid-soundfont-gm/ (photo), b43-fwcutter (wallpaper), chromium-browser/kopano-webapp-lighttpd/libc6 (mobile app), pspg (Fedora), mancala (another implementation), nginx (Russian flag), chromium-browser (homework?), qflipper (firmware not updater), chromium-browser (just a QR code), kde-telepathy-contact-list (random website), gcc (bug report?)

Administration

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

Communication

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

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

Given that B lint just braggedblogged about how efficiently he can build a Linux kernel (less than 8 seconds, wow! Well, yes, until you read it is the result of aggressive caching and is achieved only for a second run), and that a question just popped up today on the Debian ARM mailing list, is an ARM computer a good choice? Which one? , I decided to share my results of an experiment I did several months ago, to graphically show to my students the effects of parallelism, the artifacts of hyperthreading, the effects of different architecture sets, and even illustrate about the actual futility of my experiment (somewhat referring to John Gustafson s reevaluation of Amdahl s law, already 30 years ago One does not take a fixed-size problem and run it on various numbers of processors except when doing academic research ; thanks for referring to my inconsequential reiterative compilations as academic research! ) I don t expect any of the following images to be groundbreaking, but at least, next time I need to find them it is quite likely I ll be able to find them and I will be able to more easily refer to them in online discussions So What did I do? I compiled Linux repeatedly, on several of the machines I had available, varying the -j flag (how many cores to use simultaneously), starting with single-core, and pushing up until just a bit over the physical number of cores the CPU has. Sadly, I lost several of my output images, but the three following are enough to tell interesting bits of the story:

• A nice little server my Institute acquired in early 2021: Xeon Silver 4208, with 8 physical cores (plus hyperthreading)
• My laptop, an 8-ARM-core Lenovo Yoga C630. Do note it s a big.LITTLE system, where 4 cores are smaller and 4 are bigger.
• A Raspberry Pi 4 (8GB version)

Of course, I have to add that this is not a scientific comparison; the server and my laptop have much better I/O than the Raspberry s puny micro-SD card (and compiling hundreds of thousands of files is quite an IO-stressed job, even though the full task does exhibit the very low compared single-threaded performance of the Raspberry even compared with the Yoga). No optimizations were done (they would be harmful to the effects I wanted to show!), the compile was made straight from the upstream sources.

De 2 a 4 de novembro de 2022 aconteceu a 19 edi o do Latinoware - Congresso Latino-americano de Software Livre e Tecnologias Abertas, em Foz do Igua u. Ap s 2 anos acontecendo de forma online devido a pandemia do COVID-19, o evento voltou a ser presencial e sentimos que a comunidade Debian Brasil deveria estar presente. Nossa ltima participa o no Latinoware foi em 2016 A organiza o do Latinoware cedeu para a comunidade Debian Brasil um estande para que pud ssemos ter contato com as pessoas que visitavam a rea aberta de exposi es e assim divulgarmos o projeto Debian. Durante os 3 dias do evento, o estande foi organizado por mim (Paulo Henrique Santana) como Desenvolvedor Debian, e pelo Leonardo Rodrigues como contribuidor Debian. Infelizmente o Daniel Lenharo teve um imprevisto de ltima hora e n o pode ir para Foz do Igua u (sentimos sua falta l !). V rias pessoas visitaram o estande e aquelas mais iniciantes (principalmente estudantes) que n o conheciam o Debian, perguntavam do que se tratava o nosso grupo e a gente explicava v rios conceitos como o que Software Livre, distribui o GNU/Linux e o Debian propriamente dito. Tamb m recebemos pessoas da comunidade de Software Livre brasileira e de outros pa ses da Am rica Latina que j utilizavam uma distribui o GNU/Linux e claro, muitas pessoas que j utilizavam Debian. Tivemos algumas visitas especiais como do Jon maddog Hall, do Desenvolvedor Debian Emeritus Ot vio Salvador, do Desenvolvedor Debian Eriberto Mota, e dos Mantenedores Debian Guilherme de Paula Segundo e Paulo Kretcheu. Foto da esquerda pra direita: Leonardo, Paulo, Eriberto e Ot vio. Foto da esquerda pra direita: Paulo, Fabian (Argentina) e Leonardo. Al m de conversarmos bastante, distribu mos adesivos do Debian que foram produzidos alguns meses atr s com o patroc nio do Debian para serem distribu dos na DebConf22(e que haviam sobrado), e vendemos v rias camisetas do Debian produzidas pela comunidade Curitiba Livre. Tamb m tivemos 3 palestras inseridas na programa o oficial do Latinoware. Eu fiz as palestras: como tornar um(a) contribuidor(a) do Debian fazendo tradu es e como os SysAdmins de uma empresa global usam Debian . E o Leonardo fez a palestra: vantagens da telefonia Open Source nas empresas . Foto Paulo na palestra. Agradecemos a organiza o do Latinoware por receber mais uma vez a comunidade Debian e gentilmente ceder os espa os para a nossa participa o, e parabenizamos a todas as pessoas envolvidas na organiza o pelo sucesso desse importante evento para a nossa comunidade. Esperamos estar presentes novamente em 2023. Agracemos tamb m ao Jonathan Carter por aprovar o suporte financeiro do Debian para a nossa participa o no Latinoware. Vers o em ingl s

