Increase IPC-Stream size

ba_f ba_f at rbg.informatik.tu-darmstadt.de
Tue Jan 27 15:41:28 CET 2015


Am 2015-01-27 01:04, schrieb Adam Lackorzynski:
> On Sun Jan 25, 2015 at 14:50:01 +0100, ba_f wrote:
>> the IPC-Stream seems to be limited to 252 objects, for one ios.call().
> 
> Indeed, it is limited.
> 
>> How can i double that size, so that more objects fit in one IOStream?
> 
> The size could be increased by changing both the kernel and user-level
> constants accordingly, at least up to a certain limit until even more
> needs to be done.
> Now, to exchange more data than fits in a UTCB, we usually recommend
> shared memory. Would that be an option in your case? Another option
> could be to use multiple IPCs to transmit the data in chunks.


Hello,


Changing kernel constants seems a bit dirty, isn't it?

But tell me some about shared memory, please.

1.) is there an example, anywhere?
2.) Maybe on a further step, i'm planning to adapt my project to 
TrustZone. How does a communication between TrustZone Worlds work? Is 
Shared Mem. a better starting point than l4-IPC, when going to 
TrustZone.



Thanks.



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