- Devel - lists.sel4.systems

libsel4 status
by Yanfeng Liu 30 May '26

30 May '26

Dear experts, It seems that currently libsel4 has many inlined functions thus user space code size is large. I am wondering if this is really necessary? If current libsel4 is not for production use, then it doesnt matter. Otherwise I am wondering if we need support size optimized config as well? I am hoping that libsel4 changes wont affect kernel verification? Regards, yf

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seL4 developer hangout reminder
by Birgit Brecknell 25 May '26

25 May '26

Hi all A friendly reminder that the seL4 developer hangout is on again next week. Wed 27 May, 8:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Question about ASpec → ExecSpec session dependency and shared-types design choice
by li-jun zhang 20 May '26

20 May '26

shared-types design choice Hi seL4 verification team, my name is Li-Jun Zhang, a PDH student form Nanjing University. I'm studying the structure of spec/ROOT and have a question about a design choice I'd like to understand before considering whether it's worth trying to change. The observation ASpec is declared in spec/ROOT as session ASpec in "abstract" = Word_Lib + sessions "HOL-Library" Lib ExecSpec ... Across the codebase there are nine direct imports "ExecSpec.X" from spec-side files, through five targets: | Imported ExecSpec theory | Importing spec-side theory | | --- | --- | | ExecSpec.MachineTypes | CKernel.Kernel_C, CSpec.Kernel_C, ExecSpec.MachineMonad | | ExecSpec.InvocationLabels_H | ASpec.ArchDecode_A, ASpec.Decode_A | | ExecSpec.Event_H | ASpec.Syscall_A, DSpec.Syscall_D | | ExecSpec.Arch_Structs_B | ASpec.Arch_Structs_A | | ExecSpec.ArchLabelFuns_H | ASpec.InvocationLabels_A | Combined with the sessions ExecSpec declaration, this means any Haskell prototype edit transitively invalidates ASpec and AInvs builds — even when the edit doesn't touch any of the five shared targets, because sessions ExecSpec causes ExecSpec's whole content to be source-re-executed inside ASpec's ML state. The skeleton file spec/design/skel/ARM/Arch_Structs_B.thy carries the comment (* Architecture-specific data types shared by spec and abstract. *) which suggests these targets are understood as cross-pillar shared, yet they physically live inside the Haskell-derived ExecSpec session. The comment dates back to commit 2a03e81 (the initial open-source release in 2014), and the sessions ExecSpec line has survived multiple subsequent ROOT reorganizations (e.g. the 2018 session-qualified-imports work and the 2020-10 new ROOT requirements reorg), so I assume the structure is intentional rather than incidental. The hypothetical change Suppose the closure of the five shared targets within ExecSpec (12 theories total: MachineTypes, MachineMonad, MachineOps, MachineExports, Platform, Kernel_Config, Setup_Locale, Event_H, ArchInvocationLabels_H, InvocationLabels_H, ArchLabelFuns_H, Arch_Structs_B) were moved into a base KernelTypes session, with ASpec and ExecSpec both reparented to + KernelTypes. Then: sessions ExecSpec could be removed from ASpec's ROOT entry. A Haskell-side edit that doesn't touch the 12 shared theories would no longer invalidate ASpec / AInvs. Type identity is preserved as long as the moved files keep global_naming ARM_H — the fully qualified names (ARM_H.arm_vspace_region_use, etc.) referenced by downstream are unchanged. My question Was an extraction of this kind considered when the current structure was designed (presumably pre-2014, given the comment dates from the initial release)? Are there constraints — generation-pipeline output paths, type-equality concerns beyond the global_naming trick, methodological coupling between Haskell-as-canonical-source and the abstract spec, downstream tooling that references the ExecSpec.X FQNs, or anything else — that make the current sessions ExecSpec structure the deliberate choice? I'd rather not pursue a refactor that's already been considered and rejected for a reason I'm not seeing. Pointers to prior discussion (mailing-list threads, design notes, PRs) would be very helpful. Thanks Li-Jun Zhang

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seL4 developer hangout reminder
by Birgit Brecknell 11 May '26

11 May '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 12 May, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 24 Apr '26

24 Apr '26

Hi all A friendly reminder that the seL4 developer hangout is on again next week. Wed 29 Apr, 8:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Last day to submit a talk proposal to the sel4 summit!
by June Andronick 21 Apr '26

21 Apr '26

It only requires an abstract describing your talk proposal. https://form.jotform.com/260147181364858 Looking forward to your submissions. Cheers, June

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seL4 summit 2026: one week to go to submit a talk
by Birgit Brecknell 13 Apr '26

13 Apr '26

One week to go to submit a talk [0] for the seL4 Summit 2026 [1]! If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. **Abstracts are due on 20 April 2026.** **NEW!** The 2026 edition of the seL4 summit will feature a **full first day** dedicated to **applications, overviews, and perspectives** on seL4-based systems and formally verified software in the real world. This will be followed by Days 2 and 3 focusing on more technical development, research, reports, and discussions. We are particularly keen to **welcome people who are new to seL4** or still developing their familiarity with the technology. The event will offer an **ideal opportunity to gain a high-level view of the landscape and ecosystem** of seL4 and its associated tools, frameworks and languages, as well as formally verified software in general, and to take stock of the latest updates. The seL4 Summit 2026 will be held 1 - 3 September 2026 at the Hyatt Regency Vancouver, Vancouver, Canada. The summit will be an in-person event. We’re looking forward to many exciting proposals! [0] https://sel4.systems/Summit/2026/cfp [1] https://sel4.systems/Summit/2026/ [2] https://form.jotform.com/260147181364858 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 13 Apr '26

13 Apr '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 14 Apr, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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New release of seL4, Microkit, CAmkES, capDL and Rust support
by Gerwin Klein 31 Mar '26

31 Mar '26

We're pleased to announce the release of - seL4 15.0.0: The seL4 microkernel https://docs.sel4.systems/releases/sel4/15.0.0 - Microkit 2.2.0: The seL4 Microkit for building static-architecture systems https://docs.sel4.systems/releases/microkit/2.2.0 - CAmkES 3.12.0: Component Architecture for microkernel-based Embedded Systems https://docs.sel4.systems/releases/camkes/camkes-3.12.0 - capDL 0.5.0: Tools for generating, parsing and loading capability distribution specifications https://docs.sel4.systems/releases/capdl/0.5.0 - rust-sel4 4.0.0: Rust support for seL4 userspace https://github.com/seL4/rust-sel4/releases/tag/v4.0.0 seL4 15.0.0 and the corresponding Rust support come with new features and will require updates if you are using the seL4 API directly. CAmkES and the capDL tool add domain schedules as a new feature and applications will need updates if they use the seL4 domain scheduler. The Microkit release should not require any update of user code compared to Microkit 2.1.0. Enjoy! Gerwin

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seL4 developer hangout reminder
by Birgit Brecknell 30 Mar '26

30 Mar '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 1 Apr, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 16 Mar '26

16 Mar '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 17 Mar, 21:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 02 Mar '26

02 Mar '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 4 Mar, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 16 Feb '26

16 Feb '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 17 Feb, 21:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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issue with elfloader ret instruction while enabling the MMU on armv8-a
by Christian Bruel 11 Feb '26

11 Feb '26

Hello seL4 team, I would like to share an issue found with the port of seL4 and VMs to the STM32MP2 SoC, which features Armv8-A dual Cortex-A35 cores: When activating the secondary core, The RET instruction crashes while executing the arm_enable_mmu(). The exception stack and ESR register show no useful information. Simply replacing the RET instruction with BR X30 resolves the issue. Furthermore, before RET, a check with the AT S1E1R, X30 shows correct memory translation in the PAR_EL1 register, confirming proper MMU setting, which is also supported by the successful BR X30 workaround. Just to be sure I tried to replace the current 1Gb translation table with a finer 4Bb granularity and P:EX U:NX and RO access flags for the Non Secure code execution. Same results. I also set the ASID bits, same result. So back to the current implementation and BR X30 workaround: According to the Arm Architecture Reference Manual [1], the RET instruction behaves identically to BR but provides an additional hint that this is a return from a subroutine. AFAIU, such hints can be related to the branch predictor or the return address stack used for ROP protection, (if the feature is available). In “Requirements for branch predictor maintenance” [2], branch prediction maintenance operations must be performed after enabling or disabling the MMU. However, these operations translate as a NOP if the branch predictor hardware is not architecturally visible. Therefore, the ‘BL/RET’ behavior from different translation regime seems to to be implementation-dependent or dependent on optional architectural features Thus, replacing MMU enable sequence: enable_mmu sctlr_el1 x8 ldp x29,x30,[sp],#16 ret with a trampoline: adr x30,mmu_on ldp x29,x9,[sp],#16 ret mmu_on: enable_mmu sctlr_el1,x8 br x9 is enough to start seL4 with SMP=on NUM_NODES=2 and run a dual core Linux on the CAmkES VM. This is semantically equivalent to the BL X30 workaround, but this is more explicit regarding the MMU translation regime around BL/RET. NB: arm_enable_hyp_mmu() needs the same change as the issue happens equivalently in EL1 or EL2. Thank you very much for your thoughts on this issue. Best Regards Christian References: [1] Arm Architecture Reference Manual (DTI 0487) [2] Arm Architecture Reference Manual ARMv7-A and ARMv7-R edition

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seL4 developer hangout reminder
by Birgit Brecknell 02 Feb '26

02 Feb '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 4 Feb, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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** Cohesix 0.1.0‑alpha1 — Release Announcement
by Lukas Bower 24 Jan '26

24 Jan '26

Excited to ship the Cohesix 0.1.0‑alpha1 release: a control‑plane OS targeting aarch64, for secure orchestration + telemetry of edge GPU nodes, built on seL4 with a pure‑Rust userspace and a Queen/Worker hive model. This release focuses on repeatable bundles, SwarmUI replays, and CLI workflows: https://github.com/lukeb-aidev/cohesix/blob/main/README.md https://github.com/lukeb-aidev/cohesix/tree/main/releases Best, Lukas Bower

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seL4 developer hangout reminder
by Birgit Brecknell 19 Jan '26

19 Jan '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 20 Jan, 21:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 05 Jan '26

05 Jan '26

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 7 Jan, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Re: Announcing release v0.3 of Neptune OS, a Windows NT personality for seL4
by Dr. Chang Liu, PhD. 04 Jan '26

04 Jan '26

In theory if you implement the same interfaces that the NT Executive exposes to client drivers, potentially yes --- the relevant code has around 5K LOCs so it is not that big. --- Dr. Chang Liu, PhD. github.com/cl91/NeptuneOS On Tue, Dec 30, 2025 at 6:11 PM Demi Marie Obenour <demiobenour(a)gmail.com> wrote: > On 12/30/25 04:35, Dr. Chang Liu, PhD. via Devel wrote: > > Additionally, due to the lack of high quality open-source Windows > drivers, > > a big part of the next release will be focused on designing and building > a > > subsystem which allows Linux drivers to run natively (without emulation) > as > > userspace processes on Neptune OS, so stay tuned! > > Is this something that could be reused for other seL4-based OSs? > -- > Sincerely, > Demi Marie Obenour (she/her/hers)

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Announcing release v0.3 of Neptune OS, a Windows NT personality for seL4
by Dr. Chang Liu, PhD. 30 Dec '25

30 Dec '25

Dear List, I am announcing the v0.3 release [1] of Neptune OS, a Windows NT personality built on top of the seL4 microkernel. Neptune OS implements the upper layer of the Windows kernel (the "NT Executive") as a user space process under seL4, providing NT-like interfaces via standard seL4 IPC primitives to device drivers and user programs. These then allow Windows device drivers to be ported to run as user space processes under Neptune OS, with potentially greater degree of isolation and fault recovery than can be achieved under a traditional macro-kernel or hybrid-kernel design. The highlights of the v0.3 release are a bunch of computing industry acronyms: UEFI, ACPI, PCI(E), AHCI, and NVME. We have improved upon the basic NT PnP manager implementation we had in the previous release and ported over the ACPI and PCI(E) drivers from ReactOS, to enable completely dynamic discovery/enumeration, resource assignment, lifetime cycle, and power management of hardware devices. The hope is that this will eventually make Neptune OS suitable as a general purpose OS that must manage an ever-changing device landscape, while still being able to leverage seL4's strong isolation and formal guarantees. Built upon this work, we have ported over what I hope is a reasonably complete portion of the Windows storage device driver stack, consisting of the class drivers (classpnp.sys, disk.sys), the storage port driver (storport.sys), two storage miniport drivers (for AHCI and NVME), and the partition manager (partmgr.sys) and mount-point manager (mountmgr.sys). Among these, the class drivers as well as the AHCI miniport driver are from the official Microsoft sample drivers [3], the NVME miniport driver is from Open Systems Alliance [4], and storport, partmgr, and mountmgr are from ReactOS. These drivers total an over-120K codebase and with the exception of storport where some missing pieces had to be added due to the incompleteness of the ReactOS implementation, are largely unmodified. I hope the non-triviality of these drivers serves as a convincing demonstration that our design is capable of reusing complex, real-world Windows drivers in a microkernel-based OS (which NT had originally hoped to be, allegedly). I have recorded a short video [2] showing the ACPI and AHCI driver stack in action, including device tree enumeration, power management (reboot/poweroff), and basic shell commands. This release also includes a basic disk IO benchmarking tool. Based on some early testing we seem to be able to saturate the AHCI bandwidth without a problem, but NVME seems to be underperforming. This will be part of the work going into the next release. Additionally, due to the lack of high quality open-source Windows drivers, a big part of the next release will be focused on designing and building a subsystem which allows Linux drivers to run natively (without emulation) as userspace processes on Neptune OS, so stay tuned! [1] https://github.com/cl91/NeptuneOS/releases/tag/v0.3.0003 [2] https://www.youtube.com/watch?v=ejNeS7A5qq0 [3] https://github.com/microsoft/Windows-driver-samples/tree/main/storage [4] https://github.com/JoeHsu092015/Windows-NVMe-driver --- Dr. Chang Liu, PhD. github.com/cl91/NeptuneOS

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seL4 developer hangout reminder
by Birgit Brecknell 08 Dec '25

08 Dec '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 10 Dec, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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next seL4 TSC meeting Dec 3 (Dec 2 in US)
by Gerwin Klein 02 Dec '25

02 Dec '25

The Technical Steering Committee (TSC) of the seL4 Foundation will hold its next public meting on: - Sydney: Wed, 3 Dec, 6pm - Central Europe: Wed, 3 Dec, 8am - US West Coast (LA/SF): Tue, 2 Dec, 11pm See also the seL4 calendar feed available from here: https://sel4.systems/stay-informed.html The meeting is by Zoom, and you can join from here: https://unsw.zoom.us/j/89019527332 Anyone interested can join the meeting and listen to the discussion and request to speak, which will be granted if time permits. Only TSC members can vote. The seL4 code of conduct applies to the meeting [1]. The agenda for the meeting so far is: - action items from last meeting - adopting TSC charter for the new seL4 Foundation organisation - discuss/vote on open RFCs: https://github.com/seL4/rfcs/pulls We are not likely to get through all of the RFCs in this meeting. If you have an RFC open and want to facilitate it moving forward, please leave a comment that summarises the discussion so far so we can pick up there in the meeting. If there are other items that I missed or you think should be on the agenda, please let me know. If we can't get to an item this time, we can still schedule another meeting. Cheers, Gerwin (TSC chair) [1]: https://sel4.systems/Contribute/conduct.html This email and any files transmitted with it may contain confidential information. If you believe you have received this email or any of its contents in error, please notify me immediately by return email and destroy this email. Do not use, disseminate, forward, print or copy any contents of an email received in error.

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New release of seL4, Microkit, CAmkES, capDL and Rust support
by Gerwin Klein 27 Nov '25

27 Nov '25

We’re pleased to announce the release of - seL4 14.0.0: The seL4 microkernel https://docs.sel4.systems/releases/sel4/14.0.0 - Microkit 2.1.0: The seL4 Microkit for building static-architecture systems https://docs.sel4.systems/releases/microkit/2.1.0 - CAmkES 3.11.1: Component Architecture for microkernel-based Embedded Systems https://docs.sel4.systems/releases/camkes/camkes-3.11.1 - capDL 0.4.0: Tools for generating, parsing and loading capability distribution specifications https://docs.sel4.systems/releases/capdl/0.4.0 - rust-sel4 3.0.0: Rust support for seL4 userspace. See the Rust section on the seL4 docsite for more information. https://github.com/seL4/rust-sel4/releases/tag/v3.0.0 seL4 14.0.0 and the corresponding Rust support come with new features and will require updates if you are using the seL4 API directly. Microkit and CAmkES abstract those and should not require any update of user code compared to Microkit 2.0.1 and CAmkES 3.11.1. Enjoy! Gerwin

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seL4 developer hangout reminder
by Birgit Brecknell 24 Nov '25

24 Nov '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 25 Nov, 21:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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question about the seL4/camkes-vm-examples
by PX 20 Nov '25

20 Nov '25

Hi,All I am trying to build the seL4 VMM example for the qemu-arm-virt platform from seL4/camkes-vm-exmaples. I can build the vmm image successfully, but I cannot run the image. Here are what I did: 1. I use the "../init-build.sh -DCAMKES_VM_APP=vm_minimal -DPLATFORM=qemu-arm-virt" command. 2. ninja After these two steps, the vmm image, capdl-loader-image-arm-qemu-arm-virt is successfully built. But when I run the generated scripts, ./simulate, to run the VMM on qemu, the vmm fails to boot up. The error message is attached below. I use Ubuntu 20.04 and QEMU emulator version 4.2.1. Do I miss something here? Do I use the correct version of the building environment? Any help would be appreciated! ./simulate ./simulate: QEMU command: qemu-system-arm -machine virt,virtualization=on,highmem=off,secure=off -cpu cortex-a15 -nographic -m size=2048 -kernel images/capdl-loader-image-arm-qemu-arm-virt ELF-loader started on CPU: ARM Ltd. Cortex-A15 r2p1 paddr=[61805000..62c02ebf] No DTB passed in from boot loader. Looking for DTB in CPIO archive...found at 6192264c. Loaded DTB from 6192264c. paddr=[60042000..60043fff] ELF-loading image 'kernel' to 60000000 paddr=[60000000..60041fff] vaddr=[e0000000..e0041fff] virt_entry=e0000000 ELF-loading image 'capdl-loader' to 60044000 paddr=[60044000..6140cfff] vaddr=[10000..13d8fff] virt_entry=1880c Enabling hypervisor MMU and paging Jumping to kernel-image entry point... Bootstrapping kernel Warning: Could not infer GIC interrupt target ID, assuming 0. available phys memory regions: 1 [60000000..c0000000] reserved virt address space regions: 4 [e0000000..e0042000] [e0042000..e0043da9] [e0044000..e140d000] [ff000000..ff200000] Booting all finished, dropped to user space *<<*seL4(CPU 0)* [decodeUntypedInvocation/205 T0xffc13400 "rootserver" @1070c]: Untyped Retype: Insufficient memory (1 * 33554432 bytes needed, 0 bytes available).>>* *<<*seL4(CPU 0)* [decodeUntypedInvocation/205 T0xffc13400 "rootserver" @1070c]: Untyped Retype: Insufficient memory (1 * 16777216 bytes needed, 0 bytes available).>>* *<<*seL4(CPU 0)* [decodeUntypedInvocation/205 T0xffc13400 "rootserver" @1070c]: Untyped Retype: Insufficient memory (1 * 16777216 bytes needed, 0 bytes available).>>* *<<*seL4(CPU 0)* [decodeUntypedInvocation/205 T0xffc13400 "rootserver" @1070c]: Untyped Retype: Insufficient memory (1 * 2097152 bytes needed, 0 bytes available).>>* *<<*seL4(CPU 0)* [decodeUntypedInvocation/205 T0xffc13400 "rootserver" @1070c]: Untyped Retype: Insufficient memory (1 * 65536 bytes needed, 0 bytes available).>>* run@main.c:1332 Invalid 'num_vcpus' attribute setting: Exceeds maximum number of supported nodes. Capping value to CONFIG_MAX_NUM_NODES (1) install_vm_devices@main.c:704 module name: map_frame_hack install_vm_devices@main.c:704 module name: init_ram Loading Kernel: 'linux' Loading Initrd: 'linux-initrd' Loading Generated DTB -------- *Pagefault from [vm0]: read prefetch fault @ PC: 0x4 IPA: 0x4, FSR: 0x6* *Context:* *r0: 0x0* *r1: 0xffffffff* *r2: 0x4f000000* *r3: 0x0* *r4: 0x0* *r5: 0x0* *r6: 0x0* *r7: 0x0* *r8: 0x0* *r9: 0x0* *r10: 0x0* *r11: 0x0* *r12: 0x0* *pc: 0x4* *r14: 0x0* *sp: 0x0* *cpsr: 0x9b* m-------- main_continued@main.c:1310 Failed to run VM Halting...

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Trustworthy Systems releases LionsOS based firewall as a community project
by Courtney Darville 13 Nov '25

13 Nov '25

Hi all TS is proud to announce the release of a new proof-of-concept firewall running on LionsOS. You can find more details in the announcement on the TS website here<https://trustworthy.systems/content/news/#lionsos_firewall_release_25>. We are aiming to make this a collaborative project with the community! This email and any files transmitted with it may contain confidential information. If you believe you have received this email or any of its contents in error, please notify me immediately by return email and destroy this email. Do not use, disseminate, forward, print or copy any contents of an email received in error.

