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Graphical desktop, l4con, mag
by teclis High Elf 02 Jun '17

02 Jun '17

Guten Tag, I've got the Hello app runing with fiasco and l4re in qemu, how do I get the graphical UI and console running that I see on the screen shots page? Do I need to use l4con and mag? I don't see an entry with l4con in modules.list. danke * <http://german.about.com/library/media/Audio/gutentag.wav>*

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L4Linux CONFIG_MTRR must not be enabled
by 翟翔 02 Jun '17

02 Jun '17

Hi L4 hackers, When I am building L4Linux https://l4linux.org/build.shtml make O=build menuconfig changed the L4 tree build directory, then Exit for saving to .config make O=build it thrown ERROR: CONFIG_XXX must not be enabled, then I edited build/.config to comment the CONFIG_XXX is not set, then make O=build again, but it always thrown such error: make[1]: Entering directory '/home/zhaixiang/project/l4linux/build' =============================================== For quick build instructions, please visit: http://wiki.tudos.org/Quickstart http://l4linux.org/build.shtml =============================================== ERROR: CONFIG_MTRR must not be enabled. ERROR: CONFIG_DMI must not be enabled. ERROR: CONFIG_X86_SMAP must not be enabled. arch/l4/Makefile:578: recipe for target 'check_linux_config' failed make[1]: *** [check_linux_config] Error 1 make[1]: Leaving directory '/home/zhaixiang/project/l4linux/build' Makefile:150: recipe for target 'sub-make' failed make: *** [sub-make] Error 2 even I commented CONFIG_MTRR, CONFIG_DMI and CONFIG_X86_SMAP is not set, but rebuilt it again, the CONFIG_MTRR=y, are they requires by other modules? infinite dependence issue? so I simply changed the arch/l4/Makefile Index: arch/l4/Makefile =================================================================== --- arch/l4/Makefile (revision 54) +++ arch/l4/Makefile (working copy) @@ -557,9 +557,9 @@ DIS_OPTS-arm-32 := PERF_EVENTS ARM_PATCH_PHYS_VIRT HIGHMEM \ DEBUG_RODATA DEBUG_ALIGN_RODATA DIS_OPTS := HIGHMEM4G HIGHMEM64G PCI_GOANY PCI_GOBIOS \ - X86_MCE X86_MCE MTRR PARAVIRT KEXEC MCA SOFTWARE_SUSPEND APM \ - CPU_FREQ VM86 X86_DS X86_PTRACE_BTS HT_IRQ DMI \ - TRANSPARENT_HUGEPAGE COMPACTION X86_PAE ACPI X86_SMAP \ + X86_MCE X86_MCE PARAVIRT KEXEC MCA SOFTWARE_SUSPEND APM \ + CPU_FREQ VM86 X86_DS X86_PTRACE_BTS HT_IRQ \ + TRANSPARENT_HUGEPAGE COMPACTION X86_PAE ACPI \ M486 M586 M586TSC M586MMX PNP \ X86_16BIT MICROCODE \ $(DIS_OPTS-$(BASEARCH)-$(BITS)) it is monkey patch, please give me some advice, thanks a lot! -- Regards, Leslie Zhai - a LLVM hacker https://reviews.llvm.org/p/xiangzhai/

3 2

Benchmarks in l4
by Maxim Baryshnikov 01 Jun '17

01 Jun '17

Hello everybody, Does the L4re contain some kind of simple performance benchmarks which are already prepared to use? I've tried to launch some demos from the ferret package but not succeed... Thank you in advance for any suggestions. Sincerely, Maxim Baryshnikov.

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Re: libfs/ FUSE on L4Re
by Leslie Zhai 01 Jun '17

