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vbus problem
by vijay kumar Godavarthy 15 Sep '13

15 Sep '13

Dear all I am using the following code. vbus = l4re_env_get_cap("vbus"); if (l4_is_invalid_cap(vbus)) { printf("Couldn't obtain vbus capability\n"); I am getting the error "Couldn't obtain vbus capability". How to overcome this problem. -- vijay kumar

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How to start DoPe and clients ?
by Rudolf Weber 15 Sep '13

15 Sep '13

Hello, I want to start dope, an fbterminal, and an fb_spectrum, (using l4re-snapshot-2013060718) with the following Start-Script: -- vim:set ft=lua: loader = L4.default_loader; -- Start io vbus_l4linux = loader:new_channel(); local io_buses = { input = loader:new_channel(); fbdrv = loader:new_channel(); }; loader:start( { caps = { sigma0 = L4.cast(L4.Proto.Factory, L4.Env.sigma0):create(L4.Proto.Sigma0); icu = L4.Env.icu; input = io_buses.input:svr(); fbdrv = io_buses.fbdrv:svr(); l4linux = vbus_l4linux:svr(); }, }, "rom/io rom/x86-legacy.devs rom/l4lx-x86.io"); -- Start fb-drv (but only if we need to) local fb = L4.Env.vesa; if (not fb) then fb = loader:new_channel(); loader:start({ caps = { fb = fb:svr(), vbus = io_buses.fbdrv }, log = { "fbdrv", "r" }, l4re_dbg = L4.Dbg.Warn, }, "rom/fb-drv -m 0x117"); end local gui_caps = { svc = loader:new_channel(), dope = loader:new_channel(), }; -- Start dope loader:start( { caps = { vbus = io_buses.input, fb = fb, svc = gui_caps.svc:svr(), dope = gui_caps.dope:svr(), }, }, "rom/l4dope"); local term_srv = loader:new_channel(); print("Start FBterminal "); e=loader:start( { caps = { fb = gui_caps.svc:create(L4.Proto.Goos, "g=640x480"), term = term_srv:svr(), }, log = { "fbterm", "b" }, l4re_dbg = L4.Dbg.Warn, },"rom/fbterminal"); print("Start fb_spectrum"); e2 = loader:start({ caps = { fb = gui_caps.svc:create(L4.Proto.Goos, "g=320x480"), }, log = { "spectrum", "b" }, l4re_dbg = L4.Dbg.Warn, }, "rom/ex_fb_spectrum_cc"); print("fbterminal exited with: " .. e:wait()); print("ex_fb_spectrum exited with: " .. e2:wait()); -------------------- Result: dope starts, but neither the fbterminal nor the ex_fb_specturm_cc is visible. (The kerneldebugger shows, that the Tasks are not existent ...) What is wrong ? Thank you very much Rudolf P.S: I collect my good experience on http://www.infnet.verein.de/betriebssysteme/kleinkernarch/l4/l4re_conf_2013… with mag it was successfull: http://www.infnet.verein.de/betriebssysteme/kleinkernarch/l4/l4re_conf_2013…

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L4Re::Util::Dataspace_svr
by Daniel Müller 15 Sep '13

15 Sep '13

Hi again, I believe the Dataspace_svr dispatch function is missing a case for L4Re::Dataspace_::Allocate (as declared in l4/pkg/l4re/include/dataspace-sys.h) -- I receive this opcode and since there is no handling the result is a return of -L4_ENOSYS (which will make subsequent processing fail). As a quick fix the attached patch works but there should probably also be a hook (virtual function) in the Dataspace_svr class (and maybe some more sophisticated default processing, not sure). Thanks, Daniel

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Problems with SVN co
by Manuel Dejonghe 10 Sep '13

10 Sep '13

Hi all, I subscribed to this list because last night and now, I have problems checking out the source code: After a 'svn co http://svn.tudos.org/repos/oc/l4linux/trunk l4linux' I am getting these kind of error messages: ... A l4linux/include/uapi/linux/netfilter/xt_statistic.h svn: In directory 'l4linux/include/uapi/linux/netfilter' svn: Can't open file 'l4linux/include/uapi/linux/netfilter/.svn/tmp/text-base/xt_CONNMARK.h.svn-base': No such file or directory ... A l4linux/include/uapi/linux/netfilter_ipv4/ipt_ttl.h svn: In directory 'l4linux/include/uapi/linux/netfilter_ipv4' svn: Can't open file 'l4linux/include/uapi/linux/netfilter_ipv4/.svn/tmp/text-base/ipt_ecn.h.svn-base': No such file or directory ... A l4linux/include/uapi/linux/netfilter_ipv4/ipt_CLUSTERIP.h svn: In directory 'l4linux/include/uapi/linux/netfilter_ipv4' svn: Can't open file 'l4linux/include/uapi/linux/netfilter_ipv4/.svn/tmp/text-base/ipt_ttl.h.svn-base': No such file or directory I have had that as well after only a couple of seconds or after some minutes, with varying milage of completeness, of course. What could be the reason for that ? Does anyone else have strange symptoms currently with the subversion ? thank you very much, lImbus

