users March 2020

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10 participants
10 discussions

depot_query: segmentation in _query_blueprint?
by Roman Iten 14 Apr '20

14 Apr '20

Dear Genodians I'm lost and would appreciate some inspiration on how to further debug a problem in a scenario that is similar to `run/depot_query`. My scenario seems to work fine on x86_64 but on 32-bit ARM (base-linux) the `depot_query` component segfaults. Well, it doesn't always segfault but it seems to depend either on the `depot.tar` or the `deploy.config` or both. However, the `deploy.config` and `depot.tar` don't need to change much: only the depot user or the package version may vary. The segfault occurs in `Depot_query::Main::_query_blueprint(...)` when accessing the `node` parameter that has been instantiated by the class `File_content` when calling the lambda. I also need to mention that the segfault reproducibly occurs at the same "to be deployed" runtime (pkg/chroot) - at least for a given `depot.tar` / `deploy.config`. Other, much larger runtime files (~9k) have been processed successfully prior that in `pkg/chroot`. I'm aware that this is a rather vague description and therefore tried to provide a modified the `run/depot_query.run` so it uses my `deploy.config` and `depot.tar`. But no luck, I can't reproduce the problem this way... Has anyone an idea what could possibly lead to a "corrupt" instance of `Xml_node`? Or how to test hypotheses like a stack overflow, ...? Thanks, Roman

3 6

Interesting idea to ask
by Lonnie Cumberland 02 Apr '20

02 Apr '20

Hi All, Hope that everyone is well and safe from the COVID-19 virus these days. I have been watching Genode, Muen, and especially NOVA for a number of years and I have an idea that I would like to get your opinion/comments on regarding its potential as well as if it has a beneficial point to it. I would like to take and build up a system based on the MuenSK with NOVA, and Bhyve while also possibly adding the Sculpt OS GUI into the mix for a nice basis for a hypervisor. I was thinking that the layers could be (bottom to top) 1. MuenSK ---- Provides Separation Kernel for real hardware configuration 2. NOVA Hypervisor ---- Provides virtualization of the real hardware provided by the SK 3. Bhyve --- Provides the VMM for each instance given by NOVA Of course, there are other things to be included but this is just the base that I am working towards. Do you see an advantage to something like this? About the only close Virtualizing Separation Kernel that I have come across is the LynxSecure Separation Kernel Hypervisor ( https://www.lynx.com/products/lynxsecure-separation-kernel-hypervisor) but I would like to build an open sourced version. Any thoughts, suggestions, or comments? Cheers, Lonnie

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Uncaught exception when throwing within with_libc lambda
by Sid Hussmann 30 Mar '20

30 Mar '20

Dear Genodians, I just stumbled across a not so obvious characteristic of the with_libc lambda. Not so obvious to me, at least. If I run following code snipped, it will result in a "Error: Uncaught exception of type 'Genode::Exception'": ``` try { Libc::with_libc([&] () { throw Genode::Exception(); }); } catch (...) { Genode::log("caught libc exception"); } ``` I didn't find any documentation regarding the with_libc lambda in combination with exceptions. Is this expected behavior? What would be the right pattern to forward the exception to a pure Genode environment e.g. across RPC boundaries? I could think of following pattern: ``` bool libc_exception_thrown = false; Libc::with_libc([&] () { try { throw Genode::Exception(); } catch (...) { Genode::log("caught libc exception"); libc_exception_thrown = true; } }); if (libc_exception_thrown) { throw My_rpc_exception(); } ``` However, it does not look like the most elegant solution... Cheers, Sid

2 1

Quotas for VFS plugins
by Pirmin Duss 20 Mar '20

20 Mar '20

Hello Genodians We have a VFS component that provides a RAM file system to an untrusted component. If this component writes a file too large the VFS issues a resource request and is blocked. We would like to add file system quotas to in order for the VFS to be able to limit the size components can write. The idea is to add this to all plugins for which it makes sense. Has there already somebody started some work in this direction and what are the general thoughts about it? Regards, Pirmin

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Announcement: Sculpt OS version 20.02 released
by Norman Feske 10 Mar '20

