October 2019 - Devel - lists.sel4.systems

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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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

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Questions about Memory Management in seL4
by Daniel Wang 19 May '23

19 May '23

Hi all, Sorry to bother, I have some basic questions about seL4 memory management. Can someone help me? 1. where is the kernel’s address space? I know there are basically three methods: a) separate virtual address space, e.g. through changing page tables on entry into privileged mode to access b) physical space, e.g. through disable automatic hardware translation of virtual addresses on entry into privilege mode c) privilege region in each process’s virtual address space, e.g. through page table to map kernel address into use-mode process. My question is which of this is being used by seL4 microkernel? 2. Objects like CSpace, VSpace, CNode, TCB, Endpoint, etc. are called kernel objects, but it seems all dynamically allocated in thread running/creating time. Are those objects (e.g. Figure 3.3 in seL4 manual) in kernel space or in user space? 3. I read that after the kernel boot up, it passes all resources, untyped memory to the first thread. Are those untyped memory physical memory or virtual memory in a single page? The reason I ask is I’m learning the code of the UNSW AOS project (two of the assignment projects are implementing frame and papers). I’m confused that before the implementation of frames and pages what kind of memory is passed to the the first thread? I saw int AOS project, it uses ut_table_init(), ut_steal_mem(), I wonder what kind of memory it operates on? Thanks -Dan

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Is there a "modern" seL4 manifest/configuration that is known to run on CMA34CR?
by Nogin, Aleksey 24 Nov '19

24 Nov '19

Unless I am looking in the wrong place, all the CMA34CR support was removed in https://github.com/seL4/camkes-vm/commit/aab3478acc4705a3161f5bf59625f7c96a…. Is there something that remains? If not, what would be the best starting point to try to port a demo running on CMA34CR board from an old (early 2017) version of the sel4/camkes/etc to a recent stable release (e.g, 10.1.1)? Thanks. Aleksey CONFIDENTIALITY NOTICE: The information transmitted in this email, including attachments, is intended only for the person(s) or entity to which it is addressed and may contain confidential, proprietary and/or privileged material exempt from disclosure under applicable law. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this message in error, please contact the sender immediately and destroy any copies of this information in their entirety.

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Fwd: port sel4 to RK3308(quad cortex-a35)
by Yun Zhou 22 Nov '19

22 Nov '19

---------- Forwarded message --------- 发件人： Yun Zhou <shiny725829(a)gmail.com> Date: 2019年10月25日周五下午9:52 Subject: port sel4 to RK3308(quad cortex-a35) To: <devel-owner(a)sel4.systems> Dear sel4 Experts How are you I found some information about sel4, and sel4 is great microkernel OS, i want port sel4 to RK3308(quad cortex-a35, GICv2) for real time audio signal processing. Form the Tutorials I found sel4 just support cortex-a53, I would like to ask does sel4 support cortex-a35 SMP mode. and because our application is real time audio processing so system delay must lower than 3ms and hard real-time determinism. Will sel4 support real-time signal processing? Looking forward to your reply Thanks &Kind regards Yun

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releasing confidentiality
by Michael Neises 15 Nov '19

15 Nov '19

Hi, I know that seL4 provides confidentiality, which is described as a property that "means that data cannot be read without permission." Given this wording, I wonder if it is not possible to revoke those permissions in certain cases. In particular, I would like for one camkes component to be able to perform runtime measurements, such as heap analysis, on another component. Or even better, I would like for a component to be able to perform runtime measurements on a program running within the camkes linux vm. Is such a feat possible? Best, Michael Neises

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Fwd: camkes vm question
by Michael Neises 15 Nov '19

15 Nov '19

Hello, In my system, sel4 is loaded by u-boot from an sd card that contains only an ELF image. I would like to store some sensitive data in plaintext for use in a non-vm component, but I worry that it can be read from the ELF image. Can this sd card data be accessed from within a linux vm instance? Or otherwise, is it certain that the vm cannot access this data? Best, Michael Neises

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TLB issue
by Stefan Kalkowski 15 Nov '19

