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Question about upstream
by Harish Pillay 9v1hp 20 Sep '15

20 Sep '15

Hi. I came across seL4 yesterday and have not spent too much time on it. I have not found anything specific to my question in the FAQ yet, so I am posing it here: has the work done by seL4 been accepted upstream? If not, any reason why it has not been accepted yet? Thanks. Harish

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Roadmap and Developers Day announcements
by Gernot Heiser 16 Sep '15

16 Sep '15

Dear developers, Those of you who aren’t (yet) subscribed to announce(a)sel4.systems might have missed this: we announced - the seL4 roadmap: https://sel4.systems/pipermail/announce/2015/000007.html - the second Developers Day: https://sel4.systems/pipermail/announce/2015/000008.html Gernot ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.

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Mysterious Label Before sysenter
by Corey Richardson 16 Sep '15

16 Sep '15

For example, here: https://github.com/seL4/seL4/blob/master/libsel4/arch_include/x86/sel4/arch… What use is the label? Does it align the instruction or do other ABI-important things? -- /cmr

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x86-64
by Raymond Jennings 13 Sep '15

13 Sep '15

Does seL4 support x86-64 with 64-bit virtual address spaces?

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Adding a Rust kernel interface generator
by Corey Richardson 11 Sep '15

11 Sep '15

Hello, As part of the robigalia [0] project I must create a Rust interface to the kernel. I'm using the XML from kernel/libsel4 and have been creating a "new" generator by copying the existing Python scripts. Should I send a patch upstream once this is suitably complete, or should I maintain this completely externally? [0] - https://github.com/robigalia -- /cmr

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how to detect the number of CPUs in the system
by 杰尔米 01 Sep '15

01 Sep '15

Hi all, i want to get the number of CPUs in the system and how many cores in one CPU. how to do that? Thanks! Jeremy Li

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The pt/pd/as abstraction vs software TLBs
by Raymond Jennings 01 Sep '15

01 Sep '15

Hey, quick question. This is just hypothetical, but would making management of pagetables/pagedirectories a low level literal operation hurt seL4's portability to other architectures that might not even use page tables? I could be mistaken but I think there's some archs out there that only have software TLBs (openrisc IIRC among them) Please forgive me if I'm mistaken but my recent question about memory abstraction reminded me about this.

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sharing memory between processes
by Raymond Jennings 01 Sep '15

01 Sep '15

Is there an easy way for one task to share address space with another task directly or does it have to go through the kernel/os and be emulated? I noticed that support for mapping memory is mostly low level assignment of physical frames to virtual frames via page tables, unlike Mach which uses memory objects.

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virtual memory abstraction
by Raymond Jennings 31 Aug '15

31 Aug '15

I noticed that unlike mach, L4 does not directly manage virtual memory, but instead farms out address space, page directory, and page table capabilities to userspace and lets userspace decide what pages to map and where. Does this imply that virtual memory abstraction is userspace responsibility?

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Port I/O - Permissions Question
by Josef M. 25 Aug '15

25 Aug '15

Hi, I'm experimenting with some x86 code that involves reading from I/O ports. I noticed--much to my surprise--that I don't have to use seL4_IA32_IOPort_In8() to read from a port; my program works just as fine using the "in" assembly statement directly, without any caps. The TSS segment limit is initialized with 0x67 https://github.com/seL4/seL4/blob/master/src/arch/x86/kernel/vspace.c#L158 and the "I/O Map base address" is initialized with 0 (zero) https://github.com/seL4/seL4/blob/master/src/arch/x86/kernel/vspace.c#L43 I believe the result is that ring 3 programs can access I/O port addresses below 0x388 (0x67 * 8) without triggering a protection violation. So my question is: Shouldn't capabilities be required for all ports? Or what what is the reason or motivation behind this? Thanks, Josef

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