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Howto implement a periodic real-time task?
by Andre Puschmann 10 Aug '09

10 Aug '09

Hey guys, I got a L4 real-time application that should run strictly periodic. In each cycle I have to communicate with at least two other L4 threads in different address spaces. The cycle period is in the order of 1000Hz to 5000Hz. As described in [1] I tried to use the CPU reservation server but the sample implementations did not work. Anyway, I figured out that even the CPU reservation server depends on the kernel timer and thus the granularity is 1ms (in PIT mode), which is too coarse for cycle periods larger then 1000Hz. Although I like the idea to use OS primitives to keep the application as portable as possible (ARM port is a goal), I thought about implementing the periodic execution with an extra timer decoupled from the scheduling timer which generates an IRQ at each hit. Any comment/suggestions/ideas about that? Any other experience with periodic real-time tasks on L4? Cheers, Andre [1] http://os.inf.tu-dresden.de/pipermail/l4-hackers/2009/004179.html

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Re: problems running l4linux No.2
by Stefan Kögel 06 Aug '09

06 Aug '09

Hi, I started from a default l4linux26 kernel config. I did not touch anything, except for the things I had to, like acpi, apic, MTRR, MCE .. and the stuff that is missing (olpc, scx200 and these things). Everything else is default. The problem still exists but I was able to gather some info. Executing the l4linux26.cfg prints out: loader | sleeping for 1000 ms loader | vmlinuz: Starting application using libld-l4.s.so loader | vmlinuz,#11: Loading binary loader | vmlinuz,#11: Loading ldso loader | vmlinuz,#11: Starting libld-l4.s.so at 00013940 via 0000cc3c loader | DEBUG file = vmlinuz l4lx | ======> L4Linux 2.6 starting... <======== l4lx | Linux version 2.6.30-l4 (stefan@scarface) (gcc version 4.3.2 (Ubuntu l4lx : 4.3.2-1ubuntu12) ) #10 Wed Aug 5 16:45:57 CEST 2009 l4lx | Binary name: vmlinuz l4lx | Linux kernel command line (5 args): mem=64M load_ramdisk=1 ramdisk_si l4lx : ze=16384 root=/dev/ram l4env_rd=drops-rd.rd l4lx | Image: 00400000 - 00874000 [4560 KiB]. l4lx | Areas: Text: 00400000 - 006fd000 [3060kB] (a bit longer) l4lx | Data: 006fd000 - 007280e8 [172kB] l4lx | Initdata: 0072c000 - 00770000 [272kB] l4lx | BSS: 00772000 - 00853a94 [902kB] l4lx | l4lx_thread_create: Created thread 11.03 (tamer0) l4lx | Tamer0 is 11.03 l4lx | Using tamed mode. ROOT: Task #0c is not allowed to execute cli/sti loader | vmlinuz,#11: WARNING: Can't map I/O space, ROOT denies page (result=0 loader : 0004000) loader | vmlinuz,#11: Not allowed to perform any I/O l4lx | Got 0 out of 65536 I/O ports l4lx | Connecting to l4io server. l4lx | l4env_linux_startup thread 4. l4lx | l4lx_thread_create: Created thread 11.04 (cpu0) l4lx | main thread will be 11.04 l4lx | l4env_register_pointer_section: addr = 0072a000 size = 290816 l4lx | sec-w-init: virt: 0x0072a000 to 0x00770fff [284 KiB] l4lx | Noncontiguous region for sec-w-init l4lx | sec-w-init: Number of physical regions: 2, 290816 Bytes l4lx | sec-w-init: 1: Phys: 0x014f0000 to 0x01500000, Size: 65536 l4lx | sec-w-init: 2: Phys: 0x013b5000 to 0x013ec000, Size: 225280 l4lx | main thread: received startup message. l4lx | Main thread running, waiting... l4lx | memory_setup: mem=64M load_ramdisk=1 ramdisk_size=16384 root=/dev/ram l4lx : l4env_rd=drops-rd.rd l4lx | setup_l4env_memory: Forcing superpages for main memory l4lx | Main memory size: 64MB l4lx | Main memory: virt: 0x00c00000 to 0x04bfffff [65536 KiB] l4lx | Main memory: Number of physical regions: 1, 67108864 Bytes l4lx | Main memory: 1: Phys: 0x07400000 to 0x0b400000, Size: 67108864 l4lx | Filling lower ptabs... l4lx | mainmem = c00000 l4lx | Done (1864 entries). l4lx | l4env_register_pointer_section: addr = 00772000 size = 1056768 l4lx | end: virt: 0x00772000 to 0x00873fff [1032 KiB] l4lx | end: Number of physical regions: 1, 1056768 Bytes l4lx | end: 1: Phys: 0x06499000 to 0x0659b000, Size: 1056768 l4lx | memory_setup done l4lx | l4env_rd_path: drops-rd.rd l4lx | Loading: drops-rd.rd l4lx | INITRD: Size of RAMdisk is 16384KiB l4lx | RAMdisk from 04c00000 to 05c00000 [16384KiB] l4lx | l4env_phys_to_virt: Could not translate phys. address 0x80000 l4lx | l4env_phys_to_virt: Could not translate phys. address 0x80010 l4lx | l4env_phys_to_virt: Could not translate phys. address 0x80020 ... and continues untiel physical address 0x9fff0 and ends with a lock up of the computer. I am wondering about these lines: ROOT: Task #0c is not allowed to execute cli/sti loader | vmlinuz,#11: WARNING: Can't map I/O space, ROOT denies page (result=0 loader : 0004000) loader | vmlinuz,#11: Not allowed to perform any I/O Could that be causing the error? How can I fix this? Thank you for help. Kind Regards, Stefan > Hi, > > On Tue Aug 04, 2009 at 11:11:15 +0200, Stefan K?gel wrote: > >> I am still trying to run l4linux on top of fiasco. I am running it on >> top of a console system and configured L4Linux2.6 without any input >> drivers. Thanks to your suggestion I am loading vmlinuz with a start script. >> >> I can't tell you much, but once booted both serial and console are >> spammed with >> >> ... >> l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94140 >> l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94150 >> l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94160 >> ... >> >> messages. >> >> Did I forget to configure some kind of memory translation unit? >> > > No but I'd guess that there's some driver in the Linux that causes this. > Maybe you could start from the x86-ux or x86-native defconfigs and see > if the same happens? > > > > Adam >