10 Mar '20

Today, we made the Sculpt OS version 20.02 available! >From the official news announcement at genode.org: Version 20.02 of the Sculpt operating system revisits the administrative user interface for a more intuitive and logical user experience. With the release of Sculpt version 20.02, we follow our mission [1] to make Sculpt OS easier to approach. In particular, we identified the reliance on a command-line interface as a potential barrier of entry [2]. As Sculpt OS is not a Unix-like system, it should not require any Unix know-how from the user. To relieve users from this burden, Sculpt 20.02 introduces a custom graphical file browser and editor that can be used for interactively inspecting and tweaking the state of the system. The traditional command-line interface is still present as a fallback for advanced tasks though. The updated manual [3] goes into detail about the use of the new system. Thanks to the work of seasoned Genode developers, many software packages are already available for the new version. These include virtual machine monitors like VirtualBox, performance-monitoring tools, GUI components, Genode's custom Unix runtime, and several applications and games. In particular, the software depots offered by alex-ab, cnuke, and skalk are worth exploring. The ready-to-use system image for version 20.02 can be obtained from the Sculpt download page [1]. [1] https://genode.org/about/road-map [2] https://genodians.org/nfeske/2020-01-06-pending-sculpt-ui [3] https://genode.org/documentation/articles/sculpt-20-02 [4] https://genode.org/download/sculpt I wish you a lot of fun with the new version. To get inspiration about the various new things to try at home, you may enjoy my recent live demo of the system presented at FOSDEM: https://fosdem.org/2020/schedule/event/uk_sculpt/ Cheers Norman -- Dr.-Ing. Norman Feske Genode Labs https://www.genode-labs.com · https://genode.org Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

1 0

Hack'n'Hike 2020 is coming closer
by Martin Stein 10 Mar '20

10 Mar '20

Hi Genodians, Please keep in mind that our annual Hack'n'Hike gathering takes place in 2 months! It's the perfect event for getting in touch with other Genode enthusiasts and pushing forward your own Genode project in a cozy environment. If you'd like to join us this year, please send me a mail! Hack'n'Hike 2020 Github issue with all information around the event: https://github.com/genodelabs/genode/issues/3349 Cheers, Martin

2 1

java execution time
by Duss Pirmin 06 Mar '20

06 Mar '20

Hello Genodians I have a JAVA application that I execute on request by starting it in a sub init. When debugging why it takes about 6 seconds on x86_64 to handle a request I made the discovery that when Java is included via `import_from_depot` in the runs script, that the execution time goes down to under one second. But when it is included via the depot mechanism, the execution is slow. In my tries to speed up I modified the JDK package to take the content of the `classes.tar` from a ram_fs where I extracted the file to. But this did not improve the execution time in a significant way. I did this tests on sculpt. Has someone an idea what causes this increases in execution time and if there could be a way to reduce it? Regards, Pirmin

2 1

Booting large images on iMX.8-evk board
by Chris Hofer 06 Mar '20

06 Mar '20

Hi everyone, I recently wanted to test the Armv8 virtualization introduced in the 19.11 release on hardware. I ran into a limitation of the preinstalled u-boot on the i.MX8-evk board. After I loaded the uImage to a reasonable address (e.g. 0x60000000), I executed it with bootm 0x60000000. However, the preinstalled u-boot refused to execute it, since a config-parameter (CONFIG_SYS_BOOTM_LEN) limits the max. size of a bootable image and mine was too large. Stefan confirmed this issue and pointed me to position [1] in the release notes 20.02; it shows how to build a modified u-boot version without this (and other) limitation(s) and flash it to an SD card. Once u-boot is on the card, one may have to change the default boot-mode of the board from internal flash to SD card, by changing the boot mode pads on the board according to [2]. I just wanted to share this with you, in case you run into the same issue. Best, Chris Hofer [1] https://genode.org/documentation/release-notes/20.02#USB_and_Input [2] https://community.nxp.com/docs/DOC-343178

2 1

Goa introduction breaks
by Guido Witmond 04 Mar '20

04 Mar '20

Hi Norman, I'm running the goa Hello-example from the genodians page https://www.genodians.org/nfeske/2019-11-25-goa However, I got this error at the goa run step: $ goa run Error: runtime lacks a configuration You may declare a 'config' attribute in the <runtime> node, or define a <config> node inside the <runtime> node. I fixed it by adding a <config /> node in pkg/hello/runtime. ie: <runtime ram="1M" caps="100" binary="hello"> <config /> ... You might want to update the genodians page so it keeps working for others. Cheers, Guido.

2 1

Sculpt for slides presentation
by Roman Iten 03 Mar '20

03 Mar '20

Hello Norman Thanks for the inspiring Talk about the new Sculpt version. During this talk, you switched between the leitzentrale, runtime and slides layers. I tried to do the same, but failed. I can show a PDF using pkg/pdf_view by routing it - for example - to "themed wm" or "background". How can I use the "slides" layer and how do I can make sure the PDF is shown with "optimal" zoom level (page with/height)? How can I toggle the slides layer on and off? Thanks, Roman

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users March 2020