Re: [pok-devel] ARINC - partition

[Julien Delange <julien@xxxxxxxxx>]

Le Thu, Feb 09, 2012 at 03:30:32PM +0100, Matias Hastaran :
> I need to find this 3 values for GET_PARTITION_STATUS function.
> For the period, in a comment it said "not used for the moment", is it always relevant ? I don't find the period value in AADL model ... How can I found this value?
> Same problem for the start_condition value... I don't find this value elsewhere in the libpok/arinc653... 
> For lock_level, my was stupid, you said me POK can't disable preemption and the lock_level value is used to lock preemption in one partition thus I suppose this value doesn't exist..


So:
- PERIOD correspond to the partition period, this corresponds to the
  timeslice allocated in the AADL model for each partition. The ARINC653
  layer may not connect POK and ARINC653 layers but the information is
  here and this is just a matter of implementing the code
- START CONDITION is defined but not implemented
- LOCK_LEVEL is not implemented since you cannot enable/disable
  preemption. On the other hand, you can implement it but it will
  require changes in the kernel and the partition layers.

> ARINC said : "The SET_PARTITION_MODE service allows the application associated with a partition to request a change to its operating mode." Thus, for me any partition processes can change the mode.
> 

Yes, but the best would be to check what mode are allowed. Applications
tasks may call the SET_PARTITION_MODE but I think there are some
restrictions about the transitions itself. Since I no longer have the
standard I cannot say more but I don't think you can restart the
partition as you want because in that case, a faulty task can restart
indefinitely a partition ...


> My fault, the question was asked really badly. After studying the question again, the only point bothering me is the COLD_START. You don't use the COLD_START in ARINC. If I understand well, the difference between the WARM_START and the COLD start is the hardware context (e.g., no need for copying code from Non Volatile Memory to RAM). Can POK support the COLD_START ?

This is just an implementation concern. In POK, we assume that
COLD_START == WARM_START as we don't have any specific initialisation to
do that would distinguish WARM and COLD START.

Hope that helps :-)

Best regards,