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Re: interrupt registration
by eric johnson 04 Aug '09

04 Aug '09

On Tue, Aug 4, 2009 at 4:56 PM, eric johnson <eric.gd.johnson(a)gmail.com>wrote: > > > On Tue, Aug 4, 2009 at 1:48 PM, Adam Lackorzynski < > adam(a)os.inf.tu-dresden.de> wrote: > >> >> On Fri Jul 31, 2009 at 20:36:37 -0700, eric johnson wrote: >> > i m using a pistachio L4 kernel. ( with no operating system on top. ) >> > I am running this on an emulator ( qemu) . So i dont have a way of >> having >> > real interrupts. There might be a way in qemu to do that , but i dont >> know >> > how. >> > >> > My question is : i figure there is an interrupt thread for every >> interrupt. >> > ? Since i dont have any real hardware i would like to have a interrupt >> > thread for a random interrupt no. How do i make sure that this interrupt >> > thread is created ? I am trying to simulate the behaviour of an >> interrupt >> > processing in L4. >> >> Why do you think that Qemu's interrupts are not real from the point of >> view of the software running on it? > > > I dont see any of L4's interrupt code path getting called, like irq_thread > or handle_interrupt. > > In any case when is an irq thread created ? > > > > >> >> >> >> Adam >> -- >> Adam adam(a)os.inf.tu-dresden.de >> Lackorzynski http://os.inf.tu-dresden.de/~adam/<http://os.inf.tu-dresden.de/%7Eadam/> >> >> _______________________________________________ >> l4-hackers mailing list >> l4-hackers(a)os.inf.tu-dresden.de >> http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers >> > >

