l4-hackers

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

2827 discussions

Building l4re packages and linking errors
by Bryce Cronkite-Ratcliff 13 May '13

13 May '13

Hi folks, I'm afraid my configuration may have changed recently, possibly due to version changes in gcc, and I'm having some trouble compiling l4re, so I wanted to ping you to see if you had any insights. Two separate issues I've had: in an existing l4re build, executing make in an individual package sub-directory fails to find basic system headers in included files ("stddef.h" and "stdarg.h" for example). I'm running make O=basel4rebuilddir On the theory that l4re needs to be recompiled in order to set up links that may have changed since compilation of the last build, I've tried building l4re again, but I similarly run into a linker problem here: gcc: symbol lookup error: /home/bryce/L4Linux/x86/l4re4/tool/gendep/64/libgendep.so: undefined symbol: dlsym If you have any thoughts on what I might try, let me know! Thank you! Bryce

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Questions about Fiasco.OC and L4Re
by BogDan 13 May '13

13 May '13

Hello, First I'd like to introduce myself, I'm BogDan Vatra a free software hacker. Recently I've watched these http://wiki.tudos.org/HOWTOs#Introduction_to_Fiasco.OC_and_L4Re presentations on youtube. After I've seen them (many many times) I became fascinated. I started to "play" a little bit with Fiasco.OC and L4Re, I created a few apps and I must confess that I'm extremely impressed by your work. To me Fiasco.OC and L4Re seems way too good to be true, and I wonder if there are any "hidden traps" which prevents people to use it to create a general-purpose operating system on top of Fiasco.OC and L4Re, so my first question is: Can Fiasco.OC and L4Re be used to create free (GPL, BSD, apache, etc.) and non-free apps? I checked L4Re licenses and it seems that it has the necessary exceptions, but I'd like to be 100% sure :). I also look to Genode frameowrk and I it looks to me that it cannot be used to create non-GPL apps, so, it can not be used to create a general-purpose operating system where any kind of apps can run on it. I also have a few questions about the completeness of Fiasco.OC and L4Re: - does L4Re have any OpenGL support? I checked the source code and it seems that the only way to do graphics is via goos and it doesn't seem to have any OpenGL support. If I am right wouldn't be easier to port (and upstream) an existing server (e.g. xorg, wayland, mir, etc.) to L4Re, than to create one from scratch and maintain it? - does L4Re have any sound support? If it hasn't, then how hard will be to implement or to port an existing implementation? - does L4Re have any real filesystem support (e.g. ext2/3/4, xfs, raiser, etc.)? It is ok for testing to use qemu or grub to load simple apps, but for a real o.s., apps need to be loaded from disk. Again, if it hasn't, then how hard will to implement it or to port an existing implementation? - it is possible to use a debugger (e.g gdb(server)) to debug (user space) apps? - last but not least, is there any repository for Fiasco.OC and L4Re with logs? http://svn.tudos.org/repos/oc/tudos/trunk/ has no useful logs and IMHO it makes very hard any contribution to it. I've seen that you have a few repos on github (https://github.com/TUD-OS), do you have any plans to move Fiasco.OC and L4Re to github as well? IMHO being able to fork a repository and to create a pull request, to be able to open an issue and watch its progress will make contributors life much more easier :) ! Many thanks for your work! Yours, BogDan.

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Question regarding the "Jdb::handle_user_request()' function
by Christian Prochaska 11 May '13

11 May '13

Hello, the 'Jdb::enter_jdb()' function in file 'jdb.cpp' contains the following code: // check for int $3 user debugging interface if (foreach_cpu(&handle_user_request, true)) { close_debug_console(cpu); leave_trap_handler(cpu); return 0; } I'm not sure why in this case the second argument of 'foreach_cpu()' is true. I understand that it causes the result to be true only if the 'handle_user_request()' function returned true for every currently running CPU. But I found that this can be a problem when using the '-jdb_cmd=JS' kernel argument: if only one CPU is currently running, the result of 'foreach_cpu()' is true, but when two CPUs are currently running, the 'handle_user_request()' function returns true only for one CPU, which makes the end result false and causes the kernel to stop with the JDB prompt shown. Can somebody please explain? Christian

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fiasco r52 on beagleboard xm
by Sin-ta Hsiea 11 May '13

11 May '13

Hi, I've tried running r47 fiasco kernel on beagleboard xm platform, it was fine, but after upgrading sources to r52, it broke. Output message hang after this line. Hello from Startup::stage2 After debugged using JTAG, I found that after page table modified, MMU still can't translate that address. So I add this line to source: --- src/kern/arm/paging-arm.cpp (revision 52) +++ src/kern/arm/paging-arm.cpp (working copy) @@ -348,6 +348,7 @@ void Pte_ptr::write_back_if(bool, Mword asid = Mem_unit::Asid_invalid) { + Mem_unit::clean_dcache(pte); if (asid != Mem_unit::Asid_invalid) Mem_unit::tlb_flush(asid); } Then output message hang after this line: Calibrating timer loop... done. It seems that MMU doesn't notice page table was switched to sigma0's pagetable. I also tried pandaboard, it just works fine. Does anybody have idea how to fix this? Best regard, SIn-ta Hsiea

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Fiasco.OC with ARM TrustZone
by Chao-Jui Chang 11 May '13

