Running Real-time distribution on beagleboard

Hi,

i recently bought a BeagleBoard and i compiled my first Angstrom image
using open-embedded. Has anyone tried to apply the RT patch to the
linux kernel to run on the beagleboard ? Does anyone know how i could
modify the angstrom configuration in openembedded to apply the RT
patch ?

Thanks

Hello,

i recently bought a BeagleBoard and i compiled my first Angstrom image
using open-embedded. Has anyone tried to apply the RT patch to the
linux kernel to run on the beagleboard ? Does anyone know how i could
modify the angstrom configuration in openembedded to apply the RT
patch ?

This is on my todo list but new items keep appearing at the top end.

I'ld suggest to try to merge the latest:

http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.29.4-rt16.bz2

then see if any drivers misbehave.

You need to modify the recipe that builds the linux-omap kernel, just
add the above as a patch file,
and "bitbake -c rebuild linux-omap(3?)" it.

Regards,

Hi,

thanks for your answer. I 'll try what you mentionned. I have an
intern here in my lab that will give a look at the beagleboard RT
behavior. We might also try to get the RTLinux (rtlinuxfree.com)
running on the beagleboard.

John

Hi,

just to say that I’m also very interested in RTlinux on beagleboard.
So if you get something please share it :slight_smile:
also I’m not an expert but for what I’ve seen RTAI may be a better option than RTLinux.
However they don’t have a lot of support for arm so…

anyway

good luck

Maxime

HI,

i have modified my openembedded configuration to apply the patch on
the kernel, but it seems that the linux-omap-2.6.29 kernel is a little
different than the main kernel. Thus applying the patch is not
straightforward as i need to patch by hand and then extract the patch
problem is that in the omap-linux kernel some function names and
content are different from the main kernel thus some patch cannot
apply.

I'm not an expert but for what I've seen RTAI may be a better option
than RTLinux.

In fact i want to try the rt patch and also the linuxRT kernel. RTAI
doesn't seem to have a lot of support on newer architectures ...

Jonathan Piat
IETR/INSA
Rennes
France

We have patched (with modifications) the linux-omap kernel 2.6.30 with
the rt patch. The kernel compile, and boots but it freezes at "Freeing
init memory 116k". Does anyone have any idea of why this occur, and
where i can find the piece of code that performs that "Freeing init
memory 116k".
Thanks

Today we successfully patched the 2.6.29 linux-omap kernel (with a
modified 2.6.29.5-rt21 patche) , compile and boots on the beagleboard.
The boot goes to the Angstrom login prompt. We need further test to
validate the patch, but its a great success !!!

Hi,

Here is the rt patch for the linux-omap-2.6.29-omap1 kernel.
http://linux-omap-rt-p.svn.sourceforge.net/viewvc/linux-omap-rt-p/patch-omap-2.6.29.5-rt21-v2

Today we successfully patched the 2.6.29 linux-omap kernel (with a
modified 2.6.29.5-rt21 patche) , compile and boots on the beagleboard.
The boot goes to the Angstrom login prompt. We need further test to
validate the patch, but its a great success !!!

The problem is with the irq : when booting on the beagleboard, these
messages appears :
irq 72: nobody cared (try booting with the "irqpoll" option)
[...]
Disabling IRQ #72
[...]
irq 73: nobody cared (try booting with the "irqpoll" option)
[...]
Disabling IRQ #73
BUG: sleeping function called from invalid context at kernel/rtmutex.c:
685

Then the angstrom logo appears.

Does anyone have ever meet this problem, or have a solution ?

Thanks.
Regards.

Marine Ribot
IETR/INSA
Rennes
France

try identifying to what peripheral (module, driver) interrupts 72 and
73 are linked to using:
cat /proc/interrupts.

After looking in arch/arm/plat-omap/include/mach interrupts 72 and 73
seems to linked to UART :

#define INT_24XX_UART1_IRQ 72
#define INT_24XX_UART2_IRQ 73

but i may be wrong as there is no section for OMAP3530 specific
interrupts.

Hi all,

The command "modprobe" used in Linux for x86 don't work in Beagleboard? How I
use a similar command in beagleboard for change a driver?

Alessandro

Hi all,

The command "modprobe" used in Linux for x86 don't work in Beagleboard? How I
use a similar command in beagleboard for change a driver?

It works for me. Where did you get your root file system and what
module are you trying to load.

Philip

The original topic of this thread, is about running real time linux on
the beagleboard. Please avoid posting on any other subject.
Thanks