On 4/27/2026 3:25 PM, Sumit Garg via OP-TEE wrote: > From: Sumit Garg <[email protected]> > > Qcom platforms has the legacy of using non-standard SCM calls > splintered over the various kernel drivers. These SCM calls aren't > compliant with the standard SMC calling conventions which is a > prerequisite to enable migration to the FF-A specifications from Arm. > > OP-TEE as an alternative trusted OS to Qualcomm TEE (QTEE) can't > support these non-standard SCM calls. And even for newer architectures > using S-EL2 with Hafnium support, QTEE won't be able to support SCM > calls either with FF-A requirements coming in. And with both OP-TEE > and QTEE drivers well integrated in the TEE subsystem, it makes further > sense to reuse the TEE bus client drivers infrastructure. > > The added benefit of TEE bus infrastructure is that there is support > for discoverable/enumerable services. With that client drivers don't > have to manually invoke a special SCM call to know the service status. > > So enable the generic Peripheral Authentication Service (PAS) provided > by the firmware. It acts as the common layer with different TZ > backends plugged in whether it's an SCM implementation or a proper > TEE bus based PAS service implementation. > > Signed-off-by: Sumit Garg <[email protected]> > --- Reviewed-by: Harshal Dev <[email protected]> Regards, Harshal