11 May '13

Hi hackers, Is trustzone working on exynos 4412 platform? I have selected the follow item in Fiasco config menu: * Platform Timer (Multi-core timer) * Use ExtGic * Execution Model (TrustZone normal side) But it stop at early stage. Same result for Execution Model (Standard mode). but no message for Execution Model (TrustZone secure side). If the trustzone is disabled in u-boot, the 'Standard mode' works fine. ----- booting log ----- OK U-Boot 2010.12-00000-g8d816e8-dirty (May 06 2013 - 19:38:10) for Exynox4412 CPU: S5PC220 [Samsung SOC on SMP Platform Base on ARM CortexA9] APLL = 1000MHz, MPLL = 880MHz DRAM: 1023 MiB PMIC VERSION : 0x00, CHIP REV : 3 TrustZone Enabled BSP BL1 version: 20121128 Checking Boot Mode ... SDMMC MMC Device 0: 30959 MB MMC Device 1 not found ModeKey Check... run normal_boot Net: No ethernet found. Hit any key to stop autoboot: 0 Exynos4412 # run fiasco Partition2: Start Address(0x2000), Size(0x1a000) reading bootstrap.raw 835584 bytes read Boot with zImage Starting kernel ... Hello from Startup::stage2 Per_cpu_data_alloc: (orig: 0xf0044588-0xf0044f60) Number of IRQs available at this GIC: 160 ------ end of booting log ----- Best regards, Chao-Jui

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How to start new program in interactive way
by Chao-Jui Chang 02 May '13

02 May '13

Hi hacker, Is there any other way to start a new l4 program or l4linux? Currently, I can only start program by writing lua script. Can I start new program like in a shell environment? For example: $ ls -> run ls program $ df -> run df program If no shell like environment, is there any example by using L4Re API? Thanks, Chao-Jui

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Re: How to start 2 or more VMs
by Chao-Jui Chang 29 Apr '13

29 Apr '13

Hi Ganis Zulfa, You need to setup one ethX for each l4linux. When you start 2 L4Linuxes, you will only see one ethX in current console, because you are connected to the second L4Linux not the first one. It is normal to see only one ethX. One way to setup the ip of first L4Linux is to write the init config in /etc/init.d/rcS. In this case, you need 2 ramdisk for each L4Linux. Here is my config for first L4Linux: # cat /etc/init.d/rcS > #! /bin/sh > mount -t proc proc /proc > mount -t devtmpfs devtmpfs /dev > mkdir /dev/pts > mount -t devpts devpts /dev/pts > ifconfig lo up > ifconfig eth0 192.168.50.1 > telnetd -l /bin/sh > exit 0 For second L4Linux, just change the ip to 192.168.50.2 After 2 L4Linuxes start, you will be in second L4Linux(192.168.50.2) then, you can telnet 192.168.50.1 to go to another L4Linux. Cheers, Chao-Jui 2013/4/16 Ganis Zulfa Santoso <ganiszulfa(a)gmail.com> > Hi Chao-Jui, have u figured out a way to do what Adam said? > > I followed the instructions from http://wiki.tudos.org/L4Linux/shmnet, > but I have problems: > > A. i ran two l4linux arms but i only found one ethX > > B. how do i set up the ip of another l4linux arm? > > thanks. > > > Best regards, > > > Ganis Zulfa Santoso > > > On Mon, Apr 8, 2013 at 7:03 AM, Adam Lackorzynski < > adam(a)os.inf.tu-dresden.de> wrote: > >> Hi, >> >> On Fri Apr 05, 2013 at 13:29:37 +0800, Chao-Jui Chang wrote: >> > Is it possible to multiplex multiple text-based console? >> > I want to try to start multiple VMs on ARM board which only provides >> serial >> > console. >> >> You can connect two L4Linuxes using a l4shmnet-based local network >> connection, so you can go from one to the other via e.g. telnet or ssh. >> >> >> Adam >> -- >> Adam adam(a)os.inf.tu-dresden.de >> Lackorzynski http://os.inf.tu-dresden.de/~adam/ >> >> _______________________________________________ >> 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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does the driver directly operate the device?
by gaober 27 Apr '13

27 Apr '13

hi! drivers in linux are in kernel mode.but in a microkernel-based system,drivers are like apps,do they operate the device directly?or the microkernel will do something to operate device.

2 1

l4linux and sysenter
by Ryan Brown 24 Apr '13

24 Apr '13

Thanks for the ptrace fix, that really helped with debugging. We were seeing programs crash at the first system call when using some versions of glibc, but not others. It seems the difference is that the working glibc's are compiled without vdso support. When glibc tries to use the vdso for system calls, it crashes at the sysenter instruction. If we start l4linux with vdso32=0, the program is able to run. Is sysenter expected to work under l4linux? It looks like it requires using msr's, so perhaps l4linux isn't able to setup sysenter? Should it be installing the int80 vdso function instead? While investigating the vdso stuff to I also became curious. How difficult would it be to set up an l4 specific vdso? I assume just using l4 ipc directly would be more efficient than using int80? Thanks, Ryan Brown

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How to start 2 or more VMs
by Chao-Jui Chang 18 Apr '13

18 Apr '13

Hi hackers, Is there any document that describes how to start 2 or more VMs on Fiasco.OC ? Is it possible to switch consoles between VMs ? Could you point out the direction to me? Thanks, Chao-Jui

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