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Open source development
by teclis High Elf 25 Jun '15

25 Jun '15

Hi, This is more just a general comment, but compared to other open source project I have contributed to Fiasco L4Re is difficult to work with. In most GNU open source projects new features and improvements are discussed actively on a mailing list and/or IRC channel so its easy to follow what is being done and jump in. While I very much appreciate that developers have taken the time to answer my questions, the l4-hackers mailing list seems to be just Q and A there is no discussion on what is currently being worked on for Fiasco and L4Re as there is in the Linux kernel or drivers. Also the svn logs just have generic import messages like: r67 | l4check | 2015-01-12 16:57:36 -0500 (Mon, 12 Jan 2015) | 1 line So it looks like all the core development is being done privately and then exported to a public repository. This makes it difficult in my opinion to build an open source development community. You can't look back through the svn logs messages and diffs to see the evolution of the system and get up to speed on the state of the art. For example, who is the committer? How would I go about submitting a patch for L4Re or Fiasco?

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Re: Testing Fiasco.OC+L4re on ODROID-X2(Exynos4412)
by Reinier Millo Sánchez 25 Jun '15

25 Jun '15

Hi Adam and L4 community I've been testing somethings on the Odroid-X2(Exynos4412). It seems that the IRQ handler only handles the first IRQ and disables the IRQs. I have added the following code to check the IRQs in the function Kernel_thread::bootstrap() in the file src/kernel/fiasco/src/kern/kernel_thread.cpp Per_cpu_data::run_late_ctors(Cpu::invalid()); bootstrap_arch(); Timer_tick::enable(current_cpu()); Proc::sti(); ++ Proc::Status st = Proc::interrupts(); ++ if(st & Proc::Status_interrupts_disabled) ++ printf("IRQs are enabled\n"); ++ else ++ printf("IRQs are disabled\n"); Watchdog::enable(); I'm trying to check that the IRQs are enabled. The Proc::sti() must activate the IRQs in the CPSR registers, and Proc::interrupts() must return if the interrupts are enabled, but always i'm getting "IRQs are disabled". I have tested the hardware with a Linux kernel and it's working fine. I have tested "CPSIE i" and "CPSIE f" to enable the interrupts and get the same result. I have incremented the warn level on Fiasco.OC, i'm getting: KERNEL: Warning Buddy:alloc Size mismatch: a80 v 1000 I have also tested the local timers on the Exynos4412. The local timer at CPU0 is working fine. It has been configured to auto-reload with 12000 as interval. The local counter decrements the value and reload when arrives zero, but don't raises the interrupt. To test the interrupts have created an small buffer to store the Kip::k()->clock on every interrupt. I have used the buffer to avoid the call of an interrupt inside another interrupt. I have tried to print the values on the function Delay::mesaure(), but it only stores one value. The same thing happens if I use a interrupt counter. Now i'm trying to check the IRQ handler caller, from the general mechanism to the specific interrupt handler, to catch the point where the IRQs are been disabled. Anyone have any suggestions? Best regards -- Lic. Reinier Millo Sánchez Centro de Estudios de Informática Universidad Central "Marta Abreu" de Las Villas Carretera a Camajuaní Km 5 1/2 Santa Clara, Villa Clara, Cuba CP 54830 "antes de discutir ... respira; antes de hablar ... escucha; antes de escribir ... piensa; antes de herir ... siente; antes de rendirte ... intenta; antes de morir ... vive"

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question about libgcc, libspuc++ in the l4re
by Yuxin Ren 25 Jun '15

25 Jun '15

Hi, I find in the src/l4/pkg directory, there are some libraries -- libgcc, libstdc++-v3, and libsupc++. But in those libraries, I just found very little source code. Instead, they include many makefiles. Where is the source code of those libraries? And why are there those makefiles? Thanks a lot. Yuxin

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why fiasco use -fno-rtti compile option?
by liu.xiaodong2＠zte.com.cn 25 Jun '15

25 Jun '15

Hi, Guys! I want to use typeid() and dynamic_cast() in fiasco, but failed, because of the -fno-rtti option. Why fiasco disable rtti? Are there some bad effects if we enable it? thanks! -------------------------------------------------------- ZTE Information Security Notice: The information contained in this mail (and any attachment transmitted herewith) is privileged and confidential and is intended for the exclusive use of the addressee(s). If you are not an intended recipient, any disclosure, reproduction, distribution or other dissemination or use of the information contained is strictly prohibited. If you have received this mail in error, please delete it and notify us immediately.