01 Jun '17

diff --git a/libfs/lib/libc_backend/l4fs.cc b/libfs/lib/libc_backend/l4fs.cc index 7a229ff..31ad120 100644 --- a/libfs/lib/libc_backend/l4fs.cc +++ b/libfs/lib/libc_backend/l4fs.cc @@ -219,10 +219,10 @@ int L4fs_dir::get_entry(const char *name, int flags, mode_t mode, //printf("mode=%x,flags=%x\n", mode, flags); if (S_ISDIR(mode)) { //printf("open '%s' as directory\n", name); - *file = new L4fs_dir(_svr, fh); + *file = cxx::ref_ptr(new L4fs_dir(_svr, fh)); } else { //printf("open '%s' as file\n", name); - *file = new L4fs_file(_svr, fh); + *file = cxx::ref_ptr(new L4fs_file(_svr, fh)); } return (*file) ? 0 : -ENOMEM; @@ -325,7 +325,7 @@ int L4fs_file_system::mount(char const *source, unsigned long mountflags, if (fh < 0) return fh; - *dir = new L4fs_dir(svr, fh); + *dir = cxx::ref_ptr(new L4fs_dir(svr, fh)); if (!dir) return -ENOMEM; 在 2017年06月01日 15:36, Xiang Zhai 写道: > Hi Florian, > > > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc: In > member function ‘virtual int L4fs::L4fs_dir::get_entry(const char*, > int, mode_t, cxx::Ref_ptr<L4Re::Vfs::File>*)’: > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:222:38: > error: no match for ‘operator=’ (operand types are > ‘cxx::Ref_ptr<L4Re::Vfs::File>’ and ‘L4fs::L4fs_dir*’) > *file = new L4fs_dir(_svr, fh); > ^ > In file included from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/vfs.h:41:0, > from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/backend:22, > from > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:15: > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:186:8: > note: candidate: template<class OT> void cxx::Ref_ptr<T, > CNT>::operator=(const cxx::Ref_ptr<OT>&) [with OT = OT; T = > L4Re::Vfs::File; CNT = cxx::Default_ref_counter] > void operator = (Ref_ptr<OT> const &o) throw() > ^~~~~~~~ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:186:8: > note: template argument deduction/substitution failed: > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:222:38: > note: mismatched types ‘const cxx::Ref_ptr<T>’ and ‘L4fs::L4fs_dir*’ > *file = new L4fs_dir(_svr, fh); > ^ > In file included from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/vfs.h:41:0, > from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/backend:22, > from > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:15: > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:193:8: > note: candidate: void cxx::Ref_ptr<T, CNT>::operator=(const > cxx::Ref_ptr<T>&) [with T = L4Re::Vfs::File; CNT = > cxx::Default_ref_counter] > void operator = (Ref_ptr<T> const &o) throw() > ^~~~~~~~ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:193:8: > note: no known conversion for argument 1 from ‘L4fs::L4fs_dir*’ to > ‘const cxx::Ref_ptr<L4Re::Vfs::File>&’ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:203:8: > note: candidate: void cxx::Ref_ptr<T, CNT>::operator=(cxx::Ref_ptr<T, > CNT>::Null_type) [with T = L4Re::Vfs::File; CNT = > cxx::Default_ref_counter; cxx::Ref_ptr<T, CNT>::Null_type = > std::nullptr_t] > void operator = (Null_type) throw() > ^~~~~~~~ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:203:8: > note: no known conversion for argument 1 from ‘L4fs::L4fs_dir*’ to > ‘cxx::Ref_ptr<L4Re::Vfs::File>::Null_type {aka std::nullptr_t}’ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:218:8: > note: candidate: template<class OT> void cxx::Ref_ptr<T, > CNT>::operator=(cxx::Ref_ptr<OT>&&) [with OT = OT; T = > L4Re::Vfs::File; CNT = cxx::Default_ref_counter] > void operator = (Ref_ptr<OT> &&o) throw() > ^~~~~~~~ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:218:8: > note: template argument deduction/substitution failed: > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:222:38: > note: mismatched types ‘cxx::Ref_ptr<T>’ and ‘L4fs::L4fs_dir*’ > *file = new L4fs_dir(_svr, fh); > ^ > In file included from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/vfs.h:41:0, > from > /home/zhaixiang/project/l4re/l4/build/include/l4/l4re_vfs/backend:22, > from > /home/zhaixiang/project/l4re/l4/pkg/libfs/lib/libc_backend/l4fs.cc:15: > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:224:8: > note: candidate: void cxx::Ref_ptr<T, > CNT>::operator=(cxx::Ref_ptr<T>&&) [with T = L4Re::Vfs::File; CNT = > cxx::Default_ref_counter] > void operator = (Ref_ptr<T> &&o) throw() > ^~~~~~~~ > /home/zhaixiang/project/l4re/l4/build/include/l4/cxx/ref_ptr:224:8: > note: no known conversion for argument 1 from ‘L4fs::L4fs_dir*’ to > ‘cxx::Ref_ptr<L4Re::Vfs::File>&&’ > > > So I simply added cxx::ref_ptr() for reference counting pointer with > automatic cleanup: > > > diff --git a/libfs/lib/libc_backend/l4fs.cc > b/libfs/lib/libc_backend/l4fs.cc > index 7a229ff..31ad120 100644 > --- a/libfs/lib/libc_backend/l4fs.cc > +++ b/libfs/lib/libc_backend/l4fs.cc > @@ -219,10 +219,10 @@ int L4fs_dir::get_entry(const char *name, int > flags, mode_t mode, > //printf("mode=%x,flags=%x\n", mode, flags); > if (S_ISDIR(mode)) { > //printf("open '%s' as directory\n", name); > - *file = new L4fs_dir(_svr, fh); > + *file = cxx::ref_ptr(new L4fs_dir(_svr, fh)); > } else { > //printf("open '%s' as file\n", name); > - *file = new L4fs_file(_svr, fh); > + *file = cxx::ref_ptr(new L4fs_file(_svr, fh)); > } > > return (*file) ? 0 : -ENOMEM; > @@ -325,7 +325,7 @@ int L4fs_file_system::mount(char const *source, > unsigned long mountflags, > if (fh < 0) > return fh; > > - *dir = new L4fs_dir(svr, fh); > + *dir = cxx::ref_ptr(new L4fs_dir(svr, fh)); > if (!dir) > return -ENOMEM; > > > please review my patch, thanks a lot! > -- Regards, Leslie Zhai - a LLVM hacker https://reviews.llvm.org/p/xiangzhai/