De 2 a 4 de novembro de 2022 aconteceu a 19 edi o do Latinoware - Congresso Latino-americano de Software Livre e Tecnologias Abertas, em Foz do Igua u. Ap s 2 anos acontecendo de forma online devido a pandemia do COVID-19, o evento voltou a ser presencial e sentimos que a comunidade Debian Brasil deveria estar presente. Nossa ltima participa o no Latinoware foi em 2016 A organiza o do Latinoware cedeu para a comunidade Debian Brasil um estande para que pud ssemos ter contato com as pessoas que visitavam a rea aberta de exposi es e assim divulgarmos o projeto Debian. Durante os 3 dias do evento, o estande foi organizado por mim (Paulo Henrique Santana) como Desenvolvedor Debian, e pelo Leonardo Rodrigues como contribuidor Debian. Infelizmente o Daniel Lenharo teve um imprevisto de ltima hora e n o pode ir para Foz do Igua u (sentimos sua falta l !). V rias pessoas visitaram o estande e aquelas mais iniciantes (principalmente estudantes) que n o conheciam o Debian, perguntavam do que se tratava o nosso grupo e a gente explicava v rios conceitos como o que Software Livre, distribui o GNU/Linux e o Debian propriamente dito. Tamb m recebemos pessoas da comunidade de Software Livre brasileira e de outros pa ses da Am rica Latina que j utilizavam uma distribui o GNU/Linux e claro, muitas pessoas que j utilizavam Debian. Tivemos algumas visitas especiais como do Jon maddog Hall, do Desenvolvedor Debian Emeritus Ot vio Salvador, do Desenvolvedor Debian Eriberto Mota, e dos Mantenedores Debian Guilherme de Paula Segundo e Paulo Kretcheu. Foto da esquerda pra direita: Leonardo, Paulo, Eriberto e Ot vio. Foto da esquerda pra direita: Paulo, Fabian (Argentina) e Leonardo. Al m de conversarmos bastante, distribu mos adesivos do Debian que foram produzidos alguns meses atr s com o patroc nio do Debian para serem distribu dos na DebConf22(e que haviam sobrado), e vendemos v rias camisetas do Debian produzidas pela comunidade Curitiba Livre. Tamb m tivemos 3 palestras inseridas na programa o oficial do Latinoware. Eu fiz as palestras: como tornar um(a) contribuidor(a) do Debian fazendo tradu es e como os SysAdmins de uma empresa global usam Debian . E o Leonardo fez a palestra: vantagens da telefonia Open Source nas empresas . Foto Paulo na palestra. Agradecemos a organiza o do Latinoware por receber mais uma vez a comunidade Debian e gentilmente ceder os espa os para a nossa participa o, e parabenizamos a todas as pessoas envolvidas na organiza o pelo sucesso desse importante evento para a nossa comunidade. Esperamos estar presentes novamente em 2023. Agracemos tamb m ao Jonathan Carter por aprovar o suporte financeiro do Debian para a nossa participa o no Latinoware. Vers o em ingl s

Desde de setembro de 2015, o time de publicidade do Projeto Debian passou a publicar a cada dois meses listas com os nomes dos(as) novos(as) Desenvolvedores(as) Debian (DD - do ingl s Debian Developer) e Mantenedores(as) Debian (DM - do ingl s Debian Maintainer). Estamos aproveitando estas listas para publicar abaixo os nomes dos(as) brasileiros(as) que se tornaram Desenvolvedores(as) e Mantenedores(as) Debian a partir de julho de 2015. Desenvolvedores(as) Debian / Debian Developers / DDs: Marcos Talau