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L4kproxy::Factory_svr
by Daniel Müller 09 Sep '13

09 Sep '13

Hello, Please find attached a minimal example illustrating a bug in Factory_svr. When executing this example the output is something like: Ned: loading file: 'rom/minimal.lua' Ned: ERROR: ned.lua:199: could not create process: Insufficient memory (: -12) The problem is in parsing the utcb_area parameter in the Factory_hndl::handle_task() method. A patch could be the attached libkproxy.diff which will make the task creation succeed. I would also like to point out that in my opinion there is no point in writing this functionality but never testing or using it (I have been unable to find a single client or test using it). Thanks, Daniel

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Fosdem'14
by Sartakov A. Vasily 09 Sep '13

09 Sep '13

Hello, my dear friends. I am sorry if you receive multiple copies of this message (but I know, most of you will receive copies), but mailing list from uKernel dev room at FOSDEM'13 was destroyed (https://lists.fosdem.org/listinfo) Time rolls on, a FOSDEM'14 is not too far and now it is good time to submit a "uKernel and component based os" dev room. Who would like to organize dev room in this year? I would be proud to make this, but I heard someone from TUD would like to organize Dev room in this year. -- Sartakov A. Vasily sartakov(a)ksyslabs.org

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L4::Cap::move
by Daniel Müller 06 Sep '13

06 Sep '13

Hello, I am wondering is there any particular reason why Cap::move() uses L4_FPAGE_RWX instead of a mask of all bits? l4_task_map(L4_BASE_TASK_CAP, L4_BASE_TASK_CAP, src.fpage(L4_FPAGE_RWX), snd_base(L4_MAP_ITEM_GRANT)); Shouldn't L4_FPAGE_RWX be replaced with L4_CAP_FPAGE_RWSD in order to not restrict rights artificially? I am seeing subtle differences in application behavior in a scenario of mine... Daniel

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Cross-CPU TLB flush problem with Fiasco.OC (r56, r58; exynos5)
by Christian Prochaska 01 Sep '13

01 Sep '13

Hello, I had a situation where CPU 1 accessed the wrong (same as before) physical memory location after it was idle while CPU 0 unmapped the memory page and mapped a different page at the same virtual address afterwards. When a CPU is idle, its TLB gets marked as 'inactive' in the kernel and the CPU doesn't receive cross-CPU TLB flush requests during this time. It seems there is a TLB flush missing somewhere after CPU 1 leaves the idle thread, to compensate for any missed flush requests during the idle time. When I added a 'Mem_unit::tlb_flush()' call after 'enable_tlb(cpu)' in 'Kernel_thread::idle_op()' as a test, this problem did not occur anymore. Christian

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Top runscript
by Daniel Müller 28 Aug '13

28 Aug '13

Hello, I've seen the l4/pkg/top package and find it to be quite interesting. Can someone point me to a lua-runscript to start a program to be monitored by it? What caps do I have to redirect? Thanks, Daniel

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Data transfer mechanisms
by Lluís Vilanova 20 Aug '13

20 Aug '13

Hi, I'd like to compare the performance of two different synchronous data transfer mechanisms: * Copies * Page maps / unmaps For the second one, it looks like I can use the streammap example (pkg/examples/libs/l4re/streammap), although I'm lacking a mechanism to unmap the page before returning control to the client. It would also be nice to be able to pass the server a read-only region. For the first one, I've only found the use of multiple send/recv operations through the limited amount of data available on the message registers. There is a "Gen_string" class in the "ipc_stream" header, which looks like it could support offline string transfers, but it's disabled at compile time and I could not find the actual code in fiasco that handles these transfers. Thanks, Lluis -- "And it's much the same thing with knowledge, for whenever you learn something new, the whole world becomes that much richer." -- The Princess of Pure Reason, as told by Norton Juster in The Phantom Tollbooth

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