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libfs/ FUSE on L4Re
by Stark, Josef 31 May '17

31 May '17

Hello, yesterday I came across a very interesting paper titled "Porting FUSE to L4Re", accessible here: http://os.inf.tu-dresden.de/papers_ps/pester-beleg.pdf For porting FUSE, the author uses a library called "libfs" which provides filesystem request forwarding and processing, if I understood correctly. It reads as if libfs is already included in L4Re. However, I couldn't find neither FUSE nor libfs in the current L4Re snapshot. Are they by any chance publicly available somewhere else, or are both not to be published? Cheers, Josef

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Microkernel + Alumni Meetup
by Bjoern Doebel 30 May '17

30 May '17

Hi all, it has been a while since we last met for a beer. Water went down the Elbe river, companies were closed, companies were started, research papers got accepted, technical advancements were made. Let's catch up on all of that! To find a suitable time, please visit https://dudle.inf.tu-dresden.de/ukm-01-2017/ Bjoern

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clang-5.0 is not supported. Please use one of the following versions
by Leslie Zhai 28 May '17

28 May '17

Hi L4 hackers, I am using clang (svn trunk 303321) to build fiasco, it thrown such error: kernel/fiasco/src/Makeconf:264: *** clang-5.0 is not supported. Please use one of the following versions: 3.5 3.6 3.7 3.8 so I simply add other versions for clang, please review my patch, thanks a lot! Index: kernel/fiasco/src/Makeconf =================================================================== --- kernel/fiasco/src/Makeconf (revision 72) +++ kernel/fiasco/src/Makeconf (working copy) @@ -245,7 +245,7 @@ CC_WHITELIST-gcc := 4.5 4.6 4.7 4.8 4.9 5 6 -CC_WHITELIST-clang := 3.5 3.6 3.7 3.8 +CC_WHITELIST-clang := 3.5 3.6 3.7 3.8 3.9 4.0 5.0 CC_WHITELIST := $(CC_WHITELIST-$(CC_TYPE)) CC_BLACKLIST-arm-gcc := 4.8.0 4.8.1 4.8.2 -- Regards, Leslie Zhai https://reviews.llvm.org/p/xiangzhai/

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Share exist memory over IPC with L4Re
by Alexander Fratzer 15 May '17