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interrupt registration
by eric johnson 04 Aug '09

04 Aug '09

i m using a pistachio L4 kernel. ( with no operating system on top. ) I am running this on an emulator ( qemu) . So i dont have a way of having real interrupts. There might be a way in qemu to do that , but i dont know how. My question is : i figure there is an interrupt thread for every interrupt. ? Since i dont have any real hardware i would like to have a interrupt thread for a random interrupt no. How do i make sure that this interrupt thread is created ? I am trying to simulate the behaviour of an interrupt processing in L4. suresh

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compiling Fiasco trunk, Bison trouble
by Roman Beslik 04 Aug '09

04 Aug '09

Hello. I'm trying to compile Fiasco trunk using this manual: http://os.inf.tu-dresden.de/fiasco/use.html . When I compile tudos/l4 tree, many errors appear in tudos/dice/src/parser/idl : {{{ g++ -DHAVE_CONFIG_H -I. -I. -I../../.. -I../../../src -Wall -I../../../src -g -O2 -MT idl-scanner.o -MD -MP -MF .deps/idl-scanner.Tpo -c -o idl-scanner.o idl-scanner.cc In file included from ../../../src/parser/idl/location.hh:44, from idl-parser.tab.hh:65, from idl-parser-driver.hh:35, from idl-scanner.ll:6: position.hh: In function ‘bool yy::operator==(const yy::position&, const yy::position&)’: position.hh:136: warning: suggest parentheses around ‘&&’ within ‘||’ In file included from idl-parser-driver.hh:35, from idl-scanner.ll:6: idl-parser.yy: At global scope: idl-parser.yy:76: error: use of enum ‘EXPT_OPERATOR’ without previous declaration idl-parser.yy:78: error: ISO C++ forbids declaration of ‘CFETypeSpec’ with no type idl-parser.yy:78: error: expected ‘;’ before ‘*’ token idl-parser.yy:79: error: ISO C++ forbids declaration of ‘CFEAttribute’ with no type idl-parser.yy:79: error: expected ‘;’ before ‘*’ token idl-parser.yy:80: error: ISO C++ forbids declaration of ‘CFEExpression’ with no type idl-parser.yy:80: error: expected ‘;’ before ‘*’ token {{{many errors skipped}}} make[6]: *** [idl-scanner.o] Error 1 make[6]: Leaving directory `/tudos/dice/src/parser/idl' }}} It seems that tudos/dice/src/fe/*.h files is not included with "#include" in tudos/dice/src/parser/idl/idl-parser.tab.hh, because when I include them by hand, "g++ ..." works out without an error. >yacc --version bison (GNU Bison) 2.4.1 >g++ --version g++ (GCC) 4.4.0 20090630 (prerelease) >ls -l /usr/local/bin/byacc lrwxrwxrwx 1 root root 13 2009-07-14 04:24 /usr/local/bin/byacc -> /usr/bin/yacc -- Best regards, Roman Beslik.

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problems running l4linux No.2
by Stefan Kögel 04 Aug '09