• DDPO
• Desde agosto de 2022
• Cidade de resid ncia: Curitiba - PR

Fabio Augusto De Muzio Tobich

• DDPO
• Desde maio de 2021
• Cidade de resid ncia: Curitiba - PR

Gabriel F. T. Gomes

• DDPO
• Desde maio de 2020
• Cidade de resid ncia: Campinas - SP

Thiago Andrade Marques

• DDPO
• Desde maio de 2020
• Cidade de resid ncia: Campinas - SP

M rcio de Souza Oliveira

• DDPO
• Desde fevereiro de 2019
• Cidade de resid ncia: Bras lia - DF

Paulo Henrique de Lima Santana

• DDPO
• Desde janeiro de 2019
• Cidade de resid ncia: Curitiba - PR

Samuel Henrique

• DDPO
• Desde abril de 2018
• Cidade de resid ncia: Curitiba - PR

S rgio Durigan J nior

• DDPO
• Desde mar o de 2018
• Cidade de resid ncia: Toronto - Canad

Daniel Lenharo de Souza

• DDPO
• Desde maio de 2017
• Cidade de resid ncia: Curitiba - PR

Giovani Augusto Ferreira

• DDPO
• Desde dezembro de 2016
• Cidade de resid ncia: Po o Fundo - MG

Adriano Rafael Gomes

• Desde agosto de 2016
• Cidade de resid ncia: Novo Hamburgo - RS

Breno Leit o

• DDPO
• Desde agosto de 2016
• Cidade de resid ncia: Campinas - SP

Lucas Kanashiro

• DDPO
• Desde junho de 2016
• Cidade de resid ncia: Bras lia - DF

Herbert Parentes Fortes Neto

• DDPO
• Desde junho de 2016
• Cidade de resid ncia: Rio de Janeiro RJ

Mantenedores(as) Debian / Debian Maintainers / DMs: Guilherme de Paula Xavier Segundo

• DDPO
• Desde abril de 2022
• Cidade de resid ncia: Campo Mour o - PR

David da Silva Polverari

• DDPO
• Desde janeiro de 2022
• Cidade de resid ncia: Bras lia - DF

Paulo Roberto Alves de Oliveira

• DDPO
• Desde novembro de 2021
• Cidade de resid ncia: S o Vicente - SP

Sergio Almeida Cipriano Junior

• DDPO
• Desde novembro de 2021
• Cidade de resid ncia: Bras lia - DF

Francisco Vilmar Cardoso Ruviaro

• DDPO
• Desde agosto de 2020
• Cidade de resid ncia: Santa Maria - RS

William Grzybowski

• DDPO
• Desde dezembro de 2019
• Cidade de resid ncia: Curitiba - PR

Tiago Ilieve

• DDPO
• Desde maio de 2016
• Cidade de resid ncia: Belo Horizonte - MG

---

Observa es:

1. Esta lista ser atualizada quando o time de publicidade do Debian publicar novas listas com DMs e DDs e tiver brasileiros.
2. Para ver a lista completa de Mantenedores(as) e Desenvolvedores(as) Debian, inclusive outros(as) brasileiros(as) antes de julho de 2015 acesse: https://nm.debian.org/public/people

Desde de setembro de 2015, o time de publicidade do Projeto Debian passou a publicar a cada dois meses listas com os nomes dos(as) novos(as) Desenvolvedores(as) Debian (DD - do ingl s Debian Developer) e Mantenedores(as) Debian (DM - do ingl s Debian Maintainer). Estamos aproveitando estas listas para publicar abaixo os nomes dos(as) brasileiros(as) que se tornaram Desenvolvedores(as) e Mantenedores(as) Debian a partir de julho de 2015. Desenvolvedores(as) Debian / Debian Developers / DDs: Marcos Talau