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seL4 developer hangout reminder
by Birgit Brecknell 10 Nov '25

10 Nov '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 12 Nov, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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FOSDEM’26: Microkernel and Component-Based OS - Call for Papers
by Alexander Boettcher 04 Nov '25

04 Nov '25

Hello, the planning started for the next FOSDEM 2026 and my colleagues managed to get a devroom, https://fosdem.org/2026/news/2025-10-31-devrooms-announced They are looking for great talks and demos. The “call for participation” (CfP) follows: We are happy to announce the CfP for the "Microkernel and Component-Based OS" devroom at the upcoming FOSDEM 2026. Developers and users of various free and open-source microkernel-based and component-based operating systems will meet again at FOSDEM during the weekend of January 31st and February 1st 2026 and will share a developer room. The Microkernel and Component-Based OS devroom is currently looking for your participation in the form of proposals for talks, demos and other related activities. Possible topics for the devroom include, but are not limited to: * Introduction of a specific OS or framework * Design of subsystems and the general architecture of an OS * Languages, tools and toolchains used * Enabling support for hardware architectures, devices and programming languages * Development processes, debugging * Maintenance, testing and release engineering * Safety, security and robustness * Trends and challenges * Research and open questions * Community and governance * Use cases, experiences and status updates * Best practices and lessons learned * Live demos Important Dates The deadline for submitting proposals is December 1, 2025 (23:55 CET). Please use the FOSDEM website at https://fosdem.org/submit, select the track "Microkernel and Component-Based OS" and include at least the following information: * Title of your proposal * Short abstract (one or two paragraphs) * Duration (20 - 30 minutes, including demos and Q&A) * Your full name * Your short bio The devroom schedule (with accepted talks) will be announced on the devroom website at https://fosdem.org/2026/schedule/track/microkernel by December 15, 2025. The schedule will also be posted to the devroom mailing list and the speakers will be notified via email. Like previous years, the devroom will take place as an in-person event at the ULB Campus Solbosch in Brussels, Belgium during the second half of February 1, 2026 (Sunday). Due to the high number of submissions that FOSDEM received again this year, our devroom has only been allocated half a day. Therefore, the final decision on the duration of the talks will be made by the devroom organizers based on the number of accepted proposals. Given these restrictions, eight to nine half hour slots with a speaking time of 20 to 25 minutes and 5 to 10 minutes of Q&A form the upper limit. Requirements The communication language of the devroom is English. All content must relate to free and open-source software. By participating in the event, you agree to the publication of your talk recordings, slides and other content provided under the same CC-BY license as all other FOSDEM content. All participants are expected to adhere to the Code of Conduct: https://fosdem.org/2026/practical/conduct/ Contact For the 2026 edition, the organizers of the devroom are * Sebastian Sumpf (sebastian.sumpf [at] genode-labs.com) * Josef Söntgen (josef.soentgen [at] genode-labs.com) For any comments, questions and suggestions, please do not hesitate to contact us directly or via microkernel-devroom-manager at fosdem.org. Announcements and inquiries are additionally available through the devroom mailing list https://lists.fosdem.org/listinfo/microkernel-devroom About the Devroom Since the first Microkernel OS Devroom at FOSDEM 2012, this devroom has been a part of each subsequent FOSDEM (with slight variations of the name). The focus gradually widened to include component-based and other operating systems. It has now become somewhat of a tradition for the open-source operating systems community, a kind of "extended family meeting" and it is one of the very few places where microkernel and operating-system enthusiasts meet regularly. To date, over two dozen projects have participated in one way or another. Many of the projects face similar challenges but come up with partially different solutions. Therefore, the goal of the devroom is to bring the various projects together, let them exchange ideas, cross-pollinate and socialize. As in the past, the devroom will offer the stage both to established community members and to newcomers. Our goal is to select talks in an inclusive manner and to create a balanced and unbiased schedule, while keeping the quality of the devroom as high as in previous years. About FOSDEM FOSDEM is a two-day conference organized by volunteers to promote the widespread use of free and open-source software. FOSDEM is widely recognized as one of the largest and best such events worldwide. FOSDEM covers a wide spectrum of free and open-source software and hardware projects and offers a platform for people to collaborate. To this end, FOSDEM has set up developer rooms (devrooms) where teams can meet and showcase their projects. Devrooms are a place for teams to discuss, hack and publicly present new ideas, latest results, lightning talks, news and proposals. Besides developer rooms, FOSDEM also offers main tracks, lightning talks, certification exams and project stands. In recent years, FOSDEM has been hosting more than 5000 developers annually at the ULB Solbosch Campus in Brussels, Belgium. The participation in FOSDEM is totally free and requires no registration, although the organizers gratefully accept donations and sponsorship. Devroom Dinner Over the years, it has become a tradition that devroom speakers and enthusiasts meet for dinner somewhere in Brussels after the event to continue discussions, socialize and meet old and new friends. We plan to follow that tradition in some form as well in 2026 and will inform you about the exact arrangements later. Hope to see all of you in Brussels! -- Alexander Boettcher Genode Labs https://www.genodians.org - https://www.genode.org

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Sculpt 25.10 with seL4 image
by Alexander Boettcher 03 Nov '25

03 Nov '25

Hello, last week Genode released a new version of its open source OS - Sculpt OS 25.10 [0]. I took the opportunity to craft an PC image that also contains an (unofficial and experimental) Sculpt variant based upon seL4 as kernel [1]. The variant reflects to large degree the state I presented live [2,3] on the seL4 summit 2025 [4], beside that it is now based upon seL4 13.0 instead of 12.3. In case you are interested, feel free to check out [1] to run seL4 yourself with an interactive dynamic OS. Cheers, Alex. [0] https://genode.org/download/sculpt [1] https://genodians.org/alex-ab/2025-11-02-sculpt-multi-kernel [2] https://www.youtube.com/watch?v=N624i4X1UDw [3] https://sel4.systems/Summit/2025/abstracts2025.html#a-sculpt-os [4] https://sel4.systems/Summit/2025/ -- Alexander Boettcher Genode Labs https://www.genodians.org - https://www.genode.org

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[RFC] New CAmkES-VM Example: supermicro_wg (Secure Communication using WireGuard)
by Alberto Lange 31 Oct '25

31 Oct '25

Hi all, As part of my final project in Telecommunications Engineering, I’ve been developing a new CAmkES-VM example that demonstrates secure communication between two instances of an encrypter application. The draft is available here: https://github.com/adl09/camkes-vm-examples/tree/master/apps/x86/supermicro… The supermicro_wg example extends zmq_samples and integrates WireGuard between three Linux 6.1 VMs. It runs on both QEMU and Supermicro E300-9D hardware with PCI passthrough. Since I’d like to make a PR of this work, I’d appreciate any feedback. Additionally, regarding Chris’s post on virtio-net for multicore ARM, I’ve applied that code to this example to resolve errors related to virtqueue memory size. Since I didn’t see a PR associated with that code, would it be appropriate for me to base a PR on it to contribute improvements in the x86 VMM, even though it isn’t my original work? I’d prefer if the original author submitted it, but I’m happy to help integrate or adapt it if needed. Best regards, Alberto Daniel Lange Instituto Balseiro - INVAP

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seL4 developer hangout reminder
by Birgit Brecknell 27 Oct '25

27 Oct '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 28 Oct, 21:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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"HVC is not supported for PSCI!" error for SMP on QEMU
by Jake Hamby 24 Oct '25

24 Oct '25

I've just started looking at seL4 for a hobby project to port RISC OS to run on 64-bit ARM. Since the OS is written primarily in 32-bit ARM assembly language, that means rewriting a lot of code in C, which is fine since I won't be having to write the supervisor-mode code that seL4 handles (the most difficult part to get right). I'm still working through the seL4 tutorials, and I'm sure I'll have more questions later, but here's an easy one that maybe someone can provide context for. When I tried running a tutorial in QEMU with SMP enabled, it failed with "HVC is not supported for PSCI!" Some investigation revealed that ARM has two different opcodes to make the same calls to the PSCI interface to turn on the other CPU cores. The only difference is HVC goes to EL2 and SMC goes to EL3. As part of the build, QEMU dumps a device tree that specifically defines "hvc" as the method to use. I also noticed the Raspberry Pi device trees have no "psci' nodes. I can patch seL4 to only work with HVC by patching the check and the assembly file to use "hvc" instead of "smc" but it'd be nice if there were a build config option to specify one or the other method for making PSCI calls, and then fail at runtime if the other method was found, especially since QEMU is so popular for testing that I assume people run into this often. It'd be a small #ifdef to require and use one or the other opcode. The one area of seL4 that I know I will need to modify will be to add a 32-bit ARM mode for running existing RISC OS software and modules. The only special criteria it needs to have is to route all SWI (SVC) calls to a fault handler so I can pass them to either a 32-bit handler or to the new 64-bit SWI handlers that I'll hopefully be able to start porting one at a time from the original A32 code. The 32-bit SWI handler can get/set the input/output parameters from the machine registers in the TCB, so that part's straightforward. I'll need to do some fakery for 32-bit code that wants to run in supervisor mode, to fake success when it calls privileged instructions. I'll know more as I continue designing and start implementing code. Unfortunately there'll eventually need to be an A32/T32 emulation mode of some sort for 64-bit only ARM CPUs like Apple's M-series, but that can come later, and I can use QEMU's CPU emulation until then (as opposed to hypervisor mode with "-accel hvf", which is 64-bit only). Also, I know the Raspberry Pi 5 that I want to support can run 32-bit ARM code at EL0 only, which is all I need. If anyone has suggestions or can see some fatal flaws in my assumptions, please let me know. Best regards, Jake Hamby

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Not getting a verification email for Mattermost
by Koo Zhengqun 23 Oct '25

23 Oct '25

Hi all, I've signed up for the Trustworthy Systems Mattermost, but it's been a few days and I still haven't received a verification email. Yours sincerely, Zhengqun Koo

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Re: [seL4 Announce] seL4 summit 2026: location survey
by Birgit Brecknell 20 Oct '25

20 Oct '25

Just a friendly reminder to fill in the survey about summit locations for 2026. https://form.jotform.com/252117628736865 *Please do so by 26 Oct 2025.* Feel free to forward to anyone you believe may want to attend the seL4 summit [0] next year. [0] https://sel4.systems/Summit On Mon, 13 Oct 2025 at 19:18, Announcements about seL4 -- low volume list <announce(a)sel4.systems> wrote: > After wrapping up a successful seL4 summit 2025 [0], we are now preparing for the seL4 summit 2026! The summit be in Canada, around Sep 2026. > > We have started investigating options for cities, and would like your feedback. We would greatly appreciate it if you could fill in this very short survey to tell us your opinions: > > https://form.jotform.com/252117628736865 > > *Please do so by 26 Oct 2025.* > > Feel free to forward to anyone you believe may want to attend the summit next year. > > [0] https://sel4.systems/Summit/2025/ > > Birgit Brecknell > seL4 Foundation Project Coordinator > Sydney, Australia > Mon 9-5 > Wed 2-5 > Fri 9-5 > birgit(a)sel4.systems <mailto:birgit@sel4.systems <mailto:birgit@sel4.systems>> > bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com> <mailto:bbrcknl@gmail.com <mailto:bbrcknl@gmail.com>> > _______________________________________________ > Announce mailing list -- announce(a)sel4.systems > To unsubscribe send an email to announce-leave(a)sel4.systems

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seL4 summit 2026: location survey
by Birgit Brecknell 13 Oct '25

13 Oct '25

After wrapping up a successful seL4 summit 2025 [0], we are now preparing for the seL4 summit 2026! The summit be in Canada, around Sep 2026. We have started investigating options for cities, and would like your feedback. We would greatly appreciate it if you could fill in this very short survey to tell us your opinions: https://form.jotform.com/252117628736865 *Please do so by 26 Oct 2025.* Feel free to forward to anyone you believe may want to attend the summit next year. [0] https://sel4.systems/Summit/2025/ Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Porting seL4 to STM32MP157
by Hugo V.C. 13 Oct '25

13 Oct '25

Hi, I want to port seL4 to STM32MP157 platform. I'm reading this: https://docs.sel4.systems/projects/sel4/porting.html and honestly its being a show stopper for me. Any plan to show, step by step (without assumptions) and with a real example, how to do that? Best,

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seL4 developer hangout reminder
by Birgit Brecknell 13 Oct '25

13 Oct '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 15 Oct, 7:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Summit 2025: Multikernel BoF
by Daniel Schwyn 08 Oct '25

08 Oct '25

Dear all, Attached you will find the notes from the Birds of a feather session on the multikernel at the summit in Prague. Please let me know if something is missing or misrepresented. Best regards, Daniel

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seL4 vs QNX and Linux benchmarks
by Andrew Warkentin 07 Oct '25

07 Oct '25

Somebody in the Zoom call the other day (IIRC it was Gernot) said that seL4 IPC is considerably faster than QNX IPC, but it seems that QNX is somehow faster in a simple benchmarking experiment in which a client repeatedly sends messages to a bit-bucket server, using the TSC to determine timing. I'm running both QNX and seL4 under identical VirtualBox configurations with a single core. I'm using a QNX 6.3.1 x86-32 image i have in my collection (x86-64 support was only added in 7.0; this is the most recent image I have with dev tools installed). The seL4 version I'm using is from February 2022 and is built for x86-64 with MCS enabled (the priority of the threads is 255, and both the timeslice and budget are the initial thread default of 5 ms). My benchmark times a loop of 10000 RPCs; for QNX it's just using the regular read() function on /dev/null or a custom server that also acts like /dev/null but forces a copy of the message into a server-provided buffer, and for seL4 I'm directly calling Send()/Recv()/Reply(). I've also tested Linux's /dev/null, and QNX's implementation actually seems somewhat faster than it (for the system /dev/null; the custom server's best case seems only slightly worse than under Linux). Under QNX and Linux I'm running a C implementation of the benchmark and under seL4 I tried both C and Rust implementations (which have very similar performance). The messages on QNX and Linux are 100 bytes, and on seL4 they are 2 words, which should be hitting the fast path. Here are the best and worst cases I got: seL4: 0.114-0.136s QNX, custom null server: 0.006-0.063s QNX, system null server: 0.002-0.022s Linux: 0.004-0.005s Has anyone else benchmarked seL4 IPC against that of QNX and gotten better (or comparable) results for seL4, unlike what I got? Is synchronous IPC just less optimized under seL4 than QNX?

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seL4 developer hangout reminder
by Birgit Brecknell 29 Sep '25

29 Sep '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 30 Sep, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Systems Researcher Position
by Yanyan Shen 24 Sep '25

24 Sep '25

Hi seL4 developers NIO uses seL4 as the kernel for the vehicle operating system, and we are seeking a systems software researcher / developer to join the team. Please see the job description. [https://nio.wd3.myworkdayjobs.com/NIO_Careers/job/San-Jose-US/Systems-Softw…] If you enjoy building systems from scratch, writing high quality system code, optimizing performance, turning your research ideas into awesome real-world products, and shaping the future of systems software for intelligent EVs, the position is for you. Please drop me an email if you would like to know more. Looking forward to hearing from you. Regards, Yanyan [Banner]<http://www.nio.io> This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. You may NOT use, disclose, copy or disseminate this information. If you have received this email in error, please notify the sender and destroy all copies of the original message and all attachments. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the company. Finally, the recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email.

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seL4 developer hangout reminder
by Birgit Brecknell 15 Sep '25

15 Sep '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 17 Sep, 8:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Kernel use of MPIDR_EL1 register on ARM
by Julia Vassiliki 10 Sep '25

10 Sep '25

For ARM platforms, the hardware provides access to the MPIDR ("Multiprocessor Identification Register") [1], which, amongst other things, provides access to 2 (or 3, for AArch64) affinity levels: Aff0, Aff1, Aff2, and possibly Aff3. However, seL4 instead seems to gather the CPU index from a loader-set `tpidr_el1`. /* tpidr_el1 has the logic ID of the core, starting from 0 */ mrs x6, tpidr_el1 /* Set the sp for each core assuming linear indices */ ldr x5, =BIT(CONFIG_KERNEL_STACK_BITS) mul x5, x5, x6 This is then overwritten later. with the kernel stack address. Is there any reasoning for why it was done this way? The elfloader [3] then has read the MPIDR and converted it to TPIDR_EL1 for the kernel, and it uses a generated table to map the MPIDR IDs to "logical core IDs" [4]. Here is the boot log for the TX2, which does use non-contiguous Aff0 IDs. Boot cpu id = 0x100, index=2 Core 257 is up with logic id 1 Core 258 is up with logic id 2 Core 259 is up with logic id 3 Enabling MMU and paging Of note here is 2 things: 1. That the ARM PSCI specification [5], for "target_cpu" when calling PSCI_ON or OFF methods (such as done in the elfloader) expects a MPIDR-like ID (I say "like" because it is with the "U" and "MT" bits masked out). In its current state, the seL4_BootInfo provided ID is instead the logical ID, which means that there's no way to see the value of MPIDR from userspace. 2. The GICv3 uses MPIDR affinity values when sending IPIs, and so the kernel does actually maintain a "mpidr_map" which wouldn't be necessary if everything talked in terms of MPIDRs. (It would still be required for other reasons on SMP as opposed to multikernel, though). BOOT_CODE void cpu_initLocalIRQController(void) { word_t mpidr = 0; SYSTEM_READ_WORD(MPIDR, mpidr); mpidr_map[CURRENT_CPU_INDEX()] = mpidr; active_irq[CURRENT_CPU_INDEX()] = IRQ_NONE; gicr_init(); cpu_iface_init(); } In the spirit of being a minimal hardware abstraction, I feel that it makes more sense for the kernel's APIs to be in terms of MPIDRs [6], but that it would probably be a breaking change. Internally, aside from this, it makes *more* sense for the kernel to think in terms of MPIDRs for the core values, rather than a "logical core ID". Some context for how this is represented in the device trees: In the device tree documentation 'Documentation/devicetree/bindings/arm/cpus.yaml' [2] the `<reg>` field of the cpus node tells the values of each of the CPU nodes; mapping the affinities (possibly non-contiguous) to a contiguous CPU index could be done with a build-time lookup table. For example, here is the first part of the OdroidC4 device tree, which tells us that node 0 is Aff0=0, Aff1=0. cpus { #address-cells = <0x02>; #size-cells = <0x00>; cpu@0 { device_type = "cpu"; reg = <0x00 0x00>; }; /* etc */ } [1]: https://arm.jonpalmisc.com/latest_sysreg/AArch64-mpidr_el1 [2] https://www.kernel.org/doc/Documentation/devicetree/bindings/arm/cpus.yaml [3]: https://github.com/seL4/seL4_tools/blob/26f94df7e97a04f8ee49c1e94a0aa120365… [4]: https://github.com/seL4/seL4_tools/blob/master/elfloader-tool/src/arch-arm/… [5]: https://documentation-service.arm.com/static/6703a8b8d7e4b739d817e10d [6]: So, the SMP affinity APIs, and BootInfo->nodeID field. Julia This email and any files transmitted with it may contain confidential information. If you believe you have received this email or any of its contents in error, please notify me immediately by return email and destroy this email. Do not use, disseminate, forward, print or copy any contents of an email received in error.

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About MSI-X interrupts on x86
by Alberto Lange 06 Sep '25

06 Sep '25

Hi all, here Albert I’m working on a SuperMicro E300-9D server and trying to passthrough an Intel X557-AT2 NIC to a Linux 6.1 guest. The .camkes configuration seems to be right, here are the configs for the device (the device is correctly detected on the VM): vm2.vm_ioports = []; vm2.pci_devices = [ { "name":"outer_eth", "bus":0xb5, "dev":0x0, "fun":1, "irq":"outer_eth", "memory":[ {"paddr":0xf9000000, "size":0x01000000, "page_bits":12}, // BAR0 {"paddr":0xfb000000, "size":0x00008000, "page_bits":12}, // BAR3 ] } ]; vm2.vm_irqs = [ {"name":"outer_eth", "ioapic":0, "source":0xb, "level_trig":0, "active_low":1, "dest":12} ]; I’m seeing the following errors during boot and when bringing the interface up: [ 2.040786] i40e 0000:00:01.0: MAC address: 3c:ec:ef:d2:88:85 [ 2.090786] i40e 0000:00:01.0: MSI-X vector reservation failed: -38 [ 2.109960] i40e 0000:00:01.0: MSI-X not available, trying MSI [ 2.115660] i40e 0000:00:01.0: MSI init failed - -38 [ 2.121656] i40e 0000:00:01.0: MSI-X and MSI not available, falling back to Legacy IRQ [ 2.220802] i40e 0000:00:01.0 eth1: NIC Link is Up, 1000 Mbps Full Duplex, Flow Control: None [ 2.290774] i40e 0000:00:01.0: Features: PF-id[1] VSIs: 66 QP: 1 VxLAN Geneve PTP VEPA ... # ifconfig eth1 up [ 451.042525] i40e 0000:00:01.0 eth1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5770 ms [ 451.052764] i40e 0000:00:01.0 eth1: tx_timeout: VSI_seid: 391, Q 0, NTC: 0x0, HWB: 0x1, NTU: 0x1, TAIL: 0x1, INT: 0x0 [ 451.065876] i40e 0000:00:01.0 eth1: tx_timeout recovery level 2, txqueue 0 [ 456.082601] i40e 0000:00:01.0 eth1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 10810 ms My thought is that this NIC does not work reliably with legacy IRQ mode. My question is: Is there any implementation of MSI-X interrupts for x86 in the seL4 VMM, or plans to support it? If such support exists, I would like to contribute, as I plan to share my project once it’s finished. Thanks in advance for any guidance or suggestions. Albert

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Error on managing the same IRQ in 2 VM (x86) #84
by Alberto Lange 20 Aug '25

20 Aug '25

Hi! I'm working on top of the zmq_samples example, trying to set up 2 Ethernet devices on 2 of the 3 VM's. The passthrough for both VM's has been done, and both detect the NICs. For more information, this is the setup for the irqs in the camkes file: vm0.vm_irqs = [ {"name":"inner_eth", "ioapic":0, "source":0xb, "level_trig":1, "active_low":1, "dest":10} ]; vm2.vm_irqs = [ {"name":"outer_eth", "ioapic":0, "source":0xb, "level_trig":1, "active_low":1, "dest":12} ]; My problem is related to having the same IRQ11 in both e1000e devices. I can't control this; that is what QEMU provides. When I set up the first NIC in any VM, say VM0, doing ifconfig eth1 up, it works correctly, but when I try to bring up the other one, VM2, the whole system freezes for a moment. Then VM0 complains about this: [ 48.557120] irq 10: nobody cared (try booting with the "irqpoll" option) [ 48.557120] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.9.337+ #19 [ 48.557120] df811f94 d08f1778 df807d00 00000000 df811fa8 d08f08e0 df807d00 00000000 [ 48.557120] d0459f68 df811fc4 d04596ec 0000000b 00000000 df807d00 00000000 d0459f68 [ 48.557120] df811fd8 d0457a55 00000000 df807d00 df807d64 df811fe8 d0457a7e df807d00 [ 48.557120] Call Trace: [ 48.557120] [ 48.557120] [] dump_stack+0x4f/0x63 [ 48.557120] [] __report_bad_irq+0x33/0x98 [ 48.557120] [] ? unmask_irq+0x22/0x22 [ 48.557120] [] note_interrupt+0x185/0x1c3 [ 48.557120] [] ? unmask_irq+0x22/0x22 [ 48.557120] [] handle_irq_event_percpu+0x31/0x38 [ 48.557120] [] handle_irq_event+0x22/0x3b [ 48.557120] [] handle_level_irq+0x52/0x80 [ 48.557120] [] handle_irq+0x91/0xb6 [ 48.557120] [ 48.557120] [ 48.557120] [] do_IRQ+0x33/0x99 [ 48.557120] [] common_interrupt+0x2c/0x34 [ 48.557120] [] ? __do_softirq+0x55/0x1a1 [ 48.557120] [] ? _local_bh_enable+0x6c/0x6c [ 48.557120] [] call_on_stack+0x40/0x46 [ 48.557120] [ 48.557120] [] ? irq_exit+0x56/0x91 [ 48.557120] [] ? do_IRQ+0x7f/0x99 [ 48.557120] [] ? common_interrupt+0x2c/0x34 [ 48.557120] [] ? default_idle+0x16/0x18 [ 48.557120] [] ? arch_cpu_idle+0xd/0xf [ 48.557120] [] ? default_idle_call+0x14/0x16 [ 48.557120] [] ? cpu_startup_entry+0xbb/0x158 [ 48.557120] [] ? rest_init+0x5d/0x5f [ 48.557120] [] ? start_kernel+0x339/0x343 [ 48.557120] [] ? i386_start_kernel+0x3e/0x40 [ 48.557120] handlers: [ 48.557120] [] e1000_intr [ 48.557120] Disabling IRQ #10 Any interruption goes to VM2; they all go to VM0 but are not intended to go to that one, so they are ignored. Any thoughts on this would be appreciated!

