l4-hackers

l4-hackers@os.inf.tu-dresden.de

2827 discussions

How to fix RAM size limit 256MB on realview-pbxa9 platform.
by e.fedotov 24 Dec '11

24 Dec '11

Hello, All! This post is about how to eliminate memory restriction 256MB in realview-pbxa9 platform (ARM Cortex A9 processor). The problem is that L4 bootstrap doesn't scan all RAM memory presented on this board. In QEMU source code for this platform (see hw/realview.c in QEMU source directory, function: realview_init) we can find that it can be 3 memory intervals in pbx a9: 1) base=0x00, size=min(sz, 256MB) This is "SDRAM1" 2) base=0x20000000, size=sz-512MB (appears when sz>512) This is called "core tile ram" 3) base=0x70000000, size=512 This is "SDRAM2", where sz is a total board memory, in QEMU specified via -m option. If that memory map is true (I have no pbx-a9 board operator's manual), we can make a simple patch to L4 bootstrap (file <genode>/base-foc/contrib/l4/pkg/bootstrap/server/src/platform/rv.cc), that extends a basic 256MB memory to 256MB+512MB by overloading setup_memory_map virtual function. /namespace { class Platform_arm_rv : public Platform_single_region_ram { bool probe() { return true; } //fix a memory limit 256MB in realview-pbxa9.platform. Adds another memory chip of 512MB. //WARNING: this fix works only if 512MB memory chip (or more) is present! //In case of QEMU you must run it with -m 512 or higher. void setup_memory_map(l4util_mb_info_t *, Region_list *ram, Region_list *) { ram->add(Region::n(0x0, 0x10000000, ".ram", Region::Ram)); //SDRAM as it defined in realview.c (QUEMU sources) ram->add(Region::n(0x70000000, 0x90000000, ".ram", Region::Ram)); //the second 512MB SDRAM //TODO: add more RAM regions if you need it according to the the platform map. } void init() { static L4::Uart_pl011 _uart(36,36); _uart.startup(0x10009000); set_stdio_uart(&_uart); } }; } REGISTER_PLATFORM(Platform_arm_rv); / This is an example patch, it would be more correct (if total RAM size is less then 512) to find total memory size first, then add the memory regions, regarding a total memory size. I hope it will be usefull. Best regards, and happy cristmas&new year. Evgeny Fedotov. Samsung Research Center, Moscow.

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Build L4Re on amd64
by BratSinot aka Куршамбай 19 Dec '11

19 Dec '11

Hello there! I want build L4Re on my Slackware64 without multilib. How can i do that?

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Building l4con lib and examples
by Adi Lima 15 Dec '11

15 Dec '11

Hi, I've been trying to build l4con/lib (actually what I need is libcon.a), but unfortunately I never be able to do it. I am using *l4re-snapshot-2011081207*, which I believe is the latest release. When I check the Makefiles inside the source tree, I found a few commented lines in client_con and contxt directory contains no sources (apparently the sources are being placed inside src directory). Is this package still active or will be removed in the future? Or, is there any way for me to build the package? I need libcon.a to build some test. Thanks. -- FX. J. Adi Lima Trivision Studio

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Need help on l4_msgtag_has_error
by Chen Tian 10 Dec '11

10 Dec '11

Hello, Can some one tell me when a msg tag is set to the error code i.e., tag = 0x8000 ? I have a parent thread A, which creates a child thread B, and thread C is assigned as B's pager and exception handler. When thread A destroys B via l4_task_unmap, thread C is invoked and the tag returned from ipc_reply_and_wait cannot pass l4_msgtag_has_error check. This is very weird. When B dies, will it generate some sort of exceptions which will cause C to be invoked? If I ask thread C to ignore this IPC message, it seems fine because thread B is anyway destroyed. But I am still wondering if I did something logically wrong or the tag error can be safely ignored, especially in the situation I described above? Thanks. Chen

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Using fbterminal with L4Con
by Adi Lima 09 Dec '11

09 Dec '11

Hi all, I finally able to run fbterminal after a bit struggling with some confusions, modifying example: x86-fb.cfg and replacing* ex_fb_spectrum* with * fbterminal* doesn't seem to work if we don't add "term = term:svr()" into fbterminal's caps, where term is defined as: term = loader:new_channel(). But now I want to put this terminal into L4Con, but don't know how to do it. L4con seem to accept different caps list compare to mag. The console appear, but the fbterminal doesn't. Someone help me please...? I attached my current test configuration... Do I miss something? -- FX. J. Adi Lima Trivision Studio

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Cannot show fbterminal
by Adi Lima 06 Dec '11

06 Dec '11

Hi, I've been trying all day launching fbterminal using plain example x86-fb.cfg, and only replace ex_fb_spectrum with fbterminal, following suggestion from Adam (i found it in some old thread). Unfortunately I can't see any mag window for the fbterminal, maybe it failed to create one, or somethin else happened, but if I add a second mag window, containing ex_fb_spectrum, it shows. What do I miss? -- FX. J. Adi Lima Trivision Studio

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l4shmnet bug fixed
by Matthias Petschick 02 Dec '11

02 Dec '11

Hello, there was a small bug in L4Linux's L4shm based network driver, which broke the driver on architectures where NET_IP_ALIGN != 0, e.g. on ARM. This resulted in insufficient data being allocated for the skb in l4x_l4shmc_interrupt, causing the subsequent skb_put to fail. See attached diff for details. Cheers, Matthias

2 1

Minimal Fiasco Testing Setup
by Bryce Cronkite-Ratcliff 02 Dec '11

02 Dec '11

Hi, I have a modified version of Fiasco, & I'd like to compare the performance of this modified kernel vs the original kernel. To that end, what is the minimal module set to provide a workable testing environment? I currently build L4-Linux Mag target, but I'd like to have as minimal a testing setup as possible -- perhaps just Fiasco, L4re, necessary services, and a terminal? Thanks! __Bryce

2 1

shmc bug fixes
by Stefan Fritsch 02 Dec '11

02 Dec '11

Hi, attached are some fixes for shmc: - fix various capability slot leaks in error paths - if l4re_ns_register_obj_srv() fails, return its error code to the caller and don't invent another one - use memory barriers in l4shmc_add_chunk() because l4shmc_get_chunk_to() walks the linked list without acquiring the lock - fix l4shmc_add_signal() freeing one of env's capabilities in an error path Cheers, Stefan

2 1

Getty over L4 shared memory
by Julian Vetter 01 Dec '11

01 Dec '11

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello All, is there a driver that does the same as the L4Shmnet driver but for serial console? I want to setup a communication between two Linux instances, one should provide a getty-service and the other instance should connect to it.. Thanks in advance. Cheers, Julian -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJO1OxrAAoJEOpGAeJlWp7qFmgIAJ7CZNIBQaNdn1s12p6fy9Rx OMGpKDkp2w/kgD6VZCxj7enzAFo/Z66YwiIVihKe00SM+13tllSr3AbRKWbhpa5F 33iFyI7wAnUnS3Y31DfOleMHlo2ekX7CoLQcD3yq3iuyB61XJRwQLMMY80gZ4dsS u6MFPNBplkG+pl0FuBS7sYXhasZefxB17Cikz/DHI+4ALt/lOQfKcO/Im36fLnoh YR1d0IfY7C9n8e5zNRkOT25KRHl1udJl/Uo14tYxYV/gyWU5jEwzq2tmfqMdZ71M E/sQmSRC68jOrJ1uWNfnz9qGdExNVSuXnR2JspcaeyR356jTIiXpSe0+E9OWZ18= =teF7 -----END PGP SIGNATURE-----

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