• DDPO
• Desde agosto de 2022
• Cidade de resid ncia: Curitiba - PR

Fabio Augusto De Muzio Tobich

• DDPO
• Desde maio de 2021
• Cidade de resid ncia: Curitiba - PR

Gabriel F. T. Gomes

• DDPO
• Desde maio de 2020
• Cidade de resid ncia: Campinas - SP

Thiago Andrade Marques

• DDPO
• Desde maio de 2020
• Cidade de resid ncia: Campinas - SP

M rcio de Souza Oliveira

• DDPO
• Desde fevereiro de 2019
• Cidade de resid ncia: Bras lia - DF

Paulo Henrique de Lima Santana

• DDPO
• Desde janeiro de 2019
• Cidade de resid ncia: Curitiba - PR

Samuel Henrique

• DDPO
• Desde abril de 2018
• Cidade de resid ncia: Curitiba - PR

S rgio Durigan J nior

• DDPO
• Desde mar o de 2018
• Cidade de resid ncia: Toronto - Canad

Daniel Lenharo de Souza

• DDPO
• Desde maio de 2017
• Cidade de resid ncia: Curitiba - PR

Giovani Augusto Ferreira

• DDPO
• Desde dezembro de 2016
• Cidade de resid ncia: Po o Fundo - MG

Adriano Rafael Gomes

• Desde agosto de 2016
• Cidade de resid ncia: Novo Hamburgo - RS

Breno Leit o

• DDPO
• Desde agosto de 2016
• Cidade de resid ncia: Campinas - SP

Lucas Kanashiro

• DDPO
• Desde junho de 2016
• Cidade de resid ncia: Bras lia - DF

Herbert Parentes Fortes Neto

• DDPO
• Desde junho de 2016
• Cidade de resid ncia: Rio de Janeiro RJ

Mantenedores(as) Debian / Debian Maintainers / DMs: Guilherme de Paula Xavier Segundo

• DDPO
• Desde abril de 2022
• Cidade de resid ncia: Campo Mour o - PR

David da Silva Polverari

• DDPO
• Desde janeiro de 2022
• Cidade de resid ncia: Bras lia - DF

Paulo Roberto Alves de Oliveira

• DDPO
• Desde novembro de 2021
• Cidade de resid ncia: S o Vicente - SP

Sergio Almeida Cipriano Junior

• DDPO
• Desde novembro de 2021
• Cidade de resid ncia: Bras lia - DF

Francisco Vilmar Cardoso Ruviaro

• DDPO
• Desde agosto de 2020
• Cidade de resid ncia: Santa Maria - RS

William Grzybowski

• DDPO
• Desde dezembro de 2019
• Cidade de resid ncia: Curitiba - PR

Tiago Ilieve

• DDPO
• Desde maio de 2016
• Cidade de resid ncia: Belo Horizonte - MG

---

Observa es:

1. Esta lista ser atualizada quando o time de publicidade do Debian publicar novas listas com DMs e DDs e tiver brasileiros.
2. Para ver a lista completa de Mantenedores(as) e Desenvolvedores(as) Debian, inclusive outros(as) brasileiros(as) antes de julho de 2015 acesse: https://nm.debian.org/public/people

Introduction: an immutable OS The Steam Deck runs SteamOS, a single-user operating system based on Arch Linux. Although derived from a standard package-based distro, the OS in the Steam Deck is immutable and system updates replace the contents of the root filesystem atomically instead of using the package manager. An immutable OS makes the system more stable and its updates less error-prone, but users cannot install additional packages to add more software. This is not a problem for most users since they are only going to run Steam and its games (which are stored in the home partition). Nevertheless, the OS also has a desktop mode which provides a standard Linux desktop experience, and here it makes sense to be able to install more software. How to do that though? It is possible for the user to become root, make the root filesytem read-write and install additional software there, but any changes will be gone after the next OS update. Modifying the rootfs can also be dangerous if the user is not careful. Ways to add additional software The simplest and safest way to install additional software is with Flatpak, and that s the method recommended in the Steam Deck Desktop FAQ. Flatpak is already installed and integrated in the system via the Discover app so I won t go into more details here. However, while Flatpak works great for desktop applications not every piece of software is currently available, and Flatpak is also not designed for other types of programs like system services or command-line tools. Fortunately there are several ways to add software to the Steam Deck without touching the root filesystem, each one with different pros and cons. I will probably talk about some of them in the future, but in this post I m going to focus on one that is already available in the system: systemd-sysext. About systemd-sysext This is a tool included in recent versions of systemd and it is designed to add additional files (in the form of system extensions) to an otherwise immutable root filesystem. Each one of these extensions contains a set of files. When extensions are enabled (aka merged ) those files will appear on the root filesystem using overlayfs. From then on the user can open and run them normally as if they had been installed with a package manager. Merged extensions are seamlessly integrated with the rest of the OS. Since extensions are just collections of files they can be used to add new applications but also other things like system services, development tools, language packs, etc. Creating an extension: yakuake I m using yakuake as an example for this tutorial since the extension is very easy to create, it is an application that some users are demanding and is not easy to distribute with Flatpak. So let s create a yakuake extension. Here are the steps: 1) Create a directory and unpack the files there:

