Hello, The first IPC implementation works under isolation level 1. The high isolation levels need to be there to get compatible with PSA Firmware Framework. A design document is created about implementing isolation level 2 for IPC model: https://developer.trustedfirmware.org/w/tf_m/design/trusted_firmware-m_isola...
The mainly change of isolation level 2 compare to isolation level 1 is: * Put AppRoT Secure Partitions' components with same attribute (code, read-only data, read-write data) into the same region, which helps MPU setting region attributes. * Change Secure Partition privileged setting based on Secure Partition type while scheduling. * Change mechanism of privileged API, such as printf.
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Thank you!
-Ken