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Is mapping database still in use now?
by Sheng-Wei Cheng 15 Sep '13

15 Sep '13

Hi hackers, I've read the paper “µ-kernel Memory Management” and know that, in theory, mapping database is designed for quickly unmaping a page which is recursively mapped to several address spaces. However, is it still in use now in popular implementations like Fiasco.OC? If that is the case, is it used intensively when virtualization on microkernel is involved? (for example, L4Linux etc) Best regards, Lawrence

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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 05 Sep '13

05 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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