$ mkdir yakuake
$ wget https://steamdeck-packages.steamos.cloud/archlinux-mirror/extra/os/x86_64/yakuake-21.12.1-1-x86_64.pkg.tar.zst
$ tar -C yakuake -xaf yakuake-*.tar.zst usr

2) Create a file called extension-release.NAME under usr/lib/extension-release.d with the fields ID and VERSION_ID taken from the Steam Deck s /etc/os-release file.

$ mkdir -p yakuake/usr/lib/extension-release.d/
$ echo ID=steamos > yakuake/usr/lib/extension-release.d/extension-release.yakuake
$ echo VERSION_ID=3.3.1 >> yakuake/usr/lib/extension-release.d/extension-release.yakuake

3) Create an image file with the contents of the extension:

$ mksquashfs yakuake yakuake.raw

That s it! The extension is ready. A couple of important things: image files must have the .raw suffix and, despite the name, they can contain any filesystem that the OS can mount. In this example I used SquashFS but other alternatives like EroFS or ext4 are equally valid. NOTE: systemd-sysext can also use extensions from plain directories (i.e skipping the mksquashfs part). Unfortunately we cannot use them in our case because overlayfs does not work with the casefold feature that is enabled on the Steam Deck. Using the extension Once the extension is created you simply need to copy it to a place where systemd-systext can find it. There are several places where they can be installed (see the manual for a list) but due to the Deck s partition layout and the potentially large size of some extensions it probably makes more sense to store them in the home partition and create a link from one of the supported locations (/var/lib/extensions in this example):

(deck@steamdeck ~)$ mkdir extensions
(deck@steamdeck ~)$ scp user@host:/path/to/yakuake.raw extensions/
(deck@steamdeck ~)$ sudo ln -s $PWD/extensions /var/lib/extensions

Once the extension is installed in that directory you only need to enable and start systemd-sysext:

(deck@steamdeck ~)$ sudo systemctl enable systemd-sysext
(deck@steamdeck ~)$ sudo systemctl start systemd-sysext

After this, if everything went fine you should be able to see (and run) /usr/bin/yakuake. The files should remain there from now on, also if you reboot the device. You can see what extensions are enabled with this command:

$ systemd-sysext status
HIERARCHY EXTENSIONS SINCE
/opt      none       -
/usr      yakuake    Tue 2022-09-13 18:21:53 CEST

If you add or remove extensions from the directory then a simple systemd-sysext refresh is enough to apply the changes. Unfortunately, and unlike distro packages, extensions don t have any kind of post-installation hooks or triggers, so in the case of Yakuake you probably won t see an entry in the KDE application menu immediately after enabling the extension. You can solve that by running kbuildsycoca5 once from the command line. Limitations and caveats Using systemd extensions is generally very easy but there are some things that you need to take into account:

1. Using extensions is easy (you put them in the directory and voil !). However, creating extensions is not necessarily always easy. To begin with, any libraries, files, etc., that your extensions may need should be either present in the root filesystem or provided by the extension itself. You may need to combine files from different sources or packages into a single extension, or compile them yourself.
2. In particular, if the extension contains binaries they should probably come from the Steam Deck repository or they should be built to work with those packages. If you need to build your own binaries then having a SteamOS virtual machine can be handy. There you can install all development files and also test that everything works as expected. One could also create a Steam Deck SDK extension with all the necessary files to develop directly on the Deck
3. Extensions are not distribution packages, they don t have dependency information and therefore they should be self-contained. They also lack triggers and other features available in packages. For desktop applications I still recommend using a system like Flatpak when possible.
4. Extensions are tied to a particular version of the OS and, as explained above, the ID and VERSION_ID of each extension must match the values from /etc/os-release. If the fields don t match then the extension will be ignored. This is to be expected because there s no guarantee that a particular extension is going to work with a different version of the OS. This can happen after a system update. In the best case one simply needs to update the extension s VERSION_ID, but in some cases it might be necessary to create the extension again with different/updated files.
5. Extensions only install files in /usr and /opt. Any other file in the image will be ignored. This can be a problem if a particular piece of software needs files in other directories.
6. When extensions are enabled the /usr and /opt directories become read-only because they are now part of an overlayfs. They will remain read-only even if you run steamos-readonly disable !!. If you really want to make the rootfs read-write you need to disable the extensions (systemd-sysext unmerge) first.
7. Unlike Flatpak or Podman (including toolbox / distrobox), this is (by design) not meant to isolate the contents of the extension from the rest of the system, so you should be careful with what you re installing. On the other hand, this lack of isolation makes systemd-sysext better suited to some use cases than those container-based systems.

