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l4shmnet and its structure
by cem akpolat 13 Jun '14

13 Jun '14

Dear all, As far as I tested, l4smnet.c file establishes a communication channel between client ann server l4linux and I asked couple of weeks ago about the posibility of multiple clients and one server example and Adam recommended me to use one of the l4linux, in this case server, as a router. That is exactly the way that I am following. For this reason, I tried first of all a simple example: one server two clients with two different shm. Interestingly, I couldn't see the second client. I couldn't evaluate whether this trial was logical or not, but if this works for one of the clients why not for the second? Apart from this case, I attempt to convert l4shmnet from two l4linux to multiple case, but this is really not easy. I tried one shared memory first of all, modifying some parts of the code is quite difficult, you can easily encounter a failure such as page_fault. That's why I did two shared memory as mentioned above. My simple question, which way is really more logical, 1- using one shared memory for all clients and server or 2- multiple shared memory for each separate client. Is there any document or source snippet that I can to use a similar structure in l4re. shm code is already here, but it doesn't really give insight into this part. Thanks, Best Regards, Cem Akpolat

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Trouble building l4linux
by Sören Jonsson 10 Jun '14

10 Jun '14

Hello, I have successfully built L4Fiasco and L4Re, and tested it by running the hello test program under quemu. After that I attempted to build L4linux, using instructions from this site: http://wiki.tudos.org/L4Linux/build . Unfortunately, when I came to the stage of "make O=/home/osj/l4linux_bld/" I get an error message "make[2]: *** [/home/osj/l4/l4linux_bld/Makeconf.l4conf] Error 1 make[1]: *** No rule for creating the target "/home/osj/l4/l4linux_bld/Makeconf.l4conf" Is there another web page I should get my instructions from, or is there anything I have missed in my attempt to build l4linux? Best regards, Sören Jonsson Sweden

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EFI boot fails
by Ayad Mostafa 10 Jun '14

10 Jun '14

hello l4-hackers, i'm trying to boot l4 on intel galileo board, but i'm getting error 13 from grub "Error 13: Invalid or unsupported executable format". the error is generated after issuing kernel /bootstrap -modaddr 0x01100000 here is my grub.conf title hw_test0 root (hd0,0) kernel /bootstrap -modaddr 0x01100000 module /fiasco -jdb_cmd=JS -serial_esc module /sigma0 module /moe rom/lwip.lua module /l4re module /ned module /io module /ankh module /ankh.vbus module /lwip.lua module /Aw.lua module /hw_test0 the same setup was tested successfully under qemu i appreciate any help thanks in advance

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Dresden Microkernel Hackers Meet-up
by Julian Stecklina 08 Jun '14

08 Jun '14

Hey fellow microkernel hackers, a lot of us are still in Dresden, but are now scattered across several work places. Let's meet up and have some beer next week. Please vote for when[1] and where[2] until Sunday 18:00 CEST. I'll send one additional mail on Sunday evening to announce the results. Forward this mail as you like. The more the merrier. For all of you too far away: My apologies for the off-topic mail. Julian [1] https://dudle.inf.tu-dresden.de/ukernelbeerwhen/ [2] https://dudle.inf.tu-dresden.de/ukernelbeerwhat/

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Adding hardware access to L4Linux, and killing serial console
by Peter Howard 07 Jun '14

07 Jun '14

Dear all, I'm currently trying to add extra hardware access to L4Linux on the da850. I'm having reasonable success (thanks Taueng!), but have hit a problem with interrupts. I have enabled: * GPIO access (working, with problem described below), * DMA access (working, I think), * Clock access (working, insomuch as the GPIO and DMA stop giving clock errors), * MMC/SD access (not working - and until it does I'm not 100% sure about DMA). (For anyone who knows the omapl138, the mux setup _is_ being handled; part of the bsp code in Fiasco). I hit my current problem when I got the Clock access working, and the GPIO driver started registering interrupts. At that point the serial console stops responding. It prints, but any attempts to type anything fail. Simply commenting out the second half of davinci_gpio_irq_setup() removes the problem. Of course then gpio interrupts can't work (not that I know if they are working yet). So clearly registering those interrupts is affecting the serial console being notified of data pending. I don't expect anyone here to have the answer. But to work out the problem I need to better understand how the virtual serial works in L4Linux. So can anyone give me/point me to a description of how it does work, along with the relevant driver code? Thanks, -- Peter Howard <pjh(a)northern-ridge.com.au>

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Clans and chiefs
by teclis High Elf 07 Jun '14

07 Jun '14

Hi, I just started hacking on Fiasco. Could someone point me to the code where the clans and chiefs are implemented? Where is the code for adding a process to a clan and where is the code where I chief checks to see if a process from another clan is allowed to send a message to a process in its clan? thanks

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error: ext2_lookup: deleted inode referenced
by cem akpolat 07 Jun '14

07 Jun '14

Dear all, I attempt to boot two l4linux instance (one from SATA Disk, the other from ramdisk) on l4re. Both instances boots normally and works fine. I create a file on a filesystem which has access to the SATA Disk. When I reboot the system, all created files permissions show ?????? and kernel message is: error: ext2_lookup: deleted inode referenced Any idea? Cem Akpolat

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Question about cross core IPC
by Yuxin Ren 07 Jun '14

07 Jun '14

Hi I am learning the IPC code in the Fiasco kernel. I have some questions here. If the receiver is not ready, we will add the sender to the sender_list. But I did find any lock to protect the sender_list. So if two threads at different cores try to add themselves to the sender_list at the same time, how can we guarantee the we are safe to do so? When sender and receiver are at different cores, we have to use IPI to communicate. Where is the code on IPC path to use IPI? I imagine the code around IPI should be complex, so it is great if someone can tell me the logic about it, especially about how we protect data structures, using locks or any other lock-free algorithm. Thank you very much. Best

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how to transfer capabilities from server to client
by Yuxin Ren 06 Jun '14

06 Jun '14

Hi, I want to write some code to transfer capabilities from server to client. But I have no idea how to do this as I am not familiar with L4Re and its interface. Could anyone give me some example code or some hints? Thank you very much. Best

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A convenient makefile
by Sören Jonsson 06 Jun '14

06 Jun '14

Hello, I have recently made fiasco and the l4Re, and found that it can be a little tricky. It is a few Debian packages that can be easy to forget to install on your computer etc. In order to make it easier to remember all details I developed the attached Makefile. I have tested it fairly well, and it makes it easy to download and make both l4Fiasco and the l4Re on a Debian or Ubuntu machine. It should be easy to modify to work with Red Hat as well. Documentation: "make envesetup" will install all necessary packages except the "make" package. That has to be installed previously. "make downloads" will download l4Fiasco, the l4Re, and l4Linux to your computer "make kernelsetup" will create the directory fiasco_bld in your current directory and configure the build there. "make resetup" will create the directory l4Re_bld in your current directory and configure the build of l4Re in that directory. I have found the Makefile very convenient, and decided to post it to the l4-hackers mailing list in the case that it can help more people than me. I hope that you like it. Best regards, Sören Jonsson Sweden

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