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Debugging Fiasco OC + L4Re + L4Linux together
by Mahdi Aichouch 09 Jun '15

09 Jun '15

Hello, I tried to debug Fiasco OC + L4Re + L4Linux using a DS-5 IDE and a DSTREAM JTAG on an i.MX 6 device. I was able to do a step-by-step through the source code of L4RE until I reach the " *virtual* *void* boot_kernel(unsigned long entry) " function in support.h (see screenshot 1) which is the function in L4Re that enters the Fiasco kernel, from there when I execute a "step into" action in order to execute the next instruction which is in Fiasco kernel the debugger go into "running" mode (see screenshot 2). I am unable to do a step-by-step walk neither in the Fiasco kernel nor in l4linux source code. Stopping the debugger after that do only give a disassembly information. Is it possible to debug all the Fiasco OC + L4Re + L4Linux together? Are there any debugger configurations that I might be missing? Many thanks in advance. Best regards, Mahdi

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Thread monitoring
by Biermans Joeri 09 Jun '15

09 Jun '15

Hey everyone, Is there a way available to perform some thread monitoring? Like for instance get some information about on which CPU a thread is running, when they're suspended, completed, etc. Thanks in advance and kind regards, Joeri

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Using a second Ethernet connector in L4Linux
by Mahdi Aichouch 03 Jun '15

03 Jun '15

Hello, I have a Freescale i.MX 6 Sabre SD board. It is equipped with one Ethernet RJ45 connector. I need to add a second Ethernet RJ45 connector to the board. The board has a micro-USB OTG port that allow to connect a plugable USB OTG Micro-B to Ethernet adapter like for instance this one: http://plugable.com/products/usb2-otge100 I would like to know if L4Linux might access such a second Ethernet device connected through micro-USB. Does anyone has tried this before. Could someone points me to a tutorial or a guide that shows what are the configurations steps that I should follow to build up a working test case. Thank you very much in advance. Best regards, Mahdi

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Cann't access git://git.l4android.org/build_script.git
by 刘海剑 02 Jun '15

02 Jun '15

When I run this command, git clone git://git.l4android.org/build_script.git, I got some error info: fatal: unable to connect to l4android.org: l4android.org[0: 141.76.48.99]: errno=Connection refused Thanks.

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Implementing a few real time scheduling algorithms on Fiasco.OC
by Biermans Joeri 30 May '15

30 May '15

Hi everyone, I'm a student at the university of Antwerp and I'm currently working on my master's thesis. My project is about comparing the performance of a few global multicore scheduling algorithms (G-RM, G-EDF, ...) on an embedded system. A part of my thesis is to make an implementation on a real embedded system equipped with a quadcore processor (i.MX6). To do that I need an RTOS. Fiasco with the l4re at a first sight seems an interesting candidate. To test the performance of the above algorithms I will schedule a bunch of randomly generated tasksets comprising some periodic tasks having implicit deadlines* with each of the algorithms and try to detect if any deadlines are missed. * Such a task is executed repeatedly after a fixed amount of time and its deadline is equal to its period, which is the point of time when the next invocation of the task takes place. This brings me to my first question: Would this be achievable with the fiasco kernel? I've been trying to interpret the project of the fiasco kernel during the last days, but this seems easier said than done. As a first step I've been trying to figure out how the scheduler works and how exactly the scheduling policies are implemented. (I have read somewhere the current scheduling policy is fixed priority round robin) Is there perhaps a more documented version of the code or an overview of the different classes, their functions and the way they interact available? It's really hard to figure out a bunch of code without any leads on how exactly the project has been implemented. Besides that I don't really have a clue about how to start developing on the fiasco kernel. Some tips about how to start working on the kernel are always welcome. Has anyone got experience with developing on the fiasco kernel? It would be nice to get some directions on this matter because I'm quite stuck on this. Thanks in advance! Kind regards, Joeri

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Booting error of L4Linux enabled SMP surpport
by Xiefeng (Stephen) 29 May '15

29 May '15

Hi all, I use entry L4Linux-mag-x86 in modules.list to start a L4Linux on L4Re successfully. The codes is l4re-snapshot-2014092821. L4Linux use x86-native_deconfig complie, use l4lx-gfx.cfg to start L4Linux. This config is just set one cpu for L4Linux. If I set l4x_cpus=2 in l4lx-gfx.cfg, use x86-mp_vPCI_defconfig and set CONFIG_NR_CPUS=2 to compile the L4Linux, when I start L4Linux, a kernel panic happened: l4linux | Loading: rom/ramdisk-x86.rd l4linux | INITRD: Size of RAMdisk is 3072KiB l4linux | RAMdisk from 88d70000 to 89070000 [3072KiB] l4linux | rtc not found l4linux | l4lx_thread_create: Created thread 41f (timer0) (u:b3000a00, v:00000000, sp:008e1fa8) l4linux | WARNING: Unknown wrmsr: 0000008b at 0x414bad l4linux | WARNING: Unknown rdmsr: 00000186 at 0x85e1d6 l4linux | WARNING: Unknown rdmsr: 00000187 at 0x85e1d6 l4linux | WARNING: Unknown wrmsr: 000000c1 at 0x85e2a7 l4linux | Launching cpu1 on pcpu 1 at 0x4024e0 l4linux | l4lx_thread_create: Created thread 420 (cpu1) (u:b3000800, v:b3000600, sp:008c7fa8) l4linux | WARNING: Unknown wrmsr: 0000008b at 0x414bad l4linux | l4lx_thread_create: Created thread 424 (timer1) (u:b3000400, v:00000000, sp:008e3fa8) l4linux | Spurious IPI on CPU0: 4 l4linux | panic: going to sleep forever, bye Has anyone encountered this problem? Stephen

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