04 Aug '09

Hi, I am still trying to run l4linux on top of fiasco. I am running it on top of a console system and configured L4Linux2.6 without any input drivers. Thanks to your suggestion I am loading vmlinuz with a start script. I can't tell you much, but once booted both serial and console are spammed with ... l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94140 l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94150 l4lx | l4env_phys_to_virt: Could not translate phys. address 0x94160 ... messages. Did I forget to configure some kind of memory translation unit? Here is my grub config: kernel /bin/svn453/bootstrap -serial modaddr 0x03000000 module /bin/svn453/fiasco -nokdb -nowait -serial -comspeed 115200 -pcsampling -debug -sp 1000000 module /bin/svn453/sigma0 module /bin/svn453/roottask task modname "bmodfs" attached 7 modules module /bin/svn453/dm_phys module /bin/svn453/names --verbose 0 --logsrv logcon module /bin/svn453/events module /bin/svn453/simple_ts --events -t 300 module /bin/svn453/l4io module /bin/svn453/bmodfs module /bin/svn453/l4linux26.cfg module /bin/svn453/libloader.s.so module /bin/svn453/libld-l4.s.so module /bin/svn453/logcon module /bin/svn453/run module /bin/svn453/vmlinuz module /bin/svn453/drops-rd.rd module /bin/svn453/loader --events --fprov=BMODFS run l4linux26.cfg logcon module /bin/svn453/con --nolog vbeset 0x117 Thanks for your help. Kind Regards, Stefan

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problems running l4linux
by Stefan Kögel 31 Jul '09

31 Jul '09

Hi, i am trying to run l4linux on top of fiasco. Using the cfg start script from the website to load vmlinux. But after that nothing really happens and the keyboard somehow gets redirected to my serial connection. jdb output is: loader | sleeping for 1000 ms loader | vmlinux: Starting sigma0-style application loader | vmlinux: Loading binary loader | vmlinux,#f: Entry at 00009c3c => 00400000 loader | vmlinux,#f: Started loader | DEBUG file = vmlinux loader | vmlinux,#f: Double PF (r) at 00000000 eip 00000000 (F.00) It seems to load quite ok, but nothing else. But I may have not payed enough attention to configuring the l4linux kernel. I know I tryed to turn off any serial drivers. Which part should have control over the keyboard? Thank you for your help. Kind Regards, Stefan

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problem with l4linux
by fang zhengshu 27 Jul '09

27 Jul '09

hi, I'm sorry to trouble you,but I have a question with X server when start l4linux on dope. I have search a mail which you have sent: > Yes, I know that this setup is not easy. For overlay_wm driver to work it is necessary to apply patches to X Server sources, as I read. But I thought it must work with linux server with ordinary l4con/dope frambuffer driver. So, it won't, ok. -- When I checked on real machine (not with ramdisk), l4linux started and XServer starts OK. > I can start l4linux on dope and con,and also on serial console.The below is what I use in l4linux.cfg: task "vmlinuz" "earlyprintk=yes mem=64M video=l4fb root=/dev/hda9 " all_sects_writable allow_vga allow_cli could you please tell me what I missing? thank you. -- fang,

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the dde_linux26 link error
by Guanghui, Cheng 27 Jul '09

27 Jul '09

Hello: i write a device driver for L4 with DDE but when i compile the server and client code it can't link into the lib dde_linux26 with the error like this: ld: cannot find -ldde_linux26 I check the files in the libdde* and there are only these files: libddekit.a libdde_linux26_block.a libdde_linux26_net.a libdde_linux26.o.a libdde_linux26_sound.a No libdde_linux26.a but libdde_linux26.o.a instead. Maybe some configuation is wrong and thanks for your any suggestion. Cheng

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Call for Papers: Embedded Software Track at DATE 2010
by André Hergenhan 25 Jul '09

