- Devel - lists.sel4.systems

Virtio on camkes-vm
by Robert VanVossen 08 Dec '16

08 Dec '16

Hello, We are looking to add another virtio device to camkes-vm for guests to use. I have been looking through the code at how virtio_net works and I have a pretty decent understanding of how it is configured and used. I have a few design/philosophical questions though. 1. Was any of this (libethdriver, libpci, Ethdriver component, virtio_net.c, virtio_emul.c) ported from somewhere else, or was it all written from scratch? 2. Why is components/Init/src/virtio_net.c used in conjunction with vm0_config.init_cons instead of just using the VMNet templates? 3. Looks like pci handling was decoupled from drivers like libethdriver and it is left up to the VM Init component to configure PCI. What is the reason for that? 4. Virtio_emul.c appears to be the layer that actually provides the virtio interface to the VM. Would it make more sense to make this more generic to cover more devices, or should new emulation files be created for each device? Thanks, Robbie VanVossen

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Huge kernel images no more
by Jeff Waugh 06 Dec '16

06 Dec '16

Hurrah, I was curious about the huge kernel images, and had it on my list to poke at. Adrian's changes merged last night sorted it: x86: Explicitly declare adress of .phys.bss x86: Add BSS regions for BOOT and PHYS code Simulation debug x86_64 image is down from 7.1M to 1.1M. That's more like it! Nice! :-) Thanks, Jeff

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Bitcoin on seL4?
by Carl Dong 02 Dec '16

02 Dec '16

Hi all, I recently acquired a BD-SL-I.MX6 and will be tinkering with it to install seL4. A major use case for me is if I could run [bitcoind](https://en.bitcoin.it/wiki/Bitcoind) or at least [vanitygen](https://en.bitcoin.it/wiki/Vanitygen) on seL4. I'm very new to the system, but is there a relatively easy way of cross-compiling said software for seL4? Would love to spend some time learning. Cheers, Carl Dong accounts(a)carldong.me

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seL4 Memory Management
by Mark Reus 01 Dec '16

01 Dec '16

Hi I have been going through some of the research papers about seL4. I wanted to understand the security features in the memory management. I am a little confused, hope someone can I help me. Quote from the paper "Finally, the kernel ensures that each physical frame mapped by the MMU at a useraccessible address is of the Frame object type. These Frame objects contain no kernel data and since they cannot overlap with other typed objects, direct user access to kernel data is not possible" I understand that seL4 promotes isolation between processes and no allocation is done by the kernel itself rather it is done by user level manager. Since we use untyped memory and we retype them, there is no overlap of objects. The user level resource managers can access both the kernel memory and other memory as well because they have capabilities to both. What exactly in the above quote causes the isolation of user level memory with kernel memory. I am of the notion that the kernel allocated objects are still accessible and can be modified to point to some other memory? Am I misunderstanding something? Regards Mark

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Good C, bad C, verifiable C
by Jeff Waugh 30 Nov '16

30 Nov '16

Howdy, Is there a guide to the dos and don'ts of C according to the seL4 verification process? I kinda remember reading a quick summary somewhere, but can't find it on the wiki. Maybe I read it in one of the papers? I certainly remember reading the moral equivalent of "lol no strings". ;-) Thanks, Jeff

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contiguous physical memory allocation for seL4
by PX 30 Nov '16

30 Nov '16

Hi, all I want to allocate a contiguous physical memory block (larger than a physical page) and map it to contiguous virtual addresses in the vspace, what's the best way to do it? Are there existing libraries allowing me to do that? thanks Peng

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First International seL4 Workshop
by Gernot.Heiser＠data61.csiro.au 29 Nov '16

29 Nov '16

Hey seL4 community! We’d like to invite you to participate in the inaugural seL4 Workshop. Given the growth in the community we are starting an annual seL4 workshop where we can come together to share and learn what is being done with seL4. Unlike the previous developers days, the focus is much more on what is happening with seL4 and what interesting things are being done using seL4 rather than a learning or tutorial event. We’d like participants to join and: - present what they are doing with seL4 - demonstrate seL4-based projects - give tutorials on aspects of seL4 or tools, libraries, environments for working with seL4 - show results or progress of verification work involving seL4 - discuss interesting challenges (and possible solutions) they’ve encountered when using seL4 - discuss visions for the future of seL4 and high-assurance systems This workshop will take place on Thursday December 15, 2016 (and may be extended to December 16th if there is enough demand) in Malibu, CA, USA. Note that you are welcome to attend even if you do not present anything. Please register participation at: https://sel4.systems/Community/Devdays/ Participation is free, and we may be able to provide students with financial assistance for travel. This workshop is sponsored by the Center for Secure and Resilient Systems at HRL Laboratories, LLC, and by Data61. Gernot for the Data61 Trustworthy Systems Team

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Re: [seL4] Timer for Performance Measurement
by Kofidoku.Atuah＠data61.csiro.au 29 Nov '16

29 Nov '16

?Hey Andrew, Sorry I took so long to get back to you: we have a benchmarking suite, seL4Bench (https://github.com/seL4/sel4bench/blob/master/apps/ipc/src/main.c) which should have userspace timers and precise timestamps available for most platforms. As I understand, you will just have to write a new microbenchmark of your own, and import your library, and then insert calls to the relevant timestamp counter functions (https://wiki.sel4.systems/Benchmarking%20guide)? Kofi Doku Atuah Kernel engineer DATA61 | CSIRO E kofidoku.atuah(a)data61.csiro.au www.data61.csiro.au CSIRO's Digital Productivity business unit and NICTA have joined forces to create digital powerhouse Data61 ________________________________ From: Devel <devel-bounces(a)sel4.systems> on behalf of Andrew Mine <secondmine(a)gmail.com> Sent: 04 November 2016 16:30 To: devel(a)sel4.systems Subject: [seL4] Timer for Performance Measurement Hi Is there any inbuilt library to get the time like get_time in seL4? I want to measure IPC performance and overheads for my tasks. Regards Andrew

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Re: [seL4] how to get timing information on seL4 user space
by Kofidoku.Atuah＠data61.csiro.au 29 Nov '16

29 Nov '16

??Hi Peng, Well, an atomic counter would suffice, and if you need to secure the counter, you could wrap it around with a server. You either need a hardware upcounter, or else a periodic event-timer that you can use to emulate a hardware upcounter; from there, you just use your upcounter for your jiffies. Libplatsupport has userspace timer drivers for most platforms we support: https://github.com/seL4/util_libs/tree/master/libplatsupport? Kofi Doku Atuah Kernel engineer DATA61 | CSIRO E kofidoku.atuah(a)data61.csiro.au www.data61.csiro.au CSIRO's Digital Productivity business unit and NICTA have joined forces to create digital powerhouse Data61 ________________________________ From: Devel <devel-bounces(a)sel4.systems> on behalf of PX <seawolf.peng(a)gmail.com> Sent: 29 November 2016 08:27 To: devel(a)sel4.systems Subject: [seL4] how to get timing information on seL4 user space Hi, all I want to get number of ticks, similar to jiffies in Linux, in the ARM seL4 user space. How can I do it? Are there existing libraries I can use? If not, what's the best way to implement it? thanks Peng

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how to get timing information on seL4 user space
by PX 28 Nov '16

28 Nov '16

Hi, all I want to get number of ticks, similar to jiffies in Linux, in the ARM seL4 user space. How can I do it? Are there existing libraries I can use? If not, what's the best way to implement it? thanks Peng

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