15 Nov '19

Dear sel4 community, yesterday I've started to develop a low-level platform test to stress several multi-processor aspects on top of the Genode API. Thereby, I've recognized that on sel4/x86_64 the TLB is practically not always cleaned properly in SMP systems. The test spawns threads of one protection domain on each available cpu. Each thread accesses one of the first words of a shared dataspace. Afterwards the main thread on CPU 0 detaches and destroys the dataspace. Unfortunately, the threads on other CPUs still successfully access the corresponding memory instead of triggering a fault. To be able to reproduce the problem, you might investigate the simple test case here: https://github.com/skalk/genode/commit/2d2d7f982555f551227ad5dcbf9df46705d7… My colleague Alexander Boettcher already investigated the problem in part, and might share his insights with you. Best regards Stefan -- Stefan Kalkowski Genode labs https://github.com.skalk | https://genode.org

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Re: [seL4] Devel Digest, Vol 65, Issue 24
by abdi mahmud haji 31 Oct '19

31 Oct '19

i am working on sel4-tutorials for the first time .i setup my machine accordingly and then when i trying to generate the tutorials like this "./init --tut hello-world" i keep getting an error message and dont know what to do or how to fix it . the error was like bellowing =================================================== abdi@abdi-HP-P-PC:~/sel4-tutorials-manifest$ ./init --tut hello-world loading initial cache file ../settings.cmake CMake Error: Error: generator : Ninja Does not match the generator used previously: Unix Makefiles Either remove the CMakeCache.txt file and CMakeFiles directory or choose a different binary directory. Traceback (most recent call last): File "./init", line 96, in <module> File "./init", line 85, in main File "/home/abdi/sel4-tutorials-manifest/projects/sel4-tutorials/common.py", line 107, in init_directories return _init_build_directory(config, initialised, build_directory, tute_directory, output, config_dict=config_dict) File "/home/abdi/sel4-tutorials-manifest/projects/sel4-tutorials/common.py", line 75, in _init_build_directory return sh.cmake(args + ['..'], _cwd=directory, _out=output, _err=output) File "/home/abdi/.local/lib/python3.6/site-packages/sh.py", line 1427, in __call__ return RunningCommand(cmd, call_args, stdin, stdout, stderr) File "/home/abdi/.local/lib/python3.6/site-packages/sh.py", line 774, in __init__ self.wait() File "/home/abdi/.local/lib/python3.6/site-packages/sh.py", line 792, in wait self.handle_command_exit_code(exit_code) File "/home/abdi/.local/lib/python3.6/site-packages/sh.py", line 815, in handle_command_exit_code raise exc sh.ErrorReturnCode_1: RAN: /home/abdi/.local/bin/cmake -DCMAKE_TOOLCHAIN_FILE=../kernel/gcc.cmake -G Ninja -DTUT_BOARD=pc -DTUT_ARCH=x86_64 -DTUTORIAL_DIR=hello-world82varrcf -C ../settings.cmake .. STDOUT: STDERR: ====================================================================== is there someone who suggests what i should do please. thanks On Sun, Oct 27, 2019 at 4:00 AM <devel-request(a)sel4.systems> wrote: > Send Devel mailing list submissions to > devel(a)sel4.systems > > To subscribe or unsubscribe via the World Wide Web, visit > https://sel4.systems/lists/listinfo/devel > or, via email, send a message with subject or body 'help' to > devel-request(a)sel4.systems > > You can reach the person managing the list at > devel-owner(a)sel4.systems > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Devel digest..." > > > Today's Topics: > > 1. Re: releasing confidentiality > (Heiser, Gernot (Data61, Kensington NSW)) > 2. Fwd: port sel4 to RK3308(quad cortex-a35) (Yun Zhou) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 26 Oct 2019 03:07:23 +0000 > From: "Heiser, Gernot (Data61, Kensington NSW)" > <Gernot.Heiser(a)data61.csiro.au> > To: "devel(a)sel4.systems" <devel(a)sel4.systems> > Subject: Re: [seL4] releasing confidentiality > Message-ID: <5FEA58C5-9011-49B7-9790-28B4B54849EF(a)data61.csiro.au> > Content-Type: text/plain; charset="utf-8" > > On 26 Oct 2019, at 08:00, Michael Neises <neisesmichael(a)gmail.com> wrote: > > > > Hi, > > > > I know that seL4 provides confidentiality, which is described as a > property that "means that data cannot be read without permission." Given > this wording, I wonder if it is not possible to revoke those permissions in > certain cases. In particular, I would like for one camkes component to be > able to perform runtime measurements, such as heap analysis, on another > component. Or even better, I would like for a component to be able to > perform runtime measurements on a program running within the camkes linux > vm. Is such a feat possible? > > Hi Michael > > seL4’s confidentiality (and other security) enforcement means that the > kernel guarantees that you can only access objects to which you have been > given explicit permission (in the form of a capability). How those > permissions are allocated is a matter of policy, the kernel doesn’t care, > it only enforces. > > In particular, it is totally possible in seL4 to give one component access > to another component’s address space, that’s for the user-level policy > framework to decide. > > Whether the present CAmkES framework supports this is a different > question, which I’ll leave to someone who’s more up to date with CAmkES > details. > > Gernot > > > ------------------------------ > > Message: 2 > Date: Sat, 26 Oct 2019 10:35:50 +0800 > From: Yun Zhou <shiny725829(a)gmail.com> > To: devel(a)sel4.systems > Subject: [seL4] Fwd: port sel4 to RK3308(quad cortex-a35) > Message-ID: > <CAHNKqcxb7ws3MD=- > nwJka6HKEcA4hXZipJv0vdsStetJjxP-yg(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > ---------- Forwarded message --------- > 发件人： Yun Zhou <shiny725829(a)gmail.com> > Date: 2019年10月25日周五下午9:52 > Subject: port sel4 to RK3308(quad cortex-a35) > To: <devel-owner(a)sel4.systems> > > > Dear sel4 Experts > How are you > I found some information about sel4, and sel4 is great microkernel OS, i > want port sel4 to RK3308(quad cortex-a35, GICv2) for real time audio signal > processing. Form the Tutorials I found sel4 just support cortex-a53, I > would like to ask does sel4 support cortex-a35 SMP mode. and because our > application is real time audio processing so system delay must lower than > 3ms and hard real-time determinism. > Will sel4 support real-time signal processing? > Looking forward to your reply > > Thanks &Kind regards > Yun >