25 Jul '09

Hello, I would like to invite you to submit your research contributions and advanced (industrial) applications to the Embedded Software Track at DATE 2010. With this respect, I would especially like to refer to topic E4, which may be of particular interest to the L4 community. Best regards, André. Call for Papers Embedded Software Track at DATE 2010 Dresden, Germany March 8-12, 2010 The Design, Automation and Test in Europe conference and exhibition is the main European event bringing together design automation researchers, users and vendors, as well as specialists in the design, test, and manufacturing of electronic systems and circuits. It puts strong emphasis on embedded systems, including embedded software which has become a main track of DATE. The DATE conference is a five-day event consisting of plenary keynotes, regular papers, interactive presentations, panels and hot-topic sessions, tutorials, master courses and workshops. The DATE conference and the exhibition, together with the many user group meetings, fringe meetings, university booth and social events offer a wide variety of opportunities to meet and to exchange information. Embedded Topic Areas: E1 Real-time, Networked, and Dependable Systems Chairs: Petru Eles, Linkoping University, Sweden; Luís Almeida, Universidade do Porto, Portugal Real-time programming languages and software; formal models for real-time systems; software performance analysis; worst case execution time analysis; scheduling and software estimation; real-time system optimization; verification; tools and design methods; adaptive real-time systems; dependable systems; software for safety critical systems; software for sensor networks and networked applications; network control and QoS for embedded applications. E2 Compilers and Code Generation for Embedded Systems Chairs: Shuvra Bhattacharyya, University of Maryland, USA; Rainer Leupers, RWTH Aachen,, Germany Software-centric system design exploration; software synthesis; compilers; code generation (e.g. C from matlab); dynamic compilation for embedded systems; software tool chain; generation for design space exploration (compilers, simulators, synthesis tools); retargetable compilers for MPSOC and reconfigurable platforms; compilers for multi-core systems. E3 Model-based Design for Embedded Systems Chairs: Albert Benveniste, IRISA, France; Christoph Kirsch, University of Salzburg, Austria Model-based foundations, methods, and tools for principled embedded/control system/software design; model-based embedded/control system/software testing, verification, validation, integration, deployment; model-based system and software architectures and infrastructure for principled embedded/control software deployment. E4 Embedded Software Architectures and Principles Chairs: Ahmed Jerraya, Leti, France; André Hergenhan, OpenSynergy, Germany Software for MPSoC and multi-core systems; virtualization for embedded systems, including safety and security aspects; resources constrained middleware and Run-Time Environment (RTE) architectures, e.g., AUTOSAR; software support for reconfigurable components and accelerators. E5 Embedded Software Applications - Architectures, Tools, and Methodologies Chairs: Wolfgang Ecker, Infineon Technologies, Germany; Werner Damm, OFFIS, Germany Real-time and dependable software applications; embedded run-time environments - practice and applications; embedded software verification and certification; design processes and experience in dependable software design; model driven design in industrial practice; embedded software architectures and applications in aerospace, automotive, industrial, medical industries; embedded software in wireless and consumer electronics applications; sensor network applications. Submission Instructions: All manuscripts must be submitted electronically before September 6th, 2009, following the instructions on the conference Web page: http://www.date-conference.com The accepted file format is PDF Manuscripts received in hard-copy form will not be processed. Papers can be submitted for either standard oral presentation or for interactive presentation. Standard oral presentations require novel and complete research work supported by experimental results, and are held in front of a full audience. Besides these, DATE will again include interactive presentations of novel ideas that may require additional research or lack experimental data. Interactive presentations are given on a laptop in a face-to-face discussion area. Submissions should not exceed 6 pages in length for oral-presentation and 4 pages in length for interactive-presentation papers, and should be formatted as close as possible to the final format: A4 or letter sheets, double column, single spaced, Times or equivalent font of minimum 10pt (templates are available on the DATE Web site for your convenience). To permit blind review, submissions should not include the author names. Any submission not in line with the above rules will be discarded. All papers will be evaluated with regard to their suitability for the conference, originality and technical soundness. The Programme Committee reserves the right to accept interesting contributions that do not meet the criteria for standard oral presentations, as interactive presentations. Information: Rolf Ernst - DATE Embedded Software Track Chair IDA Technische Universität Braunschweig Hans-Sommer-Str. 66 38106 Braunschweig, Germany e-mail: r.ernst(a)tu-bs.de Wolfgang Mueller - DATE Program Chair Paderborn University C-LAB, Fuerstenallee 11 33098 Paderborn, Germany e-mail: wolfgang(a)acm.org

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