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Reminder seL4 developer hangout
by Birgit Brecknell 12 Dec '22

12 Dec '22

Hi all A friendly reminder that the seL4 developer hangout is on again this week: Wed, Dec 14, 6am (UTC), Topics: (open) * Sydney: Wed, Dec 14, 5pm * Central Europe: Wed, Dec 14, 7am * US Pacific Time: Tue, Dec 13, 10pm Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Dr. Birgit Brecknell Project Officer Trustworthy Systems, UNSW, birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> seL4 Foundation, birgit(a)sel4.systems<mailto:birgit@sel4.systems> 0433 880 571 Mon 9am-5pm Wed 9am-12pm Fri 9am-5pm

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Call for nominations for Special Interest Group Chairs
by Gerwin Klein 05 Dec '22

05 Dec '22

At this year's seL4 summit the community expressed strong interest in starting a number of special interest groups (SIGs) around seL4 and in particular around the following topics: - Virtual machines and virtual machine monitors (SIG VMM) - Drivers (SIG Drivers) - Multicore design + verification (SIG Multicore) The multicore verification topic also showed large overlap with interest in user-level verification at the summit. One suggestion would be to cover both topics in that SIG. To start these SIGs, we are calling for the nomation of a chair for each of them. Anyone can nominate anyone from the seL4 community, including themselves. If there is more than one nomination who is willing to do the job for a specific SIG, we will organise a vote and if possible appoint a chair + vice-chair (for backup). The appointement will be confirmed by the technical steering committee TSC. The main job of the chair of a SIG will be (lightweight) moderatation, keeping the conversation going, and to be a point of contact with the TSC. An initial task for the chair would be to lead the discussion on what the SIG will be about in more detail and what it wants to achieve. Examples could be: - to coordinate concrete work - to discuss the topic of the SIG - to make recommendations to the TSC - to work together on RFCs on the topic of the SIG This should result in a short description that we can use on the seL4 website and discourse groups for the SIG to describe what its purpose is. We suggest that the main communciation medium for SIGs be the seL4 discourse forum, where each SIG could have its own topic area, but we are happy for SIGs to self-organise differently if they prefer. Please send nominations to Gerwin Klein <kleing(a)unsw.edu.au>. Please indicate which SIG they are for. Cheers, Gerwin (seL4 TSC chair)

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[FOSDEM'23] Submit talk for the "Microkernel and Component-based OS" devroom
by Razvan Deaconescu 05 Dec '22

05 Dec '22

Hi. I am Razvan Deaconescu, I'm from University POLITEHNICA of Bucharest (working on Unikraft unikernel) and I'm managing the "Microkernel and Component-based OS" devroom[2] at FOSDEM'2023[1]. The devroom will take place in person, at FOSDEM'23, in Brussels, on Sunday, February 5, 2023. If you have an interesting topic to talk about it would be great if you made a submission. This is something easy to do, takes about 15-20 minutes on Pentabarf[3]. The deadline for submission is today, Friday, December 2, 2022. [1] https://fosdem.org/2023/ [2] https://fosdem.org/2023/schedule/track/microkernel_and_component_based_os/ [3] https://penta.fosdem.org/submission/ Razvan

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Reminder seL4 developer hangout
by Birgit Brecknell 28 Nov '22

28 Nov '22

Hi all A friendly reminder that the seL4 developer hangout is on again this week: Tue, Nov 29, 9pm (UTC), Topics: (open) * Sydney: Wed, Nov 30, 8am * Central Europe: Tue, Nov 29, 10pm * US Pacific Time: Tue, Nov 29, 1pm Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Dr. Birgit Brecknell Project Officer Trustworthy Systems, UNSW, birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> seL4 Foundation, birgit(a)sel4.systems<mailto:birgit@sel4.systems> 0433 880 571 Mon 9am-5pm Wed 9am-12pm Fri 9am-5pm

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Survey about the seL4 summit 2023's location
by June Andronick (seL4 Foundation) 21 Nov '22

21 Nov '22

Dear seL4 friends, With the great success of the seL4 summit 2022 behind us, we are now already looking at the seL4 summit 2023! This should happen around Sep/Oct 2023. We have started investigating options for the location, and we would like your feedback. We would very much appreciate if you could fill in this very short survey to tell us your opinion between USA (likely Minneapolis) and Australia (likely Sydney) or any other feedback you have: https://forms.gle/k4XxYaYeudYUie9U8 <https://forms.gle/k4XxYaYeudYUie9U8> Please do so by Nov 22nd 2022. Feel free to forward to anyone you believe may want to attend the summit next year. Many thanks! June -- June Andronick CEO of the seL4 Foundation https://sel4.systems/Foundation

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Experimental project on seL4 microbenchmarking
by Nataliya Korovkina 20 Nov '22