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seL4 developer hangout reminder
by Birgit Brecknell 18 Aug '25

18 Aug '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 20 Aug, 8:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Experimental prototype of CHERI-enabled seL4 is released
by Hesham Almatary 13 Aug '25

13 Aug '25

Hello, The CHERI Alliance has released a prototype of CHERI-seL4, an experimental version of the seL4 microkernel with CHERI support. This release includes CHERI-Microkit, a lightweight userspace framework, and a set of exercises and tutorials designed to help developers explore CHERI’s potential in a real microkernel environment. The release is aimed at developers who want to build and experiment with memory-safe C/C++ software on seL4. It supports the draft CHERI-RISC-V architecture and runs on QEMU, Codasip’s X730 processor, CHERI-Toooba, and CHERI-CVA6 on FPGA. For those who are unfamiliar with CHERI, CHERI support in seL4 enables memory-safe C/C++ user-level projects and applications without having to (re)write code in languages like Rust. This complement's seL4's strong isolation between different components, enforced by the MMU and seL4's software capabilities. We welcome any feedback. Learn more: https://cheri-alliance.org/cheri-sel4-and-cheri-microkit-released/ Regards, Hesham

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seL4 developer hangout reminder
by Birgit Brecknell 04 Aug '25

04 Aug '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 5 Aug, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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On LionsOS and Switches
by wocexeg869＠forexru.com 22 Jul '25

22 Jul '25

Many enterprise grade switches from Cisco to Juniper switches are running on Linux. That also is the case with prosumer hardware such as Ubiquiti, Mikrotik (CRS line), Aruba, etc... Wouldn't this be a good use case for LionsOS? The security of the layer 2 is an important part of the security of the overall network and it should be easier to implement compared to the firewall that is currently being worked on. Thank you for your attention to this matter!

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seL4 developer hangout reminder
by Birgit Brecknell 21 Jul '25

21 Jul '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 23 July, 8:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 07 Jul '25

07 Jul '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 8 July, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 23 Jun '25

23 Jun '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 25 June, 8am UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Fwd: Re: I am interested in porting LionOS to X64 architecture
by Jingyao Zhou 11 Jun '25

11 Jun '25

Resend because I forgot to CC the mailing list. Begin forwarded message: From: Jingyao Zhou <jingyao.zhou(a)unsw.edu.au> Date: 5 June 2025 at 11:47:49 GMT+8 To: Peter Relich <prelich(a)intellisenseinc.com> Subject: Re: [seL4] Re: I am interested in porting LionOS to X64 architecture Hi Peter, I am glad to see that you are interested in contributing to x86 support for LionsOS! Several x86-related works/plans are going on in the Trustworthy Systems Team. For the seL4 kernel, there are pending pull requests for remappable MSI and IOAPIC supports that need to be updated and tested; we would like to add posted interrupts and MSI-x, but there are no concrete plans yet. For the x86 Microkit, we adopted Neutrality-CH's works and have been updating it (e.g. adding virtulization support). There are two major issues: * We need to figure out a nicer way to generate the machine description for x86 machines * We also need to add IOMMU supports We hope to upstream the work soon. For seL4 Device Driver Framework: we have working examples running on Supermicro servers as well as QEMU. We hope to upstream them soon as well. For adding x86 support for libvmm: the work is on hold due to the prerequisites, plus a kernel issue with multi-IOAPIC support. We will resume it as soon as possible. We apologize for the lack of information; we will keep our progress on x86 supports updated on GitHub in the future. Regards, Jade. ________________________________ From: Peter Relich via Devel <devel(a)sel4.systems> Sent: Wednesday, June 4, 2025 3:49 AM To: devel(a)sel4.systems <devel(a)sel4.systems> Subject: [seL4] Re: I am interested in porting LionOS to X64 architecture Thanks everyone. I got authorized to continue my effort, and I was looking into what is currently available. I don't have to worry about red/black channels for now, so confidentiality is not yet a priority. My main priority is to create a steel thread so that if the main operating system crashes, a giant robotic vehicle can be teleoperated or shutdown without hurting anyone. I saw that Neutrality-CH (Switzerland) had forked the Microkit library for x86 (https://github.com/Neutrality-ch/microkit) but they had only made two commits, the last one was in December 17. I tried to contact them a few weeks ago, but I didn't hear back so I'm not sure the status/funding of their project. Anyway, currently the VMM capabilities are not developed for their fork which would make deployment of an OS tedious. At first glance, it looks like I need to put some work into building a VMM into their fork by studying and then calling the seL4 vcpu, interrupt, x86_src routines into their Microkit fork? I guess my question now as I parse through everything. Is the Neutrality-CH fork the best, most recent x86 fork of the microkit? Or is there another library/fork I should consider for development? I saw that their approach for pre-generating an ELF file for the bootloader was the main obstacle for their pull request, but since I'm working on a specific Intel architecture (8th gen, uses Intel VT-x and VT-d for virtualization), I can avoid over generalizing my solution and focus on this specific application. Is there any value in extracting/porting the work performed in CAmkES x86 virtualization for the microkit x86 fork? Thanks again for all the help! -Peter ________________________________ The information contained in this e-mail and any attachments from Intellisense Systems may contain confidential and/or proprietary information, and is intended only for the named recipient to whom it was originally addressed. If you are not the intended recipient, any disclosure, distribution, or copying of this e-mail or its attachments is strictly prohibited. If you have received this e-mail in error, please notify the sender immediately by return e-mail and permanently delete the e-mail and any attachments. _______________________________________________ Devel mailing list -- devel(a)sel4.systems To unsubscribe send an email to devel-leave(a)sel4.systems Confidential communication - This email and any files transmitted with it are confidential and are intended solely for the addressee. If you are not the intended recipient, please be advised that you have received this email in error and that any use, dissemination, forwarding, printing, or copying of this email and any file attachments is strictly prohibited. If you have received this email in error, please notify me immediately by return email and destroy this email.

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Re: I am interested in porting LionOS to X64 architecture
by Peter Relich 11 Jun '25

11 Jun '25

Thanks everyone. I got authorized to continue my effort, and I was looking into what is currently available. I don't have to worry about red/black channels for now, so confidentiality is not yet a priority. My main priority is to create a steel thread so that if the main operating system crashes, a giant robotic vehicle can be teleoperated or shutdown without hurting anyone. I saw that Neutrality-CH (Switzerland) had forked the Microkit library for x86 (https://github.com/Neutrality-ch/microkit) but they had only made two commits, the last one was in December 17. I tried to contact them a few weeks ago, but I didn't hear back so I'm not sure the status/funding of their project. Anyway, currently the VMM capabilities are not developed for their fork which would make deployment of an OS tedious. At first glance, it looks like I need to put some work into building a VMM into their fork by studying and then calling the seL4 vcpu, interrupt, x86_src routines into their Microkit fork? I guess my question now as I parse through everything. Is the Neutrality-CH fork the best, most recent x86 fork of the microkit? Or is there another library/fork I should consider for development? I saw that their approach for pre-generating an ELF file for the bootloader was the main obstacle for their pull request, but since I'm working on a specific Intel architecture (8th gen, uses Intel VT-x and VT-d for virtualization), I can avoid over generalizing my solution and focus on this specific application. Is there any value in extracting/porting the work performed in CAmkES x86 virtualization for the microkit x86 fork? Thanks again for all the help! -Peter ________________________________ The information contained in this e-mail and any attachments from Intellisense Systems may contain confidential and/or proprietary information, and is intended only for the named recipient to whom it was originally addressed. If you are not the intended recipient, any disclosure, distribution, or copying of this e-mail or its attachments is strictly prohibited. If you have received this e-mail in error, please notify the sender immediately by return e-mail and permanently delete the e-mail and any attachments.

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Booting software on Odroid-C4
by Julia Royer 06 Jun '25

06 Jun '25

Hello, I would like to boot my Microkit software on an Odroid-C4, but I’m a bit confused about the process. Is there any tutorial available, or perhaps an existing U-Boot image that I could use? Thank you for your help. Best regards, Julia Royer

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seL4 developer hangout reminder
by Birgit Brecknell 06 Jun '25

06 Jun '25

Hi all A friendly reminder that the seL4 developer hangout is on again next week. Tue 10 Jun, 22:00 UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 26 May '25

26 May '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 28 May, 8am UTC For your local date and time please see https://sel4.systems/stay-informed.html#calendar Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 14 May '25

14 May '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 13 May, 10:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 1

Libc on Microkit
by Julia Royer 06 May '25

06 May '25

Hello, I'm currently developing a simple communication application to explore seL4 and Microkit, and I'd like to use a C standard library (libc) in my project. I came across libsel4muslcsys and the seL4/musllibc repository. Are there any other components I should be aware of? Also, is there a specific way to integrate these into my project? Thank you for your help. Best regards, Julia Royer

2 2

Ethernet passthrough on x86 (QEMU)
by alberto.lange＠ib.edu.ar 29 Apr '25

29 Apr '25

Hi! I wanted to share another problem with you again, I hope it doesn't bother you. I'm trying to set up a small network between two simulations on QEMU of seL4 running a VM before dealing with hardware. I saw the tutorials related to Ethernet passthrough, but I'm not sure if the same approach applies when using QEMU. These are my configs for the minimal app example: vm0_config.ioports = [ {"start":0xc000, "end":0xc03f, "pci_device":0, "name":"Ethernet5"}, ]; vm0_config.pci_devices = [ { "name":"Ethernet5", "bus":0x0, "dev":0x3, "fun":0, "irq":"Ethernet5", "memory":[ {"paddr":0xfeb80000, "size":0x20000, "page_bits":12}, ], }, ]; vm0_config.irqs = [ {"name":"Ethernet5", "source":11, "level_trig":1, "active_low":1, "dest":10} ]; And checking what QEMU presents to seL4 as hardware: Bus 0, device 3, function 0: Ethernet controller: PCI device 8086:100e PCI subsystem 1af4:1100 IRQ 11, pin A BAR0: 32 bit memory at 0xfeb80000 [0xfeb9ffff]. BAR1: I/O at 0xc000 [0xc03f]. BAR6: 32 bit memory at 0xffffffffffffffff [0x0007fffe]. id "" But when I'm looking for the device on the VM: # lspci 00:00.0 Class 0600: 5e14:0042 I would appreciate any comments on this. Thanks in advance. Alberto Lange

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Custom kernel for x86 VM
by alberto.lange＠ib.edu.ar 29 Apr '25

29 Apr '25

Hi! I'm Alberto, and I'm currently working on my Telecommunications Engineering thesis, which focuses on building a secure system using an seL4 virtual machine. Right now, I'm trying to use the minimal app from the camkes-vm-examples repository with a modified Linux kernel (v6.12.9) built using Buildroot. To do this, I've been replacing the kernel and rootfs files in the vm-linux/images directory with my custom ones. However, this has led to multiple errors during execution. I’d really appreciate some guidance on the correct way to integrate a custom kernel into the CAmkES VM framework. Specifically, should I be using the functions provided in the linux-source-helpers.cmake file to update the kernel and rootfs? Thanks in advance!

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seL4 Summit 2025: extended deadline to submit a talk
by Birgit Brecknell 28 Apr '25

28 Apr '25

The deadline to submit a talk [0] for the seL4 Summit 2025 [1] has been extended until 2 May 2025. If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. **Abstracts are due on 2 May 2025.** Also note the open invitation for a 5-minute slot to talk about your seL4 deployment [3]. The seL4 Summit 2025 will be held 3 - 5 September 2025 at the Grandior Hotel Prague, Prague, Czech Republic. The summit will be an in-person event. Registration and location details are available here [4] [0] https://sel4.systems/Foundation/Summit/2025/cfp [1] https://sel4.systems/Foundation/Summit/2025/ [2] https://form.jotform.com/250436091673861 [3] https://sel4.systems/Foundation/Summit/2025/cfp#sel4-deployment [4] https://events.linuxfoundation.org/sel4-summit/register/ Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 28 Apr '25

28 Apr '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 30 Apr, 8:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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hello_rumprun app not worked
by MOHAMAD REZA SHAFIEI 19 Apr '25

19 Apr '25

hi. i'm recently worked on sel4 with camkes framework. when i compile rumprun_hello on x86_64 platform its compiled and build correctly but when run with qemu by ./simulate script, program crashed with this errors: simple_get_extended_bootinfo_length@simple.h:600 simple_get_extended_bootinfo_length not implemented FAULT HANDLER: data fault from hello.hello_0_control (ID 0x1) on address 0x8, pc = 0x402b7f, fsr = 0x6 FAULT HANDLER: Register dump: FAULT HANDLER: rip :0x402b7f , . . so i found that this method not implemented yet so i return 0 in this method and resolved. for second problem that cause failure if trace program and i found that in "init rumprun" process the program failed in the /projects/sel4runtime/include/sel4_arch/x86_64/sel4runtime/thread_arch.h file and sel4runtime_set_tls_base method. so i read git log and in recently commit your team use sel4runtime for thread TLS, so when we run rumprun_hello, the program failed in sel4runtime_set_tls_base method. can you help me fix this bug? thanks for your attention. -- This email was Anti Virus checked by Security Gateway.

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Issue when running rumprun_hello app from the CAmkES manifest
by dinukaamarasinghe817＠gmail.com 19 Apr '25

19 Apr '25

Hello all, mostly Kent, When I run the rumprun_hello app that's included in the CAmkES manifest, I encounter the following runtime errors: [...] Booting all finished, dropped to user space simple_get_extended_bootinfo_length@simple.h:608 simple_get_extended_bootinfo_length not implemented vka_cspace_alloc@vka.h:149 Unimplemented vka_alloc_object_at_maybe_dev@object.h:47 Failed to allocate cslot: error -1 init_rumprun@entry.c:306 [Cond failed: res != 0] Failed to allocate notification object This seems related to the simple->extended_bootinfo_len callback not being implemented, which causes downstream failures in object allocation (e.g. notification object). This issue appears specifically when running Rumprun-based apps. Would appreciate any insights or suggestions on how to resolve or properly set up this functionality. Note that i haven't modified any of the code here. Just tried to run the existing 'rumprun_hello' application.

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Re: Register for the seL4 summit 2025
by Vasily A. Sartakov 16 Apr '25

16 Apr '25

Dear all, > Thanks for the info! A quick question for clarification: What is the difference between the Professional and the Hobbyist registration type? (Sorry if this is obvious to someone, but I'm unable to find an explicit explanation anywhere.) I guess, If you pay out of your own pocket, you are an enthusiast. if it is sponsored by your employer, you are a professional. — Dr.-Eng. V. A. Sartakov

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Register for the seL4 summit 2025
by Birgit Brecknell 14 Apr '25

14 Apr '25

The seL4 summit 2025 [0] will be held in Prague, Czech Republic, 3 - 5 September 2025. The seL4 summit will cover the complete seL4 ecosystem, consisting of the verified microkernel, as well as all seL4-related technology, tools, infrastructure, products, projects, and people. Tickets include: - Participation in the 3-day conference, including talks, keynotes, seL4 updates & discussions - Networking with other seL4 experts and enthusiasts - Reception and dinner Register here [1] The early bird cut-off date is 3 August 2025. A number of informal social activities will be organised by the seL4 community for Tuesday 2 Sep 2025. Stay tuned for more info! [0] https://sel4.systems/Foundation/Summit/2025/ [1] https://events.linuxfoundation.org/sel4-summit/register/ Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

2 1

DKernelSkimWindow=off
by Sanyou 14 Apr '25

14 Apr '25

Hi, I am testing sel4 on real Sanyou> x86 board now. I found that if we use parameter DKernelSkimWindow=off, we can see nothing on the uart. Can you give me any advice. Regards, Sanyoo

1 0

seL4 Summit 2025: one week to go to submit a talk
by Birgit Brecknell 14 Apr '25

14 Apr '25

One week to go to submit a talk [0] for the seL4 Summit 2025 [1]! If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. **Abstracts are due on 21 April 2025.** Also note the open invitation for a 5-minute slot to talk about your seL4 deployment [3]. The seL4 Summit 2025 will be held 3 - 5 September 2025 at the Grandior Hotel Prague, Prague, Czech Republic. The summit will be an in-person event. Registration details to follow soon. We’re looking forward to many exciting proposals! [0] https://sel4.systems/Foundation/Summit/2025/cfp [1] https://sel4.systems/Foundation/Summit/2025/ [2] https://form.jotform.com/250436091673861 [3] https://sel4.systems/Foundation/Summit/2025/cfp#sel4-deployment Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 14 Apr '25

14 Apr '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 15 Apr, 10:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Running seL4 on bare-metal x86_64 PC
by saftab.rashid＠gmail.com 11 Apr '25

11 Apr '25

Hi, I am very new to sel4 and I am trying to run it bare-metal on an Intel Xeon x86_64 machine. I am following the instructions here PC99 | seL4 docs. I can run seL4 using the ./simulate script which runs the kernel under QEMU. However, I would like the run seL4 natively on my machine. After the build, I have the following images in the images/ directory. kernel-x86_64-pc99 sel4test-driver-image-x86_64-pc99 I have created a Grub2 menu entry by copying these images under /boot. However, when I boot using the created menu entry I get a black screen and I also see no output on the serial port. My Grub2 menu entry is as follows menuentry “Load seL4 VM” --class os { load_video insmod gzio insmod part_msdos insmod ext2 set root=‘(hd0,msdos2)’ multiboot /boot/kernel-x86_64-pc99 module /boot/sel4test-driver-image-x86_64-pc99 } I have also tried the multiboot2 protocol as I have an UEFI-supported system but it also doesn’t work. After booting into the seL4 VM I get a black screen and there is no output on the serial port. Any Idea what I am doing wrong?

2 2

Interactions between sDDF and libvmm
by Julia Royer 09 Apr '25

09 Apr '25

Hello, I am currently exploring libvmm and sDDF and I have a question regarding how sDDF is intended to be used in practice. From what I understand, sDDF is often seen in conjunction with libvmm in examples and documentation. My question is: Is sDDF meant to be used exclusively with libvmm, or can it also be used independently? If the latter is possible, is it considered a recommended or meaningful use case, or is the project mainly designed around integration with libvmm? Thank you for your help. Best regards, Julia Royer

2 1

seL4 Summit 2025: two weeks to go to submit a talk
by Birgit Brecknell 07 Apr '25

07 Apr '25

Two weeks to go to submit a talk [0] for the seL4 Summit 2025 [1]! If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. **Abstracts are due on 21 April 2025.** Also note the open invitation for a 5-minute slot to talk about your seL4 deployment [3]. The seL4 Summit 2025 will be held 3 - 5 September 2025 at the Grandior Hotel Prague, Prague, Czech Republic. The summit will be an in-person event. Registration details to follow soon. We’re looking forward to many exciting proposals! [0] https://sel4.systems/Foundation/Summit/2025/cfp [1] https://sel4.systems/Foundation/Summit/2025/ [2] https://form.jotform.com/250436091673861 [3] https://sel4.systems/Foundation/Summit/2025/cfp#sel4-deployment Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Question about extensibility
by 1plus.yijia＠gmail.com 01 Apr '25

01 Apr '25

One the advantages of microkernel is the extensibility of user space components; however, doesn't the static system design eliminate this advantage? Do I miss something? I wonder if it possible to only recompile a component and replace an older one; if yes, if it possible to replace it in runtime.

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seL4 developer hangout reminder
by Birgit Brecknell 31 Mar '25

31 Mar '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 2 Apr, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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User-level proofs and capability revocation
by Anton Burtsev 28 Mar '25

28 Mar '25

Hi all I have a couple of questions on how user-level proofs are constructed in the seL4 ecosystem. Just to start, can someone point me to an example of a user-level proof, just so I can take a look at how specifications are exported to user processes and how everything is stitched together. But also, I'm a bit confused on what kind of assumptions are needed to build verified user-level code in the face of revocable memory. I.e., it seems that one needs to assume (and trust) that the memory of any verified (or even rather mission critical) process is never revoked. Maybe I'm wrong and missing something and you have a way in mind for how to bypass such trust. Or maybe one can argue that such trust is reasonable, which is probably true for a "flat" system in which the mission critical domain is created right from the trusted boot process or some trusted TCB above it. Yet it seems hard to argue that such trust is reasonable when the recursion is deeper, e.g., the boot process launches Linux, and then Linux tries to start some kind of a mission critical process like a microkernel-protected software TEE or something (out of its memory hence it can later revoke it). And one wants to build a proof about this TCB yet such proof needs to deal with memory that can be revoked at any time or assume that revocation is impossible. Just wandering what is the take on this. I apologize if this all is covered somewhere in seL4 docs and I just didn't dig deep enough. Thank you! Anton

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seL4 libraries compatibility with Microkit
by Julia Royer 22 Mar '25

22 Mar '25

Hi, I understand that Microkit simplifies the seL4 API. However, I would like to know if it is still possible to use seL4 libraries when working with Microkit. If so, is there any benefit to doing so? Thank you in advance for your help. Kind regards, Julia Royer

2 2

seL4 developer hangout reminder
by Birgit Brecknell 17 Mar '25

17 Mar '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 18 Mar, 9:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Reminder: Call For Presentations for the seL4 Summit 2025
by Birgit Brecknell 14 Mar '25

14 Mar '25

Reminder: Call For Presentations [0] for the seL4 Summit 2025 [1] - Share your seL4 work - Share your seL4 experience - Share your seL4 thoughts Check the full Call For Presentations [0]. To propose a talk, upload an abstract of one page or less by **21 April 2025** to the submission portal [2]. Also note the open invitation for a 5-minute slot to talk about your seL4 deployment [3]. [0] https://sel4.systems/Foundation/Summit/2025/cfp [1] https://sel4.systems/Foundation/Summit/2025/ [2] https://form.jotform.com/250436091673861 [3] https://sel4.systems/Foundation/Summit/2025/cfp#sel4-deployment Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Libvmm on Rasperry Pi 4B
by Julia Royer 12 Mar '25

12 Mar '25

Hello, I am currently working on a project aimed at exploring the capabilities of the seL4 microkernel and Microkit. For this purpose, I have chosen the Raspberry Pi 4B board. I noticed that libvmm is not yet supported for this platform. Do you have an estimate on when Raspberry Pi 4B might be supported? Thank you for your time and support. Kind regards, Julia Royer

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Release 2.0.0 of Microkit
by Ivan Velickovic 09 Mar '25

09 Mar '25

Hello everyone, There is a new release of Microkit, version 2.0.0. This release contains various bug fixes, quality-of-life changes, features, and new board support. This is a major version bump due to a breaking change. Below the release notes, there is a section on how to upgrade from Microkit 1.4.1. You can download the pre-built SDK from GitHub: https://github.com/seL4/microkit/releases/tag/2.0.0 Ivan

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seL4 for general purpose/desktop operating systems?
by Isaac Beckett 09 Mar '25

09 Mar '25

Hello! I saw Microkit 2.0 has just been released, and it’s prompted a question I’ve been thinking about since before Microkit, when CaMKes was the main thing: Both Microkit and Camkes are designed for embedded and/or static systems, where there is no detection/configuration of hardware at runtime, and in Microkit no swapping of components such as drivers. Is there any work ongoing to use seL4 for a general purpose operating system? Like, a situation where you may have e.g. PC style hardware that can have all sorts of reconfiguration between power-off and next boot, or even while booted and running. Of course this introduces a lot of attack surface, but it makes a lot more sense for a general purpose computer, rather than an embedded one. Is there any recent work/prior art on using seL4 outside of the context of deeply embedded systems? Thanks, Isaac

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Deprecating old boards in the CI system
by Peter Chubb 05 Mar '25

05 Mar '25

Hi folks, There are a number of boards we currently support that we can no longer test, as the boards we had have died. Some of these have been out of production for more than five years. I'm intending to write up deprecation RFCs for any that noone is using -- please reply if you still have software you support on any of the SoCs on these boards: Arndale Exynos 5250 -- Introduced 2012, last available in 2018 Odroid X Exynos 4412 -- introduced 2012, last available 2018 Beagleboard Xm DM3730 -- introduced 2014, still available as new-old-stock, but no longer manufactured. Hikey960 Kirin 620 -- Introduced 2017, last available 2020 Inforce IFC6410 Snapdragon -- Introduced 2013; no userspace support at present -- Dr Peter Chubb https://trustworthy.systems/ Trustworthy Systems Group CSE, UNSW Core hours: Mon 8am-3pm; Wed: 8am-5pm; Fri 8am-12pm.

