On Tue, Aug 18, 2015 at 09:04:39PM +0000, Blotsky, Sergey wrote:
Jens,
Thanks again for your help.
I have couple of other questions:
- does OP-TEE allow for scheduling TA threads periodically (as opposed to standard Global Platform entry points)?
No, we don't have any design for that.
- does it allow for TAs having more than one thread?
We're following GP specifications so only one active thread per TA instance is allowed. Depending on how the TA is configured it will either have one instace for all sessions, or it will get a separate instance for each session. In the former case different sessions can share a state inside the TA while in the latter each session has its own state inside the TA.
- I assume if there are multiple TAs that have pending tasks, then they will be scheduled in round-robin fashion, right?
We don't have any policy in the code that enforces round-robin, but I assume that the natural order will be more or less round-robin.
Thanks, Sergey
-----Original Message----- From: Blotsky, Sergey Sent: August-18-15 10:35 AM To: 'Jens Wiklander' Cc: 'tee-dev@lists.linaro.org' Subject: RE: [Tee-dev] Need help understanding high level design of OP-TEE Secure OS
Thanks Jens!
I've briefly looked through tee_mm_alloc() and it does apply some shift which is 20 bit in case of TA DDR pool. So, there is no security concerns here. Only DDR size is a bit of an issue.
Agree, we'll have to do something about that at some point.
Regards, Jens