20 Nov '22

Hi seL4 friends, I’d like to share an experimental project on seL4 microbenchmarking inspired with my experience with sel4bench suite. Your thoughts on the concept and its practical use will be greatly appreciated. Motivation (informal) Measuring execution times of short code paths, which we can meet in seL4 microbenchmarking, is a good way to immerse oneself into the domain of compiler and microarchitectural optimizations. Implementation of “early processing” measurement methodology in sel4bench suite (for Notification delivery case, as a trial step; PR #26) was an amazing experience in that respect. So, I gladly share the work highlights to explain my motivation. First, latencies of some microarchitectural events can be comparable with execution time of a measured code path. So, if microarchitectural event not planned by a benchmark design happens during a measuring period, deviation of the observed value considerably increases. Second, the both kinds of optimizations of instrumental code cause instability of measured values from one measurement iteration to another. Third, debugging the instrumental code is very challenging. Injection of diagnostic code into it changes effects of the both types of optimizations; therefore, initially witnessed symptoms effectively transform to other ones. When you think about how to control optimizations effects, the situation appears uninspiring, considering the need to treat various microarchitectures and optimization features. As a result, the situation left me with the question on hands: how to distance a benchmark design from necessity to control optimizations effects in instrumental code that impair repeatability? Eventually, it reduced to the foundational one: What we measure, and Why? This experimental work is attempt to find and try the solution for the challenge: designing more predictable measurement context. The work was published in github. Description paper https://github.com/malus-brandywine/sel4KanataBench-papers/blob/main/Kanata… Project repository https://github.com/malus-brandywine/sel4KanataBench Project manifest repository https://github.com/malus-brandywine/sel4KanataBench-manifest Tables of data collected on four TS platforms: files KBenchTable-xxxx.pdf in https://github.com/malus-brandywine/sel4KanataBench-papers Thank you!

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Reminder seL4 developer hangout
by Birgit Brecknell 14 Nov '22

14 Nov '22

Hi all A friendly reminder that the seL4 developer hangout is on again this week: Wed, Nov 16, 6am (UTC), Topics: (open) * Sydney: Wed, Nov 16, 5pm * Central Europe: Wed, Nov 16, 7am * US Pacific Time: Tue, Nov 15, 10pm Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Dr. Birgit Brecknell Project Officer Trustworthy Systems, UNSW, birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> seL4 Foundation, birgit(a)sel4.systems<mailto:birgit@sel4.systems> 0433 880 571 Mon 9am-5pm Wed 9am-12pm Fri 9am-5pm

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Reminder seL4 developer hangout
by Birgit Brecknell 31 Oct '22

31 Oct '22

Hi all A friendly reminder that the seL4 developer hangout is on again next week: Tue, Nov 1, 9pm (UTC), Topics: (open) * Sydney: Wed, Nov 2, 8am * Central Europe: Tue, Nov 1, 10pm * US Pacific Time: Tue, Nov 1, 2pm Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Dr. Birgit Brecknell Project Officer Trustworthy Systems, UNSW, birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> seL4 Foundation, birgit(a)sel4.systems<mailto:birgit@sel4.systems> 0433 880 571 Mon 9am-5pm Wed 9am-12pm Fri 9am-5pm

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Cross Core IPC
by Sid Agrawal 24 Oct '22

24 Oct '22

Hi, I came across Gernot Heiser's blog post on "How to use seL4 IPC" [1]. The article explicitly says that doing cross-core IPC is a bad idea. This statement led to a series of questions for me, which I hope you guys can help me with. Scenario ------------ We have a system with two cores. Let's say that a physical memory server is running on core0, my application is on core1, and they are somehow pinned to those cores. The application wants some physical memory (frame capabilities) from the memory server. Questions ------------- Q1. Will the application be able to invoke the endpoint given that the TCB which will respond to it is on a separate core? If yes, will sending a capability back via cross-core IPC be allowed? I did not read anything in the manual which said otherwise. Q2. Why is a cross-core IPC a bad idea? This might be a loaded question, but I am not able to appreciate the badness of the idea :) Q3. What would be the right way to do it? For example, in Barrelfish(limited experience from a course), the application(on core1) would make an IPC to a monitor running on the same core1. This monitor did synchronization with another monitor running on the other core(core0) via a shared memory region (all in user space). That monitor(core0) then sent an IPC to the memory server running on core0. And then back again via the monitors. Best, Sid [1] https://microkerneldude.org/2019/03/07/how-to-and-how-not-to-use-sel4-ipc/

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Suitability for a project
by James Hillman 19 Oct '22

19 Oct '22

Hi Sel4 developers, I am new to this forum and hoping this is the right place to bounce my project idea off. I typically use FPGA to enforce security in my products but there are lots of reasons why FPGAs are not suitable for all use cases. I have also used low end microcontroller where one can review all the code to understand the security risks. My latest project however involves two USB processes (one for each physical connection) with high throughput expectations. And to pass data streams at high typical throughput between them. Due to the wide range of USB type of devices I fear this would be too much code to review - it feels very OS like. Note, I don't need a GUI, it's headless. So I'm interested in sel4 as I could run the processes in Linux VMs if I understand sel4 correctly. And whilst it's not the smallest processors I think they need to be more powerful to support the speeds. So this is fine . I am unsure how much of this project is already done, mainly thinking the usb driver perspective. Thanks in advance, Best wishes James

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