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seL4 developer hangout reminder
by Birgit Brecknell 03 Mar '25

03 Mar '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 5 Mar, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Call For Presentations for the seL4 Summit 2025
by Birgit Brecknell 17 Feb '25

17 Feb '25

Call For Presentations [0] for the seL4 Summit 2025 [1] - Share your seL4 work - Share your seL4 experience - Share your seL4 thoughts Check the full Call For Presentations [0]. To propose a talk, upload an abstract of one page or less by 21 April 2025 to the submission portal [2]. Also note the open invitation for a 5-minute slot to talk about your seL4 deployment [3]. [0] https://sel4.systems/Foundation/Summit/2025/cfp [1] https://sel4.systems/Foundation/Summit/2025/ [2] https://form.jotform.com/250436091673861 [3] https://sel4.systems/Foundation/Summit/2025/cfp#sel4-deployment Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 17 Feb '25

17 Feb '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 18 Feb, 9:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 developer hangout reminder
by Birgit Brecknell 03 Feb '25

03 Feb '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 5 Feb, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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seL4 test on x86
by Yevgeny Lavrov 30 Jan '25

30 Jan '25

Hello, I'm new to seL4 and I'm just doing it for learning purpose. I'm trying to run seL4 test suite or simple hello world task from seL4 tutorials on the real hardware. So far I had no problems compiling seL4 test suite and running via QEMU for both x32 and x64 platforms. However, when I try to run it on the actual hardware following Running on real hardware tutorial for x86 I end up with no output at all and no error msgs that can give me a clue on where something went wrong. After compiling seL4test for x86, I ended up with two images in sel4_dir/images/ folder. Copied them over to /boot/sel4/ folder and created a new GRUB2 entry that looks like this menuentry “seL4 test suite” --class os { load video insmod gzio insmod part_msdos insmod ext2 set root=’(hd0,msdos5)’ multiboot /boot/sel4/kernel-ia32-pc99 module /boot/sel4/sel4test-driver-image-ia32-pc99 } update grub, restart and select the new entry from GRUB menu. I end up with blinking cursor on the top-left side of the screen. Please advise.

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seL4 developer hangout reminder
by Birgit Brecknell 20 Jan '25

20 Jan '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 21 Jan, 9:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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reclaiming root server memory frames
by Yanfeng Liu 18 Jan '25

18 Jan '25

Dear experts, I am wondering how seL4 app can reclaim some root server memory frames at later stage of bootstrapping? Regards, yf

1 1

seL4 developer hangout reminder
by Birgit Brecknell 06 Jan '25

06 Jan '25

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 8 Jan, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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CDT traveling
by Yanfeng Liu 18 Dec '24

18 Dec '24

Dear experts, I am trying to understand the memory usage of a running seL4 demo with help of GDB. I am wondering how I can travel the Capability derivation tree starting from original untyped objects and see how memory are used. I noticed that `mdb_node_t` has `mdbPrev` and `mdbNext` pointer fields but not sure how can they be used to travel the capability derivation tree? Regards, yf

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On Common IPC Patterns in Microkit
by Wanja.Zaeske＠dlr.de 16 Dec '24

16 Dec '24

Hi together, during the proceedings of the last seL4 summit I participated in a discussion about Microkit usability. In particular we were talking about common patterns for IPC in Microkit, potential pitfalls and how the Microkit Tutorial introduces some of them implicitly (by requiring the user to apply them). At some point Kent suggested to put the topic on the mailing list, so here we go 😊. When initially playing through the Microkit Tutorial, I assumed that the budget/period of a protection domain were providing uninterrupted time-slots. I was thus slightly surprised, when I found out that sending a notification to a higher priority PD would immediately preempt my current PD. Now, this on its own is not problematic, Gernot simply commented my mistake with "Yes, priorities are observed". However: When playing the Microkit tutorial, I understood the way to solve Part 2 (Serial Server to Client Communication) to be as follows: * [serial server] write received char to shared buffer. * [serial server] notify client. * [client] read char from shared buffer. This is also the current approach found in the provided solution [1]. This works in some (most!) cases, but it is not reliable. It could be that chars get lost, due to the serial server overwriting the buffer before it was consumed form the client. The specific details if this works depend upon the combination of: * Data size (not-so-critical with one byte, but more data means more time is required to consume the buffer form the client) * Budget/Period of the client (can the client read all data before it is preempted by exhaustion of its budget in the current period) * Hardware Performance (same as above) * Priorities (if the serial server is higher priority and gets triggered by another hardware event before the client can consume the char, it gets lost again) This is problematic: the details of the scheduling are not very explicit in the manual (roughly one half of a page), but the first example of IPC taught via the tutorial relies on a lot of implicit circumstance on how PDs are scheduled to function correctly. Now I have three suggestions to improve upon this. 1. In the tutorial, explicitly mention the possibility of using the same notification channel in the opposite direction for a read-ACK. If another serial interrupt comes, but no ACK was received, just log an error. The point is not, to introduce ring-buffers and a the machinery for robust communication -- that would like explode the scope for a simple tutorial. Rather, the point is to teach people that this IPC mechanism may silently fail (as in chars get dropped). 2. For certain scheduling + IPC scenarios, examples with a graphical representation would be good. Here are two examples: Sending data to a higher priority PD (via notifications + shared memory) [2] and sending data to a lower priority PD (via notification + shared memory + ACK notification) [3]. Please bear with me, my talent to intuitive graphical representation is of limited nature, this for sure could be made better looking. In the end, I'd like to have an engineer short on time quickly look up the current scenario (sharing data bi-/unidir?, other PD is strictly higher prio/lower prio?, silent loss of data tolerable or not?, ...) from a table, take a look at the timing diagram and pick the correct approach for the task at hand. Microkit does not provide very sophisticated IPC APIs, and that is good! It keeps Microkit small, and the API IMHO provides everything needed, for synchronous and asynchronous communication, for large and small data, ... But composing the IPC correctly is not trivial, so anything we can to take sharp edges of the experience without bloating the API should be considered. 3. I think, there is a finite number of relevant IPC scenarios. Maybe one can build a tool to verify them (something something Promela?) and display them graphically (something something PlantUML Timing Diagrams?). This could either be used to fill a chapter in the Microkit Manual ("Common IPC Patterns, their Behavior and Pitfalls"?), or exposed as small (Web?) GUI Tool. Maybe this could become part of a student thesis even? I hope the above might spark some thought on improving accessibility of Microkit. Kind Regards, Wanja [PlantUML diagram] [PlantUML diagram] [1] https://github.com/au-ts/microkit_tutorial/blob/6733b7864217831e4e77616647e… [2] https://www.plantuml.com/plantuml/uml/VL9DYzim4BthLppIGoxP49kwWHvADlHOIYc5F… [3] https://www.plantuml.com/plantuml/uml/XLDDYzim4BthLpnosKisnA4Ecq9BjlHOIkbbp… —————————————————————————— Deutsches Zentrum für Luft- und Raumfahrt (DLR) Institut für Flugsystemtechnik | Sichere Systeme & Systems Engineering | Lilienthalplatz 7 | 38108 Braunschweig Wanja Zaeske Telefon 0531 295-1114 | Fax 0531 295-2931 | wanja.zaeske(a)dlr.de<mailto:wanja.zaeske@dlr.de> DLR.de<http://www.dlr.de/>

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address of L1 CNode Cap
by Yanfeng Liu 12 Dec '24

12 Dec '24

Dear experts, When reading section 3.3.2 of the latest seL4 manual, it says: > Figure 3.3 depicts an example CSpace. In order to illustrate these ideas, we determine the address of each of the 10 capabilities in this CSpace. I guess the total number of 10 is made of 3 caps for CNode types and 7 for non- CNode ones A~G as shown in diagram. However, in the following graph, the address of the L1 CNode Cap is missed. Thus I am curious what the address for that L1 CNode Cap? Regards, yf

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seL4 developer hangout reminder
by Birgit Brecknell 09 Dec '24

09 Dec '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 11 Dec, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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LionsOS musllibc old version? Vulnerable?
by Hugo V.C. 30 Nov '24

30 Nov '24

Hi, reading the dependencies of LionsOS I realized it is using an old version of muslibc : https://github.com/au-ts/musllibc/blob/81842bc43d0b49bbcca03ff5f506c6df8e2b… if this version has not been patched may be vulnerable to a remotely exploitable buffer overflow in the dns resolution: https://git.musl-libc.org/cgit/musl/commit/?id=45ca5d3fcb6f874bf5ba55d0e965… Can someone confirm or reject? Thanks.

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find all seL4 threads
by Yanfeng 25 Nov '24

25 Nov '24

Dear experts, I am wondering when checking a running seL4 target from GDB, how can we find all threads? It seems that `ksReadyQueues[]` only holds a sub set. Regards, yf

3 3

seL4 developer hangout reminder
by Birgit Brecknell 25 Nov '24

25 Nov '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 26 Nov, 9:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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iMX8MM seL4 12.1.0 running a VM
by Zippy Manaic 22 Nov '24

22 Nov '24

Hi, I have encountered a problem where the device tree is not correctly being parsed resulting in interrupts not being routed to the VM. A node which exhibits this issue is (there are several more in the iMX8MM device tree that also trigger the problem) ``` snvs@30370000 { compatible = "fsl,sec-v4.0-mon\0syscon\0simple-mfd"; reg = <0x30370000 0x10000>; phandle = <0x1b>; snvs-rtc-lp { compatible = "fsl,sec-v4.0-mon-rtc-lp"; regmap = <0x1b>; offset = <0x34>; interrupts = <0x00 0x13 0x04 0x00 0x14 0x04>; clocks = <0x02 0xe4>; clock-names = "snvs-rtc"; }; }; ``` Interrupts 0x13 and 0x14 should be included in the camkes_dtb_irqs[] variable but they are not. Looking at the node as it is parsed in macros.py via the function parse_dtb_node_interrupts {'compatible': ['fsl,sec-v4.0-mon', 'syscon', 'simple-mfd'], 'reg': [808910848, 65536], 'phandle': [27], 'snvs_rtc_lp': [<pyfdt.pyfdt.FdtPropertyStrings object at 0x7483b4c28f10>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c28f70>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c28fd0>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f070>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f0d0>, <pyfdt.pyfdt.FdtPropertyStrings object at 0x7483b4c2f130>], 'snvs_rtc_lp_compatible': ['fsl,sec-v4.0-mon-rtc-lp'], 'snvs_rtc_lp_regmap': [27], 'snvs_rtc_lp_offset': [52], 'snvs_rtc_lp_interrupts': [0, 19, 4, 0, 20, 4], 'snvs_rtc_lp_clocks': [2, 228], 'snvs_rtc_lp_clock_names': ['snvs-rtc'], 'snvs_powerkey': [<pyfdt.pyfdt.FdtPropertyStrings object at 0x7483b4c2f1f0>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f250>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f2b0>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f310>, <pyfdt.pyfdt.FdtPropertyStrings object at 0x7483b4c2f370>, <pyfdt.pyfdt.FdtPropertyWords object at 0x7483b4c2f3d0>, <pyfdt.pyfdt.FdtProperty object at 0x7483b4c2f430>, <pyfdt.pyfdt.FdtPropertyStrings object at 0x7483b4c2f490>], 'snvs_powerkey_compatible': ['fsl,sec-v4.0-pwrkey'], 'snvs_powerkey_regmap': [27], 'snvs_powerkey_interrupts': [0, 4, 4], 'snvs_powerkey_clocks': [2, 228], 'snvs_powerkey_clock_names': ['snvs-pwrkey'], 'snvs_powerkey_linux_keycode': [116], 'snvs_powerkey_wakeup_source': [], 'snvs_powerkey_status': ['okay'], 'this_address_cells': [1], 'this_size_cells': [1], 'this_node_path': '/soc@0/bus@30000000/snvs@30370000'} The function is looking for 'interrupts' but the interrupt declaration in the child node has been renamed to 'snvs_rtc_lp_interrupts'. This explains why the interrupts are omitted from the template generated code. A hacky fix, that does appear to work, is to paste the interrupt declarations into the parent node. I'm sure there's a more elegant way to resolve this but my detailed knowledge in this area is lacking. I am going to have a look at seL4 13.0.0 to see if this has already been fixed with a view to a potential backport but thought I'd check here before starting to dig a new hole to fall into. Many thanks, Zippy

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seL4 summit 2025: survey about location
by Birgit Brecknell 20 Nov '24

20 Nov '24

With the great success of the seL4 summit 2024 [0] behind us, we are now looking at the seL4 summit 2025! This should happen around Sep/Oct 2025, and will be held in Europe. We have started investigating options for the location, and would like your feedback. We would greatly appreciate it if you could fill in this very short survey to tell us your opinions: https://form.jotform.com/243076885259874 *Please do so by 29 Nov 2024.* Feel free to forward to anyone you believe may want to attend the summit next year. [0] https://sel4.systems/Foundation/Summit/2024/ Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Re: Modifying the root user thread's CSpace
by Indan Zupancic 16 Nov '24

16 Nov '24

Hi Ben, (Please don't drop CC.) Glad I could help. Don't be too hard on yourself, hindsight is easy. For defensive programming reasons (which also makes attacks harder), it's good to have a non-zero guard for your caps which doesn't overlap with your virtual address space, at least for the first level. For the last level it depends on how you want overflows to behave: If you want to seamlessly continue into the next CNode, have a zero guard size (good for e.g. dynamic CNode allocation). If you want to detect overflow errors on sets of caps, make sure you have a guard size of at least 1 bit. Having a non-zero guard value has less advantage for later CNode levels. Greetings, Indan On 2024-11-15 16:25, Ben McCart wrote: > Indan, > > Thank you so much! seL4_CNode_Mint instead of seL4_CNode_Copy solved > my problem. The piece I was missing was that I needed to change the > guard on the original seL4_CapInitThreadCNode when copying it into the > first CSlot of the new root CNode. (Doh!) I should have caught that > as you said explicitly in you prior response that each CNode capability > can have different guard bits set. (I just didn't think carefully > enough about that.) > > On 11/15/2024 4:55 AM, Indan Zupancic wrote: >> >> seL4_CNode_Copy can't change the guard, you have to use >> seL4_CNode_Mint() if you need to change it: >> >> assert(bi->initThreadCNodeSizeBits <= 16); >> seL4_CNode_Mint( >> cspace_cap, >> 0, // Destination index in the >> new Cap table. >> 16, // Number of bits for the new >> Cap table. >> seL4_CapInitThreadCNode, >> seL4_CapInitThreadCNode, >> seL4_WordBits, >> seL4_AllRights, >> 16 - bi->initThreadCNodeSizeBits); // Zero pad guard to reach 16 >> bits. >> <SNIP> >> Indan > > -Ben

1 0

Modifying the root user thread's CSpace
by Ben McCart 16 Nov '24

16 Nov '24

Hello, I read the manual for v12.0 chapters 1-3, and 10. I have been attempting to experiment with CSpaces for the user space root thread. I am trying to modify the CSpace to support multiple CNode levels by changing the guard from all zero bits above the radix (16 bits of radix on PC99 x64), to support multiple CNode levels. I have been using seL4_TCB_SetSpace to modify the CSpace for seL4_CapInitThreadTCB. The result is seL4_NoError and once I make this call the previously working capabilities tutorial quits working as expected. (Calls taking the original seL4_CapInitThreadTCB value are now returning seL4_InvalidCapability). I have studied chapter three of the manual and I think I understand how the CSpace addressing works in depth. What I can't seem to figure out is how to construct a cspace_root_data argument for the call to seL4_TCB_SetSpace for the number of guard bits and the guard values I want to use. For example, if I wanted two levels each with a 4 bit guard and a 16 bit radix how would I construct cspace_root_data argument for a gaurd value of 0x0? And for a gaurd value of 0xF? (I intend to keep the original seL4_CapInitThreadTCB CNode as my level-1 CNode for this experimentation.) Thank you in advance if you can point me to some reference documentation that may cover how to construct the cspace_root_data argument, guidance, or direction you may be able to give. Sincerely, Ben McCart

3 6

Potential vulnerabilities
by Hugo V.C. 15 Nov '24

15 Nov '24

I'm forwarding this question here (tried on Mattermost Trustworthy Systems group first) hoping someone can put some light on this? --- Hi, I'm having a look to the vulns (in areas of the kernel that have not been formally verified) patched in seL4 13.0.0. We have: 1) "NULL pointer dereference when injecting an IRQ for a non-associated VCPU on SMP configurations." 2) "On AArch64, when seL4 runs in EL1 the kernel would fault with a data abort in seL4_ARM_Page_Invalidate_Data and seL4_ARM_VSpace_Invalidate_Data when the user requested a dc ivac cache maintenance operation on a page that is not mapped writeable." Extremely simple question: running version < 13.0.0 on top of Qemu (in example like https://docs.sel4.systems/projects/sel4webserver/) would it be vulnerable to any of those? --- Best,

4 13

seL4 developer hangout reminder
by Birgit Brecknell 11 Nov '24

11 Nov '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 13 Nov, 7:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

ci-actions/preprocess
by Yanfeng 07 Nov '24

07 Nov '24

Dear experts, I am seL4 newbie. When I changed compile options in seL4/CMakeLists.txt, I got check errors from "ci-actions/preprocess" check like this one: https://github.com/seL4/seL4/actions/runs/11682457028/job/32529623251 Can someone teach where I can see details of "ci-actions/preprocess" check? Regards, yf

2 2

Introduction to seL4's Architecture & Concepts
by tunacici7＠gmail.com 03 Nov '24

03 Nov '24

Hey everyone. I've created an introductory documentation to seL4’s architecture & concepts. I thought it would be helpful for anyone interested in seL4 and wanted to share. The documentation includes many hand-written visualizations to make seL4 (and its abstractions) more accessible to people. You can access it on GitHub: https://github.com/TunaCici/seL4_Architecture Hope you enjoy it! NOTE: I’m sorry if this isn’t the best place to share this. I don’t know of any other active seL4 communities besides the mailing list.

6 6

AMD64 - how much virtual address space does the kernel map?
by Ben McCart 31 Oct '24

31 Oct '24

Hellow all, I have been working through the tutorials and doing some experimenting and ran into behavior that very much surprised me. I can seL4_X86_PageTable_Map & seL4_X86_Page_Map to virtual addresses starting at the 96 MB address (0x06000000) with no errors. However, as soon as I try to seL4_X86_PageDirectory_Map that same virtual address I get the error seL4_DeleteFirst. I didn't think the kernel mapped anything for the root address above 64 MB virtual address range for the root address in these tutorials. If it did I would have expected an error for seL4_X86_PageTable_Map & seL4_X86_Page_Map. What is going on? What am I missing? How can I avoid expecting to map a virtual address in a range already mapped by the kernel for the root process on a given architecture? - Ben McCart

2 1

seL4 fails to boot multiple core at CPU 0x1.
by Vishal Gupta 31 Oct '24

31 Oct '24

Dear All, I am a seL4 enthusiast , I am trying to port , build and test seL4 for ARM64 Cortex A53 based hardware. For Single core , I am able to boot via elf-loader then jump to kernel and successfully run Hello World program without any issues. But when I am trying to change it to multiple core SMP enabled on my hardware or even in ARM Qemu setup it is failing to boot. Can anyone please guide me , if seL4 supports multicore than for which version of ARM / board it currently supports , as I could see support for only Sabre-Arm32, which is ARMv7A. Boot log attach for reference. ———————————————————————— ELF-loader started on CPU: ARM Ltd. Cortex-A53 r0p4 paddr=[40a4c000…40f57137] No DTB passed in from boot loader. Looking for DTB in CPIO archive…found at 40bacbe8. Loaded DTB from 40bacbe8. paddr=[4024c000…4024dfff] ELF-loading image ‘kernel’ to 40000000 paddr=[40000000…4024bfff] vaddr=[ffffff8040000000…ffffff804024bfff] virt_entry=ffffff8040000000 ELF-loading image ‘sel4test-driver’ to 4024e000 paddr=[4024e000…40654fff] vaddr=[400000…806fff] virt_entry=40e700 Boot cpu id = 0x0, index=0 HVC is not supported for PSCI! Failed to boot cpu 0x1: 18446744073709551615 abort() called. ——————————————————————————— Looking for any guidance, as it will be helpful for me to move forward . Regards, Vishal

2 1

seL4 developer hangout reminder
by Birgit Brecknell 28 Oct '24

28 Oct '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 29 Oct, 9:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Device memory access issue on sel4 user driver
by misbah khan 25 Oct '24

25 Oct '24

Hello sel4 developers, I am using seL4 for in our arm64 based hardware platform. I need to write a simple driver where i need to read/write some memory mapped registers The device physical address is "0x40520000" When i print the bootinfo using the below code: /*-- filter TaskContent("untyped-start", TaskContentType.ALL, subtask='init') -*/ printf(" CSlot \tPaddr \tSize\tType\n"); for (seL4_CPtr slot = info->untyped.start; slot != info->untyped.end; slot++) { seL4_UntypedDesc *desc = &info->untypedList[slot - info->untyped.start]; printf("%8p\t%16p\t2^%d\t%s\n", (void *) slot, (void *) desc->paddr, desc->sizeBits, desc->isDevice ? "device untyped" : "untyped"); I get the following output: CSlot Paddr Size Type 0x1ac 0 2^30 device untyped 0x1ad 0x40000000 2^28 device untyped 0x1ae 0x50000000 2^23 device untyped 0x1af 0x50810000 2^16 device untyped 0x1b0 0x50820000 2^17 device untyped I am mappint the physical address to virtual and trying to access it as: va = ps_io_map(&ops.io_mapper, (uintptr_t) 0x40520000,0x3000, PS_MEM_NORMAL); ZF_LOGE("Physical address 0x%x mapped to virtual address %p \n",DEV_REG_PADDR,va); for(int j=0;j<DEV_REG_SIZE;j+=sizeof(unsigned int)) { ZF_LOGE("Loc %d --> 0x%x ",j,*(unsigned int*)(va+j)); } I am able to access some registers, but then it gives a fault (after printing 5-6 register values) Similar is the behaviour with any reg between the range 0x40000000 - 0x50000000 Attaching the sample code and output: I am able to access first two address location, after that it gives halt. Regards, Misbah

2 2

sel4 for Imx8Plus
by janarthanan.b＠teclever.com 23 Oct '24

23 Oct '24

Hi sel4 dev team, I'm working on imx8 Plus board for that Building seL4test is done and generated the binary image file of "sel4test-driver-image-arm-imx8mp-evk" with the size of 5mb as per the procedure on sel4 websites. I moved this into sd card and trying to boot into board.but i cant able to boot it. What is the issue on this and how to solve it? if we need to do uboot what's the procedure for that?

