l4-hackers June 2012

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

23 participants
30 discussions

L4 Driver Security
by Tobias Fink 20 Jun '12

20 Jun '12

Hey List, me again with one (hopefully final) question. I'm learning about Driver Security in L4Re. I have some statements which I would like to have confirmed to understand the underlying principles: 1. L4 Drivers use DMA and are therefore able to write directly to the device memory and thus can cause crashes or damage if not carefully implemented. 2. While the L4Re Io-Server manages the access of drivers to the hardware's address spaces, it doesn't prevent drivers to write "bad" things into the device memory. 3. Untrusted, untested drivers can cause system crashes. best regards Tobi

2 2

Re: l4linux GPU direct access
by Abhishek Gupta 19 Jun '12

19 Jun '12

Hi Adam, Where can I add x86emu inside L4Linux to switch modes??

2 1

Re: L4Android on Pandaboard
by Matthias Lange 19 Jun '12

19 Jun '12

On 19.06.2012, at 15:49, ZhangEditing wrote: > android_bus => new System_bus() > { > sys => wrap(hw-root.sys); > prcm => wrap(hw-root.prcm); > sysdma => wrap(hw-root.sysdma); > gic => wrap(hw-root.gic); > hsmmc1 => wrap(hw-root.hsmmc1); > hsmmc2 => wrap(hw-root.hsmmc2); > hsmmc3 => wrap(hw-root.hsmmc3); > hsmmc4 => wrap(hw-root.hsmmc4); > hsmmc5 => wrap(hw-root.hsmmc5); > } The gic shouldn't be assigned to L4Android as it is driven by Fiasco. > In addition, I don't know how to assign registers that affect global configuration of the platform (e.g., the system control registers), although I don't think it is appropriate to assign such registers to only one OS. You can write a L4Re server which configures those registers. Then L4Android can access those registers via the server interface. Matthias. -- Dipl.-Inf. Matthias Lange <mlange(a)sec.t-labs.tu-berlin.de> Security in Telecommunications TU Berlin / Deutsche Telekom Laboratories Ernst-Reuter-Platz 7, 10587 Berlin Phone: +49 - 30 - 8353 58 553 Mobile: +49 - 160 - 587 28 07 Web: http://www.t-labs.tu-berlin.de/sect

1 0

Re: L4Android on Pandaboard
by Matthias Lange 19 Jun '12

19 Jun '12

On 18.06.2012, at 02:59, ZhangEditing wrote: > > You should have a look into the Pandaboard TRM and gather the right MMIO regions needed for MMC etc. Then connect those to the vbus for the L4Android kernel. > > I tried to do so, but L4Android recognizes only SDHCI. Maybe I still missed something. > Are there resources other than MMIO regions and IRQs that have to be configured for the I/O server? Probably you need some GPIO pins. Have a look into the Pandaboard TRM. Matthias. -- Dipl.-Inf. Matthias Lange <mlange(a)sec.t-labs.tu-berlin.de> Security in Telecommunications TU Berlin / Deutsche Telekom Laboratories Ernst-Reuter-Platz 7, 10587 Berlin Phone: +49 - 30 - 8353 58 553 Mobile: +49 - 160 - 587 28 07 Web: http://www.t-labs.tu-berlin.de/sect

1 0

Re: l4-hackers Digest, Vol 110, Issue 14
by Abhishek Gupta 18 Jun '12

18 Jun '12

Hi Adam, Where should I add x86emu inside L4Linux to switch modes??

1 0

L4Android on Pandaboard
by ZhangEditing 17 Jun '12

17 Jun '12

Hello, everyone! I'm new to L4Android and I'm interested in running L4Android on Pandaboard (OMAP4430). I tried to pack the system image of Android userland together with the kernel into a single U-image, but Pandaboard cannot finish loading the U-image. If the system image of Android userland is not included in the U-image, Pandaboard is able to load the U-image and boot the kernel. So I unpacked the system image to a separate partition on the SD card and I'm now trying to make L4Android use the partition. However, L4Android does not seem to recognize the entire SD card. There is no MMC devices under /dev/block. Instead, only 15 ram devices and 1 l4bdds device are there. I'm not sure whether L4Android has the right driver for SD card-related devices on Pandaboard. On the other hand, since I'm not familiar with Pandaboard, I don't know if I'm using the right device configuration (in the form of a .devs file) for the I/O server of L4Re. Could anyone help? Does anyone have a suitable .devs file for Pandaboard OMAP4430? Thank you in advance!

2 1

Re: l4linux GPU direct access
by Abhishek Gupta 16 Jun '12

16 Jun '12

Hi Adam, Thanks for your suggestion. We tried what you suggested and it worked. But that's not what we want. We want Graphics Acceleration and use vesa framebuffer. How can I make sure that int10 is passed to the l4linux by l4 and executes int10 module successfully.

2 1

adding libraries to L4/fiasco & L4re
by smkim 15 Jun '12

15 Jun '12

Hi hackers. I have questions about adding additional libraries for L4/fiasco & L4re. I tried to find some documents about it, but I failed. My question is Is there any guildlines which explains the process how to port additional libaries in L4/fiasco & L4re? If not, I hope you to suggest the way to solve it. What I wanna port is OpenCV. Best regards, Seongmin Kim.

2 1

IPC between Tasks
by Tobias Fink 15 Jun '12

15 Jun '12

Hi, I'm planning on building a small example of a producer/consumer build on top of L4Re. From the documentation I know about the shared memory inteface which will help to pass information from the producer to the consumer but I am a bit clueless on how I notify the consumer that there is something new to read. The semaphore is only to be used in between threads so there is no way to use them for IPC between Tasks?! Is there another possibility to make this work other than to use polling? regards Tobi

4 7

Connect two devices to vbus
by Pierre Larus 13 Jun '12

13 Jun '12

Hi, In my project, I have defined two io memory ressources as devices. I want connect these two devices to vbus. "io_bus.gpt2" is actually connected to vbus. But is it possible to also connect "io_bus.intc" to vbus ? local name = "l4rtos"; local DeviceFile = "beagle.devs" local IOFile = "beagle.io" local loader = L4.default_loader; local io_bus = { gpt2 = loader:new_channel(); intc = loader:new_channel(); }; loader:start({ caps = { gpt2 = io_bus.gpt2:svr(), intc = io_bus.intc:svr(), icu = L4.Env.icu, sigma0 = L4.cast(L4.Proto.Factory, L4.Env.sigma0):create(L4.Proto.Sigma0), }, }, "rom/io rom/" .. DeviceFile .. " rom/" .. IOFile); loader:start( { caps = { vbus = io_bus.gpt2, icu = L4.Env.icu, log = L4.Env.log:m("rws"), }, }, "rom/" .. name); Regards, Pierre Larus

2 1

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 June 2012