l4-hackers

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

2 participants
2880 discussions

L4Re Update
by Adam Lackorzynski 04 Jan '16

04 Jan '16

Hi, After a longer break I'm pleased to announce an update of the L4Re system software. https://l4re.org Besides bug fixes and enhancements, noteworthy changes and additions of this update include: All: - LLVM/Clang: Fiasco.OC is supported with Clang now, for the userland we're nearly there - Updates for recent GCC versions - CROSS_COMPILE is the preferred way to set the compiler prefix now - URLs have been consolidated to be under the l4re.org domain but old ones will remain to work for a foreseeable future. L4Re: - Package reorganization: Core packages have been moved to a more hierarchical structure, e.g. l4re-core and io - New RPC framework using C++ that generates client and server side code from a single definition, code and examples have been adapted accordingly - Software updates, e.g. libstdc++, lua, libpng, libjpeg, lwip - New L4Re::Dma_space interface to support DMA and IOMMUs - io gained support for IOMMUs and MSI remapping - Virtio library to support the development of virtio host applications - Documentation improvements: https://l4re.org/doc/ Fiasco.OC: - IOMMU support, including MSI remapping (currently VT-d) - Clang support L4Linux: - Added x86-64 variant - Updated to version Linux 4.3 - MSI / MSI-X support Happy new year, Adam

4 3

Performance of L4
by Patrick Staeblein 28 Dec '15

28 Dec '15

Hello Dear L4 Hackers, I am still writing on my bachelors-thesis on the performance of L4/Fiasco and wanted to ask you if you can give me some hints and ideas. My goal was to find out how the time-costs are divided between ipc, memory access and scheduling and resulting out of this what properties programs should have that makes them execute as fast as possible. For measuring the ipc-time i used the ipc_example.c-file in the ./src/l4/pkg/examples/sys directory and added rdtsc (Read Time Stamp Counter)-instructions before and after making the ipc-call and then calculating the difference between the two values. This was executed in a loop and the resulting values were divided into ten equal-sized range-classes depicting them as a histogram.The results showed the ipc-time to be pretty stable with almost all values falling into one class (Sorry for my shitty Englisch anyway). Does anyone have an idea what kind of measurement one could do for a measurement of the scheduling? I found the function l4_scheduler_idle_time (...), but I don't have an idea for using it in a concrete program or experiment setup. I also thought about repeatedly measuring the time it takes for one context-switch, but I don't know in which place exactly I would have to insert the rdtsc-instructions. Does anyone know which exact C-file would have to be modified for that? I am thankful for any answer, regards, the Steppenwolf

2 1

Serial console not working
by Lluís Vilanova 22 Dec '15

22 Dec '15

Hi there! I'm trying to find out why my setup is not booting on a real machine (some Dell PowerEdge R210 node; ned says it cannot find rom/l4re), but I'm unable to redirect output to the serial console. I'm able to use the serial console for both grub and linux, so it's not a hardware issue. An excerpt of my grub2 configuration: serial --unit=1 --speed=115200 --word=8 --parity=no --stop=1 terminal_input serial terminal_output serial # ... # for the linux entry linux /vmlinuz-3.16.0-4-amd64 root=UUID=7573ed62-a910-4b97-a577-dde47a16f87a ro console=ttyS1,115200n8 quiet Now, here's the entry I'm using for L4, which never gets me any output on the serial console: menuentry 'Test' { set root=(hd0,1) multiboot /l4/bootstrap -serial module /l4/fiasco -serial_esc -comspeed 115200 -comport 1 module /l4/sigma0 module /l4/moe rom/test.cfg module /l4/l4re module /l4/ned module /l4/test.cfg module /l4/bin/test } Thanks, Lluis

2 3

Problem with Hello app on Zedboard
by Manolis Ragkousis 14 Dec '15

14 Dec '15

Hello everyone, I am trying to make the Hello app run on the zedboard but it gets stuck at "Scanning up to 512 MB RAM, starting at offset 32MB". I have configured both fiasco and l4re with the correct configuration (I have attached my config files) and cross compiled them from a x86_64 linux machine with "Linaro GCC 4.9-2014.09 4.9.2 20140904". I searched the mailing lists archives but I can't seem to find a similar problem. I tried changing the uart port I was using, in case it was printing in another port, but nothing changed. Any ideas/suggestions on what could go be going wrong and/or how can I solve it? Thank you for your time, Manolis The output of u-boot: reading uImage 970816 bytes read in 108 ms (8.6 MiB/s) reading initramfs.cpio.gz 128 bytes read in 17 ms (6.8 KiB/s) reading devicetree.dtb 9331 bytes read in 16 ms (569.3 KiB/s) ## Booting kernel from Legacy Image at 03000000 ... Image Name: L4 Image #2 Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 970752 Bytes = 948 KiB Load Address: 01000000 Entry Point: 01000000 Verifying Checksum ... OK ## Loading init Ramdisk from Legacy Image at 02000000 ... Image Name: Image Type: ARM Linux RAMDisk Image (gzip compressed) Data Size: 64 Bytes = 64 Bytes Load Address: 00000000 Entry Point: 00000000 Verifying Checksum ... OK ## Flattened Device Tree blob at 02a00000 Booting using the fdt blob at 0x2a00000 Loading Kernel Image ... OK Loading Ramdisk to 0f31d000, end 0f31d040 ... OK Loading Device T^H.��.\\Build: #2 Fri Dec 11 14:35:25 EET 2015, 4.9.2 20140904 (prerelease) Scanning up to 512 MB RAM, starting at offset 32MB