3 4

seL4 hangs during invalidate local TLB
by Vishal Gupta 16 Oct '24

16 Oct '24

Dear seL4 developers, I am a seL4 enthusiast. I am trying to port seL4 on arm64 cortex a53. I am able to port elf-loader successfully and move to the kernel initialisation which reaches till “try_init_kernel->init_cpu->activate_global_pd->invalidateLocalTLB->asm volatile()”. Under InvalidatelocalTLB with asm volatile(“tlbi vmalle1”); in this , the system gets hanged and the asm function does not move forward. Any input or guidance would be really appreciated. Thank you . Regards, Vishal

1 0

Stuck during invalidate local TLB in Tx2
by Muneeswaran Rajendran 16 Oct '24

16 Oct '24

Hi seL4 Dev team, Can someone explain the reason (share the reference) to invalidate the local TLB during kernel vspace activation as part CPU initialisation. The Tx2 board stuck while performing this operation. As per my understanding both Tx1 and Tx2 are using same A57 core. so the TLB initialisation and invalidation remain same for Tx2 and should not stuck during invalidation.Please correct me if anything wrong here. I understand from that instruction (tlbi vmalle1) which is invalidating stage 1 entries associated to the current VMID. Also from arm mmu code the seL4 setting up (TCR_EL1) TCR register addressing space as 48bit, ASID as 16bit and page table setup 4k granular size. I am using MRS macro to dump the spsr_el1 and dspsr_el0 register to see the state of processor but its throwing synchronous exception. Do we have any other option to dump all the register content to see the state of processor like we have one in 'sel4debug_dump_registers' which is used in sel4test code. Regards, Muneeswaran R

3 4

seL4 developer hangout reminder
by Birgit Brecknell 30 Sep '24

30 Sep '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 1 Oct, 10:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

General Question On Object Methods
by tunacici7＠gmail.com 25 Sep '24

25 Sep '24

I've recently started to learn seL4 by following the Tutorials, which have been great so far. I've been also reading the Manual & API reference to understand and gain insight into different mechanisms. However, I have one fundamental question: Are the object methods system calls? It is said that seL4 only has 3 logical system calls: Send, Recv and Yield. (In all the slides, videos and other documents I have seen) And the rest is just variations of those ones. But what about object methods? Are they system calls? Are they executed in kernel space? If they are system calls, then wouldn't all the resources out there be misleading? Since there are way more than just Send, Recv and Yield. If they are not, then how are they handled? Does 'libsel4' have anything to do with it? I can't imagine 'seL4_Untype_Retype' executing in user space. Unfortunately, I couldn't find any answers to this question online. So that's why I'm asking it here. Maybe there are others who wonders the same thing. NOTE The API Reference page confuses me even more. It lists Object Methods in its own category (instead of being under System Calls). Does this means Object Methods are NOT system calls? Or the term System Call is just not what I think it is(basically an endpoint to kernel)?. END NOTE Thanks for the answers in advance. -T

8 21

seL4 developer hangout reminder
by Birgit Brecknell 16 Sep '24

16 Sep '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 18 Sep, 8:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Less than 1 week left to get the early-bird registration for the seL4 summit
by Birgit Brecknell 09 Sep '24

09 Sep '24

Less than 1 week left to get the early-bird registration for the seL4 summit The early bird cut-off date for the seL4 summit 2024 [0] is 15 September 2024. The summit will be held in Sydney, Australia, 15-17 October 2024. The seL4 summit will cover the complete seL4 ecosystem, consisting of the verified microkernel, as well as all seL4-related technology, tools, infrastructure, products, projects, and people. Tickets include: - Participation in the 3-day conference, including talks, keynotes, seL4 updates & discussions - Networking with other seL4 experts and enthusiasts - Reception and dinner Register here [1] A number of informal social activities [2] are being organised by local Sydney-siders. Check out the list [2] and contact the organiser to register your interest. [0] https://sel4.systems/Foundation/Summit/2024/ [1] https://events.linuxfoundation.org/sel4-summit/register/ [2] https://sel4.systems/Foundation/Summit/2024/social-activities Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Virtual address ranges used in seL4 initial thread after boot?
by Ben McCart 06 Sep '24

06 Sep '24

I have read the manual in section 9.2 about userImageFrames and how to infer the virtual address range for the pages being used for the userland image, which I frankly do not concretely understand. For example, I can take the address of main() and that leads me to believe my first user image frame (page frame actually I suspect) is probably at 0x40000, but it feels like guessing. (Not good!) In addition, I like to know the address range used for the stack of the initial thread, as well as any other reserved regions (I read somewhere in the manual about reserved virtual address space for the kernel, but I can't remember where I read that and now I can't find it.) Are there any macros included in public header files that I can use in my project to get the starting addresses for any of these regions? Barring that, is there any straight-forward reliable way to find the starting address for these regions (or in the case of kernel reserved virtual address range is it documented anywhere?) I am on version 12.0 of seL4 for my project. Thank you! -Ben

2 2

Less than 2 weeks left to get the early-bird registration for the seL4 summit
by Birgit Brecknell 02 Sep '24

02 Sep '24

Less than 2 weeks left to get the early-bird registration for the seL4 summit The early bird cut-off date for the seL4 summit 2024 [0] is 15 September 2024. The summit will be held in Sydney, Australia, 15-17 October 2024. The seL4 summit will cover the complete seL4 ecosystem, consisting of the verified microkernel, as well as all seL4-related technology, tools, infrastructure, products, projects, and people. Tickets include: - Participation in the 3-day conference, including talks, keynotes, seL4 updates & discussions - Networking with other seL4 experts and enthusiasts - Reception and dinner Register here [1] A number of informal social activities [2] are being organised by local Sydney-siders. Check out the list [2] and contact the organiser to register your interest. [0] https://sel4.systems/Foundation/Summit/2024/ [1] https://events.linuxfoundation.org/sel4-summit/register/ [2] https://sel4.systems/Foundation/Summit/2024/social-activities Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 02 Sep '24

02 Sep '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 3 Sep, 10:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 19 Aug '24

19 Aug '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 21 Aug, 8:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Gpu passthrough
by Hugo V.C. 15 Aug '24

15 Aug '24

Hi all, here a simple question: is there any example/tutorial off gpu passthrough to a Linux guest? Best,

4 6

Build failure for sel4 on raspberry pi 5
by l4＠photiczone.com 14 Aug '24

14 Aug '24

Hi everyone, I am getting a link failure during the build of sel4test-tests: /usr/bin/ld: apps/sel4test-driver/musllibc/build-temp/stage/lib/libc.a(__stdio_exit.o): copy relocation against non-copyable protected symbol `__stdin_used' collect2: error: ld returned 1 exit status Searching t'interwebs seems to imply this is a gnarly problem caused by the nuances of various build tools - but one that should not apply to Arm. You can summarise everything I did before the build like this: sudo apt install ninja-build libxml2-utils repo pip3 install pyyaml typing hardware pyfdt jinja2 jsonschema six future ply python3-protobuf grpcio-tools cd && mkdir xxx && cd xxx Then to follow your build repo init -u https://github.com/seL4/sel4test-manifest.git repo sync mkdir build && cd build ../init-build.sh -DPLATFORM=bcm2711 ninja And yes I know it is not supported and the BCM2711 is for the Pi 4. I am evaluating ;) Any help greatly appreciated. Thanks, Smiley

3 4

I am interested in porting LionOS to X64 architecture
by Peter Relich 14 Aug '24

14 Aug '24

Hello, I am a researcher at Intellisense Systems, Inc. We are a small business that performs R&D for the U.S. Military. We have an active contractor to build a hypervisor for a microkernel. We recently selected Sel4 as the microkernel and I learned that the Army (our customer) used a camKes implementation of a VMM to host a fork of Ubuntu, but the limitations prompted them to try another approach. I think since that time, microkit has developed quite a bit and I saw the trustworthy systems has even been developing an operating system on the Sel4 microkernel. However, LionOS appears to be developed for ARM systems as the use case. For the Army use, we are using a Nuvo7000LP: https://www.neousys-tech.com/Resource/Product_Document/Nuvo-7000LP/Nuvo-700… Which is an X64 architecture. I just started learning microkit through your available tutorials and I am aware that building a comprehensive VMM is no easy task. However, I was wondering if you had some intuition or if you could provide me an estimate of the libraries in the LionOS that I would need to adjust/redesign to make an X64 architecture fork? Is this even a feasible approach? It looks like I just need to swap out the aarch64 libraries with compatible x64 libraries and do some testing. Before I commit, I just wanted to get some advice on the endeavor. Is forking LionOS to an X64 architecture feasible, or should I start at a lower level (i.e., redesigning the vmm?) Thanks so much for your time. Respectfully, Peter Relich Research Scientist Intellisense Systems, Inc. ________________________________ The information contained in this e-mail and any attachments from Intellisense Systems may contain confidential and/or proprietary information, and is intended only for the named recipient to whom it was originally addressed. If you are not the intended recipient, any disclosure, distribution, or copying of this e-mail or its attachments is strictly prohibited. If you have received this e-mail in error, please notify the sender immediately by return e-mail and permanently delete the e-mail and any attachments.

5 5

MCS round-robin scheduling not behaving as expected
by liam.vervecken＠gmail.com 12 Aug '24

12 Aug '24

Hello, I'm trying to understand MCS and how the scheduling works but I'm running into some issues. My setup: RISCV on BeagleVFire in sel4test I have configured 2 threads: seL4_SchedControl_ConfigureFlags(info->schedcontrol.start, sched_context_thread2, 1000000, 1000000, 0, 0, 0); seL4_SchedContext_Bind(sched_context_thread2, thread2_TCB); seL4_SchedControl_ConfigureFlags(info->schedcontrol.start, sched_context_thread3, 1000000, 1000000, 0, 0, 0); seL4_SchedContext_Bind(sched_context_thread3, thread3_TCB); The threads have the same priority. From the documentation I was expecting them to behave like this: - Thread1 does something - Thread2 does something - Thread1 does something - ... But it seems instead only the first thread gets scheduled, and it never allows the second thread to get any CPU time. Am I correct in assuming that 2 threads with period=budget and equal priority should be scheduled round-robin? I found that if I call seL4_SchedContext_Consumed(sched_context_thread) periodically in the threads they will switch if the budget has expired. It doesn't make much sense to me why this is the case, I thought they would switch automatically once their budget is expired and that seL4_SchedContext_Consumed() was simply used to keep track of this. I'm hoping it can offer some clue as to what I'm doing wrong. Any help or guidance would be greatly appreciated. Kind Regards, Liam

6 6

LionsOS as basis for mobile/handheld OS
by Isaac Beckett 10 Aug '24

10 Aug '24

I was looking at LionsOS docs recently, and noted it is meant for static systems with no support for changing hardware at runtime. This is less of a problem for phones and other handhelds given they generally keep the same hardware throughout their service life, but I was concerned about peripheral support. What if I want to be able to connect an external display to a phone or tablet running a LionsOS based userspace? Or I have privacy switches on the device that physically disconnect components such as the modem or camera assembly? Most of the system would be static, and only really changing for things such as loading isolated, untrusted application code (such as a Linux kernel, or something pretending to be a Linux kernel), but it would still have some hardware components that can be disconnected. Though at least in the case of privacy switches they would be the same components every time. What do y’all think? Does this idea of building a mobile phone OS on LionsOS have merit or would it make more sense to use a different framework or build something on seL4 directly?

3 3

LionOS Docs
by Hugo V.C. 09 Aug '24

09 Aug '24

Hi! I'm planning to switch from CAmkES to LionOS but I got a 404 on this link: https://github.com/au-ts/lionsos-docs that is on this URL: https://www.lionsos.org/docs/tutorials/ Best,

2 1

Release 0.2.0 of LionsOS
by Ivan Velickovic 06 Aug '24

06 Aug '24

Hello everyone, There has been a new release of LionsOS, 0.2.0. This release is primarily focused on maturing the existing OS services and making it easier to build LionsOS-based systems. You can find detailed release notes here: https://github.com/au-ts/lionsos/releases/tag/0.2.0 Thanks, Ivan

1 0

Release 0.5.0 of the seL4 Device Driver Framework
by Ivan Velickovic 06 Aug '24

06 Aug '24

Hello everyone, There has been a new release of the seL4 Device Driver Framework, 0.5.0. This release is primarily focused on making the various device classes we support more mature. You can find detailed release notes here: https://github.com/au-ts/sddf/releases/tag/0.5.0 You can find the latest design documentation attached to the release artefacts. Thanks, Ivan

1 0

Release 1.4.0 of Microkit
by Ivan Velickovic 05 Aug '24

05 Aug '24

Hello everyone, We have made a new release of the seL4 Microkit, version 1.4.0. This release contains a number of features requested by the community. You can find the release notes here: https://docs.sel4.systems/releases/microkit/1.4.0 You can find the SDK downloads here: https://github.com/seL4/microkit/releases/tag/1.4.0 Thanks, Ivan

1 0

seL4 developer hangout reminder
by Birgit Brecknell 05 Aug '24

05 Aug '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 6 Aug, 10:00pm UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

How do I reduce the size of the seL4 executable?
by liam.vervecken＠gmail.com 26 Jul '24

26 Jul '24

Hello, I'm trying to compile a simple 'hello world' sel4 program for the polarfire (riscv) and I want the executable to be as small as possible. According to the FAQ (https://docs.sel4.systems/projects/sel4/frequently-asked-questions.html) the single core kernel can compile to a <200kb executable but in my testing, I always end up with an image of approx 2MB. I worked with this (https://github.com/mskordal/SeL4-hello-world) example project and changed main.c to work with seL4_DebugPutChar instead of printf. Besides that, I added opensbi to the tools folder and slightly modified line 32 of projects/hello/CMakeList.txt to target_link_libraries(hello sel4 sel4_autoconf sel4runtime sel4platsupport). After running ../init-build.sh -DPLATFORM=polarfire and ninja, I end up with an executable of about 2MB. I'm guessing musllibc, util_libs and sel4_libs contribute to the size, but if I change my cmakelist file to try to get rid of them the build will fail. I was hoping since my hello world only uses sel4 APIs I could compile it without musllibc, util_libs and sel4_libs but I haven't been able to figure out how. Any help or tips would be greatly appreciated. Kind Regards, Liam

1 0

next seL4 TSC meeting on Thu 25 Jul
by Gerwin Klein 24 Jul '24

24 Jul '24

The Technical Steering Committee (TSC) of the seL4 Foundation will hold its next public meting on: - Sydney: Thu, 25 Jul, 4pm - Central Europe: Thu, 25 Jul, 8am - US West Coast (LA/SF): Thu, 25 Jul, 0:00h See also the seL4 calendar feed available from here: https://sel4.systems/contact/home.pml The meeting is by Zoom, and you can join from here: https://unsw.zoom.us/j/89949317341?pwd=JSC976ciVYmbDJByjSFH0chh78sCsg.1 Anyone interested can join the meeting and listen to the discussion and request to speak, which will be granted if time permits. Only TSC members can vote. The seL4 code of conduct applies to the meeting [1]. The agenda for the meeting so far is: - action items from last meeting - discuss new FPU RFC: https://github.com/seL4/rfcs/pull/26 - hear about progress on PMU, budget limit, device driver framework - make decision on old RFC-4: https://github.com/seL4/rfcs/pull/12 - any feedback on GitHub RFC implementation - bump version of cmake-format (will break current formatting) to reduce python dependency hell If there are other items that I missed or you think should be on the agenda, please let me know. If we can't get to an item this time, we can still schedule another meeting. Cheers, Gerwin (TSC chair) [1]: https://docs.sel4.systems/processes/conduct.html

3 6

seL4 developer hangout reminder
by Birgit Brecknell 22 Jul '24

22 Jul '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 24 Jul, 8:00am UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Announcing beta.sel4.systems running on LionsOS
by James Archer 11 Jul '24

11 Jul '24

Trustworthy Systems is now serving a copy of the seL4.systems website from a beta LionsOS-based[1] webserver. It can be accessed at https://beta.sel4.systems/. The source code can be found in the LionsOS repository[2]. More information about the implementation can be found at https://beta.sel4.systems/Info/Website/. Any feedback or attempts to break it are welcome. [1] https://lionsos.org/ [2] https://github.com/au-ts/lionsos James

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seL4_X86_Page_Map on seL4_X86_LargePageObject != 2MiB
by Ben McCart 10 Jul '24

10 Jul '24

I have created my own project on the PC99 architecture (x64) and have been working through the tutorial source (copy & pasted into my project) to learn and then prototype with seL4. I have done the mapping tutorial (pc99) and utilized that code within my project and everything seems to work just fine, but if I change out the seL4_X86_4K to seL4_X86_LargePageObject I don't end up with 2MiB of mappable virtual space. All the seL4 system calls through the client API return seL4_NoError. The seL4_LargePageBits value is 21 (2^21 == 2MB, and intel documentation for IA-32e shows that 2 MiB should be the large page size. However, if I address memory outside of the first 256 KiB it halts. The following works: seL4_Word *x = (seL4_Word *) TEST_VADDR; printf("Read x: %lu\n", *x); And this works: seL4_Word *x = (seL4_Word *) TEST_VADDR + 0x0003FFF0; printf("Read x: %lu\n", *x); But this halts when trying to dereference x to print it: seL4_Word *x = (seL4_Word *) TEST_VADDR + 0x00040000; printf("Read x: %lu\n", *x); I am running seL4 12.1 using QEMU with the following command line: qemu-system-x86_64 -cpu Nehalem,-vme,+pdpe1gb,-fsgsbase,-invpcid,+syscall,+lm,enforce -nographic -serial mon:stdio -m size=512M -s -S -kernel ../sel4-project/build/images/kernel-x86_64-pc99 -initrd build/cxxkit Does anybody have any idea why I might be having this issue and what I may do about it? -Ben McCart

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seL4 developer hangout reminder
by Birgit Brecknell 08 Jul '24

08 Jul '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 9 Jul, 22:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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New release of seL4, Microkit, CAmkES, capDL and Rust support
by Gerwin Klein 02 Jul '24

02 Jul '24

We’re pleased to announce the release of - seL4 13.0.0: The seL4 microkernel https://docs.sel4.systems/releases/sel4/13.0.0 - Microkit 1.3.0: The seL4 Microkit for building static-architecture systems https://docs.sel4.systems/releases/microkit/1.3.0 - CAmkES 3.11.0: Component Architecture for microkernel-based Embedded Systems https://docs.sel4.systems/releases/camkes/camkes-3.11.0 - capDL 0.3.0: Tools for generating, parsing and loading capability distribution specifications https://docs.sel4.systems/releases/capdl/0.3.0 - rust-sel4 1.0.0: Rust support for seL4 userspace https://github.com/seL4/rust-sel4/releases/tag/v1.0.0 See https://github.com/seL4/rust-sel4/ for more information. Microkit 1.3.0 and rust-sel4-1.0.0 are the first official releases under the seL4 foundation. Cheers, Gerwin

1 0

New release of seL4, Microkit, CAmkES, capDL and Rust support
by Gerwin Klein 02 Jul '24

02 Jul '24

We’re pleased to announce the release of - seL4 13.0.0: The seL4 microkernel https://docs.sel4.systems/releases/sel4/13.0.0 - Microkit 1.3.0: The seL4 Microkit for building static-architecture systems https://docs.sel4.systems/releases/microkit/1.3.0 - CAmkES 3.11.0: Component Architecture for microkernel-based Embedded Systems https://docs.sel4.systems/releases/camkes/camkes-3.11.0 - capDL 0.3.0: Tools for generating, parsing and loading capability distribution specifications https://docs.sel4.systems/releases/capdl/0.3.0 - rust-sel4 1.0.0: Rust support for seL4 userspace https://github.com/seL4/rust-sel4/releases/tag/v1.0.0 See https://github.com/seL4/rust-sel4/ for more information. Microkit 1.3.0 and rust-sel4-1.0.0 are the first official releases under the seL4 foundation. Cheers, Gerwin

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seL4 MCS flavour with RISCV
by David Martin 01 Jul '24

01 Jul '24

Hello, I'm trying to understand the current situation of the MCS branch. Our setup: - Microchip Polarfire SoC (1xE51 RV64IMAC + 4xU54 RV64IMAFD) We are starting to "play" with threads but when coming to the scheduling of them, I'm a bit lost. If I understand correctly, the latest version of seL4 (12.1.0) if compatible with RV64IMAFD, so floating point operations included. The latest MCS version (10.1.1-mcs) on the contrary is only RV64IMAC so no FPU support. I haven't seen any MR nor discussion about including that FPU support when using RISCV processors... Am I correct in here? or I am missing something? (It's not really clear to me when I read the docs to be honest) Thanks for your support. - David.

