On Wed, 2015-01-21 at 16:21 +0000, Rob Herring wrote: > > * Not possible to identify whether a device is shared or not between > > the secure and non-secure worlds. > > Typically, sharing requires a peripheral to be designed to be shared > like PL330 or MMU-400. I have seen some h/w with locking registers so > 2 different cores/OSs can share an i2c bus. You could do something > like that for Trustzone as well I suppose. That's not really secure, > but allows shared access. I think it is generally a limited number of > peripherals which are shared.
Interestingly enough, the most common case for a shared peripheral is a keypad/keyboard for secure PIN entry. A secure-programmable-only filter like TZC-400 can be used to change the "designation" of a AXI master connected to it. Pawel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
