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Interrupt driven TrustZone application

Motorolasolutions

Hello,

I would like to know if a Trustzone application can be interrupt driven instead of being triggered by the non-secured world (scm).

Thanks,

Fabrice.

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  • +1

    Yes, you could have an interrupt drive task in Secure state (or a combination of interrupt and SMC driven tasks).

    Most A class processors will use an interrupt controller based on the Generic Interrupt Controller (GIC) architecture.  The GIC architecture has support for Secure and Non-secure interrupts, the exact details vary based on which of the spec you are using.

    One of the things to consider when using Secure interrupts is their affect on the Non-secure state code.  The Non-secure kernel (typically Linux) won't know about, or have visibility of, Secure interrupts.  You need to consider how long you, and when, you will be in Secure state to deal with the interrupt.  Could this lead you to missing a deadline in the OS?

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  • +1

    Yes, you could have an interrupt drive task in Secure state (or a combination of interrupt and SMC driven tasks).

    Most A class processors will use an interrupt controller based on the Generic Interrupt Controller (GIC) architecture.  The GIC architecture has support for Secure and Non-secure interrupts, the exact details vary based on which of the spec you are using.

    One of the things to consider when using Secure interrupts is their affect on the Non-secure state code.  The Non-secure kernel (typically Linux) won't know about, or have visibility of, Secure interrupts.  You need to consider how long you, and when, you will be in Secure state to deal with the interrupt.  Could this lead you to missing a deadline in the OS?

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