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CPU/ISA tuned specifically for seL4?
by Isaac Beckett 26 Jun '24

26 Jun '24

Hello! I recall reading about old CPUs/ISAs made for Lisp machines, with features and optimized for specifically running Lisp. And I’ve heard people discuss how current CPUs are optimized for C code and similar programming paradigms, and vice versa: C and others are optimized for those CPUs. This got me wondering, what might a CPU or instruction set designed more specifically to run seL4 look like? I’m guessing it might involve capability hardware like CHERI to accelerate seL4’s software implementation of capabilities, but what else might be relevant? Thanks, Isaac Beckett

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seL4 developer hangout reminder
by Gerwin Klein 23 Jun '24

23 Jun '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 26 Jun, 08:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Cheers, Gerwin

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Success and Effort in seL4 x86_64 Virtualbox
by thomas.j.hampton＠gmail.com 21 Jun '24

21 Jun '24

Hey; configuration is a pretty big space and I didn't see anything specific, and may have bumped into a bug along the way. Here's some details about getting seL4test working, and using the EGA driver on this platform. Here's the commits I'm on: - sel4test 95522e9 - seL4 ddeb18a01 I managed to get seL4test running in VirtualBox on a Tiger Lake chip some weeks ago, not terribly impressive, things worked pretty well, generally. - I discovered that on the platform I needed to manually set all the '*HAVE_TIMER*' flags in the code to 0 - to get the tests to succeed on VirtualBox; CMake doesn't appear to support this transformation. - a major stumbling block was that these changes were being reverted each time I re-ran CMake, under my feet. So that's pretty cool... Some further exploration I discovered that there's the pc99/ega (ega.c) driver, since I'm curious about the requirements for starting to build a custom OS on top of seL4 for this platform, and seeing it run on the hardware in front of me (again, a Tiger Lake laptop). I spent many weeks trying to massage things into place. Reading and learning along side the bootstrap pathway; multiboot.S -> head.S -> boot_sys -> common -> char_dev ... to no avail. However I came into some time and decided to revisit the problem. - #define MULTIBOOT_GRAPHICS_TEXT 2 is an error; Multiboot1 spec has that this should be 1, instead - When I was trying to boot UEFI, this would manifest as a Protection Fault - Fixing this left the system booting, utilizing high amount of CPU, and then going quiet. - UEFI on this platform has unclear / additional requirements / doesn't actually support EGA/VGA text mode - https://www.reddit.com/r/osdev/comments/st0psl/framebuffer_output_for_multi…

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Assertion failure when booting seL4 image on x86 UEFI via Grub
by fennelfoxxo＠gmail.com 16 Jun '24

16 Jun '24

Hello all! This is my first time posting here, but I'll try to provide all the detail I can, and I'm grateful for any advice others have to fix this issue. I've been trying to boot the seL4 Hello World tutorial in QEMU with UEFI support on the x86 platform, with the help of the Grub bootloader. It seems I can load the kernel okay, but an error occurs when the kernel tries to load the rootserver: > seL4 failed assertion 'mods_end_paddr > boot_state.ki_p_reg.end' at /home/fennel/grubbuild/stacktest/sel4-tutorials/kernel/src/arch/x86/kernel/boot_sys.c:452 in function try_boot_sys From my research, it seems to be happening because grub is loading the rootserver module at a lower address than expected. These two lines from serial output during boot indeed show that the module end address is lower than the kernel end address: > module #0: start=0x751000 end=0x7954c8 size=0x444c8 name='' > Kernel loaded to: start=0x100000 end=0xc12000 size=0xb12000 entry=0x100298 When running the same hello world project using ./simulate in the build directory, the rootserver module is placed at a higher address and boots ok: > module #0: start=0xc13000 end=0xc574c8 size=0x444c8 name='images/hello-world-image-x86_64-pc99' > Kernel loaded to: start=0x100000 end=0xc12000 size=0xb12000 entry=0x100298 Does anyone know if this is a mistake in how I am compiling and building the project, my QEMU settings, or perhaps an issue with how Grub is handling loading the module? Booting from Grub should be possible in theory (https://docs.sel4.systems/Hardware/IA32.html) so any guidance is appreciated. Thank you! - Fennel STEPS TO REPRODUCE: # Contents of grub.cfg - place in current directory menuentry "Load seL4" --class os { insmod efi_gop insmod efi_uga insmod all_video set root='(hd0,gpt1)' multiboot2 /EFI/BOOT/sel4kernel module2 /EFI/BOOT/sel4rootserver } # End of grub.cfg # Compile Grub 2.06 from source to ./grub-2.06 wget https://ftp.gnu.org/gnu/grub/grub-2.06.tar.gz -O grub.tar.gz # Download grub source tar -xvzf grub.tar.gz -C ./ && rm grub.tar.gz # Unzip and remove original file cd grub-2.06 && ./autogen.sh && ./configure --target=x86_64 --with-platform=efi && make # Configure & compile # Install, configure, and compile hello-world seL4 project to ./sel4-tutorials mkdir sel4-tutorials cd sel4-tutorials repo init -u https://github.com/seL4/sel4-tutorials-manifest # Install tutorials repo sync ./init --plat pc99 --tut hello-world cd hello-world_build cmake -DCMAKE_TOOLCHAIN_FILE=../kernel/gcc.cmake -DKernelHugePage=OFF -G Ninja . # Disable huge page requirement ninja # Create final image as disk.img mkdir EFI EFI/BOOT grub-2.06/grub-mkimage -d grub-2.06/grub-core -o EFI/BOOT/BOOTX64.EFI -O x86_64-efi -p "" configfile fat part_gpt gzio multiboot video efi_gop efi_uga normal chain boot multiboot2 all_video cp sel4-tutorials/hello-world_build/images/kernel-x86_64-pc99 EFI/BOOT/sel4kernel cp sel4-tutorials/hello-world_build/images/hello-world-image-x86_64-pc99 EFI/BOOT/sel4rootserver cp grub.cfg EFI/BOOT/grub.cfg dd if=/dev/zero of=disk.img bs=1M count=35 # 35MB is just about the smallest FAT32 partition possible mformat -i disk.img@@2048s -v "EFI SYSTEM" -F # Create fat32 partition 2048 sectors in mcopy -i disk.img@@2048s -s EFI :: parted -s disk.img mklabel gpt mkpart '"EFI SYSTEM"' fat32 2048s 100% set 1 esp on # Create partition entry for ESP # Run in QEMU (most of these arguments are copied from the seL4 ./simulate script - replace OVMF path with your path to OVMF_CODE.fd for UEFI boot) qemu-system-x86_64 -cpu Nehalem,-vme,+pdpe1gb,-xsave,-xsaveopt,-xsavec,-fsgsbase,-invpcid,+syscall,+lm,enforce -serial mon:stdio -m size=512M -drive if=pflash,format=raw,readonly=on,file=PATH_TO_OVMF_CODE.fd -drive file=disk.img

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Unblocking the caller of seL4_Call when the receiver is killed
by Arya Stevinson 13 Jun '24

13 Jun '24

Hello, I'll give a brief introduction since this is my first message here. I'm an undergraduate research assistant at the University of British Columbia, and I'm working with Margo Seltzer (https://www.seltzer.com/margo/) in the Systopia Lab. I'm helping with development of Sid Agrawal's (https://sid-agrawal.ca/) project built on seL4. I'm trying to determine what is the correct way to handle this situation: 1. Process 1 makes an seL4_Call to an endpoint that Process 2 is listening on. 2. Process 2 receives the message, and since we are running in non-MCS kernel, it will get a reply capability in its TCB. 3. Process 2 dies, for whatever reason, before it can reply to Process 1. If we wanted to unblock Process 1, what would be the correct approach? - I can use seL4_CNode_SaveCaller in Process 2 as soon as it receives a message, and store the slot number in some shared memory with the root task. Then when Process 2 dies, the root task is able to move the reply capability into its own cspace and send a reply indicating an error. This is not ideal for our purpose, because we do not want Process 2 to be able to perform any operations on its own cspace, but it needs its own root cnode capability in order to perform seL4_CNode_SaveCaller. - Is seL4_Call the wrong function for this purpose? We also considered using NBRecv and considering the call a failure after some timeout period. This is also not ideal since we would lose the convenience of the Call's reply cap, etc. - Is there some other solution that we are missing? As an aside: I notice that for the MCS kernel, if the reply cap is deleted, Process 1's thread state would be moved from ThreadState_BlockedOnReceive to ThreadState_Inactive. In non-MCS kernel, it seems that the state would remain ThreadState_BlockedOnReceive? Is there a reason for this? Best, Arya

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seL4 developer hangout reminder
by Birgit Brecknell 06 Jun '24

06 Jun '24

Hi all A friendly reminder that the seL4 developer hangout is on again next week. Tue 11 Jun, 22:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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Multikernel in RISCV
by David Martin 06 Jun '24

06 Jun '24

Hello, I'm currently working with seL4 & Polarfire (RISCV) and I'm working with a single core at the moment (doing some testing and understanding how seL4 works). Polarfire has 4 cores and I'd like to start using all of them in a multikernel configuration (every hart running its own sel4 kernel). I've found the following RFC: https://sel4.atlassian.net/browse/RFC-17 where Kent McLeod has done some work (https://github.com/kent-mcleod/camkes-manifest/blob/kent/multicore2/master.…) but only for ARM. Does someone know if the same approach will be taken for RISCV? or even better, if someone has already done it? Thanks, David.

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seL4 developer hangout reminder
by Birgit Brecknell 27 May '24

27 May '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 29 May, 8:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator Sydney, Australia Mon 9-5 Wed 2-5 Fri 9-5 birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

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sel4bench grub iso
by Bengt.Lennicke＠mailbox.tu-dresden.de 24 May '24

24 May '24

Hello everyone, I am trying to create a grub iso image in order to run sel4bench on real hardware. The target architecture is x86_64 and I would prefer a grub iso because no changes to the hardware setup would be necessary then. What I did so far: I create the sel4bench images as follows mkdir sel4bench cd sel4bench repo init -u -u https://github.com/seL4/sel4bench-manifest.git repo sync mkdir build cd build ../init-build.sh -DPLATFORM=x86_64 ninja I get two elf images in the build/images directory as expected. Now in order to creat a bootable iso image i followed this guide https://www.gnu.org/software/grub/manual/grub/html_node/Making-a-GRUB-boota… Which means: mkdir -p iso/boot/grub grub-mkrescue -o grub.iso cp /path/to/kernel-x86_64-pc99 iso cp /path/to/sel4benchapp-image-x86_64-pc99 iso Then I add the grub.cfg under iso/boot/grub/grub.cfg menuentry "Load seL4 VM" --class os { multiboot /kernel-x86_64-pc99 module /sel4benchapp-image-x86_64-pc99 } There are a few lines missing from your offered grub stanza here https://docs.sel4.systems/Hardware/IA32 Mainly because I was having issues with getting it to run with them and without them I got further. Then I run grub-mkrescue -o grub.iso iso And try out the resulting iso as follows: qemu-system-x86_64 -cdrom grub.iso -nographic -enable-kvm -cpu Haswell,-vme,+pdpe1gb,+xsave,+xsaveopt,-xsavec,+fsgsbase,+invpcid,+syscall,+lm,enforce -m size=512M I get the following output: seL4 Benchmark ============== Switching to a safer, bigger stack... Setting up global fault handler... Failed to allocate object of size 140737488355328, error 1 Failed to allocate object of size 70368744177664, error 1 Failed to allocate object of size 35184372088832, error 1 Failed to allocate object of size 17592186044416, error 1 Failed to allocate object of size 8796093022208, error 1 Failed to allocate object of size 4398046511104, error 1 Failed to allocate object of size 2199023255552, error 1 Failed to allocate object of size 1099511627776, error 1 Failed to allocate object of size 549755813888, error 1 Failed to allocate object of size 274877906944, error 1 Failed to allocate object of size 137438953472, error 1 Failed to allocate object of size 68719476736, error 1 Failed to allocate object of size 34359738368, error 1 Failed to allocate object of size 17179869184, error 1 Failed to allocate object of size 8589934592, error 1 Failed to allocate object of size 4294967296, error 1 Failed to allocate object of size 2147483648, error 1 Failed to allocate object of size 1073741824, error 1 Failed to allocate object of size 536870912, error 1 Failed to allocate object of size 268435456, error 1 ipc Benchmarks ============== irquser Benchmarks ============== arch_simple_get_IOPort_cap not implemented Failed to get capability for IOPort range 0x43-0x43 PIT command failed! [Cond failed: error] Failed to init timer Benchmark failed, result 1 Register dump: rip: 0x4138a0 rsp: 0x10011640 rflags: 0x246 rax: 0x10000000 rbx: 0x10011660 rcx: 0x420c48 rdx: 0xffffffffffffffff rsi: 0x1 rdi: 0x2 rbp: 0x10011680 r8: 0x2b r9: 0x12008180c100f r10: 0x1 r11: 0x206 r12: 0x10011d88 r13: 0x10011d98 r14: 0x0 r15: 0x0 fs_base: 0x7494d0 gs_base: 0x0 [Cond failed: result == NULL] Failed to run benchmark irquser So ipc seems to run fine but irquser is not. Now I am only interested in the benchmark IPC for now. And maybe FAULT as well later. So I do not need to get irquser to run. Therefore I do the following setup again: mkdir sel4bench cd sel4bench repo init -u -u https://github.com/seL4/sel4bench-manifest.git repo sync mkdir build cd build ../init-build.sh -DPLATFORM=x86_64 and not i run ccmake . which opens a configuration screen where I can choose which benchmarks I want to include in the image. I disable everything except FASTPATH (this does not seem to be a benchmark) and IPC. I run ninja again and use the resulting images are build into an iso as stated above. Now running qemu results in this: Boot config: debug_port = 0x3f8 Boot config: disable_iommu = false Detected 1 boot module(s): module #0: start=0xa87000 end=0xd4e6a0 size=0x2c76a0 name='' Parsing GRUB physical memory map Physical Memory Region from 0 size 9fc00 type 1 Physical Memory Region from 9fc00 size 400 type 2 Physical Memory Region from f0000 size 10000 type 2 Physical Memory Region from 100000 size 1fee0000 type 1 Adding physical memory region 0x100000-0x1ffe0000 Physical Memory Region from 1ffe0000 size 20000 type 2 Physical Memory Region from feffc000 size 4000 type 2 Physical Memory Region from fffc0000 size 40000 type 2 Got VBE info in multiboot. Current video mode is 3 ACPI: RSDP paddr=0xf5b20 ACPI: RSDP vaddr=0xf5b20 ACPI: RSDT paddr=0x1ffe1550 ACPI: RSDT vaddr=0x1ffe1550 Kernel loaded to: start=0x100000 end=0xa14000 size=0x914000 entry=0x10040b ACPI: RSDT paddr=0x1ffe1550 ACPI: RSDT vaddr=0x1ffe1550 ACPI: FADT paddr=0x1ffe1404 ACPI: FADT vaddr=0x1ffe1404 ACPI: FADT flags=0x80a5 ACPI: 0 IOMMUs detected ACPI: MADT paddr=0x1ffe1478 ACPI: MADT vaddr=0x1ffe1478 ACPI: MADT apic_addr=0xfee00000 ACPI: MADT flags=0x1 ACPI: MADT_APIC apic_id=0x0 ACPI: MADT_IOAPIC ioapic_id=0 ioapic_addr=0xfec00000 gsib=0 ACPI: MADT_ISO bus=0 source=0 gsi=2 flags=0x0 ACPI: MADT_ISO bus=0 source=5 gsi=5 flags=0xd ACPI: MADT_ISO bus=0 source=9 gsi=9 flags=0xd ACPI: MADT_ISO bus=0 source=10 gsi=10 flags=0xd ACPI: MADT_ISO bus=0 source=11 gsi=11 flags=0xd ACPI: 1 CPU(s) detected ELF-loading userland images from boot modules: size=0x242000 v_entry=0x449631 v_start=0x400000 v_end=0x642000 p_start=0xd4f000 p_end=0xf91000 Moving loaded userland images to final location: from=0xd4f000 to=0xa14000 size=0x242000 Starting node #0 with APIC ID 0 Mapping kernel window is done available phys memory regions: 1 [100000..1ffe0000] reserved virt address space regions: 1 [ffffff8000100000..ffffff8000c56000] Booting all finished, dropped to user space seL4 Benchmark ============== Switching to a safer, bigger stack... Setting up global fault handler... vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 140737488355328, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 70368744177664, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 35184372088832, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 17592186044416, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 8796093022208, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 4398046511104, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 2199023255552, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 1099511627776, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 549755813888, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 274877906944, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 137438953472, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 68719476736, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 34359738368, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 17179869184, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 8589934592, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 4294967296, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 2147483648, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 1073741824, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 536870912, error 1 vka_alloc_object_at_maybe_dev@object.h:57 Failed to allocate object of size 268435456, error 1 ipc Benchmarks ============== libsel4muslcsys: Error attempting syscall 228 libsel4muslcsys: Error attempting syscall 96 JSON OUTPUT [{"Benchmark": "One way IPC microbenchmarks", "Results": [{"Function": "seL4_Call", "Direction": "client->server", "Client Prio": 254, "Server Prio": 254, "Same vspace?": true, "IPT .... All is well in the universe. Fin So the benchmark runs but now a libsel4muslcsys error is new. syscall 228 is sys_clock_gettime so I assume it is important for the benchmark and even so it is not terminating I am not sure whether the results are correct with that error. So somehow removing the other benchmarks resulted in an error in the ipc benchmark which was not there or at least not shown there when compiling with all benchmarks. When trying to find out which removal is causing the problem a variety of other problems is appearing. Do you think the musllib error is related to the missing lines in the grub.cfg? If so do you have an idea which one? Why do the different benchmarks influence each other, am I compiling it wrong? If there are information missing feel free to let me know and I will try to add them Kind regards, Bengt

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Register for the seL4 summit 2024
by Birgit Brecknell 17 May '24

17 May '24

The seL4 summit 2024 [0] will be held in Sydney, Australia, 15-17 October 2024. The seL4 summit will cover the complete seL4 ecosystem, consisting of the verified microkernel, as well as all seL4-related technology, tools, infrastructure, products, projects, and people. Tickets include: * Participation in the 3-day conference, including talks, keynotes, seL4 updates & discussions * Networking with other seL4 experts and enthusiasts * Reception and dinner Register here [1] The early bird cut-off date is 15 September 2024. Local seL4 Sydney-siders will look into organising some informal activities for Monday 14 October 2024, before the summit kicks off, for anyone who wants to join. Gernot may also organise a bush walk for the weekend before the summit. Stayed tuned for more info! [0] https://sel4.systems/Foundation/Summit/2024 [1] https://events.linuxfoundation.org/sel4-summit/ Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Loading a large sel4test image on Odroid-C4 Fails
by Linh Pham 16 May '24

16 May '24

Hello, I am running into an issue with booting up an sel4test image on the Odroid-C4. When the calculated memory bound for the sel4test-driver's ELF is around 100MB or larger, I get an asychronous data abort like so: ELF-loader started on CPU: ARM Ltd. Cortex-A55 r1p0 paddr=[c3d2000..e068117] No DTB passed in from boot loader. Looking for DTB in CPIO archive...found at c502760. Loaded DTB from c502760. paddr=[256000..261fff] ELF-loading image 'kernel' to 0 paddr=[0..255fff] vaddr=[8000000000..8000255fff] virt_entry=8000000000 ELF-loading image 'sel4test-driver' to 262000 paddr=[262000..6cd7fff] vaddr=[400000..6e75fff] virt_entry=443090 "Error" handler, esr 0xbe000011 elr: ffffffff1a4996e4 lr : ffffffff1a497654 (reloc) elr: 000000000c3d96e4 lr : 000000000c3d7654 x0 : 0000000001ad7340 x1 : 0000000000000000 x2 : 0000000006a75348 x3 : 000000000c3dfdc0 x4 : 0000000001b494c8 x5 : 000000000c3dca50 x6 : 0000000000262000 x7 : 0000000000000001 x8 : 0000000000000008 x9 : ffffffffffffffff x10: 0000000000000000 x11: 0000000000000002 x12: 00000000f4fef9e0 x13: 0000000000000001 x14: 00000000f4fef9e0 x15: 0000000000000000 x16: 0000000020000000 x17: 0000000000c0c0c0 x18: 00000000f0f3dda0 x19: 000000000c3dfff0 x20: 0000000020000000 x21: 0000000000000002 x22: 00000000f0f769c0 x23: 0000000000000002 x24: 00000000f2ff556c x25: 0000000000000000 x26: 0000000000000000 x27: 0000000000000000 x28: 00000000f0f6d380 x29: 000000000c3dfda0 Code: f94017e0 91002000 f90017e0 f94007e0 (f1001c1f) Resetting CPU ... Our sel4test image is large because we're using a static heap. Note that the relevant region from the log output is [262000..6cd7fff], the exception occurs when trying to write into memory in this range. After some investigation, writing to physical address 0x5100000 is what causes the problem. I haven't been able to find any documentation on why this physical address range can't be written to. Is this some sort of device memory region? I was able to eventually boot by changing the ELF loader to load into a much higher memory address (e.g. somewhere around 0x80000000), but I would like to have a clearer idea of the Odroid's memory layout so that I could choose an address range that is definitely safe to load the image into. Thank you, Linh

2 2

seL4 docker support for Apple Silicon
by Gerwin Klein 15 May '24

15 May '24

The seL4 development docker containers at https://github.com/seL4/seL4-CAmkES-L4v-dockerfiles now provide multi-architecture images for x86 and arm64. That means development on Apple Silicon (M1/2/3) with docker for seL4 should now work properly (including qemu) and should also be much faster than before. Intel machines should work as before. You should not need to do anything special or different to before, Docker should be pulling the correct kind of container for your architecture. This is brand new (as of today), so please check it out and report any issues you find. If you haven’t used the containers before, have a look at the README in the repository above. If you have been using them and want to make sure that the new versions are picked up: cd seL4-CAmkES-L4v-dockerfiles/ git checkout master git pull make pull_camkes_image user Enjoy! Gerwin

1 0

Re: Announcing release v0.2 of Neptune OS: a Windows NT personality for the seL4 microkernel
by Hugo V.C. 14 May '24

14 May '24

Are we talking about the same ReactOS ... ? As far I can see here: https://reactos.org/forum/ they have an active community. Try to post there. You also have this LinkedIn resource: https://www.linkedin.com/company/reactos-foundation/ Let me know if you have any problem contacting them and I'll try to help you. seL4 + ReactOS looks like a killer combination for the industry, they need to know about your work. Best, El lun, 13 may 2024 a las 15:07, Dr. Chang Liu, PhD. (<cl91tp(a)gmail.com>) escribió: > Dear Hugo, > > Thank you very much for your interest. I did try to find the ReactOS > mailing list to post this announcement in but it seems that their mailing > list has long been dead since late 2022, so I'm not sure where the main > communication channel of ReactOS development is. Perhaps you could point me > to the right place. > > Best regards, > > On Mon, May 13, 2024, 12:50 AM Hugo V.C. <skydivebcn(a)gmail.com> wrote: > >> Hats off. >> I'll test it and give my feedback. I'm very interested in your project, >> IMHO is one of the most interesting ones I have seen in years. >> >> BTW: are you in contact with ReactOS guys? Maybe would make sense to join >> efforts with them...? >> >> El dom, 12 may 2024 a las 17:40, Dr. Chang Liu, PhD. (<cl91tp(a)gmail.com>) >> escribió: >> >>> Dear seL4 community, >>> >>> I'm announcing the release of v0.2 of Neptune OS, an operating system >>> that >>> I have been developing that aims to create a Windows NT personality on >>> top >>> of the seL4 microkernel, by implementing the upper layer of the Windows >>> kernel called the NT Executive, as well as Windows kernel drivers, as >>> userspace processes under seL4. For those that remember the release of >>> v0.1 >>> two years ago and have been wondering, yes, the project is still alive. I >>> have been a bit busy with postdoc work (academia is hard!!) last year but >>> finally got a bit of free time lately to get enough work done that I >>> think >>> is interesting enough to warrant a v0.2 release. The project can be found >>> on github (https://github.com/cl91/NeptuneOS) >>> >>> The biggest feature of the v0.2 release is a (I hope) reasonably complete >>> file system stack supporting read-ahead and write-back caching, that >>> includes a FAT12/16/32 file system driver and a floppy controller driver, >>> both of which are ported over from ReactOS (but running in userspace >>> instead of kernel space). I'll explain the technical points below but you >>> can watch a short video (https://www.youtube.com/watch?v=o3FLRnkh0ic) >>> that >>> demonstrates the basic file system commands, including cd, dir, copy, >>> move, >>> del, md, and mount/umount. >>> >>> Arguably the biggest challenge for a userspace file system stack is >>> minimizing the performance penalties of the additional context switches. >>> There are radical solutions to this problem along the lines of Unikernels >>> that require linking the FS code with the applications. These solutions >>> are >>> not very practical for everyday desktop or server OSes. On traditional >>> OSes >>> there is FUSE on Linux/Unix which is often regarded as having inferior >>> performance compared to equivalent kernel-mode drivers. To some extent >>> this >>> problem is inevitable, as context switches are always more expensive than >>> function calls, no matter how much you optimize the former. However, that >>> doesn't mean we can't optimize our OS design so that the performance >>> penalties of running file systems in userspace are small enough that the >>> benefit of userspace file systems outweighs their performance cons. >>> >>> The key to this performance goal I believe is an efficient cache design. >>> Indeed, for FUSE it is possible to tune the cache parameters to >>> drastically >>> increase its performance (see [1] and the citation therein). On Neptune >>> OS >>> we cache aggressively: not only do we cache the underlying block device >>> pages, we also maintain the relationship between file regions and their >>> underlying disk regions. In other words, the primary role of the file >>> system driver is to translate an offset of a file object into an offset >>> of >>> the underlying storage device, and this relationship is cached since they >>> are not expected to change, at least for currently open files. >>> Furthermore, >>> we cache file attributes as well as the file hierarchy itself, so that >>> if a >>> process opened a file and the file system driver returned a valid handle, >>> we do not need to query the FS driver again (at least not before the >>> first >>> process closes the handle) when another process opens the same file with >>> the same attributes (because we know it exists and know about its >>> attributes). Of course, we need to be careful when things get >>> closed/deleted/moved, etc, so we need a mechanism to synchronize >>> information with the file system driver process. This is done by sending >>> messages using the seL4 IPC. >>> >>> What is amazing is the fact that despite these changes to the inner >>> workings of the NT cache manager, not to mention the fact that all >>> drivers >>> are now running in userspace, the Windows kernel driver API remains >>> largely >>> unchanged, so that it is indeed possible to port the relevant ReactOS >>> drivers to our architecture without doing too much work (I believe I >>> spent >>> three to four man-weeks worth of work porting the FAT file system >>> itself). >>> The vast majority of work is in fact removing code rather than writing >>> new >>> code, because of the simplifications of locking and other synchronization >>> issues that simply disappear when drivers run in userspace. For those who >>> are interested in knowing more about our architecture and are perhaps >>> interested in porting drivers from ReactOS, I am in the process of >>> writing >>> a book (found under the docs of the github repo) called "Neptune OS >>> Developer Guide" that explains all these things. Note this is very much a >>> work-in-progress. >>> >>> In addition to the cache manager work, in order for the file system stack >>> to function, several other system components must be implemented, most >>> notably DMA and Win32 SEH (structured exception handling). Our DMA >>> architecture supports both PCI bus mastering and the weird ISA DMA that >>> must go through the ISA DMA controller. The latter requires managing the >>> so-called "map registers" that must be shared across different ISA >>> devices. >>> Again we find that the Windows kernel API can be adapted to a seL4-based >>> userspace driver model almost straightforwardly. This is perhaps not so >>> surprising, because NT was allegedly originally designed as a microkernel >>> OS (this is inevitably an urban legend, but early NT design documents >>> refer >>> to the code beneath the NT Executive as the "microkernel", so there is >>> reason to believe). >>> >>> To summarize, what I hope is that with the design outlined above, we can >>> in >>> fact have a practical, reasonably performant userspace file system stack >>> without resorting to radical departures from traditional desktop/server >>> computing paradigms. Of course, it's ridiculous to talk about performance >>> for floppy disk controllers, so the primary goal of the next release is >>> to >>> port the ATA/AHCI hard disk drivers from ReactOS to Neptune OS, in order >>> to >>> produce a valid benchmark against equivalent kernel mode designs. Anyway, >>> if you read so far, I hope you find the work interesting (I personally >>> do!). If you have any comments, or even better if you ran the code and >>> found bugs/issues, please do open an issue in the github repo. Thank you! >>> >>> [1] >>> >>> https://medium.com/@xiaolongjiang/linux-fuse-file-system-performance-learni… >>> >>> --- >>> Dr. Chang Liu, PhD. >>> github.com/cl91/NeptuneOS >>> _______________________________________________ >>> Devel mailing list -- devel(a)sel4.systems >>> To unsubscribe send an email to devel-leave(a)sel4.systems >>> >>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 13 May '24