2 1

real time app on l4linux
by cem akpolat 14 Dec '15

14 Dec '15

Hi, I want to ask, if you have any guide or documentation, how to write a real time app on l4linux. As you know, l4llinux doesn't guarantee whether the application .which run on top of it, will be close to real time or not. In this case, should we write an separate l4 app and communicate with l4linux over IPC? If yes, again, how can I implement this kind of an app. For instance, if we take the server-client app under examples folder, can we apply the same scenario? How can I communicate with L4Linux? Sincerely, Cem Akpolat

2 3

Reminder: Microkernel-devroom CfP deadline is on this Sunday
by Jakub Jermar 07 Dec '15

07 Dec '15

Hi folks, the CfP deadline for the Microkernel devroom at FOSDEM 2016 is due this Sunday. See the original CfP [1] for information on what to do if you would like to give a talk about some microkernel-related topic. At the same time, I would like to encourage you to submit a talk proposal. It would be shame not to let the wider microkernel community know about the latest and greatest developments in your project. Lastly, please forward this reminder to whoever you think may want to give a talk in the devroom and is not among the recipients of this message. Thanks, Jakub [1] http://trac.helenos.org/wiki/Devroom2016

1 0

L4Re halts at boot, waiting for console input
by Arttu Pulli 28 Nov '15

28 Nov '15

Hello hackers, the subject line summarizes my problem pretty well. To expand, the halting happens first when Ned begins booting the user space services defined in the modules.list config, after it has loaded the Lua config script file. First I thought that my setup is just wrong, but feeding some amount of newlines through the serial console causes the boot to continue normally. The system is still waiting for input during this, though, as can be seen from the fact that the boot will go forward to starting Io with a couple of newlines, then it halts after that again, then newlines start my own user space modules, the system halting between every module if no input is given. This only happens on warm boots. When powering the board for the first time, the boot goes all the way to the finish without any user input. I'm using a custom i.MX6Q based board. So, with that background, my question is is there some general place where this kind of behaviour can be configured? Or is it just that my setup is somehow broken, and this is not any kind of feature of Fiasco.OC/L4? BR, Arttu Pulli

2 1

Re: L4Linux update? Driver support
by li94575 28 Nov '15

28 Nov '15

At 2015-11-22 23:42:55, "Adam Lackorzynski" <adam(a)os.inf.tu-dresden.de> wrote: >hi, > >On Sun Nov 22, 2015 at 22:07:46 +0800, li94575 wrote: >> hello Adam, >> I also have a question about the Interrupt mechanism in l4linux. I want to move some interrupts to specified cpu core. When I try to write to "/proc/irq/*/smp_affinity" with cpu bitmask, it will call the function l4lx_irq_dev_set_affinity(), which attachs the irq to corresponding vcpu thread. After that, I find the irq is still staying on previous cpu core through linux proc system. So I doubt whether linux proc filesystem's view is synchronized with the interrupt settings of the L4 kernel, or it can not be achieved in l4linux? (I use genode for the runtime environment of fiasco.oc) > >The l4lx_irq_dev_set_affinity function that is called by Linux >interrupt code, i.e. I think all the book keeping shall be done by the >Linux code, including the output of /proc/interrupts. >You should check in the jdb to which thread the interrupt is attached. >You can see this in the object list, use shift-Q to see it. >WIth CONFIG_L4_DEBUG_REGISTER_NAMES=y enabled in L4Linux, you'll have >proper descriptions of the objects, so you'll find the interrupt you're >looking for: l4lx.irqXX with XX being the same number as in >/proc/interrupts. >Then, look for the T= value of that particular interrupt, it points to >the thread the interrupt is attached to. Pressing TAB brings you to the >thread in the list. Is it the right onw? >I have tried your methed in the jdb, and find all the irqs we used is on the same thread( on cpu0 ) which has no name.But CONFIG_L4_DEBUG_REGISTER_NAMES is enabled in L4Linux. Regardless of how the irq setting in L4Linux, it alwaysstays the same in the jdb, this makes me so confused.

2 3

Qt on L4
by Nancy Joshua 27 Nov '15

27 Nov '15

Hi all i wanna port QT to l4.The documentation and tutorial in www.trolltech.com is not available any more. I have no idea how to start porting either. Any help in this regard is highly appreciated. -- Thanks and Regard Nancy Joshua

2 1

QT on L4re
by Nancy 27 Nov '15

27 Nov '15

hi, am trying to port qt on l4re, but i wasn't able to find any qt resources in the tudos website.The documentation and tutorial from trolltech.com seem to have been removed. So any help in this regard will be appreciated. thank you Nancy Josh

1 0

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

l4-hackers