- Devel - lists.sel4.systems

seL4 runs on Rocket Chip (RISCV/FPGA)
by Hesham ALMatary 17 Jul '15

17 Jul '15

Hi all, This is a status update of the seL4/RISC-V project. It can run now on Rocket Chip (FPGA) and jor1k (online emulator), for more details have a look at this link [1]. [1] http://heshamelmatary.blogspot.co.uk/2015/07/sel4-runs-on-rocket-chip-riscv… Thanks, -- Hesham

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Some questions about seL4 operating system
by Qing Wei 16 Jul '15

16 Jul '15

Hi, I am a beginner to seL4 as well as microkernel, and very interested in it. I think it is great in terms of its minimality and formally verified security. However, I have some questions about it, (1) How is its performance compared to other monolithic kernel, say, Linux. Could it make use of multicore, multiprocessor to enjoy the performance scalability? (2) How is its ecosystem, fox example, how to support new hardware, does it need write the driver from scratch or could it make use of Linux driver? And how to write application on it, or, could it run Linux application without modification? (3) How is its virtualization support, could it run Linux vm, and does it need any modification to the guest os? Cheers, Qing Wei

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what are these comments meaning
by Pei.XiLong(裴喜龙) 15 Jul '15

15 Jul '15

Hi, In recent seL4 commit https://github.com/seL4/seL4/commit/67d8d041de0c435a1cc59ef8c237be6e39beb1c6 , A lot of comments like these: /** AUXUPD: "(True, ptr_retyps (2 ^ (unat \<acute>userSize)) (Ptr (ptr_val \<acute>regionBase) :: cte_C ptr))" */ /** GHOSTUPD: "(True, gs_new_cnodes (unat \<acute>userSize) (ptr_val \<acute>regionBase) (4 + unat \<acute>userSize))" */ have been added into source code, What is their meaning? I don't know isablle, and just know a little about haskell. thanks! Xilong Pei Tongji University 2015/7/14

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Raspberry Pi version for learning about seL4
by Simon Apperley 14 Jul '15

14 Jul '15

Hi, I wondered if there was any news on the Raspberry Pi 2 port of seL4 which I saw mentioned when I did a search? I am interested in using the Raspberry Pi to learn about seL4 - not as a target for a full system (as I know there is an issue with trusting the boot mechanism). I just thought it would be a nice platform to use to get my head around seL4 and experiment with virtualising Linux and maybe Android? Simon Sent from my iPad

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reply: This checkin cause a build error
by XilongPei(裴喜龙) 13 Jul '15

13 Jul '15

Hi, Adria, I have fix this build error, it is because I use an old version of apps/sel4test-driver/scripts/extract-test-names.sh I am developing an operating system which can support Microsoft COM like component programing module based on seL4, so I have to sync every repository manually. Xilong Pei Tongji University 2015/7/13

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This checkin cause a build error
by XilongPei(裴喜龙) 13 Jul '15

13 Jul '15

Hi, This checkin cause a build error: Drop static qualifier from tests so that C++ compilers will use extern C linkage instead of name mangling https://github.com/seL4/libsel4test/commit/930744eaf43260ceb37ce2793eefbe77c d808ff0 the error information: .../libs/libsel4test/src/test.c:161: undefined reference to `__start__test_case' .../libs/libsel4test/src/test.c:161: undefined reference to `__stop__test_case' Xilong Pei Tongji University 2015/7/13

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Streamline seL4/libsel4 and make it not depend on libc
by Wink Saville 10 Jul '15

10 Jul '15

I've got sel4test running with libsel4 not having a dependency on libc. I've pulled out libsel4assert, libsel4benchmark, libsel4printf and libsel4putchar from libsel4 and they are separate libraries The biggest change is to seL4/libsel4 and sel4/tools/bitfield_gen.py. The changes to bitfield_gen.py allow it to generate the same code as before for the kernel but uses the new names for entities in user space. Please let me know what you think. -- Wink https://github.com/winksaville/seL4/tree/libsel4-no-libc-dependency https://github.com/winksaville/libsel4test/tree/libsel4-no-libc-dependency https://github.com/winksaville/libsel4allocman/tree/libsel4-no-libc-depende… https://github.com/winksaville/libsel4utils/tree/libsel4-no-libc-dependency https://github.com/winksaville/sel4test/tree/libsel4-no-libc-dependency https://github.com/winksaville/libsel4assert https://github.com/winksaville/libsel4benchmark https://github.com/winksaville/libsel4printf https://github.com/winksaville/libsel4putchar

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can IPC be concurrent running?
by Pei.XiLong(裴喜龙) 07 Jul '15

07 Jul '15

Hi, We can get the definition of IPCBuffer from here https://github.com/seL4/seL4/blob/master/libsel4/arch_include/arm/sel4/arch… enum { seL4_GlobalsFrame = 0xffffc000, }; It is fixed in one virtual space, that means the IPC in seL4's thread cann't be concurrent, we can't prepare more than 1 IPC request at the same time, for we call these function: seL4_SetTag, seL4_SetMR, seL4_SetUserData wil use this buffer, but there is no locker to protect the buffer. Is my understanding correct? Xilong Pei Tongji University 2015/7/6

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Where is the definition of seL4_TCB_BindAEP and seL4_TCB_UnbindAEP?
by XilongPei(裴喜龙) 07 Jul '15

07 Jul '15

Hi, In test program binding.c https://github.com/seL4/sel4test/blob/master/apps/sel4test-tests/src/tests/b inding.c , there are two functions, seL4_TCB_BindAEP and seL4_TCB_UnbindAEP, where can I get their definitions? Xilong Pei Tongji University 2015/7/6

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Try two for libsel4 not having a dependency on libc
by Wink Saville 04 Jul '15

04 Jul '15

Here <https://github.com/winksaville/sel4-min-sel4/tree/new-libs> is a different approach for removing the libc dependency, it seemed like people thought libsel4 was to big and that as part of the effort of breaking the dependency it should be made smaller. Basically libsel4 does nothing expect satisfy dependency needed for the kernel for some xml files. And I've broken libsel4 into basically 8 other libraries. see here <https://github.com/winksaville/sel4-min-sel4/tree/new-libs/libs>. This maybe taking things to far, but it does mean people can use only what they need, which I like. The smallest example is app/min-hw which only uses libsel4_gen, libsel4_startup. libsel4_bootinfo and libsel4_putchar. At the other extreme apps/test-newlibs uses everything. Anyway other organizations are certainly possible. Currently there is at least one known problem, I modified bitfield_gen.py so types_gen.h has no asserts since at the moment the kernel uses assert and userspace is libsel4_assert. We could either do something like I've done and remove them or change the kernel to use libsel4_assert or something else. Anyway, before creating a pull request I'd like to know what people think. -- Wink

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