13 May '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 14 May, 22:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Announcing release v0.2 of Neptune OS: a Windows NT personality for the seL4 microkernel
by Dr. Chang Liu, PhD. 13 May '24

13 May '24

Dear seL4 community, I'm announcing the release of v0.2 of Neptune OS, an operating system that I have been developing that aims to create a Windows NT personality on top of the seL4 microkernel, by implementing the upper layer of the Windows kernel called the NT Executive, as well as Windows kernel drivers, as userspace processes under seL4. For those that remember the release of v0.1 two years ago and have been wondering, yes, the project is still alive. I have been a bit busy with postdoc work (academia is hard!!) last year but finally got a bit of free time lately to get enough work done that I think is interesting enough to warrant a v0.2 release. The project can be found on github (https://github.com/cl91/NeptuneOS) The biggest feature of the v0.2 release is a (I hope) reasonably complete file system stack supporting read-ahead and write-back caching, that includes a FAT12/16/32 file system driver and a floppy controller driver, both of which are ported over from ReactOS (but running in userspace instead of kernel space). I'll explain the technical points below but you can watch a short video (https://www.youtube.com/watch?v=o3FLRnkh0ic) that demonstrates the basic file system commands, including cd, dir, copy, move, del, md, and mount/umount. Arguably the biggest challenge for a userspace file system stack is minimizing the performance penalties of the additional context switches. There are radical solutions to this problem along the lines of Unikernels that require linking the FS code with the applications. These solutions are not very practical for everyday desktop or server OSes. On traditional OSes there is FUSE on Linux/Unix which is often regarded as having inferior performance compared to equivalent kernel-mode drivers. To some extent this problem is inevitable, as context switches are always more expensive than function calls, no matter how much you optimize the former. However, that doesn't mean we can't optimize our OS design so that the performance penalties of running file systems in userspace are small enough that the benefit of userspace file systems outweighs their performance cons. The key to this performance goal I believe is an efficient cache design. Indeed, for FUSE it is possible to tune the cache parameters to drastically increase its performance (see [1] and the citation therein). On Neptune OS we cache aggressively: not only do we cache the underlying block device pages, we also maintain the relationship between file regions and their underlying disk regions. In other words, the primary role of the file system driver is to translate an offset of a file object into an offset of the underlying storage device, and this relationship is cached since they are not expected to change, at least for currently open files. Furthermore, we cache file attributes as well as the file hierarchy itself, so that if a process opened a file and the file system driver returned a valid handle, we do not need to query the FS driver again (at least not before the first process closes the handle) when another process opens the same file with the same attributes (because we know it exists and know about its attributes). Of course, we need to be careful when things get closed/deleted/moved, etc, so we need a mechanism to synchronize information with the file system driver process. This is done by sending messages using the seL4 IPC. What is amazing is the fact that despite these changes to the inner workings of the NT cache manager, not to mention the fact that all drivers are now running in userspace, the Windows kernel driver API remains largely unchanged, so that it is indeed possible to port the relevant ReactOS drivers to our architecture without doing too much work (I believe I spent three to four man-weeks worth of work porting the FAT file system itself). The vast majority of work is in fact removing code rather than writing new code, because of the simplifications of locking and other synchronization issues that simply disappear when drivers run in userspace. For those who are interested in knowing more about our architecture and are perhaps interested in porting drivers from ReactOS, I am in the process of writing a book (found under the docs of the github repo) called "Neptune OS Developer Guide" that explains all these things. Note this is very much a work-in-progress. In addition to the cache manager work, in order for the file system stack to function, several other system components must be implemented, most notably DMA and Win32 SEH (structured exception handling). Our DMA architecture supports both PCI bus mastering and the weird ISA DMA that must go through the ISA DMA controller. The latter requires managing the so-called "map registers" that must be shared across different ISA devices. Again we find that the Windows kernel API can be adapted to a seL4-based userspace driver model almost straightforwardly. This is perhaps not so surprising, because NT was allegedly originally designed as a microkernel OS (this is inevitably an urban legend, but early NT design documents refer to the code beneath the NT Executive as the "microkernel", so there is reason to believe). To summarize, what I hope is that with the design outlined above, we can in fact have a practical, reasonably performant userspace file system stack without resorting to radical departures from traditional desktop/server computing paradigms. Of course, it's ridiculous to talk about performance for floppy disk controllers, so the primary goal of the next release is to port the ATA/AHCI hard disk drivers from ReactOS to Neptune OS, in order to produce a valid benchmark against equivalent kernel mode designs. Anyway, if you read so far, I hope you find the work interesting (I personally do!). If you have any comments, or even better if you ran the code and found bugs/issues, please do open an issue in the github repo. Thank you! [1] https://medium.com/@xiaolongjiang/linux-fuse-file-system-performance-learni… --- Dr. Chang Liu, PhD. github.com/cl91/NeptuneOS

2 1

seL4 multicore boot failed on arm64
by Leonid Meyerovich 10 May '24

10 May '24

Hello, I run my seL4 application on 4 core ARMv8. Recently I have developed some more application code (I mention it because file system size is increased an I believe it may change boot time) and from time to time I observed that boot process failed (stuck after the following print) calling schedule calling activate thread kernel boot done.. CPU=1 calling schedule calling activate thread kernel boot done.. CPU=2 calling schedule calling activate thread kernel boot done.. CPU=3 Booting all finished, dropped to user space calling schedule calling activate thread kernel boot done.. CPU=0 Some time I see that only 2 CPU have been booted (like CPU1 and CPU3, or CPU2 and CPU3) Last print is the last one in init_kernel() function Thanks you, Leonid

2 3

Building seL4test 12.1.0 fails on Ubuntu 22.04 (WSL2)
by Ben McCart 09 May '24

09 May '24

I have run into the following build error when running ninja to build seL4test (following instructions at: https://docs.sel4.systems/GettingStarted#setting-up-your-machine) Here is what I get for output. Any suggestions on a work-around? (Do I have the wrong version of a python tool or library?) -- [65/263] Generating circular_includes_valid FAILED: kernel/circular_includes_valid /home/dev/seL4test/build-x86/kernel/circular_includes_valid cd /home/dev/seL4test/build-x86/kernel && /home/dev/seL4test/kernel/tools/circular_includes.py --ignore kernel_all_copy.c < kernel_all.i && touch circular_includes_valid Traceback (most recent call last): File "/home/dev/seL4test/kernel/tools/circular_includes.py", line 74, in <module> sys.exit(main(args)) File "/home/dev/seL4test/kernel/tools/circular_includes.py", line 61, in main while file_stack[-1] != header: IndexError: list index out of range [66/263] Invoking muslc build system /home/dev/seL4test/projects/musllibc/src/prng/seed48.c:6:40: warning: argument 1 of type ‘short unsigned int *’ declared as a pointer [-Warray-parameter=] 6 | unsigned short *seed48(unsigned short *s) | ~~~~~~~~~~~~~~~~^ In file included from /home/dev/seL4test/projects/musllibc/src/prng/seed48.c:1: /home/dev/seL4test/projects/musllibc/include/stdlib.h:133:25: note: previously declared as an array ‘short unsigned int[3]’ 133 | unsigned short *seed48 (unsigned short [3]); | ^~~~~~~~~~~~~~~~~~ /home/dev/seL4test/projects/musllibc/src/unistd/getcwd.c: In function ‘getcwd’: cc1: warning: function may return address of local variable [-Wreturn-local-addr] /home/dev/seL4test/projects/musllibc/src/unistd/getcwd.c:9:14: note: declared here 9 | char tmp[PATH_MAX]; | ^~~ ninja: build stopped: subcommand failed.

2 2

seL4 developer hangout reminder
by Birgit Brecknell 29 Apr '24

29 Apr '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Wed 1 May, 8:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 summit: deadline extension to 29 April 2024
by Birgit Brecknell 22 Apr '24

22 Apr '24

The deadline to submit a presentation to the seL4 summit 2024 [0] has been extended by 1 week. You now have until 29 April 2024 to propose a talk [1], by uploading an abstract of one page or less to the submission portal [2]. Looking forward to receiving your proposals. We want to hear about your cool seL4 work! And spread the word! If you want to hear about specific seL4 work, ping people around you or let us know at summit(a)sel4.systems. [0] https://sel4.systems/Foundation/Summit/2024/ [1] https://sel4.systems/Foundation/Summit/2024/cfp [2] https://sel4.systems/Foundation/Summit/2024/submit Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

Question about LionsOS
by Isaac Beckett 20 Apr '24

20 Apr '24

Hello! Looking at the LionsOS website and documentation you posted, it seems like Lions is an operating system built using Microkit out of components/drivers that use the sDDF? Do I have the right shape of things in my head? Also, would sDDF drivers for a static OS like Lions (or other OS built in Microkit, since that’s what’s it’s built for) be potentially portable to other operating systems using the seL4 kernel and sDDF? Like, if I design a non-static operating system that uses sDDF drivers, could I use existing code from Lions or would I face issues with code assuming that the system’s components can’t change at runtime? Thanks, Isaac

11 26

Release 0.1.0 of LionsOS
by Ivan Velickovic 16 Apr '24

16 Apr '24

Hello all This is a message to let people know that version 0.1.0 of LionsOS has been released. LionsOS is aimed at embedded, IoT and cyberphysical systems and is designed to be formally verifiable, adaptable to a wide class of use cases in the target domain, while at the same time setting the benchmark for performance of microkernel-based operating systems. We expect to achieve all three aims by a highly modular yet ruthlessly performance-oriented design and strict adherence to the time-honoured KISS principle. LionsOS is still in its early stages but we are at the point where we have a non-trivial example system and initial documentation. You can find the website here: https://lionsos.org/ and the source code here: https://github.com/au-ts/lionsos Thanks, Ivan

1 0

One week to go to submit a talk for seL4 summit 2024
by Birgit Brecknell 15 Apr '24

15 Apr '24

One week to go to submit a talk [0] for seL4 summit 2024 [1]! If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. The seL4 Summit 2024 will be held 15-17 October 2024 at the Holiday Inn Potts Point, Sydney, Australia. The summit will be an in-person event. Registration details to follow soon. We’re looking forward to many exciting proposals! [0] https://sel4.systems/Foundation/Summit/2024/cfp [1] https://sel4.systems/Foundation/Summit/2024/ [2] https://sel4.systems/Foundation/Summit/2024/submit Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 developer hangout reminder
by Birgit Brecknell 15 Apr '24

15 Apr '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week. Tue 16 Apr, 22:00 UTC. For your local date and time please see https://sel4.systems/contact/. Zoom link: https://unsw.zoom.us/j/82640784431 Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems <mailto:birgit@sel4.systems> bbrcknl(a)gmail.com <mailto:bbrcknl@gmail.com>

1 0

seL4 docker build issues on Apple Silicon
by Mark Jones 14 Apr '24

14 Apr '24

Dear All, I’m trying to use the instructions on https://docs.sel4.systems/projects/dockerfiles/ to set up an seL4 docker build environment on an Apple Silicon Mac. I’ve actually tried this on two different machines (with small variations in the versions of macOS Sonoma, Apple Silicon, and Docker between each of the machines), but get the same result on each one. I’m hoping that other folks on this list might know how to fix this. I start by running: git clone https://github.com/seL4/seL4-CAmkES-L4v-dockerfiles.git cd seL4-CAmkES-L4v-dockerfiles make user But the make command fails with the output appended below. Any hints (including other places to post this question) would be much appreciated! Best wishes, Mark ______________ scripts/utils/check_for_old_docker_imgs.sh WARNING: Unable to check if your trustworthysystems docker images are getting a bit old! The date command did not behave as expected. Skipping the check. docker build --force-rm=true \ --build-arg=USER_BASE_IMG=trustworthysystems/camkes \ -f dockerfiles/extras.Dockerfile \ -t extras \ . [+] Building 109.7s (6/6) FINISHED docker:desktop-linux => [internal] load build definition from extras.Dockerfile 0.0s => => transferring dockerfile: 602B 0.0s => [internal] load metadata for docker.io/trustworthysystems/camkes:latest 1.4s => [internal] load .dockerignore 0.0s => => transferring context: 153B 0.0s => [1/2] FROM docker.io/trustworthysystems/camkes:latest@sha256:29206d51ef1d09bb5e1934b11a1946a13d13333ab0ff7c2ff2645ea 96.3s => => resolve docker.io/trustworthysystems/camkes:latest@sha256:29206d51ef1d09bb5e1934b11a1946a13d13333ab0ff7c2ff2645ea2 0.0s => => sha256:e943b5afb84223c55b5dfdbe2f383970021765c345c51b08fa8b9b0d4d69ccd7 9.97kB / 9.97kB 0.3s => => sha256:46cbb6e89f5727950fb43b0c4b18a28073c18ad928ccf16c6e2a9f6d708ccb35 80.82MB / 80.82MB 6.9s => => sha256:29206d51ef1d09bb5e1934b11a1946a13d13333ab0ff7c2ff2645ea2e12c65f2 1.79kB / 1.79kB 0.0s => => sha256:678186f76064904e561bbec5cc0fb200e1c7d0435dbeeaf2433d050631a132ab 6.82kB / 6.82kB 0.0s => => sha256:99046ad9247f8a1cbd1048d9099d026191ad9cda63c08aadeb704b7000a51717 31.36MB / 31.36MB 3.0s => => sha256:4f4fb700ef54461cfa02571ae0db9a0dc1e0cdb5577484a6d75e68dc38e8acc1 32B / 32B 0.8s => => sha256:be52171dda4a5d045a589cf92b25fe60ac5b74dac75bb03997d5a049d47b361e 1.15GB / 1.15GB 53.1s => => extracting sha256:99046ad9247f8a1cbd1048d9099d026191ad9cda63c08aadeb704b7000a51717 1.2s => => sha256:460c68d68ad3efcc4c324e3da3ea9a8d7ebee818d87643e78fa551c90106c218 1.19GB / 1.19GB 65.4s => => extracting sha256:e943b5afb84223c55b5dfdbe2f383970021765c345c51b08fa8b9b0d4d69ccd7 0.0s => => extracting sha256:46cbb6e89f5727950fb43b0c4b18a28073c18ad928ccf16c6e2a9f6d708ccb35 3.0s => => extracting sha256:4f4fb700ef54461cfa02571ae0db9a0dc1e0cdb5577484a6d75e68dc38e8acc1 0.0s => => extracting sha256:be52171dda4a5d045a589cf92b25fe60ac5b74dac75bb03997d5a049d47b361e 20.1s => => extracting sha256:460c68d68ad3efcc4c324e3da3ea9a8d7ebee818d87643e78fa551c90106c218 22.7s => [2/2] RUN apt-get update -q && apt-get install -y --no-install-recommends cowsay sudo 11.8s => exporting to image 0.1s => => exporting layers 0.1s => => writing image sha256:29bf5499ec09fe5c0398c5023deb519373d25d2c8ea0d3d0d964759317511415 0.0s => => naming to docker.io/library/extras 0.0s View build details: docker-desktop://dashboard/build/desktop-linux/desktop-linux/ohi6vc8w1dj06hmvvu5ocypjs What's Next? 1. Sign in to your Docker account → docker login 2. View a summary of image vulnerabilities and recommendations → docker scout quickview docker build --force-rm=true \ --build-arg=EXTRAS_IMG=extras \ --build-arg=UNAME=user \ --build-arg=UID=502 \ --build-arg=GID=20 \ --build-arg=GROUP=staff \ -f dockerfiles/user.Dockerfile \ -t user_img-user . [+] Building 0.7s (2/2) FINISHED docker:desktop-linux => [internal] load build definition from user.Dockerfile 0.0s => => transferring dockerfile: 353B 0.0s => ERROR [internal] load metadata for docker.io/library/extras:latest 0.6s ------ > [internal] load metadata for docker.io/library/extras:latest: ------ user.Dockerfile:9 -------------------- 7 | ARG EXTRAS_IMG=extras 8 | # hadolint ignore=DL3006 9 | >>> FROM $EXTRAS_IMG 10 | 11 | # Get user UID and username -------------------- ERROR: failed to solve: extras: pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed View build details: docker-desktop://dashboard/build/desktop-linux/desktop-linux/q25mw2voldchjfgf3ybhy2q0d make: *** [build_user] Error 1

2 2

Release 0.4.0 of the seL4 Device Driver Framework
by Ivan Velickovic 09 Apr '24

09 Apr '24

Hello all This is a message to let people know that version 0.4.0 of the seL4 Device Driver Framework (sDDF) has been released. The sDDF aims to provide a collection of interfaces, libraries and tools for writing device drivers for seL4 that allow accessing devices securely and with low overhead. Some may be familiar with the sDDF from previous seL4 Summit talks. Since the pre-release at the 2023 Summit, we have made significant improvements to the networking sub-system, generally rationalising interfaces and further improving performance, the Ethernet device-class interfaces are now mature. We have also introduced preliminary specs and prototype implementations for serial, I2C, block, audio and graphics device classes. You can find information about the release and the accompanying documentation here: https://github.com/au-ts/sddf/releases/tag/0.4.0 Thanks, Ivan

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Two weeks to go to submit a talk for seL4 summit 2024
by Birgit Brecknell 08 Apr '24

08 Apr '24

Two weeks to go to submit a talk [0] for seL4 summit 2024 [1]! If you’d like to submit a talk, please upload an abstract of one page or less to the submission portal [2]. The seL4 Summit 2024 will be held 15-17 October 2024 at the Holiday Inn Potts Point, Sydney, Australia. The summit will be an in-person event. Registration details to follow soon. We’re looking forward to many exciting proposals! [0] https://sel4.systems/Foundation/Summit/2024/cfp [1] https://sel4.systems/Foundation/Summit/2024/ [2] https://sel4.systems/Foundation/Summit/2024/submit -- Birgit Brecknell seL4 Foundation Project Coordinator birgit(a)sel4.systems bbrcknl(a)gmail.com

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sel4test CACHEFLUSH0001 failed
by Leonid Meyerovich 29 Mar '24

29 Mar '24

Hello, I run sel4test on the aarch64 platform. My CACHEFLUSH0001 test in sel4test failed /* Clean makes data observable to non-cached page */ *ptr = 0xC0FFEE; *ptrc = 0xDEADBEEF; test_assert(*ptr == 0xC0FFEE); test_assert(*ptrc == 0xDEADBEEF); I have tried to make to 'improve' memory/cache coherence, but the last assertion still failed /* Clean makes data observable to non-cached page */ *ptr = 0xC0FFEE; *ptrc = 0xDEADBEEF; error = seL4_ARM_Page_Clean_Data(framec, 0, PAGE_SIZE_4K); error = seL4_ARM_Page_Invalidate_Data(framec, 0, PAGE_SIZE_4K); __asm volatile("dmb sy" ::: "memory"); test_assert(*ptr == 0xC0FFEE); test_assert(*ptrc == 0xDEADBEEF); Thank you, Leonid

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Re: Only 512mb ram available on capdl-loader-image-arm-qemu-arm-virt image
by Peter Chubb 26 Mar '24

26 Mar '24

>>>>> "Daniele" == Daniele Feliciani <felicianidaniele(a)gmail.com> writes: Daniele> Hello Peter, I have the same Daniele> problem. i tried to change the guest ram value to Daniele> 0x40000000. I added set(QEMU_MEMORY "2048") in config.cmake Daniele> but I get the following errors while running : " Daniele> map_vm_memory_reservation@guest_memory.c:477 Failed to get Daniele> frame for reservation address 0x60000000" and " Daniele> vm_ram_touch@guest_ram.c:165 Failed to touch ram region: Not Daniele> registered RAM region 32 bit ARM insts not decoded" Check the size of the MMIO region. By default it uses 29 bits; for a 2G region you need 31 bits. In the devices.camkes file, in the untyped_mmios section. There's probably an entry, "0x40000000:29", try increasing this to "0x40000000:31" to get a 2^31 region. -- Dr Peter Chubb https://trustworthy.systems/ Trustworthy Systems Group CSE, UNSW Core hours: Mon 8am-3pm; Wed: 8am-5pm; Fri 8am-12pm.