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The seL4 Foundation is coming!
by Heiser, Gernot (Data61, Kensington NSW) 25 Oct '19

25 Oct '19

Re-post from announce(a)sel4.systems<mailto:announce@sel4.systems> regarding the seL4 Foundation. We’ll start recruiting members soon. Gernot Begin forwarded message: From: Announcements about seL4 -- low volume list <announce(a)sel4.systems<mailto:announce@sel4.systems>> Subject: [seL4 Announce] The seL4 Foundation is coming! Date: 25 October 2019 at 17:09:30 AEDT To: "announce(a)sel4.systems<mailto:announce@sel4.systems>" <announce(a)sel4.systems<mailto:announce@sel4.systems>> Reply-To: <announce(a)sel4.systems<mailto:announce@sel4.systems>> Dear seL4 community, With great excitement we announce that we are in the process of setting up an seL4 Foundation, similar to foundations for other open-source projects, such as Linux and RISC-V. This will form an open, transparent and neutral organisation tasked with growing the seL4 ecosystem. It will bring together developers of the seL4 kernel, developers of seL4-based components and frameworks, and those deploying seL4-based systems. Its focus will be on coordinating, directing and standardising development of the seL4 ecosystem in order to reduce barriers to adoption, raising funds for accelerating development, and ensuring clarity of verification claims. This was originally announced at the seL4 Summit in the US last month. I apologise for the delay in this posting (side-tracked with various issues). Gernot on behalf of the Trustworthy Systems team _______________________________________________ Announce mailing list Announce(a)sel4.systems<mailto:Announce@sel4.systems> https://sel4.systems/lists/listinfo/announce

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