Conclusion systemd extensions are an easy way to add software (or data files) to the immutable OS of the Steam Deck in a way that is seamlessly integrated with the rest of the system. Creating them can be more or less easy depending on the case, but using them is extremely simple. Extensions are not packages, and systemd-sysext is not a package manager or a general-purpose tool to solve all problems, but if you are aware of its limitations it can be a practical tool. It is also possible to share extensions with other users, but here the usual warning against installing binaries from untrusted sources applies. Use with caution, and enjoy!

Introduction The Steam Deck is a handheld gaming computer that runs a Linux-based operating system called SteamOS. The machine comes with SteamOS 3 (code name holo ), which is in turn based on Arch Linux. Although there is no SteamOS 3 installer for a generic PC (yet), it is very easy to install on a virtual machine using QEMU. This post explains how to do it. The goal of this VM is not to play games (you can already install Steam on your computer after all) but to use SteamOS in desktop mode. The Gamescope mode (the console-like interface you normally see when you use the machine) requires additional development to make it work with QEMU and will not work with these instructions. A SteamOS VM can be useful for debugging, development, and generally playing and tinkering with the OS without risking breaking the Steam Deck. Running the SteamOS desktop in a virtual machine only requires QEMU and the OVMF UEFI firmware and should work in any relatively recent distribution. In this post I m using QEMU directly, but you can also use virt-manager or some other tool if you prefer, we re emulating a standard x86_64 machine here. General concepts SteamOS is a single-user operating system and it uses an A/B partition scheme, which means that there are two sets of partitions and two copies of the operating system. The root filesystem is read-only and system updates happen on the partition set that is not active. This allows for safer updates, among other things. There is one single /home partition, shared by both partition sets. It contains the games, user files, and anything that the user wants to install there. Although the user can trivially become root, make the root filesystem read-write and install or change anything (the pacman package manager is available), this is not recommended because

• it increases the chances of breaking the OS, and
• any changes will disappear with the next OS update.

A simple way for the user to install additional software that survives OS updates and doesn t touch the root filesystem is Flatpak. It comes preinstalled with the OS and is integrated with the KDE Discover app. Preparing all necessary files The first thing that we need is the installer. For that we have to download the Steam Deck recovery image from here: https://store.steampowered.com/steamos/download/?ver=steamdeck&snr= Once the file has been downloaded, we can uncompress it and we ll get a raw disk image called steamdeck-recovery-4.img (the number may vary). Note that the recovery image is already SteamOS (just not the most up-to-date version). If you simply want to have a quick look you can play a bit with it and skip the installation step. In this case I recommend that you extend the image before using it, for example with truncate -s 64G steamdeck-recovery-4.img or, better, create a qcow2 overlay file and leave the original raw image unmodified: qemu-img create -f qcow2 -F raw -b steamdeck-recovery-4.img steamdeck-recovery-extended.qcow2 64G But here we want to perform the actual installation, so we need a destination image. Let s create one: $ qemu-img create -f qcow2 steamos.qcow2 64G Installing SteamOS Now that we have all files we can start the virtual machine:

$ qemu-system-x86_64 -enable-kvm -smp cores=4 -m 8G \
    -device usb-ehci -device usb-tablet \
    -device intel-hda -device hda-duplex \
    -device VGA,xres=1280,yres=800 \
    -drive if=pflash,format=raw,readonly=on,file=/usr/share/ovmf/OVMF.fd \
    -drive if=virtio,file=steamdeck-recovery-4.img,driver=raw \
    -device nvme,drive=drive0,serial=badbeef \
    -drive if=none,id=drive0,file=steamos.qcow2