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Re: Only 512mb ram available on capdl-loader-image-arm-qemu-arm-virt image
by Daniele Feliciani 25 Mar '24

25 Mar '24

It doesn't seem to work. I'm attaching the device.camkes file and the error screenshots. Il giorno lun 25 mar 2024 alle ore 10:43 Peter Chubb < peter.chubb(a)unsw.edu.au> ha scritto: > >>>>> "Daniele" == Daniele Feliciani <felicianidaniele(a)gmail.com> writes: > > Daniele> I changed the value but now i > Daniele> have the following error: > > Danielle> ./simulate: QEMU command: qemu-system-aarch64 -machine > Danielle> virt,virtualization=on,highmem=off,secure=off -cpu cortex-a53 > -nographic > Danielle> -m size=2048 -kernel > images/capdl-loader-image-arm-qemu-arm-virt > Danielle> ELF-loader started on CPU: ARM Ltd. Cortex-A53 r0p4 > Danielle> paddr=[61b07000..62ee00b7] > Danielle> No DTB passed in from boot loader. > Danielle> Looking for DTB in CPIO archive...found at 61c07c68. > Danielle> Loaded DTB from 61c07c68. > Danielle> paddr=[60242000..60243fff] > Danielle> ELF-loading image 'kernel' to 60000000 > Danielle> paddr=[60000000..60241fff] > Danielle> vaddr=[8060000000..8060241fff] > Danielle> virt_entry=8060000000 > Danielle> ELF-loading image 'capdl-loader' to 60244000 > Danielle> paddr=[60244000..6170cfff] > Danielle> vaddr=[400000..18c8fff] > Danielle> virt_entry=408d88 > Danielle> Enabling hypervisor MMU and paging > Danielle> Jumping to kernel-image entry point... > Danielle> > Danielle> Bootstrapping kernel > Danielle> Warning: Could not infer GIC interrupt target ID, assuming 0. > Danielle> available phys memory regions: 1 > Danielle> [60000000..c0000000] > ^^^^^^^^^ this is the physical memory region you have to play > with. Make the region given to the VM start at 0x60000000 > instead of 040000000 > > -- > Dr Peter Chubb https://trustworthy.systems/ > Trustworthy Systems Group CSE, UNSW > Core hours: Mon 8am-3pm; Wed: 8am-5pm; Fri 8am-12pm. >

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Reminder seL4 developer hangout
by Birgit Brecknell 25 Mar '24

25 Mar '24

Hi all A friendly reminder that the seL4 developer hangout is on next week: * Wed Apr 3, 7am UTC For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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Only 512mb ram available on capdl-loader-image-arm-qemu-arm-virt image
by skydivebcn＠gmail.com 25 Mar '24

25 Mar '24

Hi! I'm running a an aarch64 Linux guest with qemu with "qemu-system-aarch64 -machine virt,virtualization=on,highmem=off,secure=off -cpu cortex-a53 -m size=2048 (...) -kernel capdl-loader-image-arm-qemu-arm-virt". I have noticed that no matter how I set the "-m size" parameter that only 512MB are available to the Linux guest. Removing the "highmem=off" crashes the system. Ok, what is the fastest, easiest way to get a workaround to this (if possible)? and have much more RAM available to Linux guest? Best,

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next seL4 TSC meeting on Fri 22 Mar
by Gerwin Klein 20 Mar '24

20 Mar '24

The Technical Steering Committee (TSC) of the seL4 Foundation will hold its next public meting on: - Sydney: Fri, 22 Mar, 6pm - Central Europe: Fri, 22 Mar, 8am - US West Coast (LA/SF): Fri, 22 Mar, 0:00h See also the seL4 calendar feed available from here: https://sel4.systems/contact/home.pml The meeting is by Zoom, and you can join from here: https://unsw.zoom.us/j/83417411537 Anyone interested can join the meeting and listen to the discussion and request to speak, which will be granted if time permits. Only TSC members can vote. The seL4 code of conduct applies to the meeting [1]. The agenda for the meeting so far is: - action items from last meeting - RFC-17: IPI API - RFC-16: PMU (for discussion/feedback, not enough detail yet to vote) - RFC-15: Morello (for discussion/feedback, not enough detail yet to vote) - RFC-14: MCS budget limit thresholds — status? - should we remove deprecated sel4lib functions to enable verification? - steps for next seL4 release - discussion if there is time: - use GitHub discussions instead of discourse? (i.e. retire discourse?) - use GitHub for RFC process? (i.e. retire/archive JIRA?) If there are other items that I missed or you think should be on the agenda, please let me know. If we can't get to an item this time, we can still schedule another meeting. Cheers, Gerwin (TSC chair) [1]: https://docs.sel4.systems/processes/conduct.html _______________________________________________ Devel mailing list -- devel(a)sel4.systems To unsubscribe send an email to devel-leave(a)sel4.systems

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Reminder seL4 developer hangout
by Birgit Brecknell 18 Mar '24

18 Mar '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Tue Mar 19, 9pm UTC For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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Re: DIFFICULTY RUNNING SEL4TEST ON RASPBERRY PI 4 REV 1.5 4GB
by Peter Chubb 15 Mar '24

15 Mar '24

>>>>> "Mario" == Mario CUSANO <mario.cusano(a)rina.org> writes: Mario> I hope this email finds you well. I am reaching out to seek Mario> assistance regarding running sel4test on a Raspberry Pi 4 Mario> Rev1.5 4GB. seL4 is only supported at the moment on the Raspberry Pi 4B with a BCM2711. Each build of seL4 is specific to a particular SoC. The Rev 1.5 has a different SoC. I don't know if anyone has done the work to port seL4 to the Rev 1.5 Pi4, which (I think) uses a BCM2835. Peter C -- Dr Peter Chubb https://trustworthy.systems/ Trustworthy Systems Group CSE, UNSW Core hours: Mon 8am-3pm; Wed: 8am-5pm; Fri 8am-12pm.

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How would you approach supporting a new processor architecture?
by Isaac Beckett 09 Mar '24

09 Mar '24

Hello! I’m writing to ask how someone would approach porting seL4 to a new CPU architecture. For example, ppc64le/IBM Power, since those systems can be run with limited or no black box firmware blobs, they could offer stronger security under seL4 since you can audit or replace the platform firmware in many cases. There’s even an OEM manufacturing Power9 systems with this in mind. That said, I know supporting a new architecture is not trivial. New platform code would have to be written and verified, and existing userspace code for Arm and x86-64 may have to be adjusted. How does one approach something like this? Is it feasible for someone less familiar with seL4’s internals to get something quick and dirty running as a proof of concept?

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question about booting camkes Arm VMM on TX1 from SD card
by PX 09 Mar '24

09 Mar '24

Hi, all, I tried to boot the camkes arm vmm on TX1 from a SD Card, but failed. I just follow the instructions at https://github.com/seL4/camkes-vm-examples/blob/master/README.md, and do nothing new. I build the vmm image using the "../init-build.sh -DAARCH64=YES -DCAMKES_VM_APP=minimal DPLATFORM=tx1", I got the image, capdl-loader-image-arm-tx1, and copied it to a SD card. I believe this image is a binary image. On the TX1 board, I try to load it using the u-boot command: 1.mmc dev 1 2.fatload mmc 1 0x80000000 capdl-loader-image-arm-tx1 3.go 0x80000000 However, I cannot boot the guest VM. seL4 failed assertion "cap_get_capType(destSlot->cap)==cap_null_cap" Did I miss something here? Did I set the wrong load address for Tx1? Thanks,

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RISC-V Page Tables for SV39
by Jeff 09 Mar '24

09 Mar '24

Hello, I am trying to understand how the seL4_RISCV_PageTable_Map function works when working with SV39, where we have 3 page tables. The RISCV implementation doesn't have the advantage of the separate levels, so for all the page tables, we can only use the same function. However, based on the description, there are a few questions that I have: *Description:* Starting from the VSpace, map the page table object at any unpopulated level for the provided virtual address. If all paging structures and mappings are present for this virtual address, return an seL4_DeleteFirst error. It says it maps the page table object at *any unpopulated *level for the provided virtual address. What does that necessarily mean? When you attempt to map the pages, how do you differentiate between the different levels? Is it just based on the vaddr or do you have to point the vspace to one of the lower level pages? Or does vspace have to be the root page table? Thanks, Jeff

2 1

Reminder seL4 developer hangout
by Birgit Brecknell 04 Mar '24

04 Mar '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Mar 6, 7am UTC For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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RISC-V Simulation Support
by Jeffery Lim 26 Feb '24

26 Feb '24

Hello, What does the Simulation column mean in the RISC-V table in https://docs.sel4.systems/Hardware/? Does it mean that spike is the only supported platform to run qemu simulations? All the other platforms can only be run on hardware? Thanks, Jeff

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interested in participating in a survey on seL4 website and docsite structure next week?
by June Andronick (seL4 Foundation) 19 Feb '24

19 Feb '24

Hi, We are working on improvements to the seL4 website (https://sel4.systems/) and docsite (https://docs.sel4.systems/) Next week, we will conducting a survey (over a week) to gather feedback on the website and docsite structures. If you’re interested in participating, please email me at june(a)sel4.systems Thanks June

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Reminder seL4 developer hangout
by Birgit Brecknell 19 Feb '24

19 Feb '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * UTC: Tue, 20 Feb, 9pm For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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new RFCs
by Gerwin Klein 13 Feb '24

13 Feb '24

I would like to draw your attention to two new RFCs that have been proposed for discussion and later decision by the technical steering committee: RFC-17: seL4 multikernel IPI (Inter-Processor Interrupt) API https://sel4.atlassian.net/browse/RFC-17 RFC-16: Add new capability for the PMU (Performance Management Unit) https://sel4.atlassian.net/browse/RFC-16 Please comment and give feedback if you have any. The slightly older RFC-15 and RFC-14 that may benefit from further discussion (type RFC-15 or RFC-14 into the search field at the top of the page on https://sel4.atlassian.net/) Cheers, Gerwin

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SeL4 Question: Implementation of encrypted file types
by info＠wolffgames.com 12 Feb '24

12 Feb '24

Greetings SeL4 Development, My name is Marc Wolff, currently located in Portland, Oregon, USA. I'm CEO of Leyline Nexus, an R&D team primarily for game development, but also some other things. I have an implementation question for the SeL4 microkernel, and I was hoping you could point me in the right direction. Unfortunately I'm not a computer scientist and my knowledge is both self-taught and currently very limited. Right now we're focused on tabletop games, but our next development target is video games and hardware development. I see based on what I can understand from the whitesheet that SeL4 can hypervise, but I'm wondering about an idea to fully secure it on the hardware side, essentially solving one its primarily vulnerabilities. The basic idea starts with a modified risc-based CPU architecture on an FPGA (since x86 is compromised) for testing. This includes a microcode-embedded SeL4 mk with an added feature for encrypting a NEW SYSTEM of FILE TYPES. Here, all files types become a system-specific encrypted file type which presents a virtual (more common) file type externally for readability, e.g. ".doc" or ".exe". I suppose this would be at -0 privilage, since it happens in microcode and the processs would not be accessible through ASM instructions, except through dedicated query ports and flag registers. The result is that the system comes up with its own hidden and encrypted name, for example, for the .exe file type. I guess it could do this for any arbitrary file name, so long as its source code could be validated by the hyperviser (possibly modified?; it would have to do this both at runtime when executing code and when compiling). When compiling files, if the microkernel discovers exploits in the code (invalid requests, etc.), then it can simply compile it as the standard file type that could run on other systems (.exe) but not on this system - since this system only reads its own encrypted file types. If there's an existing standard output for invalid programs in SeL4 then this could modify that or be added to it for certain cases. I suppose this would entirely depend on the quality of encryption, save for reverse-engineering through decapping or something, but it seems like a potential solution for fully separating virtual memory from runtime execution. I definitely DO NOT know what I'm talking about, but from my perspective this seemed like a great way to implement copyright protection on game hardware SOC's. Maybe on the FPGA you could even do a sub-GPU within a microkernel core that was dedicated to encrypting? Maybe someone has already thought of all this before? If yes, we'd be very interested to know - as it could save us a lot of time and headaches... Best regards, Marc Marc Wolff Email: info(a)wolffgames.com Phone: 530.210.4811

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root task executable memory changed
by Leonid Meyerovich 08 Feb '24

08 Feb '24

Hello, I have a seL4 project that creates a number of processes with multiple threads. An application works fine. Every process periodically calculates the checksum of the executable segment and the system (Monitor process) keeps track that these values should be the same over the time. Some time when I change (add) some code in amu process I have an error that Monitor process prints CHECKSUM ERROR -------- Someone modified executable memory process=Startup 0x400000 8868997 last->10daf436f961b809 this->95ebd3119aee7736!!!! It always complains about the root (Startup) task. Checksum value changes every time the Startup process calculates it. The code that calculate executable segment are: typedef struct { unsigned char e_ident[EI_NIDENT]; /* Magic number and other info */ Elf64_Half e_type; /* Object file type */ Elf64_Half e_machine; /* Architecture */ Elf64_Word e_version; /* Object file version */ Elf64_Addr e_entry; /* Entry point virtual address */ Elf64_Off e_phoff; /* Program header table file offset */ Elf64_Off e_shoff; /* Section header table file offset */ Elf64_Word e_flags; /* Processor-specific flags */ Elf64_Half e_ehsize; /* ELF header size in bytes */ Elf64_Half e_phentsize; /* Program header table entry size */ Elf64_Half e_phnum; /* Program header table entry count */ Elf64_Half e_shentsize; /* Section header table entry size */ Elf64_Half e_shnum; /* Section header table entry count */ Elf64_Half e_shstrndx; /* Section header string table index */ } Elf64_Ehdr; extern char __executable_start[]; // function returns executable segment start address and size int initStartupElfSegsParams(Elf64_Ehdr *pELFHeader, uintptr_t *startAddr, uintptr_t *size) { seL4_Word phoff = pELFHeader->e_phoff; Elf_Phdr *currentPH = (Elf_Phdr *)((void *)pELFHeader + phoff); for (int i=0; i<pELFHeader->e_phnum; i++) { ZF_LOGD("ELF: p_type=%x p_flags=%x p_vaddr=%p p_memsz=%lu", currentPH[i].p_type, currentPH[i].p_flags, (void *)currentPH[i].p_vaddr, currentPH[i].p_memsz); if ( ((currentPH[i].p_type & 1) == 1) && ((currentPH[i].p_flags & 1) == 1)) // p_flags & 1 == 1 - executable { *startAddr = (uintptr_t)currentPH[i].p_vaddr; *size = (uintptr_t)currentPH[i].p_memsz / sizeof(uint64_t); return 0; } } return -1; }; initStartupElfSegsParams((Elf64_Ehdr *)__executable_start, &proc_validate_params[STARTUP_INDEX].p_addr, &proc_validate_params[STARTUP_INDEX].p_size); Any help will be appreciated. Thanks

2 6

Reminder seL4 developer hangout
by Birgit Brecknell 05 Feb '24

05 Feb '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Feb 7, 6pm For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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fault processing
by Leonid Meyerovich 27 Jan '24

27 Jan '24

I am working on fault processing. When I am a fault I am calling void sel4utils_print_fault_message(seL4_MessageInfo_t tag, const char *thread_name) from sel4libsutils library I have tested it for "page fault" condition and it works fine - I am getting seL4_Fault_VMFault fault type But in certain case I have got seL4_Fault_VCPUFault type, which is not implemented sel4libsutils library I try to process this fault similar to seL4_Fault_VMFault to get all neccessary registers, but the kernel does not have functions like seL4_Fault_VCPUFault_get_IP. What is the message format for VCPU fault? Thanks

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seL4 fault processing
by Leonid Meyerovich 25 Jan '24

25 Jan '24

My root task (root thread created by kernel) checks for fault from the other threads, which are created in root thread with badged fault_ep seL4_Word badge; seL4_MessageInfo_t messageInfo = seL4_NBRecv(init_objects.fault_cap, &badge); if (seL4_MessageInfo_get_label(messageInfo) != seL4_Fault_NullFault ) { process_fault(messageInfo, badge); } Normally I don't have any faults, but every time I have seL4_MessageInfo_get_label(messageInfo) == 4, which is not in seL4_Fault_tag enumeration type enum seL4_Fault_tag { seL4_Fault_NullFault = 0, seL4_Fault_CapFault = 1, seL4_Fault_UnknownSyscall = 2, seL4_Fault_UserException = 3, seL4_Fault_VMFault = 5, seL4_Fault_VGICMaintenance = 6, seL4_Fault_VCPUFault = 7, seL4_Fault_VPPIEvent = 8 }; Could somebody explain? Thanks,

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seL4 root task executable memory region
by Leonid Meyerovich 25 Jan '24

25 Jan '24

I assume that the code segment of the root task starts from __executable_start address. Does it point to ELF header? Or code starts directly from this address? Thank you,

1 0

seL4 fault handling
by Leonid Meyerovich 24 Jan '24

24 Jan '24

Hello, Where can I find a comprehensive description of fault message registers for every of the following faults enum seL4_Fault_tag { seL4_Fault_NullFault = 0, seL4_Fault_CapFault = 1, seL4_Fault_UnknownSyscall = 2, seL4_Fault_UserException = 3, seL4_Fault_VMFault = 5, seL4_Fault_VGICMaintenance = 6, seL4_Fault_VCPUFault = 7, seL4_Fault_VPPIEvent = 8 }; Thanks, LM

3 3

Reminder seL4 developer hangout
by Birgit Brecknell 22 Jan '24

22 Jan '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Jan 24, 8am For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

1 0

Reminder seL4 developer hangout
by Gerwin Klein 09 Jan '24

09 Jan '24

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Jan 10, 6pm For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 Cheers, Gerwin

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CAmkES VMM custom OS
by Hugo V.C. 18 Dec '23

18 Dec '23

Hi all, I'm wondering if someone could forward me to the path I must follow to achieve booting a Hermit unikernel (https://github.com/hermit-os/hermit-rs) via CAmkES VMM. I know CAmkES VMM are "virtualised Linux guests on seL4 for ARM and x86 platforms" but I think that being able to boot a Rust based unikernel opens the door to a fascinating World... (no more dependency on "fat/buggy" Linux kernel). Any help where I need to start? Does it require to modify CAmkES VMM to add such functionality? Best,

2 2

get interrupts in x86
by os.team.1992＠gmail.com 14 Dec '23

14 Dec '23

Hi I am trying to run linux OS on camkes seL4 hypervisor. The hardware I use is x86-64. But I do not receive the interrupts from the devices that I have passthrough, and Linux is managing the interrupts in the form of pooling. This problem exists at the kernel level. Where the IO/APIC settings should be applied to the system but are not applied correctly. Is this problem solved in internal versions? For example, physical interrupt 10 is defined for network hardware. Vector 58 is defined for this interval. The IO/APIC information used for this device is also specified. However, interrupts are not received correctly. (In fact, because the level trigger is set, interrupts are sent quickly, this is not true and causes a destructive effect on the performance of the guest OS)

1 0

Reminder seL4 developer hangout
by Birgit Brecknell 11 Dec '23

11 Dec '23

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Dec 13, 6pm For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

1 0

Question on TCB without SC in receiveSignal
by chenpingyuan＠xiaomi.com 05 Dec '23

05 Dec '23

Hello guys, I got confused on the implementation of receiveSignal in sel4 with MCS. When the notification status is NtfnState_Active, the kernel will try to donate the notification's schedule context to the thread by calling maybeDonateSchedContext. My confusion point is that: If the thread doesn't have a valid schedule context, the thread will not be able to execute, then how can this thread call receiveSignal to receive the signal? void receiveSignal(tcb_t *thread, cap_t cap, bool_t isBlocking) { notification_t *ntfnPtr; ntfnPtr = NTFN_PTR(cap_notification_cap_get_capNtfnPtr(cap)); switch (notification_ptr_get_state(ntfnPtr)) { .... case NtfnState_Active: setRegister( thread, badgeRegister, notification_ptr_get_ntfnMsgIdentifier(ntfnPtr)); notification_ptr_set_state(ntfnPtr, NtfnState_Idle); #ifdef CONFIG_KERNEL_MCS maybeDonateSchedContext(thread, ntfnPtr); // If the SC has been donated to the current thread (in a reply_recv, send_recv scenario) then // we may need to perform refill_unblock_check if the SC is becoming activated. if (thread->tcbSchedContext != NODE_STATE(ksCurSC) && sc_sporadic(thread->tcbSchedContext)) { refill_unblock_check(thread->tcbSchedContext); } #endif break; } }

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seL4 summit 2024: survey about location
by Birgit Brecknell 29 Nov '23

29 Nov '23

Dear seL4 friends, With the great success of the seL4 summit 2023 behind us, we are now looking at the seL4 summit 2024! This should happen around Sep/Oct 2024. We have started investigating options for the location, and we would like your feedback. We would greatly appreciate it if you could fill in this very short survey to tell us your opinion between Abu Dhabi and Sydney: https://forms.gle/LQKSHVrqLGNqV2Ld8 Please do so by Nov 22nd 2023. Feel free to forward to anyone you believe may want to attend the summit next year. Many thanks! June & Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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How to avoid priority inversion in seL4
by chenpingyuan＠xiaomi.com 29 Nov '23

29 Nov '23

Hello experts, I'm reading the code of seL4 kernel, but I got confused how seL4 could help to avoid priority inversion. seL4 itself doesn't change the priority of TCB at the kernel level, does it mean that seL4 leaves the user level to handle priority inversion? Regards Neil.

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A few questions regarding seL4
by Benjamin J. Kelly 29 Nov '23

29 Nov '23

To Whom It May Concern, My name is Ben Kelly. Myself and my partner James Briscoe - CC'd on this email - are in the beginning stages of starting a company that will host websites and web services for clients requiring high security on hardware that we control from the firmware up. We haven't decided which OS we want to use yet. Our initial goal is a customizable OS that contains only the minimum services to host a web server and nothing else. We will be evaluating the seL4 Microkernel. We're also intrigued by the possibilities of enhanced application performance and security that can be had from a unikernel approach. Is there anything that would forbid using the seL4 MicroKernel acting as a 'hypervisor/scheduler' for highly isolated and performant unikernel applications? If not, seL4 and Unikernel technology could potentially deliver the maximum amount of performance and security possible for hardware running seL4-compatible CPUs. In the following video Boyd Multerer, https://youtu.be/YG5BaoB24eA?si=TcxHq51Q5HLC0m1_ was asked the question if seL4 would "make sense on servers." Boyd replied that "I think it would but it's not something that we are targeting ... yet." He also said that "Yeah, I do think seL4 would be perfect at the bottom of the server once the multi-core thing gets figured out. But we don't need to solve that right away." Do you think seL4 is mature enough for our purpose? If we were to invest our time doing a deep dive into understanding seL4 do you know of any companies that are willing to pay for our acquired knowledge? Very Respectfully, Benjamin J. Kelly President Windsor Lake Computing LLC http://windsorlake.llc/ Sent with [Proton Mail](https://proton.me/) secure email.

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Reminder seL4 developer hangout
by Birgit Brecknell 27 Nov '23

27 Nov '23

Hi all A friendly reminder that the seL4 developer hangout is on again this week: * Sydney: Wed, Nov 29, 8am For your time zone, please see the calendar: https://sel4.systems/contact/ Zoom link: https://unsw.zoom.us/j/82640784431 cheers Birg --- Birgit Brecknell Project Coordinator, seL4 Foundation birgit(a)sel4.systems<mailto:birgit@sel4.systems> birgit.brecknell(a)unsw.edu.au<mailto:birgit.brecknell@unsw.edu.au> Mon 9am-5pm Wed 2pm-5pm Fri 9am-5pm

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How to run seL4 on FVP?
by Hesham Almatary 23 Nov '23

23 Nov '23

Hello, I can build sel4test for FVP, how do I run it there? I couldn't find any documentation on that, would be great if someone could drop a command line and any required dependencies. Regards, Hesham

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