Hi,

There has been a thread on this topic in the past:

https://mail.gna.org/public/xenomai-help/2009-08/msg00023.html

A quick background: We get the alignment exception, as we pass -fpack-struct option to gcc and some data in structures is misaligned.

I have been testing the patch on Linux 3.0.0, Xenomai 2.6 and it seems to work well. Do you think, it requires any additional changes to be used with Xenomai 2.6?

Also, I am trying to understand how it works and have a question. Am summarizing my understanding below. Would appreciate your comments:

alignment_exception:

+     if (test_bit(IPIPE_NOSTACK_FLAG, &ipipe_this_cpudom_var(status)) &&
+         ipipe_trap_notify(IPIPE_TRAP_ALIGNMENT, regs))
              return;

I believe, the IPIPE_NOSTACK_FLAG is set when we are running in Linux. So we should invoke ipipe_trap_notify only while we are running in linux. While running in the primary domain, we would go ahead and fix the alignment.


+     if (!ipipe_root_domain_p &&
+         ipipe_trap_notify(IPIPE_TRAP_ALIGNMENT, regs))
+             return;
+
I am not able to figure this part properly. If we are not in the root domain we invoke ipipe_trap_notify. (I believe root domain = Linux). So if we are in the primary, we would invoke ipipe_trap_notify. ipipe_trap_notify in turn would invoke the event handler (xnpod_trap_fault). This would send us to the secondary domain. All the same, we stay int he primary as per my tests. So, I am making a mistake somewhere. Would appreciate your opinion.

Rgds,
Makarand.




--
___________________________________________________________________________
NOTICE OF CONFIDENTIALITY:
This e-mail and any attachments may contain confidential and privileged 
information.  If you are
not the intended recipient, please notify the sender immediately by return 
e-mail and delete this
e-mail and any copies.  Any dissemination or use of this information by a 
person other than the
intended recipient is unauthorized and may be illegal.
_____________________________________________________________________


_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help

Reply via email to