Note that we re emulating an NVMe drive for steamos.qcow2 because that s what the installer script expects. This is not strictly necessary but it makes things a bit easier. If you don t want to do that you ll have to edit ~/tools/repair_device.sh and change DISK and DISK_SUFFIX. Once the system has booted we ll see a KDE Plasma session with a few tools on the desktop. If we select Reimage Steam Deck and click Proceed on the confirmation dialog then SteamOS will be installed on the destination drive. This process should not take a long time. Now, once the operation finishes a new confirmation dialog will ask if we want to reboot the Steam Deck, but here we have to choose Cancel . We cannot use the new image yet because it would try to boot into the Gamescope session, which won t work, so we need to change the default desktop session. SteamOS comes with a helper script that allows us to enter a chroot after automatically mounting all SteamOS partitions, so let s open a Konsole and make the Plasma session the default one in both partition sets:

$ sudo steamos-chroot --disk /dev/nvme0n1 --partset A
# steamos-readonly disable
# echo '[Autologin]' > /etc/sddm.conf.d/zz-steamos-autologin.conf
# echo 'Session=plasma.desktop' >> /etc/sddm.conf.d/zz-steamos-autologin.conf
# steamos-readonly enable
# exit
$ sudo steamos-chroot --disk /dev/nvme0n1 --partset B
# steamos-readonly disable
# echo '[Autologin]' > /etc/sddm.conf.d/zz-steamos-autologin.conf
# echo 'Session=plasma.desktop' >> /etc/sddm.conf.d/zz-steamos-autologin.conf
# steamos-readonly enable
# exit

After this we can shut down the virtual machine. Our new SteamOS drive is ready to be used. We can discard the recovery image now if we want. Booting SteamOS and first steps To boot SteamOS we can use a QEMU line similar to the one used during the installation. This time we re not emulating an NVMe drive because it s no longer necessary.

$ cp /usr/share/OVMF/OVMF_VARS.fd .
$ qemu-system-x86_64 -enable-kvm -smp cores=4 -m 8G \
   -device usb-ehci -device usb-tablet \
   -device intel-hda -device hda-duplex \
   -device VGA,xres=1280,yres=800 \
   -drive if=pflash,format=raw,readonly=on,file=/usr/share/ovmf/OVMF.fd \
   -drive if=pflash,format=raw,file=OVMF_VARS.fd \
   -drive if=virtio,file=steamos.qcow2 \
   -device virtio-net-pci,netdev=net0 \
   -netdev user,id=net0,hostfwd=tcp::2222-:22

(the last two lines redirect tcp port 2222 to port 22 of the guest to be able to SSH into the VM. If you don t want to do that you can omit them) If everything went fine, you should see KDE Plasma again, this time with a desktop icon to launch Steam and another one to Return to Gaming Mode (which we should not use because it won t work). See the screenshot that opens this post. Congratulations, you re running SteamOS now. Here are some things that you probably want to do:

• (optional) Change the keyboard layout in the system settings (the default one is US English)
• Set the password for the deck user: run passwd on a terminal
• Enable / start the SSH server: sudo systemctl enable sshd and/or sudo systemctl start sshd .
• SSH into the machine: ssh -p 2222 deck@localhost

Updating the OS to the latest version The Steam Deck recovery image doesn t install the most recent version of SteamOS, so now we should probably do a software update.

• First of all ensure that you re giving enought RAM to the VM (in my examples I run QEMU with -m 8G). The OS update might fail if you use less.
• (optional) Change the OS branch if you want to try the beta release: sudo steamos-select-branch beta (or main, if you want the bleeding edge)
• Check the currently installed version in /etc/os-release (see the BUILD_ID variable)
• Check the available version: steamos-update check
• Download and install the software update: steamos-update

Note: if the last step fails after reaching 100% with a post-install handler error then go to Connections in the system settings, rename Wired Connection 1 to something else (anything, the name doesn t matter), click Apply and run steamos-update again. This works around a bug in the update process. Recent images fix this and this workaround is not necessary with them. As we did with the recovery image, before rebooting we should ensure that the new update boots into the Plasma session, otherwise it won t work:

$ sudo steamos-chroot --partset other
# steamos-readonly disable
# echo '[Autologin]' > /etc/sddm.conf.d/zz-steamos-autologin.conf
# echo 'Session=plasma.desktop' >> /etc/sddm.conf.d/zz-steamos-autologin.conf
# steamos-readonly enable
# exit

After this we can restart the system. If everything went fine we should be running the latest SteamOS release. Enjoy! Reporting bugs SteamOS is under active development. If you find problems or want to request improvements please go to the SteamOS community tracker. Edit 06 Jul 2022: Small fixes, mention how to install the OS without using NVMe.