15 May '17

Dear L4-Hackers, I have a very simple problem but I can't find the solution in the L4Re-Doc and examples so far. I wrote a very simple Unix-Like Shell with a Filesystem-Server and a Loader-Server and I implemented some Posix-Call as an abstraction for the communication with the Filesystem-Server (virtual). Now I have a problem of double copies for a read-Operation. I want a complete abstraction from the L4Re mechanisms and the underlying Client-Server architecture for the usage of this interface. The (bad) mechanism is as follow: Function (client side): ssize_t read(int fd, void *buf, size_t count) Algorithm: 1. Allocate Dataspace with size of count. 2. Send Cap of Dataspace to the Filesystem-Server. 3. Copy content of Dataspace to buf. 4. Cleanups. Function (server side): long VFSSrv::op_file_read(VFS::Rights, TaskRegistry::TaskId task, TaskRegistry::FileDescriptor fd, size_t size, L4::Ipc::Snd_fpage& flexp, size_t& rsize) Algorithm: 1. Get Dataspace-Cap from Ipc-fpage. 2. Reserve area with Region-Manager. 3. Attach Dataspace to the area. 4. Copy content of the file to the attached area. 5. Cleanups. This was my first working solution without focus on runtime but the creation of a new task from an ELF-File of 1.4 MB size takes 20 seconds on Cortex A8. This suxx so I have to optimize. Therefor I need a way to share the content of my file (virtual, heap allocated memory) without copying to the client but i don't find a way to share exist memory over IPC. I think I'm using the Dataspace-mechanism in a wrong way but maybe a Dataspace isn't the right choice in my case. A simple solution would be a new Filesystem which is based on Dataspaces but I don't want to do this. Have anybody a better idea? Thanks for help. Best regards Alex.

2 1

Fiasco.OC: null-pointer dereference?
by Stefan Kalkowski 09 May '17

09 May '17

Dear L4-Hackers, recently, I started to upgrade the Fiasco.OC kernel version that is used by the Genode OS framework to the lastly released version (r72). I took the opportunity to upgrade, because the upcoming Genode release uses a fresh compiler toolchain that refused to build the very old Fiasco.OC kernel version that was used until now (r56). Everything went quite smoothly, and I'm glad to see how the kernel develops further. Thanks to all developers at this point! Unfortunately, I stumbled across an issue when it comes to thread destruction. In our system all threads are constructed and destructed by the roottask that is called 'core'. In some cases, not always but quite often, the Ram_quota pointer of the thread object is zero during the call of the Thread_oject's delete operator, which leads to a page-fault within the kernel-code. A simple check[1] before dereferencing the pointer solves the problem, but I wonder whether we will leak quota or memory then, or in general cover some more serious problem. Obviously, we have different usage patterns of syscalls, e.g.: the order of destructing IPC-gates, threads, IRQs, and tasks. Moreover, we still have some very few patches[2] so that the kernel meets our requirements. But none of them explains the thread's Ram_quota pointer getting zero. The page-fault triggers across all x86 and arm platforms that we use. Any hint would be very much appreciated, all the best! Stefan [1] https://github.com/skalk/foc/commit/2b01c9d16fd8e29e6af18fe750be2c8a312b4762 [2] https://github.com/skalk/foc/commits/r72 -- Stefan Kalkowski Genode Labs https://github.com/skalk · http://genode.org/

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Trying to build L4 on NixOS
by Mateusz Czaplinski 09 Apr '17

09 Apr '17

I'm trying to build L4 on NixOS in a VM (long term goal: try to learn how to replace NixOS's kernel with L4Linux, then maybe Genode). I'm getting an error like below: undefined reference to `__stack_chk_fail' during linking of bootstrap.elf - in a GCC's error-barf just after: [bootstrap] ==> Linking bootstrap.elf I've put up the precise Nix expression/script I'm using to build it on github - at: https://github.com/akavel/l4.nix/blob/0108dfcf8d84780e1ba884c41ece0d2dbf4dd… but what it generally boils down to is a sequence of commands like this: $ wget http://os.inf.tu-dresden.de/download/snapshots/l4re-core-2016082114.tar.xz $ tar xf l4re-core-2016082114.tar.xz $ cd l4re-core-2016082114 $ mkdir out $ cp src/l4/mk/defconfig/config.amd64 out/l4/.kconfig $ make -C src/l4 O=out/l4 olddefconfig $ make -C out/l4 I've tried various additional changes, based on some snippets found here and there on teh Internets, like: - adding V=0 to the last make (no idea what it does yet, just some cargo culting) - adding NIX_CFLAGS_COMPILE = "-fno-stack-protector"; to the Nix expression/script (also not really sure where it applies in the stack); but none of the above helped. Any idea what I could try doing to push it further? Thanks, /Mateusz.

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