Sciencealert has an interesting article on a game to combat misinformation by microdosing people [1]. The game seemed overly simplistic to me, but I guess I m not the target demographic. Research shows it to work. Vice has an interesting and amusing article about mass walkouts of underpaid staff in the US [2]. The way that corporations are fighting an increase in the minimum wage doesn t seem financially beneficial for them. An increase in the minimum wage means small companies have to increase salaries too and the ratio of revenue to payroll is probably worse for small companies. It seems that companies like McDonalds make oppressing their workers a higher priority than making a profit. Interesting article in Vice about how the company Shot Spotter (which determines the locations of gunshots by sound) forges evidence for US police [3]. All convictions based on Shot Spotter evidence should be declared mistrials. BitsNBites has an interesting article on the fundamental flaws of SIMD (Single Instruction Multiple Data) [4]. The Daily Dot has a disturbing article anbout the possible future of the QAnon movement [5]. Let s hope they become too busy fighting each other to hurt many innocent people. Ben Taylor wrote an interesting blog post suggesting that Web Assembly should be a default binary target [6]. I don t support that idea but I think that considering it is useful. Web assembly could be used more for non-web things and it would be a better option than Node.js for some things. There are also some interesting corner cases like games, Minecraft was written in Java and there s no reason that Web Assembly couldn t do the same things. Vice has an interesting article about the Phantom encrypted phone service that ran on Blackberry handsets [7]. Australia really needs legislation based on the US RICO law! Vice has an interesting article about an encrypted phone company run by drug dealers [8]. Apparently after making an encrypted phone system for their own use they decided to sell it to others and made millions of dollars. They could have run a successful legal business. Salon has an insightful interview with Michael Petersen about his research on fake news and people who share it because they need chaos [9]. Apparently low status people who are status seeking are a main contributor to this, they share fake news knowingly to spread chaos. A society with less inequality would have less problems with fake news. Salon has another insightful interview with Michael Petersen, about is later research on fake news as an evolutionary strategy [10]. People knowingly share fake news to mobilise their supporters and to signal allegiance to their group. The more bizarre the beliefs are the more strongly they signal allegiance. If an opposing group has a belief then they can show support for their group by having the opposite belief (EG by opposing vaccination if the other political side supports doctors). He also suggests that lying can be a way of establishing dominance, the more honest people are opposed by a lie the more dominant the liar may seem. Vice has an amusing article about how police took over the Encrochat encrypted phone network that was mostly used by criminals [11]. It s amusing to read of criminals getting taken down like this. It s also interesting to note that the authorities messed up by breaking the wipe facility which alerted the criminals that their security was compromised. The investigation could have continued for longer if they hadn t changed the functionality of compromised phones. A later vice article mentioned that the malware installed on Encrochat devices recorded MAC addresses of Wifi access points which was used to locate the phones even though they had the GPS hardware removed. Cory Doctorow wrote an insightful article for Locus about the insufficient necessity of interoperability [12]. The problem if monopolies is not just an inability to interoperate with other services or leave it s losing control over your life. A few cartel participants interoperating will be able to do all the bad things to us tha a single monopolist could do.

• [1] https://tinyurl.com/yhrq5887
• [2] https://tinyurl.com/yhmog5ex
• [3] https://tinyurl.com/ygnmjm9j
• [4] https://www.bitsnbites.eu/three-fundamental-flaws-of-simd/
• [5] https://www.dailydot.com/debug/ghostezra-telegram-fued-qanon/
• [6] https://tinyurl.com/yhvganlc
• [7] https://tinyurl.com/yfljnlq5
• [8] https://tinyurl.com/yft5qwbc
• [9] https://tinyurl.com/yjjnnyfu
• [10] https://tinyurl.com/yjxq8c2v
• [11] https://tinyurl.com/y7hhrxuz
• [12] https://tinyurl.com/yj33txpj